Table V. The stages of post-traumatic encephalopathy.

PTE stage	Salient (key) neuropsychiatric feature	Description	Additional features
Post-traumatic coma	Impaired arousal	Absence of arousal	No behaviour response to sensory input
			No spontaneous behaviour (purposeful or non-purposeful
			Preserved brain stem reflexes
Post-traumatic delirum	Impaired attention	Reduced of awareness of the environment, as evidenced by a reduced ability to focus, sustain, or shift attention	Alterations of arousal
			Disturbances of sleep-wake cycle
			Motor restlessness
			Impaired processing speed, working memory, episodic memory (including orientation), language/communication, and executive function
			Perceptual disturbances (le, illusions, hallunicinations)
			Emotional lability
			Disinhibition, agitation, and/or aggression
			Fluctuation of the disturbance (not simply arousal, but the entire constellation of problems comprising delirium)
			Although other pre-or post-injury neuropsychiatric conditions may contribute to the above problems, the diagnosis of delirium generally precludes attributing these problems to another cause
Post-traumatic amnesia	Impaired episodic memory	Impaired declarative new learning, including orientation as well as autobiographical information for the periand immediate post-injury and immediate post-injury period	Impaired new learning is not attributable to lower-level cognitive impairements, including impaired arousal or selective and simple sustained attention
			Impaired processing speed (typically less severally impaired) than during post-traumatic delirium) as well as higher-level (alternating, divided) attention, working memory, and excutive function (including insight) are often present but less clinically salient than impaired episodic memory
			Emotional and behavioural disturbances may persist (eg, emotional lability, irritability, depression, anxiety, psychosis, apathy, aggression); these often represent the neuropsychiatric sequelae of focal injuries (ie, orbitofrontal syndrome) or damage to neurobehaviorally salient networks, other pre-or post-injury neuropsychiatric conditions, or some combinationa thereof
Post-traumatic dysexecutive syndrome	Executive dysfunction	Impaired intrinsic executive function (eg, conceptualization, judgement, insight) and impaired executive control of attention (ie, alternating, divided) working memory, declarative memory (ie, impaired retrieval), language, and/or motor planning	Emotional and behavioural disturbances may persist (eg, emotional lability, irritability, depression, anxiety, psychosis, apathy, aggression); these may continue to represent the neuropsychiatric sequelae of focal injuries (ie, orbitofrontal syndrome), damage to neurobehaviorally salient networks, other pre-or post-injury neuropsychiatric conditions, or some comination thereof
Recovery	Return baseline cognitive function	Injury-related disturbances of cognition are no longer present or, if present are attributable to another non-cogntive neuropsychiatric condition (eg, depression, anxiety, sleep disturbance, pain, medications, etc)	Non-cognitive neuropsychiatric symptoms, if present may be attributable to injury-related factors, pre-injury factors, post-injury psychosocial factors, or interactions between them
			Irrespective of the attribution of subsequent neuropsychiatric symptoms to TBI and/or other issuese, TBI remains relevant as comorbidity that influences treatment selection and response expectations