Overview of Dementia
Dementia is a collective term used to describe a group of symptoms associated with diseases which decline memory and other thinking skills down to a level to make a person unable to perform routine activities. Various diseases are grouped under dementia such as Alzheimer’s disease which accounts for 50-70% of dementia cases, Vascular dementia which occurs after a stroke and is the second most common type. Other common types include Lewy body dementia which is neurodegenerative disease and accounts for 15% dementia cases and Frontotemporal dementia characterized by neuronal loss in frontal and temporal lobes and spindle neurons.
Causes and Risk Factors of Dementia
Dementia is caused by progressive death of neurons (brain cells) which can occur by injury, stroke, brain tumor or neurodegenerative diseases. Neurodegenerative diseases such as Alzheimer’s diseases, vascular dementia, Lewy bodies dementia, progressive supranuclear palsy, corticobasal degeneration cause progressive neural death in different parts of brain which affect memory, thinking and behavior. Less common causes of dementia include normal pressure hydrocephalus, neurosyphilis, Prion infection and Parkinson’s disease. Reversible dementia can also occur due to medication, vitamin B12 deficiency, hypothyroidism, neurosyphilis and lyme disease. Dementia can also be associated with several inherited disorders such as epilepsy, fatal familial insomnia, glucaric aciduria, Krabbe’s disease and Alexander disease etc.
Signs and Symptoms of Dementia
The most common affected areas in dementia patients are memory, language, visual-spatial, attention and problem-solving. Dementia is a slow and progressive process and signs appear quite late after initiation of changes in brain. Patients may have two types of dementia at the same time. The resulting behavioral and psychological problems affecting patients include agitation, speech and language difficulty, tremors, memory distortions, problems in eating and swallowing, restlessness and perception and visual problems. Patients often show signs of anxiety, depression, aggression, irritability, apathy, elated mood and delusions or hallucinations, catastrophic reaction (crying or anger in difficult situations).