Dementia is a clinical syndrome charactirized by loss of previously acquired intellectual functions in the abscence of
impairment of conciousness
• The term dementia is mostly associated with elderly but some disorders occur in the mid life, ex: Alzheimer's
Pick's disease, Huntington's Chorea.
• Huntington's Chorea, and Pick’ disease both are rare and transmitted by an Autosomal dominant gene.
• These conditions are also collectively called Pre-senile Dementia and have a strong familial disposition.
Main features of Dementia
• Loss of general intelligence
• Memory impairment
• Personality changes
• Emotional changes
• The dementia is not necessarily irreversible.Progression of dementia usually leads to global cognitive
impairment ,but some dementing disorders are more focal in early stages.
• Deterioration of intellect and performance may also be a major presenting feature of psychiatric disorders
,particularly depression;the term pseudodementia is generally used in this setting ,and recovery occurs with
effective treatment of depressive illness.
Causes of dementia:
Dementia with normal aging :
• There is decline in the cognitive function with increasing age.
• Age –related changes, the problem solving ,reaction time tests and ability to learn new material decline with
• Ill health undoubtedly affects cognitive performance , chronically raised blood pressure causes impairment in of
attention memory and new learning.
• Effective control of hypertention may delay or prevent this cognitive impairment.
- Alzheimer’ disease.
- Multisystem atrophy.
- Pick’s disease.
- Friedriech’s ataxia and other spino-cerebellar degenerations.
- Some patients with parkinson’s disease.
• Vascular: Multiple cerebral infarcts. Diffuse small vessel disease.
• Toxic: Alcohol-lead .
• Drugs: Hypnotic , tranquillisers , barbiturate
• Trauma : Head injury ,including subdural haematoma.
• Neoplastic: Frontal tumours ,multiple metastases.
• Hydrocephalus: Tumor,or Normal pressure hyrocephalus.
• Infection: TB; meningitis,syphilis encephalitis; AIDS-related dementia; Creutzfeild jakob disease (Cow madness).
• Inflamatory: MS, SLE, Sarcoidosis.
• Metabolic: Hypothyroidism , uraemia , hepatic failure, B12 deficiency, prolonged hypoglycaemia, prolonged hypoxia,
• Pseudodementia in Depression.
ALZHEIMER'S DISEASE VERSUS MULTIINFARCT DEMENTIA :
CHARACTERISTICS ALZHEIMER'S DISEASE MULTIINFARCT DEMENTIA
Sex Women more commonly affected Men more commonly affected
Age Generally over age 75 years Generally over age 60 years
Time course of deficits Gradually progressive Stuttering or episodic, with stepwise
Hx of hypertension Less common Common
Hx of stroke, TIA, or other Less common Common
focal neuro. symptoms
Hypertension Less common Common
Focal neuro. signs Uncommon Common
atherosclerotic CVS disease Less common Common
Emotional lability Less common More common
Investigation of dementia:
• Full blood count,ESR, B.Glucose, Vitamin B12.
• Renal function.
• Liver function.
• Treponemal serology.
• CSF [selected pt.]
• Chest X-ray ,ECG
• CT or MRI scan
• EEG [selected pt.]
• Alzheimer’s disease is the commonest cause of dementia in people over 60 years of age.
• It is primary degenerative disease of brain of unknown aetiology of insidious onset followed by gradual
deterioration and then death in about ten years.
• The onset can be in the middle adult life [of presenile onset] but the incidence is higher in later life.
• Patients at risk of developing Alzheimer’s disease are those who have a family history , or have Down’s
Pathophysiology of Alzheimer’s disease:
• Neuropathological changes include neuronal reduction,neurofibrillary tangles,senile neuritic plaques and a
variable amyloid angiopathy.
• These changes are particularly seen in the temproparital and frontal cortex.
• Aggregation of amyloid appears to be the central event.The gene responsible for amyloid deposition located close
to a defect on chromosome 21,causing familial Alzheimer disease..
• Neurochemical changes occur, including a marked reduction in the enzyme choline acetyl-transferase,in the
acetylcholine itself,and other neurotransmitters and neuromodulators.
Clinical features of Alzheimer’s disease:
• Impaired ability to learn new information or to recall previously learned information.
• A decline in language function and in particular, increased difficulty with names and understanding what is being
• Apraxia : an impaired ability to carry out motor activities despite intact motor function.
• Agnosia: the failure to recognise or identify objects despite intact sensory function
• Impairment of executive functioning –planning , organizing , and sequencing.
• Behavioural changes are common , include wandering , agitation & aggression
• Paranoia with persecutory delusions occurs in up to 50% of patients.
• Depressive symptoms are also common , but severe depression is unusual.
In the early stages of Alzheimer's disease, patients may experience :
memory impairment, lapses of judgment, and some changes in personality.
As the disorder progresses,
• memory and language problems worsen and
• patients begin to have difficulty performing activities of daily living,
• can not remember to take medications.
• become disoriented about places and times,
• may suffer delusions (such as the idea that someone is stealing from them)
During the late stages of the disease:
• patients begin to lose the ability to control motor functions such as swallowing, or lose bowel and bladder
• They eventually lose the ability to recognize family members and to speak.
• Disease may affect the person's emotions and behavior and they develop symptoms such as aggression, agitation,
depression, sleeplessness, or delusions.
• On average, patients with Alzheimer's disease live for 8 to 10 years after
they are diagnosed.
• However, some people live as long as 20 years. Patients with Alzheimer's disease often die of aspiration
pneumonia because they lose the ability to swallow late in the course of the disease
Investigations and management Alzheimer’s disease :
• There is no single diagnostic test for Alzheimer’s disease .
• The finding of diffuse cerebral atrophy on CT scanning and exclusion of other treatable causes of dementia usually
leave little doubt about the diagnosis
• Management is largely supportive ,though there is much current interest in a possible therapeutic effect of
• Tetrahydro-aminoacridine [Tacrine] has been reported to produce some improvement of cognitive function in up
to 40% of patients.
• Tacarine,inhibits cholinestrase , so it produces an improvement in intellectual function in a good percent of
patients up to 50%,who can tolerate the higher doses.
• However,Tacarine is potentially hepatotoxic and aminotransferase levels must be monitored weekly for the first 6
• The first drug to be licensed in UK for treatment of AD is the acetylcholinestrase inhibitor ,donepezil ,its benefits
appear modest,but it is easly administered and its side-effects appear less.
• Αlpha-Tocopherol(vitamin E),a potent anti-oxidant,can be used due to decreased anti-oxidant defences.
• HRT in postmenoposal women and NSAIDS have shown protective effects aginst developing of AD.
is a dominant inherited condition consisting of chorea and progressive dementia of unknown cause.
• Symptoms of Huntington's disease usually begin when patients are in their thirties or forties, and the average
life expectancy after diagnosis is about 15 years.
Pick’s disease :
is a rare disease, it consists of dementia with selective impairment of speech function associated with focal atrophy
of frontal and temporal lobes.