Lec:2 Amnestic disorders Amenstic disorders are syndromes characterized by memory impairment ( anterograde And / or retrograde amnesia ) which are cause by general medical condition or substance abuse, and where delirium and dementia have been excluded as causative of the amnesia. it may be transient or chronic e.g of AD

Wernickes encephalopathy : An acute syndrome with Ataxia Ophthalmoplagia Nystagmus Lack of memory caused by thiamine depletion. usually related to alcohol abuse

korsakoff psychosis Amnesia and confabulation associated with atrophy of the mamillary bodies Usually following wernickes encephalopathy Rarer causes include head injury basal temporal lobe encephalitis and vascular causes

Head Injury Mainly to anterior temporal poles, antero grade or post - traumatic amnesia ( PTA ), with retrograde amnesia almost absent, prognosis is related to length of PTA. better prognosis associated with PTA less than 1 wk.  temporal lobe surgery  hypoxic brain damage e.g following asphyxia from Co poisoning, near drowning  MS 40% of patient have some amnesia

Alcohol Blockout Significant alcohol intoxication may lead to amnesia for the period of intoxication, this only occurs in chronic alcohol misuse Transient global amnesia (TGA) This is a syndrome of amnesia affecting the temporal lobes and / or diencephalon it is more common over 50 years and may occur in hypertension or migraine

Other Causes Of Amnesia drugs ( benzodiozepines, anticholinergics ) space occupying lesions hypoglycemia

Psychiatric Sequelae Of CVA These include cognitive disorders vascular dementia subcortical dementia amnestic disorder

Personality Changes Irritability, catastrophic reactions in response to stress & loss of intellectual flexibility Post-stroke Depression In up to 60 % of cases, it's onset is usually between 3-24 months following the stroke

Psychoses Manic, hypomanic and paraniod psychosis may result from CVA korsakoff psychosis A rare chronic complication of subarachnoid haemorrhage

Psychiatric aspects of head injury most significant head injuries are closed and involve a period of loss of consciousness (which may extend from brief concussion to prolonged coma ). On recovery of consciousness is classified in terms of acute psychological effects of head injury Post - traumatic amnesia ( PTA ) Include the period of injury and the period following injury ( until normal memory resumes ) PTA may end abruptly Retrograde amnesia ( RA ) Include the period between the last clearly recalled memory prior to the injury and the injury itself, lasting seconds or minutes, and shrinks with time.

Factors associated with increased psychiatric morbidity following head injury Increased duration of loss of consciousness Increased duration PTA Increased age, arterio sclerosis, and alcoholism Increased area of damage Increased neurological sequelae C focal deficits, epilepsy, etc Dominant or bilateral hemisphere involvement The presence of compensation

Chronic psychiatric syndrome following head injury Cognitive impairment, especially after closed head injury, PTA lasting > 24 hours Personality and behavioral changes mainly head injury to orbito-frontal or anterior temporal lobes, frontal lobe syndrome characterized by disinhibition impulsivity irritability and aggressive routbursts Psychosis, a schizophrenia - like psychosis temporal injury, while affective psychoses (esp. mania in 9 % patients ) are associated with right temporal or orbito - frontal injury.

Neurotic - disorders Depressive illness is most common but anxiety states (including PTSD ) are common sequelae Post - traumatic syndrome also called " post - concusional syndrome ". main symptoms are headache, dizziness, insomnia, irritability, emotional lability, increased sensitivity to noise, light etc, fatigue, poor concentration anxiety and depression post - traumatic epilepsy - occurs in 5 % closed and 30 % open head injury Punch - drunk syndrome Boxer may develop diffuse injury to the cortex, based ganglia, and cerebellum, giving rise to extra - pyramidal symptoms or subcortical dementia, pathology shows cerebral atrophy and neuro-fibrilary tangles.

Psychiatric aspect of epilepsy Many different types of psychiatric disorders are associated with epilepsy, including cognitive, affective, emotional, & behavioural disturbances, these can occur before (pre-ictal), during (ictal), after (post- ictal) or between seizures.

The relationship between epilepsy & psychiatric disorders may reflect several factors: A shared aetiology or pathophysiology, for e.g temporal lobe epilepsy (TLE) appears to predispose to epilepsy & to psychosis. The stigma & psychosocial impairment associated with epilepsy. The side effect of anti epileptic drugs. Pre-ictal psychiatric disturbances :tension, irritability, anxiety, & depression are some times apparent as prodromata for several hr.s or even days before seizure, generally increasing in intensity as the seizure approaches

Ictal psychiatric disturbances are common & diverse : - transient confusional state - affective disturbances - anxiety - psychoses may occur ( sudden onset & termination of the disturbances) - olfactory or gustatory hallucinations - amnesia for the period of the disturbances - ictal violence is extremely rare

Post - Ictal Disturbances: - Psychotic symptoms are seen in about 10%of cases and are associated with bilateral seizure foci, long duration of epilepsy and structural brain lesions - Diverse motor, sensory, cognitive and autonomic dysfunction can also Occur - Post - Ictal Violence is rare but more common than during seizure, there is usually amnesia for the event.

Inter - Ictal Psychiatric Disturbances: - Cognitive Impairments a few epileptic patients show a progressive decline in cognitive function and of particular concern in pediatric practice - Personality - a minority of patients have serious personality difficulties and this reflect the adverse complications of epilepsy on education, employment and social life. - Inter - Ictal Psychosis

Religious and paranoid delusions appear to be common - Suicide - Suicide is four times, and D.S.H six times more frequent among people with epilepsy than among the general population. - Depression and emotional disorders. Depression is common in people with epilepsy

Risk Factors of depression in epilepsy Family history of mood disorder Focus in temporal of frontal lobe Left sided focus Perceived Stigma Fear of seizure Decreased social support Unemployment Poly pharmacy and high Serum levels of anti epileptic drugs