ANSWER 62
The mental test score is very low at 4 out of 10, indicating severe impairment of cognitive
function. A longer Mini-mental State Examination involves more questions scoring out of
- The combination of a short history of rapidly advancing dementia often with focal neuro-
logical symptoms or signs would fit a diagnosis of Creutzfeld–Jakob disease(CJD). There
may be focal or generalized fits and myoclonus is common. Speech may become severely
affected and the patient may become mute. CJD may be familial or transmitted by prions by
means of neurosurgical operations, corneal transplants or injections of growth hormone isol-
ated from human pituitary glands. New-variant CJD (nvCJD) is thought to be the human
equivalent of bovine spongiform encephalopathy (‘mad cow disease’) due to ingestion of
prions in infected cattle products. nvCJD often presents with psychiatric features and has
characteristic neuropathological features.
Dementia is a progressive decline in mental ability affecting intellect, behaviour and per-
sonality. The earliest symptoms of dementia are an impairment of higher intellectual func-
tions manifested by an inability to grasp a complex situation. Memory becomes impaired
for recent events and there is usually increased emotional lability. In the later stages of
dementia the patient becomes careless of appearance and eventually incontinent.
- Alzheimer’s disease
- Multi-infarct dementia
- As part of progressive neurological diseases, e.g. multiple sclerosis
- Normal pressure hydrocephalus: dementia, ataxia, urinary incontinence
- Neurosyphilis: general paralysis of the insane
- Vitamin B 12 deficiency
- Intracranial tumours; subdural haematomas
- Hypothyroidism
- AIDS dementia
! Causes of dementia
The investigations in this patient should include a full blood count, erythrocyte sedimenta-
tionrate, serum urea and electrolytes, serum calcium, thyroid function tests, liver function
tests, venereal disease research laboratory (VDRL) for syphilis, vitamin B 12 and folic acid,
HIV serology and computed tomography (CT) of the head. In CJD, the CT scan is usually
normal, reflecting the rapid course of the disease with little time for atrophy.
There is no treatment for this condition. The neurologist must discuss with the family the
diagnosis and prognosis. Counselling and support should be provided.
- Dementia at an early age requires rapid investigation to exclude a treatable cause.
- Most patients with presenile dementia have Alzheimer’s disease.