The concept of the Ramsay Hunt syndrome is clinically useful as long as those using it remember that it is a syndrome, not a disease. The Berkovic/Andermann campaign was obviously initiated by finding patients diagnosed as having the Ramsay Hunt syndrome without attempting to establish its cause. In the light of modem investigative methods, this is clearly bad clinical practice. Berkovic and Andermann are right to point this out, but they have gone too far.
Ramsay Hunt summarised the features of his cases as follows: "There was the progressive dyssynergia characteristic of a cerebellar disorder, in association with myoclonus and epilepsy." As Marsden and Obeso point out, the myoclonus in all of Hunt's cases was severe, and only one had frequent generalized tonic-clonic seizures. The clinical definition of this syndrome is thus clear in principle. My problem is how to define it, particularly the cerebellar component, in practice. Marsden and Obeso do not really address this issue, although they do discuss the related one of defining "progressive myoclonic epilepsy."
Aside from the fact that many patients with chronic seizure disorders may be ataxic and have abnormal eye movements as a result of anticonvulsant toxicity, how does one assess cerebellar function in patients with severe spontaneous and action myoclonus? It may be impossible, particularly in relation to examination of the limbs. Broken up pursuit eye movements with square wave jerks, a scanning dysarthria, and rebound hypotonia may indicate cerebellar dysfunction rather than myoclonus, but it is difficult to be sure. If the myoclonic jerks can be suppressed therapeutically and the "cerebellar" signs persist, then the presence of cerebellar disease seems highly probable, but this is not always possible.
I usually refer to difficult cases such as these as examples of the Ramsay Hunt syndrome, and suspect that Marsden and Obeso do too. Many patients like this first develop symptoms between the ages of 6 and IS years. The Montreal group appear to categorise these as cases of Unvemcht-Lundborg disease, which is only marginally more of a distinct disease entity than the Ramsay Hunt syndrome. It is also just as dangerous a clinical concept if considered a disease rather than a