Wide range of infective or non-infective inflammatory lesions of the spinal cord are labelled as myelitis. When there is a transverse and complete spinal syndrome it is referred as transverse myelitis, when the symptoms ascend progressively it is called as ascending myelitis.
viral infections of the cord due to olio-myelitis, herpes zoster, epidemic form of entero virus 70, rabies, bacterial infections like tuberculosis, syphilis, pyogenic cord infections, parasitic or fungal infections may cause myelitis. It can occur as a complication of typhoid or brucellosis. Small pox vaccination or anti-rabies vaccine may sometimes cause post vaccinal myelitis. Multiple sclerosis and necrotic myelitis are other forms of myelitis.
The cord is oedematous, hyperaemic and infiltrated with inflammatory cells. There is selective destruction of neurones, meninges and white matter alone or in combination with grey matter. There is destruction of myelin sheath and axis cylinders. Subsequent gliosis may occur.
Clinical features of transverse myelitis
The onset may be acute or sub acute, generally starting with backache in thoracic region followed by flaccid paralysis and partial or complete sensory loss below the site of lesion. There may be urinary retention and loss of relexes in acute stage.
Abdominal reflexes and plantar response is absent. Later on plantar response response may become extensor.