Diagnosis
The signs and symptoms of most antibody mediated neurologic diseases start suddenly and progress rapidly over several weeks or months. Specific signs and symptoms vary between diseases, but can include memory loss, seizures, vision problems, difficulty swallowing, slurred speech, difficulty walking, loss of fine motor coordination, loss of sensation, sleep disturbances and/or dementia.
Tests used to study the neurological symptoms and diagnose patients may include:
Lumbar Puncture / Spinal Tap
Cerebral spinal fluid (CSF) obtained from a spinal tap can show abnormalities that suggest inflammation of the brain or spinal cord, such as an increased white blood cell (WBC) count. CSF can also be tested for a variety of antibodies that have been known to cause disease.
Blood Tests
Blood or serum can also be tested for antibodies known to cause disease, however some of these tests have been found to be less reliable than CSF tests.
Magnetic Resonance Imaging (MRI)
An MRI of the brain is useful to identify areas that are abnormal due to inflammation or become abnormal due to the loss of tissue (atrophy) caused by the inflammation. It may also be used to rule out other neurological complications that can cause similar symptoms. MRI of the spinal cord, nerve roots, or networks of nerves leaving the spinal cord (called the pleuses) is also helpful in diseases that involve these parts of the nervous system. Not all antibody mediated neurologic diseases are associated with MRI abnormalities and abnormalities may change throughout the disease progression, so there are no standard imagining schedules.
Electroencephalogram (EEG):
This test is used when patients are suspected of having seizures. The EEG records the electric activity in the brain revealing information such as epileptic seizures or slow activity, which may also occur as a result of seizures an other abnormal brain function.
Electromyography (EMG)
These nerve conduction studies are particularly useful to assess the function of the cells in the spinal cords that are the origin of the peripheral nerves. The peripheral nerves carry the electric impulses from the spinal cord in the muscles, or in the opposite direction, from the skin an other receptor in the muscles and tissue to the spinal cord. The EMG and nerve conduction studies tests the integrity of these circuits which can be affected in diseases such as stiff person syndrome.