cognitive disorders

Fifth stage

Medicine
Lec-1
د.الهام

5/3/2017

Cognitive disorders

Cognitive disorders

Group of psychiatric disorders characterized by the primary 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 ,
. 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
- young
- post operative
- Burn-victim
- alcoholic & drug dependent
- serious illness
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 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 ,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 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