Paroxysmal choreoathetosis associated with thyrotoxicosis

Abstract

0364-5 1341791A 35-year-old woman was admitted with complaints of weakness and muscle spasms. Grand ma1 seizures had begun at age I 3 years and responded well to treatment with phenobarbital and phenytoin. At age 26 she had had an episode of status epilepticus, which left her with memory impairment that recovered after several months. Eighteen months prior to admission, dysphagia, diplopia, dysarthria, and generalized weakness developed. Myasthenia gravis was diagnosed o n the basis of response to anticholinesterase treatment. Around the same time she began to have episodes of generalized tonic spasm involving the face, arms, and legs. H e r workup at another hospital was unremarkable except for right temporal slowing on one electroencephalogram and a small area of low density in the high right parietal area o n a C T brain scan. She tolerated anticholinesterase treatment poorly, and her myasthenic symptoms gradually progressed. The episodes of muscle spasm became more severe and more frequent, occurring an average of once per week in the month before admission. Raising her arms over her head seemed to precipitate the attacks, which were more common when she was tired or excited. She did not drink alcohol and had n o family history of a similar disorder. She had taken no medication for several months before admission. General examination at admission was remarkable for proptosis, greater on the right than the left, and a precordial systolic ejection murmur. She was diaphoretic, though vital signs were normal. Neurological examination showed decreased eye movements with contracture of the right lateral rectus muscle, nasal speech, facial weakness, and reduced vital capacity. There was weakness of the neck and proximal arm muscles. Deep tendon reflexes were increased in the legs, but plantar reflexes were flexor. She had a fine tremor of the fingers and slight continual choreiform movements, particularly in the left hand and foot .Treatment with pyridostigmine, atropine, and phenytoin was started. While in the hospital the patient was noted to have episodes of paroxysmal choreoathetosis, which she called "muscle spasms," one to four times per day. The episodes usually lasted one or two minutes and began in the left arm, with tonic flexion of the fingers, wrist, and elbow and occasional coarse, rhythmic shaking of the hand. The tonic spasm would spread to involve the face, which would be contorted, with the mouth drawn open and a fixed stare. The right arm was involved in a similar manner, though less severely, and the trunk and legs were usually held in tonic extension. She remained conscious throughout, although unable t o speak, and as soon as the episode ended she was able to give a detailed account of the events that had transpired. An electroencephalogram showed only diffuse slowing. The episodes continued despite treatment with phenytoin at 300 mg per day (serum level, 10 pg/ml) and did not respond to intravenous administration of diphenhydramine or benztropine. She was started on clonazepam. O n the fourth h...

Bilateral chorea–ballism associated with hyperthyroidism

“…14 Therefore, it was proposed that chorea induced by hyperthyroidism might be linked to increased sensitivity of striatal catecholamine receptors. However, Fischbeck and Layzer, 15 based on their clinical experience, suggested that a pre-existing structural lesion of basal ganglia might be necessary for thyrotoxicosis to induce involuntary movements. Reappearance of BCB, associated with increased serum levels of thyroid hormones and lack of relevant changes on brain CT/MRI scans in our patient, favored the suggestion that the involuntary movements were likely due to thyrotoxicosis-induced biochemical changes, without necessity for the coexistence of a structural lesion or lesions.…”

X–linked paroxysmal dyskinesia and severe global retardation caused by defective MCT8 gene

“…Similar to dystonias in general [16], primary PxDs tend to be pure movement disorders, whereas secondary PxDs are characteristically associated with baseline neurological symptoms present between paroxysmal episodes, such as mental retardation and epilepsy [4]. These symptomatic PxDs are caused by a wide range of conditions [5], including thyroid disorders [8,10,19,20].…”

Persistent Hemichorea Associated with Thyrotoxicosis.

“…He wrote that true chorea is thought to exist in a few cases in childhood or youth. Early in this century, 20 years after the first report by Gowers thyrotoxicosis was already regarded as one of the important causes of choreic movements, because some other reports (4)(5) had confirmed the relationsip between thyrotoxicosis and chorea. Although hyperthyroidism is not a rare disease, only one case has been reported in the Japanese literature since 1970 (2).…”

“…Although hyperthyroidism is not a rare disease, only one case has been reported in the Japanese literature since 1970 (2). On the other hand, 14 cases were pub lished in the European and North American literature (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). Although the precise incidence rate of chorea in hyperthyroidism is obscure, the rarity of Japanese case reports possibly suggests a lower incidence in Japanese than in Caucasian patients.…”

“…As there was no effects reported in many cases with thyrotoxic chorea (5,12,16), recently, the sympathetic hypothesis is, thus, a minority opinion. The question of the efficacy of dopamine antagonists has been recently raised (14)(15).…”