Pseudobulbar affect masquerading as psychosis: Managing a case of diagnostic dilemma

Dear Editor,

Pseudo-bulbar affect (PBA) is a clinical condition characterized by uncontrollable emotional outbursts, incongruent with the person’s emotional state and often out of keeping with the situational context. It manifests mostly as uncontrollable laughter or crying in inappropriate situations.[1] PBA is also referred to as Emotional incontinence, Pathological Laughter and Crying (PLC), and Involuntary Emotional Expression Disorder (IEED).[2] PBA is most commonly seen occurring in the background of neurological disorders like in post-stroke period, multiple sclerosis, Parkinson’s disease or traumatic brain injury.[3,4,5] However, it can also be seen without any apparent neurological disorders.[5] Historically PBA has been an under-recognized and under-treated condition, which brings in significant distress, stigma and shame for the person suffering from the condition.[6] Along with the social stigma of inappropriate laughing or crying, it often carries with it the burden of being tagged with mental illness.[7] The newer and probably less stigmatizing term IEED can provide some respite to those with the condition as an acknowledgement of their suffering. This case report presents a patient with PBA without any neurological comorbidities who improved significantly with fluoxetine and dextromethorphan.

A 59-year-old, widowed female, coming from an urban background, presented with episodes of uncontrollable laughter spells in inappropriate situations for the past 1.5 years. She also reported occasional mild slurring and difficulty deglutition for the same duration. These laughter spells would occur every 2-3 days, occurring for 5-15 minutes. These would be typically incongruent to the context. For example, occurring while in inappropriate social situations like in a funeral house. These incidents would make her extremely embarrassed and she had to leave the situation altogether as she could not control her laughing. Her family members too would scold her for doing so, apparently a willful act as per them, and would ask her if she has gone mad. She would feel sad over these incidents and tell her family members that she was not doing this willfully and it was not under her control. These episodes were accompanied by on-and-off difficulty in deglutition, mild slurring of speech and a subjective sense of hypersalivation. These symptoms would aggravate prolonged speaking or chewing. All these incidents would occur with intact awareness and responsiveness. Sleep onset insomnia was present.

There was no history of associated low or elevated mood, anhedonia, disproportionate physical fatigue, somatic preoccupation or dissociative episodes. Past psychiatric history revealed nothing significant. She was not known to be diabetic, hypertensive, hypothyroid or obese. There was no history of head injury, seizures or stroke either. She had never taken any substance of abuse. She was taken to psychiatrists as her family members thought she might be having some psychiatric illness. She was suspected to have psychosis, unspecified and was given trials of quetiapine up to 100 mg and later olanzapine up to 25 mg. Both these treatments improved her sleep only but no improvement was observed in the uncontrollable laughter episodes.

On presentation, she was neither sad nor overtly cheerful, though expressed her worry and guilt about the inappropriate laughter episodes and social disgrace. No other thought or perceptual abnormality was noted. She had good insight into her symptoms.

On neurological examination, speech was normal, jaw jerk and palmomental reflex were absent. Blood sugar, thyroid panel, lipids and electrolytes came out to be normal. We admitted her for diagnostic evaluation. Neurology and otorhinolaryngology consultation-liaison were sought. MRI Brain was suggested by neurology which came out to be normal. Based on the clinical presentation, examination and investigation findings we considered a diagnosis of Pseudo-bulbar affect of unknown etiology.

Due to the unavailability of a Dextromethorphan/quinidine combination, we started her on Dextromethorphan 20 mg and Fluoxetine 40 mg. She tolerated the treatment without any side-effects. Over the next couple of days, she did not report much improvement and was discharged on the same treatment. She adhered to treatment and on follow-up visit one month later, she reported significant improvement in laughter spells, which occurred only once during that period. She had started attending social gatherings again without any issues. From the second follow up Dextromethorphan was gradually tapered and stopped; Fluoxetine has been continued. She is maintaining well on current treatment. We are regularly following her up in liaison with the Neurology team as over due course of time some underlying neurological cause may become evident.

PBA is a disorder which is poorly recognized, variably characterized, and causes significant distress and dysfunction for patients and their families. Patients are often ascribed mental illnesses like schizophrenia or mania in many of these cases of PBA leading to unnecessary treatment.[8] Further, the drug side effect burden adds to the misery of the patients. Our patient had consulted several psychiatrists, who treated her with antipsychotics without much improvement in her symptoms. We could not find any underlying neurological condition despite a neurological workup but she responded well with treatment with SSRI and Dextromethorphan.

The neurobiology of PBA is still unclear; most likely to be of multifactorial causation. Disruption of the cortico-limbic-subcortico-thalamic-pontocerebellar network, which is involved in the regulation and expression of emotion, has been hypothesized.[9] In many cases, no neurological association is found even after a thorough workup. A patient-rated instrument, Center for Neurologic Study-Lability Scale (CNS-LS) is used commonly to rate the severity of PBA.[10] It is validated for use in patients suffering from amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS).[11] The Pathological Laughing and Crying Scale (PLACS) is another patient-rated instrument validated to rate the severity of PBA in post-stroke patients.[12] PBA is a clinical diagnosis. While these scales are not used to diagnose PBA, these are used to rate the severity and improvement with treatment. Treatment with SSRI and Dextromethorphan/quinidine has shown promising results in cases of PBA.[13,14]

Our case emphasizes the need to have clinical suspicion in such cases presenting with unexplained mood outbursts before categorizing them as specific psychiatric illnesses. Detailed neurological evaluation needs to be undertaken in such cases. Timely recognition of PBA is essential for an effective treatment.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Author's contribution

Writing the original draft, editing: ANM. Conceptualization, editing, language correction: SM. Editing, language correction: SA.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.