Medical brain notes 7

  MULTIPLE SCLEROSIS The diseases of the brain and spinal cord in which myelin sheath or white matter is affected are known as demyelinating diseases. The cells of the human nervous system are anatomically and physiologically divided into grey matter and white matter. The white matter can be compared to the electrical wires that perform the important function of transporting the sensations or commands originating from gray matter cells to other parts of the nervous system. The electrical wires have an outer cover for insulation. Similarly, the white matter has a myelin sheath for insulation. The diseases damaging the myelin coating of the white matter are known as demyelinating diseases. The most important, strange and painful demyelinating disease is called multiple sclerosis. In simple language some type of allergy or disturbance in metabolism of brain, damages the white matter. This is called as demyelination and gliosis. In this disease specific symptoms are seen in the brain, ...

  ADEM (Acute Disseminated Encephalomyelitis) :   A neurological illness that comes a few days after any form of viral illness (viz. measles, chicke-npox etc.) is most likely an ADEM. The symptoms are related to the cerebrum, cerebellum or spinal cord. The incidence is 1 in 2000 patients of viral illness. Occasionally such illness may follow vaccination for rabies etc. The incidence of ADEM tends to be more in children. In some cases memory ‘impairment or behavioural disorders persist while in some seizure disorder may be precipitated. Prognosis is good in adult patients and in those with cerebellar symptoms. This disease is different from the viral infections directly damaging the brain. There is no direct or microscopic evidence of viral infection and the symptoms start after 2 to 20 days of virus infection. It is a post viral sequalae: It is believed to be due to decrease in the resistance power of the body (i.e. Immune-mediated). However, newer tests available can elicit D...