Choreo-athetosis and Encephalopathy Induced by Phenytoin

Abstract

Glaser (1973) pointed out that a reversible encephalopathy may occur in some patients treated with large doses of the drug. We describe two patients in whom choreo-athetoid involuntary movements were a prominent and presenting feature and in whom the involuntary movements and the encephalopathy were closely correlated with very high blood phenytoin concentrations.

Involuntary movements caused by phenytoin intoxication in epileptic patients.

“…Serum phenytoin levels were well into the toxic range. McLellan and Swash (1974) have also described two patients with prominent choreoathetoid movements and dystonia associated with toxic serum phenytoin levels. It was noted that voluntary movement accentuated the choreoathetosis.…”

“…It is also worthy of comment that a factor responsible for inhibition of phenytoin metabolism was mentioned in three of the published case reports of choreoathetosis in epileptic patients. Administration of anaesthetic agents preceded the onset of involuntary movements in two of the patients studied by Logan and Freeman (1969); the case reported by Engel et al (1971) was receiving isoniazid for tuberculin conversion; and one of the patients described by McLellan and Swash (1974) had been receiving sulthiame.…”

“…Less commonly, other neurological disturbances may be caused by phenytoin intoxication (Glaser, 1972). Although choreoathetosis has been described (Peters, 1962;Logan and Freeman, 1969;Kooiker and Sumi, 1974;McLellan and Swash, 1974), only a few cases have been documented adequately. During the last two years we have seen involuntary movements in four patients, two of whom presented with severe choreoathetosis.…”

Anticonvulsant drugs and mental symptoms: a review

“…Further examples in adults have been reported by Perlo and Schwab (1969) and Reynolds & Travers (1974). Sometimes the encephalopathy may be associated with unusual neurological signs including involuntary movements (Kooiker & Sumi, 1974;McLellan & Swash, 1974) which may further perpetuate a vain search for underlying neurological disease. A modest rise of CSF protein may be found (Rawson, 1968).…”

Clinical and experimental studies of phenytoin-induced hyperkinesias

“…A P.A. Chorea and other movement disorders are rare manifestations of phenytoin toxicity, which have been noted in a variety of clinical settings and are frequently reversible on withdrawal of phenytoin (Peters, Eichman, and Price, 1966;Logan and Freeman, 1969;Gerber, Lynn, and Oates, 1972;McLellan and Swash, 1974;Bellman and Haas, 1974;Rosenblum, Rodochok, and Hanson, 1974;Shuttleworth, Wise, and Paulson, 1974;Kookier and Surni, 1974;Chalhub, Devivo, and Volpe, 1976;Chadwick, Reynolds, and Marsden, 1976;Luhdorf and Lund, 1977;Rasmussen and Kristensen, 1977;DeVeaugh-Geiss, 1978;Opida, Korthals, and Somasundaram, 1978). Chorea and other movement disorders are rare manifestations of phenytoin toxicity, which have been noted in a variety of clinical settings and are frequently reversible on withdrawal of phenytoin (Peters, Eichman, and Price, 1966;Logan and Freeman, 1969;Gerber, Lynn, and Oates, 1972;McLellan and Swash, 1974;Bellman and Haas, 1974;Rosenblum, Rodochok, and Hanson, 1974;Shuttleworth, Wise, and Paulson, 1974;Kookier and Surni, 1974;Chalhub, Devivo, and Volpe, 1976;Chadwick, Reynolds, and Marsden, 1976;Luhdorf and Lund, 1977;Rasmussen and Kristensen, 1977;DeVeaugh-Geiss, 1978;Opida, Korthals, and Somasundaram, 1978).…”