Cognitive disorders

Cognitive disordersGroup 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 Lec1 14thapril2014

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