Dementia, characterized by severe impairment of the person's intellectual capacity, emotional disturbance and personality changes, is caused by a number of different reasons such as the loss of neurons in the brain due to head injury, metabolic disorders, or even due to a tumor in the brain. The human brain has 2 hemispheres -- the left hemisphere and the right hemisphere. A large section of the person's brain is usually damaged in a patient suffering from dementia.
