Current Estimation and Future Projection
Prevalence of Dementia by Age and Gender
For the year 2010, an estimated 3.7 million Indian people aged over 60 have dementia (2.1million women and 1.5 million men). The prevalence of dementia increased steadily with age and higher prevalence was seen among older women than men.
What is Dementia?
The definition of dementia
Dementia is a syndrome usually chronic, characterized by a progressive, global deterioration in intellect including memory, learning, orientation, language, comprehension and judgement due to disease of the brain. It mainly affects older people; about 2% of cases start before the age
of 65 years. After this, the prevalence doubles every five years. Dementia is one of the major causes of disability in late-life.
Common subtypes of irreversible dementia
1. Dementia Sub Type : Alzheimer's disease
Early Characteristic :
Impaired memory, apathy and depression, Gradual onset (AD)
Neuropathology : Cortical amyloid, plaques and neuro-fibrillary tangles
Proportion of symptoms case : 50-75%
2. Dementia Sub Type : Vascular dementia
Early Characteristic :
Similar to AD, but memory less affected, and mood fluctuations more prominent, Physical frailty Stepwise Progression (VaD)
Neuropathology : Cerebro-vascular disease Single infracts in critical regions, or more diffuse multi-infarct disease
Proportion of symptoms case : 20-30%
3. Dementia Sub Type : Dementia with Lewy Bodies (DLB)
Early Characteristic :
Marked fluctuation in cognitive ability Visual hallucinations Parkinsonism (tremor and rigidity)
Neuropathology : Cortical Lewy bodies (alpha-synuclein)
Proportion of symptoms case : < 5%
4. Dementia Sub Type : Frontotemporal Dementia (FTD)
Early Characteristic :
Personality changes, Mood changes, Disinhibition Language difficulties
Neuropathology : No single pathology damage limited to
frontal and temporal lobes
Proportion of symptoms case : 5-10%
Clinical features - the importance of behavioural and psychological symptoms of dementia (BPSD):
When making a diagnosis, clinicians focus their assessments on impairment in memory and other cognitive functions and loss of independent living skills referred to as ABC symptoms of
dementia:
Activities of Daily living (ADL), the Behavioural and Psychological symptoms, and the Cognitive and memory symptoms.
For carers, and, arguably, for PwD, it is the behavioural and psychological symptoms (BPSD) linked to dementia and the deficits in the ADL that are most relevant and impact most on the burden and the quality of life. Problem behaviours include agitation, aggression, calling out, sleep disturbance, wandering and apathy. Common psychological symptoms include anxiety, depression, delusions and hallucinations. BPSD occur most commonly in the middle stage of dementia (see also Course and Outcome). Most studies indicate that BPSD are an important cause of carer strain. In the 10/66 Dementia Research Group pilot studies , BPSD seemed to be just as common in low and middle income countries as in the developed ones. Many studies from India which looked at BPSD found these symptoms to be common both in the community and in clinical settings. They are considered as most distressing by carers. Given the generally low levels of awareness about dementia as an organic brain disease, carers often could not understand their relative's condition and misinterpret BPSD as misbehaviour.
The course and outcome of dementia:
Dementia affects every person in different ways. Its impact can depend on what the person was like before the disease; his/her personality, lifestyle, significant relationships and physical health.
The problems linked to dementia can be best understood in three stages : early stage - first year or two, middle stage - second to fourth or fifth year and late stage - fifth year and after.
These are guidelines only - some people deteriorate faster, and others more slowly.
Dementia reduces the lifespan of affected persons. In the developed west, a person with dementia can expect to live for roughly 5-7 years after onset / diagnosis . In low and middle income countries, diagnosis is often much delayed, and survival may be much shorter. The mortality rates could be higher in the absence of interventions and the severity at the time of identification could also predict mortality.
Patients with moderate to severe illness have a higher mortality than cognitively unimpaired elderly . Again, there is much individual variation because of intercurrent health conditions and co-morbidity is very common in this age group.
Not all PwD will display all the symptoms which have been described. Knowing them makes carers to be aware of potential problems and helps to plan the future care needs.
Early Stage:
The early stage is often overlooked. Relatives and friends (and sometimes professionals as well) see it as 'old age', just a normal part of the ageing process. The onset of the disease is gradual and difficult to recognise.
� Have problems talking properly (language problems)
� Have some memory loss, particularly of recent events
� Have difficulty in making decisions
� Become inactive and unmotivated, show mood changes, depression or anxiety and
may react angrily or aggressively
� Show a loss of interest in hobbies and activities
Middle Stage:
As the disease progresses, limitations become pronounced and more restricting. The PwD have difficulty with day-to-day living.
� May become very forgetful - especially of recent events and people's names
� May become extremely dependent on their family and carers; unable to cook, clean or
shop; needs help with personal hygiene
� Has wandering and other behaviour problems such as repeated questioning and
calling out, clinging and disturbed sleep
� Unable to recognise familiar and unfamiliar places at home or outside
� May have hallucinations (seeing or hearing things which are not really there)
Late Stage:
This stage is one of near total dependence (confined to a wheel chair or bed). Memory disturbances are very serious with more physical complications. The person may:
� Have difficulty eating, walking and be incapable of communicating
� Not recognise relatives, friends and familiar objects
� Have bladder and bowel incontinence, breathing difficulties and respiratory infections
Content courtesy : ARDSI
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