1
Fifth stage
Psychiatry
Lec-8
.د
صفية
3/4/2016
Cognitive Disorders-2
Cognitive disorders
Group of psychiatric disorders characterized by the primary P symptom common to all the
disorders, which is an impairment in cognition ( as memory , attention , concentration
.orientation , language , ....), in the past these condition were classified under the heading
"organic mental disorders ".
• Classification of Cognitive disorders
• Delirium
• Dementia
• Amnestic disorders
Delirium
Previously termed acute confusional state, is characterized by changes in the consciousness
, attention, cognition (memory deficit, disorientation , language disturbances ), or perception
. These changes develop over a short period of time , tend to fluctuate during a 24-hr periods
, & can't be solely accounted for by dementia . Depletion of acetylcholine and changes in
others neurotransmitters (y-amino butyric acid , serotonin , nor adrenaline & histamine )
have been implicated in the development of delirium
Epidemiology
extremely common in medical & surgical patients 10-20%
Particularly vulnerable include:
- elderly
- pre-existing dementia
- blind or deaf
- very young
- post operative
- Burn-victim
- alcoholic & drug dependent
- serious illness particularly multiple
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Clinical features
- impaired level of consciousness with reduced ability to direct, sustain , & shift attention
- global impairment of cognition with disorientation & impairment of recent memory &
abstract thinking
- Disturbances in sleep / wake cycle with neuronal worsening of symptoms
* psychomotor agitation & emotional lability
* perceptional disorders , illusions , & hallucination especially visual
* Speech may be rumbiling , incoherent & thought disorders
* there may be poorly developed paranoid delusions
* onset of clinical features is rapid with fluctuation in the severity over minutes & hours (
even back to apparent normality )
Differential diagnosis
* mood disorders
* psychotic illness
* post-ictal
* dementia ( characteristically has insidious onset with stable course & clear consciousness -
clarify functional level prior to admission )
Aetiology
The cause is frequently multi-factorial & the most likely cause varies with clinical setting in
which the patient presents.
intracranial: CVA, head injury, encephalitis , primary or metastatic tumor, raised ICP
metabolic : anaemia , electrolyte disturbances , hepatic encephalopathy , uremia ,
cardiac failure , hypothermia
endocrine: pituitary , thyroid , parathyroid , or adrenal diseases , hypoglycemia, DM,
vitamins deficiency (thiamine , B12, folat, nicotinic acid )
infective: UTI, chest inf. , wound abscess , cellulites , SBE
substance intoxications or withdrawal : alcohol, benzodiazepines , anticholinergic ,
psychotropics , lithium , antihypertensive , diuretics , anticonvulsant, digoxin , steroids ,
NSAIDs
hypoxia 2ry to any cause
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Course & prognosis
Delirium usually has a sudden onset, usually lasts less than wk, & resolve quickly . There is
often patchy amnesia for the period of delirium . mortality is high ( estimated to be up to
50% at 1 year). May be a marker for the subsequent development of dementia .
Assessment
Attend promptly ( situation only tend to deterioration & behaviorally disturbed patients
cause considerable anxiety on medical wards ).
Review time-course of condition with nursing & medical staff & review notes-particularly
blood results
Establish pre-morbid functional level ( e.g from relative or GP).
Management
4 main principles management
* Identify & treat precipitating cause
* Provide environmental & supportive measures (below)
* Avoid sedation unless severely agitated or necessary to minimize risk to patient or to
facilitate investigations/ treatment
* Regular clinical review & follow up ( MMSE useful in monitoring cognitive improvement at
follow up).
Sedation in delirium
* Use single medication
* Start at low dose & titrate to effects
* Give dose & reassess in 2-4 hrs before prescribing regularly Possible * avoid PRN
medication if
* Review dose regularly & taper & stop ASAP
* Consider
Haloperidol 0.5-1 mg up to max of 4 mg daily Lorazepam 0.5-1 mg up to max of 4 mg daily
Risperidone 1-4mg up to max of 6 mg daily
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Environmental & supportive measures in delirium
* education of all who interact with the patient ( doctors , nurses , family, ..etc)
* reality orientation technique . Firm clear communication-preferably by same staff member
use of clock & calendars.
* create an environment that optimize stimulation ( e.g adequate lighting), reduce
unnecessary noise , mobilize patient whenever possible
* correct sensory impairment ( e.g hearing aids , glasses )
* optimize patients condition-attention to hydration . Nutrition , elimination, pain control
* make environment safe (remove object with which patient could harm self or others )
Cognitive disorders