Differentiating between Dementia and Alzheimer’s
Dementia is a syndrome in which there is a loss of several overlapping intellectual abilities of the brain along with memory loss. Dementia can occur due to a variety of conditions, the most common of dementia is Alzheimer's disease (50-70 per cent).
Other types of dementia are - Multiinfarct dementia, Fronto-temporal dementia, Parkinson's disease, normal pressure hydrocephalus, Lewy body dementia, alcoholic dementia, AIDS, drugs, toxins, head injury and brain tumours.
Further, it is a term which is often applied to a group of symptoms that negatively impact memory. When we talk about Alzheimer’s, it is a progressive disease of the brain that slowly causes impairment in memory and cognitive function. The exact cause is unknown to us and no cure is available as of now.
In Alzheimer's disease, initial symptoms are- lack of initiative or lack of interest in work or neglect of routine tasks. Then gradually develop forgetfulness in the form of remembering and recalling the name of a person and difficulty in recalling day to day events. The patient may ask the same question repeatedly, having failed to retain the answer.
Difficulty in making a judgement and performing tasks requiring several steps, problem-solving are found difficult, change in personality and mood, more commonly depression than agitation. Sleep disturbance is quite common along with the loss of social interaction. Suspiciousness or frank paranoid behaviour is quite troublesome. The patient may have visuospatial disorientation and may get lost even along habitual routes. In advance stage, the patient becomes dependent for day to day activities and ultimately become bedbound.
Dementia patients may have variable symptoms mentioned above along with other symptoms according to the underlying cause.
In Alzheimer's disease, MRI brain shows disproportionate atrophy of hippocampus and enlargement of temporal horn of lateral ventricle. SPECT (single-photon emission computed tomography) and PET (positron emission tomography) show diminished activity in the medial temporal lobe and parietal association area. Distinctive microscopic changes in the brain in Alzheimer's disease are- neurofibrillary tangles within nerve cells, neurotic plaque (amorphous material scattered throughout the cerebral cortex) and degeneration of neurons in the hippocampus.
Although symptoms of the two conditions may overlap, distinguishing them is important for management and treatment.
