Fisher syndrome is a rare, acute neurological disorder characterized by a triad of clinical manifestations that includes brain-damage associated abnormal coordination (ataxia), a condition that involves the paralysis of the eyes called ophthalmoplegia, and a generalized absence of reflexes (areflexia).
Fisher syndrome is also known as Miller Fisher syndrome, as was described in 1956 by Canadian physician Charles Miller Fisher. It is an acute, rare nerve disease that is considered to be a variant of Guillain-Barré syndrome. In both syndromes, the associated nerve disease can be acquired after viral illness. Once the disorder is diagnosed and treated, the physical and mental effects can be minimal or absent, thus emphasizing the importance of medically identifying affected individuals and treating them accordingly.
Fisher syndrome is also known as acute idiopathic ophthalmologic neuropathy syndrome of ophthalmoplegia, ataxia, and areflexia. Related conditions include disorders called Bickerstaff's brainstem encephalopathy and acute ophthalmoparesis.
Fisher syndrome is an extremely rare disorder. It is reported to affect persons between the ages of 38 and 65 years old. The related Guillain-Barré syndrome is more common than Fisher syndrome. Age is not a factor, and anyone who produces specific antibodies can acquire it.
Causes and symptoms
The majority of affected individuals with Fisher syndrome produce an antibody by their immune system that is related to the susceptibility to develop the disease following a viral illness; it is unclear how. It is thought that the antibody anti-GQ1b IgG is associated with paralysis of the eye, or ophthalmoplegia. The cause of Fisher syndrome and Guillain-Barré syndrome in both cases is due to an autoimmune disease whereby antibodies produced by the body's immune system mistakenly attack a nerve insulator and impulse carrier called the myelin sheath. This causes inflammation and damage to the nervous system. Guillain-Barré syndrome differs from Fisher syndrome in that different nerve groups are targeted and paralysis in the former begins with the legs and moves upward. Fisher syndrome, on the other hand, begins in the head (paralysis of the eyes) and moves in the direction toward the neck and arms. Although the direct cause is unknown, 65% of cases are thought to be linked to herpes-related viral illness (although viruses other than herpes can also be involved).
The first symptoms appear to be related to a virus and include a headache, fever, and pneumonia. The characteristic triad of symptoms that result in individuals who acquire Fisher syndrome is in addition to generalized muscle atrophy (weakness) and respiratory complications that can involve respiratory failure if untreated. It is uncommon to observe a patient with Fisher syndrome that does not have some degree of generalized weakness. Damage to motor function is believed to be associated with damage sustained by the cranial nerves of the brain, with sensory nerve damage extending to the patient's arms and legs. In cases that also include abnormalities in the brainstem, it is more likely to be due to a related disorder called Bicker-staff's syndrome.
Diagnosis is made clinically by detecting manifestations involving the characteristic trio of symptoms usually following a viral infection: paralysis of the eyes (ophthalmoplegia), abnormal coordination (ataxia), and absence of reflexes (areflexia).
Treatment for Fisher syndrome involves removing the plasma from affected individuals, a procedure called plasmapheresis. In doing so, antibodies that cause the disease are also removed. In the alternative, patients can be treated with an intravenous injection of immunoglobulin (IVIg) to boost the immune system. Untreated patients can experience double vision, nausea, difficulty walking, and sensitivity to light that can continue for several months.
Recovery and rehabilitation
Once Fisher syndrome is identified, treatment can lead to recovery in as soon as two to four weeks after the symptoms are initially acquired. After six months, the symptoms are usually almost completely resolved. Although some individuals have secondary complications and relapses occur in 3% of cases, most individuals have a nearly complete recovery.
As most affected individuals who are treated have a good prognosis, clinical trials to treat the disorder are not currently being investigated. There is research being conducted to find better ways to diagnose and ultimately cure the neurological damage that sometimes occurs in Fisher syndrome.
The prognosis is good for individuals who are detected and treated soon after the onset of symptoms. In these cases, affected individuals have a favorable prognosis and (on average) should expect to have a normal lifespan. This disorder is seldom life-threatening.
Staff. The Official Patient's Sourcebook on Miller Fisher Syndrome: A Revised and Updated Directory for the Internet Age. San Diego: Icon Group International, 2002.
Derakhshan, I. "Recurrent Miller Fisher Syndrome." Neurol India. (June 2003): 283.
NINDS Miller Fisher Syndrome Information Page. National Institute of Neurological Disorders and Stroke. March 4, 2004 (May 22, 2004). <http://www.ninds.nih.gov/health_and_medical/disorders/miller_fisher.htm>.
Guillain-Barré Syndrome Foundation International. P.O. Box 262, Wynnewood, PA 19096. (610) 667-0131; Fax: (610) 667-7036. firstname.lastname@example.org. <http://www.gbsfi.com>.
Bryan Richard Cobb, PhD