Organic Mental Disorders (Deilrium) Dr. P. C. Odinka

Introduction Organic mental disorders are those with demonstrable pathology or aetiology, or which arise directly from a medical disorder. Psychiatric disorders of any type that appear, in a particular case, to be caused by an identifiable medical condition. The two major organic disorders are dementia and delirium.

Delirium  Also known as acute confusional state or acute brain syndrome.  Very common in the non- psychiatric wards.  One third of elderly patients in the wards have an episode of delirium  The differential diagnosis includes dementia, acute psychosis, and depression.

Clinical features of delirium  Clouding of consciousness is the most important diagnostic sign.  It refers to drowsiness, decreased awareness of surroundings, disorientation in time and place, and distractibility.  Fluctuating level of performance

 At its most severe, the patient may be unresponsive, but more commonly the impaired consciousness is quite subtle. o Because clouding of consciousness may not be apparent, the first clue to the presence of delirium is often one of its other features:  Fluctuating course, worse at night.

.  Visual hallucinations.  Transient persecutory delusions.  Irritability and agitation, or somnolence and decreased activity.  Cognitive impairment: memory, especially recent memory, recall, calculation, concentration, orientation and learning new items.

Causes of Delirium o Drugs  Tricyclic antidepressants  Benzodiazepines and other sedatives  Digoxin  Diuretics  Lithium  Steroids  Opiates

.  Alcohol intoxication  Alcohol withdrawal and delirium tremens o Medical conditions  Postoperative hypoxia  Febrile illness  Organ failure (cardiac, renal, hepatic)

. o Infections  Systemic: pneumonia, typhoid fever, septicaemia, etc.  Intercranial: meningitis, encephalitis  Human Immuno-deficiency virus  Other causes of high fever

. o Metabolic  Anaemia  Hypoxia  Hypercapnia  Hypoglycaemia/ Hyperglycaemia  Hypo or Hypothroidism

.  Disturbances in serum electrolyte  porphyria.  Dehydration  Constipation  Metabolic deficiencies: Vit B12, Vit B1, Folic Acid deficiencies

. o Neurological conditions  Epilepsy Post-ictal state Grand Mal Seizure Complex –partial Seizure  Head injury  Encephalitis  Cerebral haemorrahage

. o Space occupying lesion  Neoplasm  Haematomas  Abscesses  Aneurysms  Parasitic Cyst

.  Drug or alcohol abuse or drug toxicity  Alcohol withdrawal  Barbiturate withdrawal  Withdrawal from benzodiazepines

. o Anti-cholinergic effects of drugs  Anti-parkinsonism drugs  Tricyclic anti-depressants  Anti-psychotics e.g chlopromazine, thioridazine.

. o Head trauma  Sub- arachinod haematoma  Subdural haematoma.  Burns  Major trauma

. o Hypertension Hypertensive encephalopathies o Environmental Sensory deprivation- eg bilateral cataract extraction Sensory over-stimulation- some patient in intensive care

Predisposing factors for delirium.  Elderly  Male  Pre-existing dementia  Pre-existing frailty or immobility  Previous episode of delirium  Sensory impairment

Management of delirium.  Treatment depends on the cause of delirium, but the following general measures are important.  Comprehensive history, mental state and physical examination.  Appropriate laboratory and radiological tests.

. o Environmental components  Quiet surroundings (side room)  constant lighting  clock  calendar

.  Regular routine  Clear simple communications  Limit numbers of staff (e.g. key nurse)  Provide supportive nursing care  Involve family

. o Medical components  Monitor vital signs  Investigate and treat underlying cause  Ensure sleep  Maintain fluid and nutritional intake.

.  Control agitation or psychotic symptoms with antipsychotics.  Restless patients should be mildly sedated with drugs like haloperidol or resperidone.

.  Patients with alcohol, barbiturate or benzodiazepine withdrawal syndrome should be given appropriate amount of benzodiazepine to control their agitation and then tapered off.

Prognosis of delirium  Prognosis depends on the cause.  Within a week the patient is usually better or has died.  A quarter have died by 3 months.

Organic Mental Disorders SyndromesExample of Causes Organic brain syndromeDelirium, Dementia, Amnestic syndrome Organic delusional (psychotic) disorder Systemic lupus erythemathosis Organic mood disorderMultiple sclerosis Organic anxiety disorderThyrotoxocosis Organic personality disorder Head injury