Thyroid disease

The thyroid gland is located in the neck in front of the windpipe. Inflammation of the thyroid gland may occur as an autoimmune disease, in which the immune system produces a response against one of its own tissues. This immune response may be in the form of antibodies that target the thyroid gland and cause inflammation. The inflammation of the thyroid gland usually results in an underactive thyroid. When the thyroid is underactive, it does not secrete enough thyroid hormones, which are important for burning of nutrients, regulation of temperature, and body fat. An underactive thyroid may result in slowness of heart rate, weight gain, and feeling of being unduly cold. Patients with an underactive thyroid have been known to develop cerebellar ataxia. Recent research shows that cerebellar ataxia may be specifically related to the presence of antibodies against the thyroid rather than the lack of thyroid hormones themselves. These antibodies are believed to damage the cerebellum. Laboratory tests are available to test for these antibodies, and patients with cerebellar ataxia of unknown etiology should be tested for thyroid antibodies. If antibodies are detected, prednisone or other corticosteroid medication may be recommended to reduce the inflammation and autoimmunity.

The onset of cerebellar ataxia with thyroid antibodies may vary. It can be chronic, with an onset of months or years, or it may occur subacutely—in a matter of days or weeks.