Dementia
- Definition
- Diminution of cognition in clear consciousness
- Decrement of 2 or more intellectual functions
- Impairment of short and long term memory
- Changes of Dementia involve
- Cognition
- Memory
- Language
- Visuospatial
- Behavioural disturbance involve
- Restlessness
- Wandering
- Violence
- Delusions
- Social & Sexual disinhibition
Types of dementia
- Alzheimer’s
- Global
- Vascular
- Pick’s disease
- Frontal
- Lewy body
- Parkinson’s
- Huntington’s
- CJD
- Kuru
Aetiology
- Parenchymal/degenerative
- Alzheimer’s disease
- Pick’s Disease
- Intracranial Tumour
- Head Trauma
- Subdural Haematoma
- Infection
- Neurosyphilis
- TB
- SSPE
- Endocrine
- Hypothyroidism
- hyperparathyroidism
- Metabolic Uraemia
- Hypoglycaemia
- calcium imbalance
- Vitamin Deficiency
- Folate
- Pellagra (Niacin)
- Toxins
- Heavy Metal Poisoning
- Prolonged alcohol misuse
Pathophysiology
- Fronto-temporal
- Disease
- Pick’s disease (20%)
- NPH & MND (70%)
- Characterised by
- prominent ‘personality change’
- May manifest as a ‘frontal lobe syndrome’
- Early –onset dementia is often undiagnosed
- Language impairments tend to involve reduction in content
- semantic anomia
- tend to replace words with something else
- eg. dog = cat , fruits, vegetables, names
- CT shows
- fronto –temporal atrophy
- SPECT shows
- FT metabolism
- Neuropathology (Pick’s disease)
- Intraneuronal inclusion bodies
- Demyelination and gliosis of frontal lobe
- Gliosis: proliferation of astrocytes in damaged areas of the CNS. Leads to formation of glial scars
- Temporo-parietal
- Disease
- Alzheimer’s Disease
- Characterised by
- early memory loss
- Focal Cognitive Deficits
- Personality Changes
- are later manifestations
- Problem with word–finding
- lexical anomia
- cannot find the word to say
- CT shows
- thinning of cortex
- Neuropathology
- Amyloid plaques
- Neurofibrillary tangles
- 50% loss of neurons in the cortex and hippocampus
- Degeneration of cholinergic neurons in basal forebrain
- Subcortical
- Disease
- Parkinson’s disease
- Huntington’s disease
- Wilson’s disease
- Binswanger Encephalopathy
- HIV-related dementia
- Clinical Features
- Gross Psychomotor
- Slowing Depressed Mood
- Movement Disorders
- Mild amnesia
- Personality Changes
- Neuropathology
- Involves
- brainstem
- cerebellum
- basal ganglia
- Gliosis and cell loss of the above structures
- Gliosis: proliferation of astrocytes in damaged areas of CNS. Leads to formation of glial scars
- Preservation of cortex
- Calcification
Neuropsychiatric features
- Depending on the type of dementia
- Alzheimer’s
- aphasia
- speech disorder
- apraxia
- loss of ability to do purposeful movemet
- agnosia
- loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss
- abnormal executive functioning
- Vascular
- same as above
- but stepwise deterioration
- with evidence of vascular event
- Frontal
- disinhibition
- disrupted eating behavior
- sensory agnosia
- hyperorality
- Subcortical
- gait disturbance
- dysarthria
- motor speech disorder, poor articulation
- dystonic movements
- neurologic movement disorder characterized by sustained muscle contractions, usually producing twisting and repetitive movements or abnormal postures or positions
Investigations
- Mini mental state
- Wisconsin card sorting test
- Digit learning test
- Test of verbal ability
- Test for non verbal ability
- Neuroimaging