Myoclonus And Ataxia

Ramsay Hunt (1921) described the association of generalized myoclonus and signs of cerebellar dysfunction, especially intention tremor, under the designation of dyssynergia cerebellaris myoclonica. Autopsy in 1 case confirmed his impression of a lesion in the dentate nucleus of the cerebellum. His cases were nonfamilial. Gilbert et al. (1963) described 2 females and 2 males in 3 sibships of a family with the combination of myoclonus and ataxia. Cerebrospinal fluid uric acid was elevated in 2. Autosomal dominant inheritance with reduced penetrance was suggested. Takahata et al. (1978) described an extensively affected family. The main lesion affected the cerebellar dentate nuclei. Neumann (1959) described combined degeneration of the globus pallidus and the dentate nucleus, and reports of autosomal dominant inheritance of the combination were referred to by Takahata et al. (1978). Berkovic et al. (1986) concluded that the Ramsay Hunt syndrome 'does not represent a specific disease, and its use should now be abandoned.' Berkovic et al. (1987) described 11 cases previously diagnosed as having the Ramsay Hunt syndrome (among more than 70 patients with progressive myoclonus epilepsy). Two had died; the remaining 9 patients included 3 sporadic cases and a family with 6 affected members. Reevaluation of these 9 living patients showed evidence of mitochondrial abnormalities in all: ragged-red fibers on muscle biopsy in 8 and abnormal mitochondria in a skin biopsy in the remaining case. From a study 'supported by a traveling grant from the University of Navarra and under the inspiration of the products of that region,' Marsden and Obeso (1989), 2 neurologists specializing particularly in movement disorders, argued for the usefulness of the designation 'Ramsay Hunt syndrome.' They concluded that many patients with progressive myoclonus and ataxia have no tonic-chronic seizures, although most have abnormal EEGs. Andermann et al. (1989) again argued that the Ramsay Hunt syndrome is no longer a useful diagnostic category. Harding (1989) took a middle-of-the-road position, insisting that '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.' In the view of Harding (1989), there are undoubtedly cases of myoclonus, occasional tonic-chronic seizures, and ataxia in which no underlying cause such as mitochondrial myopathy, sialidosis, or ceroid lipofuscinosis can be demonstrated.