Lectures

Cognitive disordersGroup 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 Lec: 1

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 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

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