Alzheimer’s Disease
Alzheimer’s Disease is the most common cause of dementia, accounting for about 80% of cases. The disease is characterized by the buildup of abnormal proteins in the brain, including amyloid plaques and tau tangles, which damage and destroy nerve cells. Studies have found that these abnormal amyloid proteins begin to accumulate in the brain 15-20 years before the onset of cognitive impairment.

 

It's a progressive brain disorder that primarily affects memory, thinking, and behaviour. The entire disease duration can be up to 10-20 years. Symptoms often start with mild memory loss and gradually worsen over time, eventually interfering with daily tasks.

 
Vascular Dementia
Vascular Dementia is the second most common type of cognitive impairment, accounting for about 15%-20%. It is a type of dementia caused by reduced blood flow to the brain, often due to strokes or over time through a series of small strokes. Unlike the progressive deterioration of Alzheimer’s Disease, Vascular Dementia typically progresses in a stepwise manner, meaning symptoms worsen after events like strokes or vascular incidents, followed by periods of stability. The symptoms can vary widely depending on the area and extent of brain damage.
 
Dementia With Lewy Bodies
Dementia with Lewy Bodies (DLB) is a type of dementia caused by abnormal protein deposits called Lewy bodies in the brain. These deposits disrupt brain function, leading to symptoms such as cognitive decline, visual hallucinations, tremors and slow movement symptoms resembling Parkinson's disease, sleep disturbances and acting out dreams. Their periods of confusion or drowsiness that vary throughout the day.
 
Frontotemporal Dementia
Frontotemporal dementia (FTD) is a relatively rare dementia, accounting for less than 10% of all dementias. FTD generally occurs at a younger age than other dementias, often affecting people between 45 and 65 years old. It primarily affects the frontal and temporal lobes of the brain. This condition primarily affects behaviour, personality, and language skills, rather than memory in the early stages. The exact cause of FTD is not fully understood. In some cases, FTD is associated with genetic mutations, particularly in families with a history of the condition.

 
Other causes of cognitive impairment ​

Other causes of cognitive impairment symptoms include brain trauma, brain tumors or hydrocephalus, viral infections, vitamin deficiencies, sleep disorders, anxiety and depression, drug intoxication, alcoholism, etc. Some of these causes are reversible, meaning that once these physical conditions are addressed, the individual's cognitive abilities may be restored.