Organic Mental Disorders

Question 1

What are functional psychiatric disorders characterised by?

Answer 1

Disturbance in the functioning of the brain

Question 2

What are organic mental disorders characterised by?

Answer 2

Demonstrable organic brain damage or mental disorder arising in the context of demonstrable physical disease

Question 3

What are organic mental disorders?

Answer 3

a group of disorders that have a recognised organic explanation

Question 4

Types of brain disorder

Answer 4

Primary (e.g. tumour/MS/parkinsons)
Secondary (e.g. due to endocrine disorder, substance misuse)
Acute/subacute
Chronic

Question 5

Common features of an organic mental disorder

Answer 5

Cognitive impairment
- disorientation 
- impaired attention/concentration 
- memory (anterograde +/- retrograde amnesia) 
- language (expressive and receptive dysphasia)
- judgement
- insight 
Behavioural abnormalities
- agitation / aggression 
- slowing
- psychomotor retardation 
- abnormal social conduct 
mood changes
- low mood
- anxiety
- mania
Psychotic features
- hallucinations, commonly visual 
- delusions (often persecutory)

Question 6

What causes a acute/subacute organic mental disorder?

Answer 6

Delirium
organic mood disorder
organic psychotic disorder

Question 7

What is delirium?

Answer 7

Transient organic mental syndrome of acute or subacute onset which is characterised by global cognitive impairment
Acute organic confusional state

Question 8

What causes chronic organic mental disorder?

Answer 8

Dementia
Amnesic syndrome
Organic personality change

Question 9

Presenting features of delirium

Answer 9

Impaired attention / concentration
anterograde memory impairment
disorientation in time, place or person
fluctuating levels of arousal (often nocturnal exacerbations)
disordered sleep/wake cycle
increased/decreased psychomotor activity
disorganised thinking as indicated by rambling, irrelevant or incoherent speech
perceptual distortions, leading to misidentification, illusions and hallucinations
Changes in mood such as anxiety, depression and lability

Question 10

Causes of delirium

Answer 10

Infections
medications
alcohol/drug withdrawal 
drug abuse e.g. TCAs
metabolic 
vitamin deficiencies 
endocrinopathies
neurological causes
toxins/industrial exposures 
SLE
cerebral vasculitis 
Paraneoplastic syndromes

Question 11

What is dementia?

Answer 11

A syndrome which is characterised by a global cognitive impairment which is chronic in nature. The underlying brain pathology is variable and usually but not always progressive

Question 12

Types of dementia

Answer 12

Alzheimer 
Vascular
Lewy body 
fronto-temporal 
due to other brain disorders
- huntingtons chorea
- head injury 
- parkinsons

Question 13

Presentation of amnesic/koraskoffs syndrome

Answer 13

Preserved global intellectual abilities 
anterograde amnesia 
retrograde amnesia (temporal gradient)
preserved registration / working memory (e.g. digit span)
preserved procedural (implicit) memory

Question 14

Causes of amnesic/koraskoffs syndrome

Answer 14

Hippocampal damage
- HSV encephalitis
- anoxia
- surgical removal of temporal lobes
- bilateral posterior cerebral artery occlusion
- closed head injury
- early alzhimers disease
Diencephalic damage
- koraskoffs syndrome (alcohol and non alcoholic)
- 3rd ventricle tumour and cysts
- bilateral thalamic infarction - post subarachnoid haemorrhage, especially from anterior communicating artery aneurysms

Question 15

What is koraskoffs syndrome?

Answer 15

A chronic memory disorder caused by severe deficiency of thiamine (vitamin B-1)

Question 16

Most common cause of korasskofs syndrome

Answer 16

Alcohol misuse