Lec: 1
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
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
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 notesparticularly 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
Environmental & supportive
measures in delirium
* education of all who interact with the patient ( doctors ,
nurses , family, ..etc)
* reality orientation technique . Firm clear communicationpreferably 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