Disorders of neural system
Multiple sclerosis is an autoimmune disorder where there is a progressive destruction of the myelin sheath of the neurons in the central neural system. The destroyed region of the myelin sheath forms scar tissue or plaques. Every time new plaques are formed, a fresh attack occurs. Symptoms include weakness in muscles, double vision and other abnormal sensations.
• Epilepsy or seizures is characterized by abnormal synchronous electrical discharges from many neurons in the brain resulting in involuntary contractions of the skeletal muscle and abnormal sensations of smell, sight and hearing.
• Alzheimer’s disease is the most common form of dementia (a group of conditions that gradually destroys brain cells) among the elderly and leads to a progressive decline in mental function. It slowly decreases a person’s memory and ability to learn, reason, make judgments, communicate and carry out daily activities. There is no cure and currently available medications provide small symptomatic benefits for some patients but are unable to reduce disease progression.
• Parkinson’s disease is a degenerative motor system disorder that affects muscle control. It is caused by the loss of dopamine producing brain cells. Symptoms include trembling and stiffness of the limbs and trunk; postural instability, impaired balance and coordination leading to difficulty in movement, communication and day-to-day activities.
• Schizophrenia is a psychiatric mental disorder in which a person cannot differentiate between real and unreal experiences, cannot think logically, or behave normally in social situations. Patients may show a variety of symptoms, such as delusions, hallucinations, disordered thoughts, negativism, rigidity, or lack of emotions. It may be caused due to genetic, social or psychological factors.