This document discusses post-encephalitic psychiatric sequelae. Encephalitis is an inflammation of the brain that can be caused by viruses or bacteria. While some cases result in full recovery, others can lead to transient or persisting psychiatric symptoms. These post-encephalitic symptoms present in a variety of ways and can include conditions like organic personality disorder, post-encephalitic syndrome, and post-concussional syndrome. Specific viruses and infections like herpes simplex virus, Epstein-Barr virus, Japanese encephalitis, and influenza have all been linked to post-encephalitic psychiatric manifestations.

1. “ Post encephalitic psychiatric sequelae” Clinical LaisonPsychiatry, 11/09/2010

2. Encephalitis refers to an inflammation of the brain tissues. It can involve different regions of the brain and can be caused by different etiological agents. Whether directly or through immunological reaction not clear. ( more of viral cause in this context) In many cases it is followed by complete remission, but can also infrequently result in transient or persisting post encephalitis sequalae. These sequalae can manifest as a wide variety of clinical presentations, which pose challenges to clinicians in the realms of diagnosis and management.

3. 3.5 to 7.4 per 100,000 patient years. HSV most common sporadic cause in western world. Epidemic of viral encephalitis is increasing. (HIV) Clinical presentation. Encephatitis lethargica.

4. ICD –F 07 Personality and behavioural disorders due to brain disease, damage and disfunction. F 07.0 organic personality disorder F 07.1 post encephalitic syndrome F 07.2 post concussional syndrome. F07.8 other F07.9 unspecified

5. POSTENCEPHALITIC SYNDROME ( ICD) A syndrome which includes residual behavioral change that follows recovery from viral or bacterial encephalitis. The symptoms are nonspecific and depend on the individual, the infectious agent, and the age of the individual at the time of the infection. The disorder is often reversible , in contrast to the organic personality disorders. The symptoms of the disorder include general malaise, apathy or irritability, learning difficulties, altered sleep and eating patterns, and changes in sexuality and in social judgment. There may be a variety of residual neurological dysfunctions such as paralysis, deafness, aphasia, constructional apraxia and acalculia.

6. JE associated with psychiatric presentations like social inappropriteness, aggression , emotional lability, affective and paranoid symptoms ( monnet 2003) HSV , EBV acute presentations with psychiatric syndromes. Fatigue syndrome after 6 months of glandular fever. Kluver-Bucy syndrome after herpes encephalitis, tick-borne encephalitis lead to fatigue, memory problems Mood changes at recovery. Influenza epidemic, sydenhams chorea SSPE, PANDAS

7. Encephalitis lethargica Von Economo. 1917 Influenza like prodrome with variety of nervous manifestations like distuburbed sleep, lethargy, disturbance of ocular movements. Psychiatric symptoms + Post encephalitic psychosis depression, hypomania, catatonic symptoms, ocd mutism.

8. Present day Encephalitis lethargica Sporadic cases. Dale et al 2004 report 20 cases with classic neuropsychiatric manifestations. Immune mediated like in PANDAS. Clinical relevance is to keep a high index of suspicion and psychiatric symptoms may be the predominant manifestation. Whether catatonia related to encephalitic processes?