Variants of Guillain-Barre Syndrome
More details about Miller Fisher syndrome (MFS) is also known as:
- [The] Miller Fisher variant [of GBS]
- Fisher('s) syndrome
- acute idiopathic ophthalmologic neuropathy
Related conditions are:
- GBS with ophthalmoplegia
- Bickerstaff's brainstem encephalopathy
- acute ophthalmoparesis
In 1956, [Charles] Miller Fisher, a Canadian whose specialisation was stroke, described three patients with acute external ophthalmoplegia (eye paralysis), sluggish pupil reflexes, ataxia (lack of balance) and areflexia (absent tendon reflexes). Two patients had no weakness; the other had a facial palsy and possible weakness. All three recovered spontaneously.
Because some patients with GBS had ophthalmoplegia and there were other similarities, Dr Fisher concluded that these patients had suffered a disorder akin to GBS. [Fisher CM. Syndrome of ophthalmoplegia, ataxia and areflexia. N Engl J Med 1956;255:57-65]
Pure Miller Fisher syndrome (without generalised weakness) is rare. Electrodiagnostic abnormalities found in all patients are characteristic of an axonal neuropathy or a neuronopathy with predominant sensory nerve changes in the limbs and motor damage in the cranial nerves. [Fross RD, Daube JR. Neuropathy in the Miller Fisher syndrome: clinical and electrophysiologic findings. Neurology 1987 Sep;37(9):1493-1498]
Patients described as having Miller Fisher syndrome often have a neuropathy that overlaps with GBS and demonstrate generalised weakness, sometimes paralysis, as additional symptoms.
It was sometimes proposed the Miller Fisher syndrome was caused by brainstem encephalitis. It is true that the syndrome can be mimicked by a brainstem lesion, but typical cases of Miller Fisher syndrome rarely show any evidence of brainstem abnormalities either radiologically or during post-mortem examination. When clinical or radiological brainstem abnormalities are found, the condition may be referred to as Bickerstaff's syndrome or Bickerstaff's brainstem encephalopathy (or encephalitis) (BBE).
Research in recent years has concentrated in identifying the antibodies that are thought to be responsible for GBS etc. It has been confirmed clinically that MFS, GBS with ophthalmoplegia, BBE, and another condition called acute ophthalmoparesis* are closely related, forming a continuous range. This is supported by immunological findings with the antibody anti-GQ1b IgG being the common factor. [J Neurol Neurosurg Psychiatry 2001 Jan;70(1):50-55] This antibody is not found in other GBS patients so it is thought that it is responsible for the ophthalmoplegia.
*Acute ophthalmoparesis (AO) is characterised by acute onset of paresis of the extraocular muscles without ataxia or areflexia.
Although the efficacy has not been clinically proven, treatment of Miller Fisher syndrome is much the same as 'classic' GBS though the different symptoms require modified management with emphasis on the eyes. Intravenous immunoglobulin or plasma exchange treatment is likely in all but the mildest cases. The chances of recovery are good.