Polymyositis is a disease that causes muscles to become irritated and inflamed. The muscles eventually start to break down and become weak. The condition can affect muscles all over the body. It can make even simple movements hard to do. Polymyositis is 1 disease in a group of diseases called inflammatory myopathies.

Neuromyelitis optica (NMO) is a rare autoimmune disease that affects the central nervous system.

A seizure that lasts at least 30 minutes is called status epilepticus, or a prolonged seizure. This is a medical emergency that may lead to permanent brain damage or death. Many medical experts become concerned that a seizure is status epilepticus after it lasts 5 to 10 minutes.

Carcinoid tumor is a rare type of tumor that grows slowly.

People who have AIDS are much more likely to get certain types of cancer than people without the disease.

Brachial neuritis is nerve damage that affects the chest, shoulder, arm, and hand. It causes pain, weakness and lack of muscle control and lack of feeling in the shoulder or arm.

An epidural abscess is an infection that forms in the space between your skull bones and your brain lining (intracranial epidural abscess).

Bacterial meningitis is an infection of the membranes that cover the brain and spinal cord. It causes headache, stiff neck, and high fever.

Zika is a virus passed on through the bite of a mosquito. It may also be spread through sexual contact and blood transfusions.

Transverse myelitis is inflammation and scarring of the spinal cord that causes pain and weakness in the body.