Organic Mental Disorders

Question 1

What is the ICD definition of organic mental disorders

Answer 1

Mental disorder that are due to common, demonstratable aetiology in cerebral disease, brain injury or other insult leading to cerebral dysfunction

Question 2

What is primary organic mental disorder?

Answer 2

Direct effect on the brain

Question 3

What is secondary organic mental disorder?

Answer 3

Systemic diseases that affect the brain in addition to other systems/organs

Question 4

What are some common features of organic mental disorder?

Answer 4

Cognitive
-Memory, Intellect and Learning

Sensorium
-Consciousness and attention

Mood
-Depression and elation

Psychotic
-Hallucinations and delusions

Onset at any age but most in adult or later life
Some irreversible and progressive and some that respond to treatments

Question 5

What are acute or sub-acute organic mental disorders?

Answer 5

Delirium
Organic mood disorder
Organic psychotic disorder

Question 6

What are some chronic organic mental disorders?

Answer 6

Dementia
Amnesic syndrome
Organic personality change

Question 7

What is delirium?

Answer 7

Crude exogenous organic damage of the most varying kind can produce acute psychotic clinical pictures of a basically uniform kind

Question 8

Define delirium

Answer 8

An aetiologically non-specific syndrome characterised by concurrent disturbances of consciousness and attention, perception, thinking, memory, behaviour, emotion and the sleep wake cycle

Question 9

What are the presenting features of delirium?

Answer 9

organic mental disorder?

Question 10

What are the physical signs of delirium?

Answer 10

Due to underlying cause
Autonomic activation (tachy, hypertension, diaphoresis, dilated pupils,fever)
Dysgraphia often evident

Question 11

What are the causes of delirium?

Answer 11

Medications
Drug abuse + toxins
Withdrawal syndromes
Metabolic + endocrine
Vitamin deficiencies 
Infections
Neurological causes

Question 12

What are the mechanisms of delirium?

Answer 12

Pathophysiology unclear
GABAergic and cholinergic NT’s?
-Increased risk associated with GABAa agonist and anticholinergic drugs

Question 13

What are the implications of delirium?

Answer 13

Disruption to other patients
Anxiety in staff
Prolonged hospital stays
Increased risk of institutionalisation

Question 14

What is the management of delirium?

Answer 14

Treat underlying cause (dysorientation, dehydration, constipation, hypoxia, immobility, infection, pain and nutrition)
Environmental and supportive measures
-Education, environment and orientation

Question 15

What are the medications for management of delirium?

Answer 15

Avoid sedation unless for safety

Antipsychotics
BZP’s
Promethazine

Question 16

Encephalopathy vs. delirium

Answer 16

Delirium describes psychiatric presentation

Encephalopathy = describes underlying process

Question 17

What is hepatic encephalopathy?

Answer 17

Normally in advanced liver disease
-General psychomotor retardation
-Drowsiness and confusion
-Asterixis
Build up of toxic products and improves if liver function improves

Question 18

What is dementia?

Answer 18

A syndrome which is characterised by global cognitive impairment which is chronic

Underlying brain pathology is variable and (usually) progressive

Question 19

What are the types of dementia?

Answer 19

Alzheimer's
Vascular
(Mixed)
Lewy body
Frontotemporal
Due to other disorders (Huntington's, head injury, Parkinson's)

Question 20

What is amnesic syndrome?

Answer 20

Impairment of recent and remote memory
Immediate recall preserved
Learning reduced
Anterograde + reterograde amnesia
Disorientation
Confabulation
Other cognitive functions preserved

Question 21

What is amnesic syndrome prognosis?

Answer 21

Depends upon underlying lesion
Lesions typically affect hippocampal or hypothalamic region
Almost complete recovery is possible

Question 22

What is amnesic diencephalic damage?

Answer 22

Korsakoffs syndrome
3rd ventricle tumour
Bilateral thalamic infarction
Subarachnoid haemorrhage

Question 23

What is amnesic hippocampal damage?

Answer 23

HSV
Anoxia
Surgical removal of temporal lobes
Bilateral cerebral artery occlusion
Closed head injury
Alzheimer's

Question 24

What is amnesic syndrome management?

Answer 24

Depends on cause
Prevention of alcohol
-Vitamin B1
-Oral thiamine