Dementia refers to a chronic, usually progressive loss of cognitive ability in a previously unimpaired person and STML.

4 main types of dementia:

1) Alzheimer’s Disease:

- The most common cause of dementia.- Most often presents in people over 65yo, but can occur in younger patients too.- Early stages: STML, loss of Executive function, Agnosia, Apraxia, Aphasia, Apathy- Late stages: Behavioural problems, Wandering, sundowning, anosognosia, urinary

incontinence, confusion, irritability, aggression, mood swings, language breakdown and LTML.

Usually diagnosed clinically from patient history, collateral history, and observations. MRI, CT can exclude other subtypes of dementia.

Use of MMSE to evaluate cognitive impairments needed for diagnosis.

2) Vascular Dementia:

- accounts for 25% of all dementias. It represents the cumulative effects of many small strokes.

- Slightly higher occurrence in men than women and typically between 60-75 years of age.- Look for evidence of vascular pathology, eg raised BP, PMH of strokes, focal signs.- Sudden onset and stepwise deterioration is characteristic.- The symptoms of VD depend on where the stroke occurs. Problems include memory

impairment, confusion (which may worsen at night), difficulty walking and incontinence.

Diagnosis is based on clinical history and examination, and supported by MRI/CT

3) Lewy body dementia:

- 3rd most common type of dementia- Characterized by lewy bodies in brainstem and neocortex, fluctuating cognitive loss, signs of

parkinsonism (TRAP) and visual hallucinations- Symptoms may mimic that of Alzheimer’s disease, but they occur out of order. Eg Visual

hallucinations in AD presents during the later stages, while it can and often is the first sign of LBD.

- Symptoms specific to LBD include large changes in attention and alertness, REM sleep behaviour disorder

- Marked sensitivity to anti-psychotic medications. Referred to as the Neuroleptic sensitivity syndrome

Criteria for Diagnosis of Lewy Body Dementia

The classic criteria for Lewy Body dementia start with dementia, and then distinguish between core features and supportive features:

Core features

Three core features are defined, and for a diagnosis of probably Lewy body dementia, two need to be present. These are:

1. fluctuating cognition and level of consciousness2. visual hallucinations3. parkinsonism (not induced by drugs or stroke )

Supportive features

Eight supportive features are described, including repeated falls, fainting, other loss of consciousness, sensitivity to neuroleptic medications, delusions, hallucinations other than visual, specific types of sleep disorders and depression .

4) Fronto-temporal dementia

- Occurs at a younger age (onset after 40)- Usually presents is a gradual change in behaviour and emotional response to others.- Behaviour falls in 2 stereotypes: Disinhibited or withdrawn, reflecting the part of the frontal

lobe affected first. - Because of the nature of the symptoms and age which it presents, has been often

misdiagnosed as a psychiatric disorder such as depression, schizophrenia or bipolar disorder.- Early and progressive changes in language function, especially expressive language.- Oral fixation

Diagnosis is mainly clinical including changed behaviours, changes in language. Imaging (MRI) can show fronto-temporal lobe atrophy

Madam Sharifah’s pertinent history:

1) 10 year history of Short term memory loss2) Behavioral issues

a. - observed talking to herself, has auditory hallucinations; no visual or delusions b. - depression especially over the last 3 months c. - usually easily agitated, rejecting people's assistance; previous aggression to

demised husband d. - noted sleeping a lot in the daytime, son unsure of sleep pattern at night; has good

appetite until the last 1 week

CT head : No evidence of acute gross intracranial haemorrhage or large territorial infarct. Extensive chronic microvascular ischaemic changes and age-compatible cerebral atrophy are notedPossibly vascular dementia, but Alzheimer’s more likely.