Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + At a Glance Download Section PDF Listen ++ A very rare and progressive cerebellar dyssynergia with intention tremor first localized to one extremity, convulsions, and myoclonic epileptic jerks. Ragged red fibers are seen on muscle biopsies. + Synonyms Download Section PDF Listen ++ Dentate Cerebellar Ataxia; Dentatorubral Atrophy; Primary Dentatum Atrophy. + History Download Section PDF Listen ++ First described by James Ramsay Hunt, an American neurologist in 1921. + Genetic Inheritance Download Section PDF Listen ++ Autosomal dominant with reduced penetrance. + Pathophysiology Download Section PDF Listen ++ Neurological lesions or anomalies are often observed (cerebellar dentate nucleus, degeneration of globus pallidus, elevated cerebrospinal fluid [CSF] uric acid); muscle biopsy shows presence of ragged red fibers that probably are caused by mitochondrial abnormalities, which could explain the pathophysiology of this syndrome. Controversy exists about considering Ramsay Hunt syndrome as a specific entity. + Diagnosis Download Section PDF Listen ++ Association of myoclonus ataxia and occasional seizures. + Clinical Aspects Download Section PDF Listen ++ Neurological signs are isolated. No other association is known. Myoclonus, cerebellar ataxia, intention tremor, and occasional tonic-clonic seizures are the only symptoms. + Precautions before Anesthesia Download Section PDF Listen ++ Evaluate the neurological repercussion (clinical, EEG, CT) and muscular status. + Anesthetic Considerations Download Section PDF Listen ++ Patients should be considered epileptic and the use of anesthetic agents inducing seizures (e.g., enflurane, sevoflurane) should be avoided. + Pharmacological Implications Download Section PDF Listen ++ The antiepileptic medication(s) should be continued until the morning of surgery. Because of the presence of muscular abnormalities and risk (undocumented) of hyperkalemic response it is recommended to avoid succinylcholine. Consider interaction between antiepileptic treatment and anesthetic drugs. + Other Conditions to Be Considered Download Section PDF Listen ++ Juvenile Paralysis Agitans of Hunt: Autosomal dominant, this syndrome is characterized by mask-like facies, parkinsonism, tremor, bradykinesia, dysarthria, rigidity, gait disturbance, and flexion dystonia of fingers. Progression is slow. Onset in teens or earlier. ++ Dyssynergia Cerebellaris Myoclonica of Hunt (Cerebelloparenchymal Disorder V, Spinodentate Atrophy): Autosomal recessive with ataxia, myoclonic jerks, dentate neuron loss superior, and cerebellar peduncle fiber loss. + References Download Section PDF Listen ++Hunt JR: Dyssynergia cerebellaris myoclonica—Primary atrophy of the dentate system: A contribution to the pathology and symptomatology of the cerebellum. Brain 44:490, 1921. ++Marsden CD, Obeso JA: Viewpoints on the Ramsay Hunt syndrome: 1. The Ramsay Hunt syndrome is a useful clinical entity. Move Disord 4:6, 1989. [PubMed: 2494439]