Neuropediatrics 2000; 31(2): 70-74
DOI: 10.1055/s-2000-7476
Original Article

Georg Thieme Verlag Stuttgart · New York

Unilateral Involuntary Movement Associated with Streptococcal Infection: Neurophysiological Investigation

Yoshihiro Maegaki1 , Shinjiro Akaboshi1 , Masumi Inagaki2 , Kenzo Takeshita1
  • 1 Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
  • 2 Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Chiba, Japan
Further Information

Publication History

Publication Date:
31 December 2000 (online)

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Two boys developed rhythmic involuntary movements in the extremities on one side of the body after febrile illness. They also showed behavioral disturbances. In both patients, serum antistreptolysin-O and antistreptokinase titers were elevated in acute illness and decreased a few months later. One patient showed tremorous movement, and the other choreiform movement. In the former, a surface EMG showed short-duration (30 to 60 ms), highly frequent (6 to 8 Hz) and synchronous discharges of multiple muscles, including the antagonists, suggesting myoclonic jerk. In the latter, a surface EMG showed long-duration (0.5 to 1 s), repetitive (about 0.5 Hz) and synchronous or asynchronous discharges of the antagonists, suggesting choreoathetosis. In both patients, giant somatosensory evoked potentials and high-voltage slow EEG activities were observed predominantly in the hemisphere contralateral to the involuntary movement. In the myoclonic patient, long-latency EMG responses were enhanced and cortical potentials preceding the myoclonus were present by jerk-locked back averaging technique. The present data suggest that unilateral rhythmic involuntary movements occur secondary to streptococcal infection. The pathophysiology of the involuntary movements may be associated with sensorimotor cortex hyperexcitability.

References

Yoshihiro Maegaki

Division of Child Neurology Institute of Neurological Sciences Faculty of Medicine, Tottori University

36-1 Nishi-Machi

Yonago 683-8504

Japan

Email: E-mail: maegaki@grape.med.tottori-u.ac.jp