Transcript Amnestic disorders

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 (postictal) 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