dementia

DEMENTIA

Case History

• A 79 years old retired female school teacher who has been very independent, started forgetting her usual appointments about one year ago. The forgetfulness has been gradually increased and now she finds it difficult to recall the date, month etc. and “misidentifies” her daughter as her sister who died a few years ago. She gets irritable over trivial matters and seems to be less affectionate than earlier. She started wandering about aimlessly and collecting rubbish and keeping them under her pillow over the last one month. She looks unkempt and tries to wear bed linen instead of her usual clothes. She would pass urine in a corner of her bed room.

Organic Mental Disorders

• Delirium (Acute)

• Dementia (Chronic)

• Amnestic Disorder

Introduction

It is not enough for a great nation merely to have added new years to life

Our objective must also be to add new life to those years

- John F.Kennedy

EpidemiologyThe total world population increased by 26%

between 1980 and 2000

Population over 65yrs increased by more than 53%

Developed countries - 29.4%

Developing countries - 77%

Sri Lankan figures

• In 1995 Population >65yrs - 6.2%

• Predicted figure for 2010 - 8.6%

• Predicted figure for 2020 -12.1%

Sri Lankan figures - continued

• CLASSIC SURVEYS -

NEWCASTLE UPON TYNE,

KAY ET AL 1964

prevalence of dementia

>65 yrs 5.5%

>80 yrs 22%

LINDESAY ET AL (1990)FROM THE GP’S LIST

• Dementia 05%

• Depressive illness 13%

(major depression 4%)

• Anxiety states 12%

(Phobic 7%)

• Paraphrenia 0.5%

• Personality disorders,mania - Rare

Dementia (Royal College of Physicians 1981)

• Global impairment of higher mental functions including memory ,the capacity to solve the problems of day to day living,the performance of learned skills ,the correct use of social skills and control of emotional reactions without clouding of consciousness.

• It is often irreversible and progressive.

Dementia

Simpler definition

• Generalized impairment of memory, intellect & personality without impairment of consciousness

Dementia

Incidence 5% over 65 years

20% over 80 years

Alzheimer’s disease(AD) 50%

Multi infarct 20%

Mixed 15%

Other or no adequate diagnosis 15%

ICD 10

• Dementia in Alzheimer’s disease with early onset < 65 yrs

• Relatively rapid progress

• Memory impairment with aphasia,agraphia,

alexia , acalculia , apraxia

Dementia in AD with late onset

Vascular dementia

• Vascular dementia of acute onset

• Multi infarct dementia

• Subcortical vascular dementia

• Mixed cortical and subcortical dementia

• Other vascular dementia

• Vascular dementia ,unspecified

Alzheimer’s Disease

Genetic Environmental

Increased production and decreased clearance of A beta 42

Neuritic plaques Neurofibrillary tangles

Neuronal dysfunction and death with transmitter deficits

Dementia

Alzheimer’s Disease

Aetiology Genetic predisposition- Chromosome 21 APP specific

mutations Apolipoprotein e4-encoded in

chr.19 (A stronger risk factor ) Abnormality in presenilin pn 1

chr.14 (Early onset AD )

Alzheimer’s Disease

Aetiology – continued

Presenelin 2 in chr . 1

Early onset AD

Aluminium toxicity

(Infectious agent,repeated trauma)

Acetylcholine Transferase Activity

Risk

• <65 - 1/1000

• >65 - 1/50

• >80 - 1/5

Macroscopic appearance

• Often low brain weight

• Gyral atrophy and sulcal widening

• Enlargement of lateral ventricals

• Possibly pallor of locus coeruleus

Microscopic appearance

• Plaques- central amyloid core

• Tangles-paired helical filaments (abnormal cytoskeleton)

• Granulo-vacuoles

• Hirano bodies

• Neuronal loss

Vascular dementias

• Stepwise progression• TIAs or strokes• Labile affect• Associated neurological symptoms• Hypertension,Diabetes• Small infarcts or lacunes in deep white

matter

Other dementias (mainly presenile)

• Pick’s disease

• Huntington’s disease

• Creutzfeld-Jacob disease

• Parkinson’s disease

• AIDS dementia complex

• Alcohol brain damage

• Neurosyphilis

• Hypothyroidism

• Vitamin deficiencies

• Normal pressure hydrocephalus

• Subdural haematoma,

• Tumours

• Fronto- temporal dementia

• Dementia with Lewy Bodies (DLB)

• Prion dementias

• Primary progressive dysphasia

Other dementias- continued

Dementia with Lewy Bodies• Visual hallucinations - common• Memory , language ,reasoning ,attention

problems• Parkinsonian symptoms• Frequent falls• Fluctuation of symptoms• Neuroleptics & anti-cholinergics may

worsen the symptoms• Some response to dopamine replacement

drugs and cholinesterase inhibitors

Mild Cognitive Impairment (MCI)

• Transitional state between normal ageing and mild dementia

Most common type – Amnestic type

• Objective memory impairment

• Normal general cognitive function

• Intact daily living activities

• Not demented

Screening tests in dementia

• CAMDEX (Cambridge examination for mental disorder in the elderly)

• Mini mental state examination

• Newcastle 37 item test• Blessed dementia scale• Hachinski ischaemic score• CAPE (Clifton Assessment Procedure for

the elderly)

Investigations in all cases

F.B.C.

E.S.R.

Urea & Electrolytes

LFT’s / bone chemistry

Random / fasting blood glucose

Blood serology

Thyroid function tests

Investigations in all cases - continued

B12 and Folate levels

M.S.S.U.

Chest X-ray

ECG in those with cardiac problems and those with functional disorders

CT Scan

Other investigations may be arranged following discussion with the team

Management of Dementia

• Assessment

• Treat primary cause if found

• Correct nutritional deficiencies

• Attend to associated psychological symptoms

- depression up to 30% - Antidepressants eg SSRI

- paranoid symptoms,delusions & hallucinations-30% - Antipsychotics

Management of Dementia - continued

• Be aware of dangers of anti cholinergics

• Multi disciplinary approach

• Reality orientation

• Simplify the environment

• Occupational therapy/physiotherapy

• Day care /respite care

• Home care ,CPN, meals on wheels

• Caring for carers

Drug treatment NICE (National Institute of Clinical Excellence)

• Acetyl Cholinesterase inhibitors - Galantamine - Donepezil hydrochloride - Rivastigmine - Tacrine(Metrifonate ,Physostigmine)

• Non - anticholinesterases Memantine (NMDA antagonist)

Drug treatment - continued• Disease modifying agents

- Vitamin E - Selegiline - Oestrogen - NSAIDS - Ginkgo biloba• Chelation desperioxamine (doubtful benefits)• Nootropic drugs ( enhance learning abilities

and reverse learning impairment )

Future strategies

• Neuropeptides (eg. Somatostatin analogues)

• Growth factors (eg. Gangliosides )

• Transplantation

Multi infarct dementia

• Attend to hypertension

• Anti platelet drugs

• Drugs improving red cell deformability and

decreasing blood viscosity