Dementia
Definition:
Progressive global decline in intellectual & memory function interfering with social/professional activity
Epidemiology:
10% of 65+. Rises sharply with age
Risk factors:
Low level of education, age, Family history, head injury
Clinical
History
Usually
from 3rd party.
Psychiatric (pseudodementia = depression)
Cardiac risk factors (it is thought that vascular
deterioration plays a part in Alzheimers). IQ (can mask sx).
ADLs.
Early features:
Loss of recent memory (long-term goes last). Impairmeent of judgement.
Changes in personality. Disorientation in time & space.
Anxious/irritable/depressed personality.
Later features:
Expressive and then receptive aphasia. Hygiene & behaviour
including wandering, aggression, disinhibition. Reduced level of
activities of daily-living (ADLs). Incontinence. Loss of insight,
visuospatial deficiency, apraxia.
Examination
-
Minimental test: (out of 30) is a good screening test for dementia
-
Cardiological
-
Neurological (parkinsons, stroke, normal pressure hydrocephalus - gait
glued to floor, change in cognitive function, incontinence)
Investigations
-
Blood
tests: Sodium, calcium, γGT (alcoholism), TFTs (Hypotyroidism),
B12/folate deficiency (Wernickes), anaemia, syphilis serology
(VDRL, TPHL), inflammatory markers (UTI etc.)
-
CXR: prone to aspiration pneumonia in later stages
-
CT, MRI head: has there been a stroke?
-
SPECT scan: an expensive radiological investigation
-
DAT scan: exclude parkinsonism
Causes
Common:
Alzheimers, vascular dementia
Less common:
Lewy-body, fronto-temporal, Downs, tumour, extrapyrimadal, Huntingtons
Reversible:
Normal Pressure hydrocephalus, alcohol abuse, neurosyphilis, hypothyroidism, Vit B12 deficiency, pseudo-dementia, neoplasms
Alzheimers (70%) Dementia
Epidemiology:
in the young ♂=♀. In the old ♂<♀. Unremitting.
Risk factors:
2 copies of ApoE E4 allele on ch19
Pathology:
Sev atrophy with increased siize of ventricles & widened sulci.
Microscopically neurofibrillary tangles & senile plaques seen.
Diagnosis:
history and CT showing atrophy
Treatment:
-
Explanation, advice, support of relatives
-
Multidisciplinary: societies, social services, psychiatrists
-
Medical: cholinesterase inhibitors (galantine, dorepezil, rivastigmine), memantine
Prognosis:
2-10 years after diagnosis. Patients
often die of aspiration pneumonia as they lose coordination of the
swallow reflex in the latter stages. Also UTIs and pressure sores.
Lewy Body (10%)
Definition:
Widespread Lewy bodies in cerebral cortex
Clinical:
Parkinsonism features (but unlike parkinsons these patients
present
with dementia), progressive dementia, fluctuation in mental state, early visual hallucinations & behaviour disturbance.
Vascular (5%)
Clinical:
Abrupt
onset, step-wise deterioration. Cognitive impairments (selective &
uneven), minor neuro signs (dysphasia or hemiparesis), confusion,
episodes, headache & dizziness, underlying vascular disease (e.g.
DM). Personality is preserved until late.
Investigations:
CT (infarction, small vessel disease)
Treatment:
Underlying cause (cardiovascular risk factors such as cholesterol), low dose aspirin
Frontotemporal (Pick's)
Epidemiology:
age range of 45-65 years.
Frontal features:
change in personality, ↓judgement/responsibility/planning, inappropriate sexual/theft, mood swings, preference for sweet foods.
Temporal features:
fluent aphasia + fluent speech with no content & lots of “things”,
impaired everyday memory. Delusions + hallucinations seen early.
Prognosis 5-10 years.
Acute confusion/Delirium
Definition:
Global acute disruption of cognitive function. Usually changes in conscious level. Responds well to treatment.
Relationships:
Half of those with delirium have dementia
Clinical
Clouding
of consciousness, impairment of orientation, failure of recent memory,
poor concentration, visual hallucinations, fluctuations with lucid
intervals. Abrupt onset.
Causes
Many causes including:
-
Acute infection: any, but very often UTI
-
Drugs
-
Cardiac/Respiratory: ↓BP and hypoxia leads to ↓cerebral perfusion
-
Alcohol intoxication/withdrawel
-
Epilepsy
-
Electrolyte imbalance: especially hyponatraemia, hypo/hyperglycaemia, hypercalcaemia
Treatment
-
Underlying cause
-
Avoid sedation: causes falling & ↓respiration
-
Small dose antipsychotic may be useful but unlicensed for this purpose:
consider if it is in the best interest of the patient
-
Structured routine: same nurses, visits by family, ↓noise, dim lights at night, help feeding
-
Stimulation: including music and books
