Clinical practice guidelines on post-traumatic cognitive impairment: Assessment and remedial measures

INTRODUCTION

Traumatic brain injury (TBI) is an increasingly urgent public health issue and a major cause of morbidity and mortality in India. As India advances in urbanization and experiences rapid motorization, the incidence of TBIs is expected to rise significantly. Individuals who survive a TBI often face chronic disabilities. These disabilities have a profound impact on various aspects of life, including cognitive, behavioral, psychosocial, physical, and vocational areas. Cognitive impairments are difficult to manage and cause problems for the patients and their families. These impairments in cognitive functions can negatively impact the activities of daily living, employment, social relationships, recreational activities, and active community participation.

The severity of TBI can be mild or moderate or severe. This is decided depending on the consciousness. The major factor that is taken into account is the coma period; the other factor considered will be post-traumatic amnesia (PTA). Significant cognitive impairments are typically observed around 1 month after the injury or shortly after PTA resolves, and this is usually seen in severe TBI or moderate TBI. In patients with mild TBI, cognitive functions improve and this improvement will be rapid and within 3 months, they may reach their baseline.[1] Persistent cognitive impairments beyond 3 months are associated with a higher frequency of disability. In patients with severe or moderate TBI, the recovery in the cognitive domain may not happen even after 2 years.

Research and literature indicate that timely and effective cognitive rehabilitation interventions following TBI can significantly improve the recovery process and reduce functional disability. To ensure effective treatment, it is crucial to develop detailed guidelines for cognitive rehabilitation in individuals experiencing multiple cognitive impairments as a result of TBI. Indian literature in this domain is limited. Hence, global studies and intervention modules have laid a path to develop management strategies and guidelines in the Indian context. Cognitive testing itself is still in infancy in Indian context.[2] Cognitive rehabilitation recommendations should become a priority in the Indian context for various reasons as mentioned in Table 1. Furthermore, there are many challenges in the formulation of guidelines for cognitive remediation and implementation in the Indian context, which are outlined in Table 2.

Table 1.

Why should cognitive rehabilitation in TBI patients be a priority?

1. Nature of TBI: TBI not only grossly affects the brain but also leads to disruption of neuronal networks which are part of cognitive functional domain. 2. Expanding Research: The field of cognitive rehabilitation is experiencing rapid growth, with numerous international intervention studies, randomized controlled trials, and two versions of the INCOG (International Network of Cognitive Researchers and Clinicians) guidelines.[3] However, research specific to practice guidelines in India is still in nascent stage. 3. Impact on Daily Life: Although rehabilitation often emphasizes inpatient care and daily living activities, cognitive function is vital for all aspects of survival. If this happens in people in 20s and 30s, this will have an impact forever. 4. Knowledge-to-Practice Discrepancy: Clinicians encounter difficulties in implementing evidence-based cognitive rehabilitation due to the complexity and individualized nature of the field, creating a notable gap between research findings and practical application. 5. Inadequate resources: Qualified and trained clinical psychologists in the domain are not available in all places and psychiatrists alone may find it difficult to provide a comprehensive care. 6. Lack of Awareness: Family members of patients with TBI have a limited understanding of services for the cognitive impairments, and invariably, their priorities will be to ensure survival of the patient. 7. Poor Liaison: TBI patients are referred to mental health professionals by neurosurgeons invariably for the assessment of disability mainly. Creating awareness about services available and the need of cognitive rehabilitation may aid in better outcomes.

Table 2.

Challenges in Formulation and Barriers for Implementation of Guidelines for Cognitive rehabilitation in patients with TBI

Challenges in Formulation of Guidelines

1. There is limited scientific literature about post-traumatic cognitive impairment assessment and management in the Indian context.

2. Assessment tools need to be standardized for the Indian context and need to be validated for various languages.

3. Research evidence for cognitive interventions in TBI patients in the Indian context is limited.

Barriers for Implementation

1. Intervention modules: Cognitive rehabilitation involves complex processes that require thorough assessments of a TBI patient’s cognitive functions, lifestyle, and support systems. Neurosurgeons and other clinicians often lack the necessary training for these methods, and research studies frequently provide incomplete information about treatment specifics, such as exact interventions and their duration.[4] 2. Adopter Awareness and Tools: Currently, guidelines for cognitive remediation in this population in the Indian context are inadequate. Clinicians, insurance agencies, and policy makers often lack awareness of need of such guidelines or inadequately equipped to work along those lines. In the global scenario also, only a small fraction of clinicians are familiar with relevant practice guidelines, and an even smaller number apply guidelines that meet the necessary criteria.[5] 3. Clinical service setups: Cognitive rehabilitation success will depend on a multidisciplinary team, family involvement, and clear goal settings. However, optimal conditions for practice are not always feasible due to limited resources, particularly in the Indian context and especially when they are planned in an outpatient setting.[6,7] 4. Comorbidities and Impairments: Other comorbidities like depression and anxiety, as well as pre-existing personality disorders, can complicate the process. These challenges, combined with variations in access to rehabilitation services, can impede effective treatment.[8]

Scope and purpose of the present document

This document provides evidence-based guidelines for evaluating and rehabilitating cognitive function in moderate TBI patients and in severe TBI patients. These are for all phases of care. The primary focus is on enhancing patient outcomes and managing cognitive impairments post TBI. While some aspects may apply to mild TBI, the guidelines are specifically tailored to moderate to severe TBI (MS-TBI) due to the increased complexity of cognitive issues associated with it. Key details including target population, process, limitations, and evidence level are summarized in Table 3.

Table 3.

Cognitive Rehabilitation post TBI: key areas, target population, the process followed, and limitations

Key areas in cognitive domain

Posttraumatic amnesia (PTA)

Attention

Memory

Communication

Social cognition

Executive function

Target Population

Patients above the age of 18 years with cognitive impairments because of moderate TBI or severe TBI (MS TBI)

A score of <13 in Glasgow Coma Scale at any time period after the brain injury is considered as moderate or severe form of TBI. Pediatric age group is not covered as the research is limited.

Process

- Literature search from 1990 to July 2024 in PubMed

- Relevant studies in the area were searched: mainly systematic reviews, RCTs, and meta-analyses

- New guidelines on MS-TBI and cognitive rehabilitation were identified and evaluated

- Focused on cognitive assessment and remediation

- Evidence was mapped from the INCOG 2023 recommendations

- Clinical algorithms from the INCOG group were adapted for this document.

- Indian evidence in this area was hand searched in data bases and in Google.

Limitations

The recommendations are derived from evidence provided by the global scientific committee. Given the limited Indian literature in this area, it is not yet sufficient to establish as practice guidelines. Future research and new evidence may influence these recommendations. Clinicians should exercise their judgment, consider patient preferences, and take resource availability into account when applying these guidelines.

Degree of evidence used in this document

Degree A: Suggestion is based on higher level of evidence generated by at least a meta-analysis. Even a systematic review, or one RCT is also included as the higher level of evidence.

Degree B: here the suggestion is based on results from cohort study and experimental design studies.

Degree C: These are more like experience sharing. Usually expert opinion sections and case studies/series which are not controlled are included.

Target users

This document can be used by the healthcare professionals, specifically for those working in the cognitive rehabilitation of TBI patients. Guidelines are based on the existing literature mainly from the global settings as Indian literature in this is limited.

Defining traumatic brain injury

According to ICD 11, “Damage inflicted on the tissues of the brain as the direct or indirect result of an external force, with or without disruption of structural continuity” constitutes TBI.[9] Furthermore, a case is defined as a head injury (brain) caused by blunt force, penetration, or acceleration–deceleration forces if it leads to one or more of these signs: changes in consciousness (noticed by others or reported by the person), memory loss, visible neurological or psychological issues, or an identified brain injury. The TBI can be concussion, subdural hemorrhage, extradural hemorrhage, or intraparenchymal hemorrhage. However, a simplest definition of TBI can be “a disruption in brain function or signs of brain damage caused by an external force”.[10] This external force can lead to breach in the skull structures or due to movement of the intracranial structures.

Severity grading

The next step in the process is severity grading. Based on the Glasgow coma scale (GCS),[11] the severity of TBI is classified into mild, moderate, and severe. For severe TBI, the GCS score should be ≤8; if the score is in the range of 9–12, then it is considered as moderate severity. Any score above 13 falls under the mild category. These scores are in the time frame of within 30 minutes of the injury. However, additional factors are used to grade the severity. These factors include post-traumatic amnesia and duration of loss of consciousness. This is depicted in Table 4. Further clinical evaluation and neuroimaging findings need to be included while assigning a severity grade. In mild TBI, the clinical features will be headache, dizziness, fatigue, confusion, memory issues, and sometimes subtle cognitive or emotional problems.

Table 4.

Severity of Traumatic Brain Injury

	Mild	Moderate	Severe
Duration of loss of consciousness	<30 min	>30 min-<24 h	>24 h
Post Traumatic Amnesia	<1 day	>1 day-<7 days	>7 days
Glasgow Coma Scale (GCS)*	3-8	9-12	13-15

*Score within 30 min of the injury

Confirmation that the cognitive impairments are due to TBI

After confirming a TBI in a patient, the next step is to determine if their cognitive issues, such as complaints or impairments, are attributable to the injury. Although cognitive difficulties immediately following the injury might appear directly related to the TBI, the underlying causes can be varied. Considerations include the patient’s pre-existing cognitive abilities; other neurological, medical, or psychiatric conditions; additional physical problems from the injury (like headaches or seizures); the influence of substances or medications on cognition; trauma-related dissociative states; and the possibility of exaggeration or malingering. Estimation of preinjury cognitive functioning level is essential prior to attributing deficits to the TBI. The patient’s educational status and occupation level may hint about these. Alcohol and other substance use prior to the TBI will also impact the cognitive functioning of the individual.

It is also crucial to compare the patient’s cognitive difficulties and functional limitations with what is expected for their specific type and severity of injury. Cognitive impairments are typically most pronounced right after the injury and tend to improve over time, though not always completely. If the patient’s cognitive issues do not follow this expected trajectory or cause functional impairments that cannot be fully explained by the TBI alone, further investigation into alternative or additional causes (including medications as mentioned Table 5) is necessary.

Table 5.

Medications that can significantly impact cognition in patients with TBI

Opiate analgesics Sedatives First generation antipsychotics Anticholinergics Tricyclic antidepressants

Note: Given that individual clinical needs might require these medications; a strict prohibition isn’t practical. However, it’s important to be aware of their potential cognitive effects. If possible, minimizing the use of these drugs, using the lowest effective doses, and discontinuing them when feasible is advisable

Psychiatric assessment and comorbidities of TBI

A detailed psychiatric assessment prior to cognitive function evaluation is essential. This can be a clinical interview which can establish the diagnosis. Inpatient evaluation will be useful to evaluate and observe as single session evaluation may not yield a clear picture. Immediate assessment may not be useful as the recovery phase from ongoing physical ailments needs to settle. Post-TBI symptoms will be akin to the many psychiatric disorders, and differentiating them as independent entities or a part of the TBIs will be important.[12] History of pre-existing psychiatric diagnosis will help in evaluation as these may reappear or worsen post TBI.[12] Symptoms like irritability, anger, mood fluctuations, behavioral disturbances, and anxiety may be part of TBI and other psychiatric disorders which may pose a challenge in diagnosis. The prevalence of mood disorders varies in the range of 6–77%.[13] The prevalence of anxiety disorders is around 29% among all severities of head injuries, and right hemispheric TBIs are more commonly associated with anxiety disorders.[14] A 30-year follow-up study and a review revealed that generalized anxiety disorder is seen in 3–28% patients, panic disorder in 4–17% patients, phobias in 1–10% disorders, obsessive compulsive disorder in 2–15% patients, and post-traumatic stress disorder in 3–27% patients post TBI.[15,16] Psychotic symptoms post TBI are seen infrequently, and these will be in the form of hallucinations, delusions, and some disorganized thinking, which may manifest as inappropriate laughing, behavior, agitation, aggression, and ideas of reference. One review mentioned that 0.7–9.8% of TBI patients will develop schizophrenia like psychosis.[17] In a review, a three- to fourfold increased risk of death by suicide is found in comparison to the general population. Furthermore, the risk has been mentioned to persist for the first one and half decade post TBI.[18] Behavioral abnormalities like aggression may manifest in various ways. Aggression can present as verbal or physical aggression, violence, partner violence, sexual violence, or sexual disinhibition, or it can be part of other psychiatric disorders. A study reported the aggression frequency to be 11% to 96% (varied based on the tool used to assess aggression).[19] Management of these will involve symptomatic management. These are important because when unaddressed, these will be the hurdles in cognitive function assessment and any intervention modules which will be planned. Mental health professionals are involved to assess the disability following TBI, and Indian Disability Evaluation and Assessment Scale (IDEAS) provides a broader framework for the assessment disability across domains involving activities of daily living, communication, independent living, and work to name a few.[20]

Before initiating evaluations and medication trials, it is essential to conduct thorough investigations. Hematological and biochemical investigations are essential and are part of routine care: hemogram, serum electrolytes, blood sugar, hormonal assay when needed, cardiac evaluation, and infection workup as and when indicated. In clinical practice, getting an MRI scan done before starting a neuropsychiatric evaluation and intervention plan is needed. Invariably, MRI brain would have been done. Brain imaging will help us to locate the damage to specific parts of the brain, indicating probable impairment in a cognitive domain linked with that region of the brain; in addition, it will help us to know the nature of injury. When it is felt that remedial measures may not be of help considering the extent of injury, interventions will be planned accordingly, such as modifications in the environment, family education, and supportive strategies. When MRI brain reveals relatively intact brain structures, pharmacological treatments aimed at enhancing brain function may be more effective. Utilizing a checklist [Table 6] at the start of the assessment for individuals with TBI can be highly beneficial.

Table 6.

Checklist to document factors which may contribute to the cognitive impairments independently

Can the following factor contribute in index person?	Yes	No
A. Personal domain
Cultural factors?
Language barriers?
Year of schooling? Premorbid learning problems?
Premorbid cognitive functioning/intelligence?
Occupational history?
Special skills/hobbies?
Gender?
B. Pre-existing medical conditions
Substance dependence?
Diagnosed psychiatry disorder?
Epilepsy?
Dementia?
Visual or hearing impairment?
Diabetes?
Hypertension?
C. Trauma-related factors
Mood disorder?
Fatigue, pain, lack of motivation?
Sleep disorder?
Medications (given prior or after the injury)?
Seizure?
Sensorimotor changes include language changes (aphasia), vision/hearing impairment, incoordination)?
D. Post-trauma factors
Coping skills, cognitive status
New onset of psychiatry disorders
New onset of medical conditions – seizures, hormonal changes, pain, fatigue, insomnia

Assessment recommendations

Assessment of persons with TBI needs to be fine-tuned for the phase of TBI. The goal of this evaluation is to develop a treatment plan. It can be customized as per the needs depending on various factors, including the observed recovery rate and the need for data to guide future planning. This evaluation should involve observing how cognitive impairments affect daily functioning in real-life situations. It is important to complete a formal standardized assessment before starting a cognitive rehabilitation program. When choosing tests, factors such as language, race/ethnicity, acculturation, and cultural background should be taken into account.[3]

Assessment should involve collecting details from the patient, from the patient’s families/caregivers, and from all those people who were with the patient prior to the injury. Grade B evidence). This helps in understanding changes across various domains. For an adequate assessment, all stakeholders, including clinicians, from different disciplines should come together to give inputs based on evaluation in their respective domains. They should strive to avoid redundant testing or repeating tests unnecessarily (Grade C evidence). The flowchart to plan assessment of TBI is as in Figure 1.

Figure 1.

TBI assessment plan flowchart

Who should conduct cognitive assessments? (Level C evidence)

Patients with TBI have to be evaluated by a clinical psychologist or a psychiatrist who is trained in neuropsychological assessment using batteries/tools which are specific to the geographic location. The effect of cognitive impairment on functioning has to be assessed by an occupation therapist, and communication aspects need to be assessed by a speech and hearing therapist.

Post-traumatic cognitive impairments in the early phase of TBI

The neurological and behavioral manifestations and their recovery after a TBI usually progress in some predictable pattern,[21] as illustrated in Figure 2. There is no consensus on the best terminology for describing neurobehavioral changes during this early phase after moderate-to-severe TBI. Typically, individuals with moderate-to-severe TBI experience a period of unconsciousness which is then followed by post-traumatic amnesia (PTA).

Figure 2.

Typical trajectories of cognitive functioning after various severities of TBIs

The patients who are still having PTA will be better suited for rehabilitation programs which will focus on functional improvement instead of a complete neuropsychological testing and remedial measures.[3] After PTA resolves, neuropsychological testing can be planned and specific remedial measures can be outlined. Initial assessment procedures are outlined in Table 7. After a detailed cognitive assessment, four primary cognitive domains may benefit from intervention: attention and processing, executive function, cognitive communication, and memory.[3] The progression after TBI can also be effectively divided into five stages as shown in Table 8. Each stage is marked by specific cognitive, emotional, and behavioral disturbances.[22]

Table 7.

Initial assessment after TBI

All conscious patients should be assessed for the following[3] (Grade of evidence C):

Motor functions

Coordination

Injuries and pain

Difficulties in talking or swallowing

Vision, hearing, gustation, olfaction

Autonomic nervous system

Cognitive functions

Emotions and behavior

When the patient is out of PTA, further testing has to be done to assess[3] (Grade of evidence C):

Attentional abilities and the rapidity of processing of information)

Planning and execution

Memory functions

Learning

Functions of language

General communication in social contexts

Domain of social cognition

Self-awareness or insight

Understanding and expressing emotions

Visuospatial domain of functioning

Table 8.

An overview of post-TBI early phase changes

Phase	Features	Characteristics
Coma	Arousal will not be there	No response to any stimuli
Delirium	Attentional impairment is seen	There will be inability to focus or concentrate which leads to confusion state. Delirium can have wide range of features and these may fluctuate. Symptom domain can include all cognitive domains including perceptual disturbances, disinhibition, and aggression.
Post-traumatic Amnesia	Here, the patient will have problem in memory domain - episodic component	This condition is marked by difficulties in acquiring new declarative information, mainly orientation problems with respect to self, time, and place. Further divided attention and selective attention impairment may be evident. Insight will be impaired. Planning, understanding, and execution impairments are seen. Behavioral disturbances as aggression will be difficult to manage. Depression and anxiety in addition to irritability can be present.
Executive function Impairment: Dysexecutive Syndrome	Executive functions will be impaired mainly. But other cognitive functions will be relatively preserved.	Here, impairments will be mainly in understanding the contexts, evaluating the situation, planning and acting accordingly. Emotional and behavioral impairments may persist.

The initial period may be masked by delirium. Confusion Assessment Method (CAM) tool can be considered for assessing delirium.[23] In this phase, the patient needs to be assessed on orientation log or O-Log[24] tool every day. This has to be continued till the time PTA emergence is seen (if the patient meets O-Log of ≥25 for 2 consecutive days).

At this stage, further cognitive functioning can be tested using Mini-Mental State Examination (MMSE).[25] In addition, it is advisable to do frontal lobe testing using Frontal Assessment Battery (FAB).[26] These will help give a clear cognitive picture after PTA. It is advisable to go ahead with assessment tools (neuropsychological) whenever feasible during the admission for the purpose of rehabilitation. The tools which are commonly used for neuropsychological testing for cognitive functioning are depicted in Table 9. In the Indian context, many neuropsychological assessment batteries have been developed and these are outlined in Table 10. Based on the need and geographical location, one of the batteries can be used.

Table 9.

Neuropsychological assessment tools (Indian norms are available for the highlighted tests)

Cognitive Domain	Subdomains	Tools
Attention domain (Both auditory and visual attention)	Attention, concentration, how easily gets distracted, orientation to time/place/person, domain of working memory, vigilance domain, cognitive speed, multitasking	Auditory domain: WAIS-III, PASAT Visual domain: oral and written symbol modalities test, CCPT-II
Domain of Memory and Learning	Implicit memory Explicit memory Visual memory Verbal memory memory, working memory Logical memory domain[27] CERAD Word list[28,29]	Visual: CVMT Verbal: CVLT Working memory - Digit span test (backward) Component of WAIS-III: sequencing of letter and number
Visuo-spatial	Constructional praxis
Language	Naming Comprehension Fluency Categorical fluency Phonemic fluency Object naming test Naming test	Aphasia COWAT (Controlled Oral Word Association Test) Boston naming test Picture vocabulary test
Domain of Executive functioning	Understanding, conceptualizing, executing as per the plan Having goals Self-monitoring Adopting to the changes	WCST (Wisconsin Card Sorting Test) Trail Making, Stroop test, Bbackwards spatial and digit span test
General	Collective cognitive functioning	WAIS: Wechsler Adult Intelligent Scale Wechsler Abbreviated Scale of Intelligence
Domain of Psychomotor functioning	Motor function	Finger tapping Grooved pegboard
Function Assessment		EASI: Everyday Ability Assessment Scale for India[30]

CCPT-II – Conners’ Continuous Performance Test-II; PASAT – Paced Auditory Serial Attention Test; WAIS-III – Wechsler Adult Intelligence Scale-III; CVMT – Continuous visual memory test; CVLT – California verbal learning test

Table 10.

Tools for cognitive testing in Indian context

1. Mini-Mental State Examination (MMSE)[25]: It is widely utilized by Indian clinicians for global cognitive screening, both in outpatient settings and at the bedside. This paper-and-pencil assessment has a maximum score of 30, with lower scores indicating more severe cognitive impairments. A score of 24 or below is commonly used as a threshold to identify cognitive dysfunction.

2. Hindi Mental State Examination (HMSE)[31] This is the Hindi version of the MMSE can be used in illiterate patients. Maximum score is 30.

3. Montreal Cognitive Assessment (MoCA)[32]: It Is used globally and is a brief tool for bedside cognitive function assessments. It is available in various Indian languages. The maximum score is 30 and a cut-off score of 26 is considered for cognitive impairment.

4. Addenbrooke’s Cognitive Examination-III[33]: It is a 100-point comprehensive cognitive function assessment tool and is available in various Indian languages also. A cut of 88 (82 for researches) is used for clinical cognitive impairments.

5. Cognistat[34]: This is a concise tool for screening of cognitive functions in TBI patients in Indian setting.

6. The PGI Battery of Brain Dysfunction[35]: It is composition of five tests: Verbal Adult Intelligence Scale, Bhatia’s Short Scale, Bender Visual Motor Gestalt Test, Nahor-Benson Test of Perceptual Acuity, and PGI Memory Scale. It evaluates cognitive dysfunction through 19 different test variables. Developed in 1990, it provides established normative data for individuals aged 20 to 59 years.

7. The PGI Memory Scale[36]: It is a composition of 10 tests that evaluate various types of memory, including verbal and nonverbal, remote, recent, short-term, and long-term memory. It has normative data for adults in 20–45 years age ground and it has been standardized.

8. The NIMHANS Neuropsychological Battery[37]: It is developed on cerebral localization principles. This also takes into account of higher mental functions lateralization. This includes approximately 20 tests. It integrates Western tests with Indian components in responses. Tis is used for age group of 16–65 years and norms for this age group is available

9. The comprehensive neuropsychological battery[38] This was developed by the All India Institute of Medical Sciences (AIIMS). It is a detailed assessment tool designed for individuals aged 15 to 80 years. It was conceptualized with a base in Luria-Nebraska Neuropsychological Battery. It has 160 items. These items are organized into 4 secondary scales and 10 ten primary scales.

10. The 10/66 Dementia Research Group cognitive test battery[39]: This was developed and employed in studies conducted by the 10/66 Dementia Research Group. It included a wide range of assessments.

11. Indian Council of Medical Research – Neurocognitive Tool Box (ICMR-NCTB)[40] (Verma et al., 2021): This is a culturally appropriate and validated tool in the Indian context. in different languages for our country. It has been standardized in Hindi, Bengali, Telugu, Kannada, and Malayalam languages.

Initial post-TBI cognitive impairments

After a mild TBI, in the initial stages, many of the patients experience dysfunctions in various domains. These impairments can be in the attention domain mainly. The processing speed of the information, working memory, and memory retrieval (as opposed to new learning) may be impaired. In addition, the communication aspect is impaired based on the region of the brain damage. Last, the domain of executive functioning is commonly seen. Behavioral and emotional problems will be there along with cognitive problems. These are indicative of impairments in frontal lobe-related functions and impairments in control of more emotions and behaviors. At times, ‘post-traumatic dysexecutive syndrome’ term is also used to describe it.

Late post-TBI cognitive impairments

This one resolves gradually. But the resolution will be incomplete sometimes. The cognitive impairments will involve many domains, but for the sake of understanding, these have been divided and explained.

Post-traumatic amnesia

This is seen in most individuals who regain awareness after a period of coma. Patients may not have memory of this period. PTA is commonly defined by “disorientation in time, place, and identity, as well as anterograde amnesia, which impairs the ability to form new memories”.[3] Retrograde amnesia, which is invariably a finding, can remain for a longer period also. PTA can be considered as resolved when the patient’s memory gets restored; this should be for the ongoing events mainly. Prior memories like marriage day or face of person recover faster when compared to abilities which warrant new learning. PTA duration is measured as the duration from the time of injury until the person can reliably store and retrieve new information. Additional impairments in this may be attention impairment, difficulty in sustaining attention, difficulty in language understanding and expressing, impairments in perception, and problems in conceptualizing/planning and executing; the speed of processing incoming information is impaired. Attention domain cognitive functions will recover earlier than the complex domains.

The PTA course may appear as in Figure 3. There is anterograde amnesia following the TBI, and this may resolve gradually.

Figure 3.

Post-traumatic amnesia

Assessment: For Indian context, the memory component from any of the abovementioned batteries can be used. The component of ICMR-NCTB can be used. Global guidelines have mentioned about using Westmead Post-Traumatic Amnesia Scale.[41] This has Grade B evidence.[42,43]

Management:

Nonpharmacological measures with a goal to address confusion can be a priority in this phase. This confusion will also manifest as agitation. Managing these at home will be difficult, and inpatient care is advised till the patient becomes manageable. This has grade C evidence.[44,45]

During the stay, activities which are required for daily living need to be addressed as a priority taught. This has grade A evidence.[46]

The nonpharmacological recommendations are outlined Table 11. This has grade C evidence.[47] Pharmacological management recommendations are outlined in Table 12, and this has grade C evidence.[48,49] The flowchart of management of PTA is depicted in Figure 4.

Table 11.

Managing post-traumatic amnesia

Nonpharmacological Environment modification: non-noisy environment, secure environment, and consistent environment. Avoid excessive stimulation or inputs. Minimal distractions in the environment. Titration of inputs: Based on the reactions in terms of agitation/aggression, the visitors, assessments, therapies need to be fine-tuned. Sleep and rest: adequate opportunity to relax and sleep has to be provisioned. Restraints: Minimize physical restraints. Ensure that the person with TBI interacts with consistent healthcare professionals or trained caregivers. Establish and use the most effective and straightforward communication methods. Offer frequent reassurance. Introduce familiar information at a pace that the person can tolerate. Prevention: identify and avoid triggers causing impairments Promoting preferred activities like music. Family psychoeducation about these

Table 12.

Pharmacological management of PTA

Agitation and aggression: Benzodiazepines and antipsychotics are used Concerns: May act as barriers in recovery and adversely affect the cognitive functions. Recommendation: Use of antipsychotics can be restricted for unmanageable patients only with a notion of start low and go slow paired with an objective assessment of confusion.

Figure 4.

Flowchart of management of PTA

Post-traumatic attention impairment

After PTA, the person needs to be evaluated for attention impairment. This includes both visual and verbal attention. The areas which need to be assessed in this domain are focused attention and sustained attention, about orientation with time/place/person, mental speed, vigilance, and working memory to name a few. These can be part of routine clinical evaluation. Routine digit span and digit cancellation tasks and trail making test can be used to assess baseline attention impairment and can be repeated to know the change. The outcome of interventions can be measured by a subjective improvement report, with real-world performance in tasks requiring attention. Some components of standard neuropsychological assessment tools can be used as mentioned in Tables 9 and 10.

Interventions

The management algorithm is depicted in Figure 5. Once attentional impairments are identified through neuropsychological assessments and their impact on daily life is considered, it is crucial to address potential exacerbating factors. These factors include visual impairment, hearing impairment, insomnia or hypersomnia, syndromic depressive disorder or anxiety disorder, side effects of psychotropics/analgesics, history of substance dependence or use, tiredness, and pain. Efforts should be made to manage these factors where possible. Furthermore, it is essential to check the patient’s motivation in participation in tasks, insight into the illness/impairments, and willingness to cooperate. This requires that executive functions should also be intact. Based on these, intervention strategies can be planned and adopted. The level of support from family and other environmental factors should also be considered.

Figure 5.

Impaired attention management algorithm

When patients have a mild degree of impairment (to some extent moderate degree also) in attention and have insight with intact executive functions, training in metacognitive strategies tailored to everyday attentional challenges has been shown to be beneficial.[50] Managing time pressure can help address issues with information processing speed. Training may include specific tasks like clubbing two inputs for a task; one will be the main task, and the second will be introduction of some distraction like noise with which the patient has to cope. Any strategy planned should have a practical outcome in daily task and less on just engaging the patient in computer-related training modules[51] because the evidence for this is limited as of now and generalization is not possible.

The next subset will have patients with a severe degree of impairment in attention and will lack insight also. In addition, there will impairment in executive functions. Here, multitasking will be difficult. Rather, interventions here can focus on keeping one task only in the training module without any distractions or disturbances/inputs. This works on the principle that attentional demands in this task will be minimal.[52] Attention process training (APT) is a targeted program aimed at restoring and enhancing both visual and auditory attention through direct training methods. However, further research is needed to validate these approaches in general settings as the research findings are in patients with varying severities of injuries in the adult population without any impairments in sensory functions and in patients who had insight and adequate motor functioning. Patients with confounding factors like substance use or premorbid cognitive impairments have been excluded in these.

The divided doses strategy of methylphenidate yielded favorable results in enhancing the speed of information processing. This was given at a dose of 0.3 mg/kg in adult patients (16–60 years) who were recovering from varying degrees of severity of TBI.[53,54] This has been given for 6 months after excluding most confounding factors. Amantadine has demonstrated short-term benefits in arousal and function for patients in a nonrecoverable or coming out of coma; however, its effectiveness in improving attention after coma emergence remains unproven.[55]

Impairment of memory

Memory impairment is the most common cognitive impairment post TBI.[56] It is usually the first cognitive impairment to appear and the last one to recover. Prospective memory domain is the most commonly seen cognitive impairment along with retrospective (episodic) memory domain.[57] Remembering to do a planned task in future constitutes prospective domain, and recall/retrieval of prior information constitutes retrospective domain of memory.[58] Both will follow the process encode->store->retrieve. In addition, prospective domain will need other cognitive domains like executive functioning and insight to modify the course based on the outcome.

Management strategies can be along the lines of compensatory methods or restorative methods.[59] In the first one, strategies focus to address the effect of memory of routine everyday tasks. Restorative strategies focus on practicing again and again to restore the function.[60]

Assessments can be done using tests as mentioned in Tables 9 and 10.

Management strategies

Algorithm to manage memory impairment post TBI is as in Figure 6.

Figure 6.

Memory impairment management algorithm

Some of the useful strategies for patients with some preserved skills have been mentioned here. As part of instructional techniques, PQRST method can be used, and in this method, there is Preview, Question, Read, State, and Test. In addition, practicing repeatedly can be considered as an interventional measure, practicing retrieval of information can also be tried, and the patient can be made to practice visual imagery. Another technique is using the metacognitive concept, where the patient is explained about the concept of self in domains of awareness and regulation. Mix and match of these is used as per the need. These can be part of individual or group therapy. These are internal compensatory strategies, and these can be used in addition to external memory aids. This has level A evidence.[61,62] A memory notebook can be used. The memory notebook can be planned as per the requirements with basic ingredients like information for orientation, having details about memory (more like a log), having a list of what tasks have to be done and when and where, important contact details, and details of bus/train and their timings. Smart gadgets like smart phones or traditional notepads and whiteboards can be used in patients with severe memory issues. Training should focus on both the patient and the caretaker about these aids. This has grade A evidence.[63] It is important to note that remediation plan and implementation should be done by a therapist with expertise in this domain. This approach helps ensure that the strategies are integrated into real-life tasks. The evidence for computerized cognitive training (CCT) which focuses on the restorative method is limited. This is because it is used in isolation without practical implications for real life.[51]

Learning can be promoted by some standard practices as outlined in Table 13. This has grade A evidence.[1]

Table 13.

Standard practices to promote learning in post-TBI memory impairment patients

Define simple goals clearly Goal should be tailor-made for the patient and the patient’s environment and resources Time allotted should be adequate Opportunities to practice the task One task needs to be broken down into small tasks with a specific outcome which can act as stepping stone for the next task Alter the inputs given to enhance adjusting of efforts made to achieve the task Show how to process information using multiple modes like auditory, visual, tactile Minimize errors Teaching to use additional information about each task which can help in acquisition of information

Group-based interventions can be used to address memory impairments, but the evidence to support this as more effective than one-on-one intervention is lacking. To enhance effectiveness, it is advisable to minimize variability among group members, ensure adequate participation through a sufficient number of sessions, and focus on teaching the generalization of acquired skills. This has level A evidence.[64,65]

Pharmacological interventions

Donepezil for memory impairments during the chronic phase can be used. In the early phases of moderate TBI, donepezil has been shown to have a role in amelioration of neuroinflammation, as well as autophagy and mitophagy.[66] In a scoping review, adult patients post TBI had reported good tolerability and subjective/objective efficacy in reducing cognitive impairment post TBI.[67] The dose used in various studies in this review included 5 mg/d in the initial 5–10 days, followed by 10 mg/day, and the maximum duration was 18.6 months in one study. Tolerability was not an issue with minimal adverse effects. Periodic objective assessment can be done and needs to monitor adverse effects (diarrhea, stomach upset, and nausea).[68,69] Methylphenidate[53] and amantadine[70] do not have support for use for improving memory in this. Noninvasive brain stimulation (transcranial direct current stimulation (tDCS)) use has been restricted to the randomized controlled trials.[71]

Executive function impairments

Executive function indicates all cognitive abilities which are usually higher order and are for planning and execution.[72] These have multiple components beginning from being aware of oneself, planning a task, execution as per the plan, judgement in a situation, problem assessment and solving, thinking in abstract, reasoning, and managing own emotions and behaviors as per the need. Impairments in these subcomponents have been found to be strong predictors of outcomes in multiple domains and not restricted to just functional domain. Additionally, interpersonal aspects of patients’ life and psychosocial aspects also get affected.[73] These highlight the greater predictive value for clinical outcomes of these than other domains.[74]

Assessment: Executive functions can be assessed by any of these tests: digit span test and strop test, which are commonly used in clinical practice. More structured ones like Wisconsin Card Sorting Test can also be done. Standard tests to assess this domain are integral to neuropsychological batteries mentioned in Tables 9 and 10.

Management strategies

After the assessment, it will be clear whether the patient is self-aware of the impairments.

For individuals with TBI who have impaired insight, it is better to use strategies that address the patient’s monitoring by the patient. Video-feedback is one method to improve, identify, and adjust efforts while performing the task. This has grade A evidence.[75]

Metacognitive strategies can be used. These include dividing the task into subcomponents like plan a task; do it, then check it, and then review the performance; or define a goal as per the abilities or assess one’s own abilities and predict one’s own performance. These will help in planning a task and improve organization skills and problem solving abilities of the patient. The core aspect in this revolves around concepts of monitoring self, using feedback to fine-tune the performance, and managing emotions via training. These can be used for simple routine day-to-day issues which will be part of functioning.[76]

Strategies to improve reasoning skills: These will be helpful in TBI patients.

Group-based interventions

Group-based interventions can be used.[76]

Rhythmical/music therapy

To address executive functioning, implementing a structured music therapy program is recommended in global guidelines, but Indian evidence is lacking. This program should include rhythmical training, which includes “playing sequences of musical rhythms and coordinated bimanual movements on a djembe drum and own body”; structured cognitive-motor training which includes “playing musical exercises on a drum set with varying levels of movement elements and composition of drum pads, accompanied by the therapist with piano”; and personalized music playing activities to suit a patient’s interests and progress with a goal of “learning to play the participant’s own favorite songs on the piano with the help of the therapist and using figure notes”.[77,78]

Virtual reality

Where feasible, virtual reality programs alongside in-person visits can be considered. This has grade A evidence.[79,80] But evidence in the Indian context is lacking.

Cognitive communication and social cognition impairments

Communication dysfunction arises from impairments in various cognitive domains. These are seen in over 70% of patients after a severe degree of TBI.[81] This is an outcome of a combination of impairments in multiple cognitive, physical, motor, linguistic, cultural, and social domains.[82] Symptoms can vary widely, from reduced communication abilities (such as flat affect, difficulty finding words, and problems maintaining or generating topics) to excessive talking, tangential discussions, dominating conversations, and repetitiveness.[83] Communicating with someone who has TBI can be challenging, potentially leading friends, caregivers, and family members to avoid the individual, which can strain preinjury relationships. Cognitive-communication disorders can significantly impact psychosocial outcomes and affect the working of the patient, the patient’s interpersonal relationships, progress in studies, and involvement in social/community activities.[84] This itself is a hurdle for reintegration of the patient into his/her own societal system.

The social cognition concept is an essential component of communication competence. It has both cognitive and affective components: It involves conceptualizing thoughts and beliefs of other people (theory of mind, ToM); in addition, it includes perceiving emotions and demonstrating emotional empathy.[83] Those with TBI may exhibit egocentric communication, fail to respond to hints in social contexts, overlook the obvious/abstract, display excessive familiarity, and breach socially accepted boundaries such as appropriate interpersonal space. These impairments can lead to misjudgments in social situations, hindering their ability to form and sustain relationships.[85]

Evaluation and intervention

This domain needs to be evaluated and addressed by speech and hearing therapists. The assessments will focus on competence of the patient in communication. Here, the caretaker is used as a communication partner because the patients may communicate more with friends and family members.

Social cognition can be assessed using the Indian tool SOCRATIS.[86]

Interventions

When a severe cognitive communication disorder is considered, interventions can be planned, which can include:

Training the caregiver in patterns of communication with the affected patient to encourage communication and avoid negative remarks. The caregiver can be named the communication partner. This has grade A evidence.[87]

Training to improve metacognitive abilities and improve strategies in communication. This has grade A evidence.[88]

Focus should be to reintegrate the patient in his premorbid routine daily activities. The next goals will be to focus on activities which are productive and then to modify the environment to accommodate and encourage the patient to communicate. Subsequent interventions can be along the lines of improving the confidence of the patient to communicate, improving the self-esteem of the patient. This has grade C evidence. The patient and caregiver have to be psychoeducated about the impairment and progress. It is important to ensure that all inputs should have an outcome in real-life scenarios. To assess the progress, these have to be monitored periodically.

Computerized social cognition treatments, which target specific skills like emotion recognition or training in cognitive biases, emotional processing, and ToM through photographs and videos, have brought changes in the targeted domains only and failed to translate into the patient’s real life. This is the reason to restrict the computer-based intervention recommendations in this population. The algorithm for this management plan is depicted in Figure 7.

Figure 7.

Algorithm of management of cognitive communication and social cognition impairment in TBI

General principles for the management of cognitive impairments are outlined in Tables 14 and 15.[3]

Table 14.

Cognitive Intervention in patients with TBI: General Principles

General principle/Recommendation	Grade of Evidence
Patients should receive functionally oriented cognitive intervention modules. The plan of management should be made keeping in mind of patient’s premorbid abilities and should aid in survival.	B
Cognitive rehabilitation should include, when relevant: Interventions with a focus on real-life context Compensatory module of training to be used Caretakers play an important role and they need to trained Psychoeducation of all stakeholders in the patient’s life about the effects TBI on cognitive functions, which in turn affect all domains of patient’s life Modify environment as per the need to accommodate the patient	C
Cognitive rehabilitation should: Focus on relevant deficits to ensure those are meaningful to the patient. Include therapeutic interventions within the patient’s environment and patient’s circumstances Integrate strategies to promote the generalization of skills.	C
Group interventions can be looked into with targets of: Improving Social skills Improve self-regulation of emotions Problem-solving Communication Attention Memory	B
Cognition should be reassessed regularly using standardized and functional outcome measures to evaluate the effectiveness of interventions	C
Consider implementing nonpharmacological interventions before starting pharmacological treatments.	C

Table 15.

General principles for pharmacological management of cognitive functions in TBI

General principle/Recommendation	Grade of Evidence
Medications of TBI patients should be reviewed regularly	C
When initiating pharmacological interventions for TBI, it is crucial to carefully select and monitor drugs to minimize potential adverse effects on arousal, cognition, motivation, and motor coordination. Objective outcome and assessment measures should be utilized	C
It is advisable to use medications that address multiple brain injury-related symptoms or syndromes when possible (e.g., a single agent that targets both mood and insomnia, or headache and insomnia).	C
When introducing medications for individuals with TBI, start with the lowest effective dose and gradually increase it based on tolerability, clinical response, and urgency of the situation. Ensure that drug trials have sufficient duration and dosing. Clearly define therapeutic goals to gauge efficacy. If these goals are not achieved, reconsider the continuation of the medication.	C
Medications that may have harmful side effects or contribute to confusion or sedation should be gradually reduced when feasible, while continuing regular monitoring of the patient.	C
Serum drug levels in individuals with TBI should be monitored as needed to avoid toxicity.	C
Given the potential limitations in self-awareness of patients with TBI, collaborating with family members or significant others, if feasible and accepted by the patient, can be helpful in monitoring the effectiveness and side effects of treatment.	C
The use of antipsychotics and benzodiazepines to manage agitation or aggression in individuals with TBI should be minimized, as these medications may hinder recovery and negatively impact cognition. It is advisable to start with the lowest dose, increase gradually, and assess their effects on agitation and cognition using standardized tools.	C
Anticonvulsants, especially phenytoin and levetiracetam, are recommended to reduce the incidence of posttraumatic seizures within the first 7 days after injury. However, routine use of anticonvulsants to prevent late post-traumatic seizures beyond 7 days post injury is not advised.	A
Amantadine may be considered to improve arousal and consciousness and to speed up functional recovery in the short term for individuals in a vegetative or minimally responsive state, or in coma, following TBI.	A

Mobile health applications for TBI

Mobile health applications have been developed to address various domains in TBI for screening, evaluations, and interventions. A systematic review had looked at the effectiveness of these available applications in screening, education, and biomechanic monitoring of the patients after TBI.[89] These were mostly in sports-related concussions. These had integrated various assessment tools in the applications, and some external devices were also part of these monitoring and intervention services. However, the evidence for these in the management is limited at present.

Chronic subdural hematoma

Chronic subdural hematoma (CSDH) is an unnoticed relatively common entity in the elderly males, especially in those on treatment with anticoagulants, with an incidence of up to 48 per 1 lakh population per year, and this has doubled in the past few decades. With the increase in longevity and presence of cardiovascular comorbidities, incidence of CSDH is anticipated to increase.[90] These are commonly seen after TBI also. These may develop over a period of days to weeks after the initial event of trauma and may remain undetected for months to years. Subjectively reported cognitive complaints and assessed cognitive impairments in CSDH are prevalent in up to 45% of patients.[90] However, it has been recommended to use the tool which assesses important cognitive domains. These key domains are as mentioned earlier and comprise attention, working memory, new verbal learning and recall, expressive language, visual construction, executive function, and abstract reasoning. Periodic assessments using MMSE[25] have been found useful to look at the progress of the cognitive impairments. The assessment has been proposed to be done prior to the intervention (surgery) and after a gap of 3 months to ensure that the acute effects of anaesthesia, surgery, and inpatient care will not affect the cognitive assessments and patients will remain cooperative for the assessments.[90] In most cases, surgical interventions to release the pressure have been beneficial in improving the assessed cognitive impairments and inadequate brain tissue release has not revealed much improvement in cognitive impairments and cognitive complaints.[91]

CONCLUSION

Despite more than a century of advancements in psychology, neurology, and neuropsychology in India, cognitive assessments and interventions for patients with TBI remain underdeveloped. The need for assessment and intervention is not felt among stakeholders, namely, patients, family members, and primary physicians. This can be made possible by creating awareness among this population by developing and demonstrating assessment and intervention tools in the Indian population. Norms for various cognitive functions have been developed in India, but they are not used routinely unless there is a need for disability certification or other legal purposes.

Post-TBI cognitive deficits will depend on various factors including premorbid cognitive functioning status, severity of brain injury, and intervention modalities of brain injury. The initial post-traumatic period is marked by confusion and amnesia. This phase mainly involves acute management of behavioral disturbances using pharmacological and nonpharmacological measures. Subsequently, post-traumatic memory impairment, executive function impairment, social cognition impairment, and language impairment will manifest based on the region of the brain involved and the severity of impairment. Assessments for specific cognitive tasks can be undertaken using standard neuropsychological assessment batteries. Intervention modules in the Indian population are limited in terms of research and evidence.

There is a need for collaborative research and resource sharing with global scientific committees, which will help to bridge the gap between the need for brief, sensitive, and psychometrically robust cognitive interventions, the practicalities for effective management, and research.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.