Trigeminal afferent input alters the excitability of facial motoneurons in hemifacial spasm

Objective: To investigate whether skin or muscle afferent input via the trigeminal nerve alters the excitability of facial motoneurons in hemifacial spasm (HFS). Methods: Botulinum toxin type A (BTX) was injected only to the orbicularis oculi (O. oculi) muscle of 21 patients with idiopathic HFS, and the excitability of the orbicularis oris (O. oris) motoneurons was monitored. The synkinetic response (SR) of the blink reflex and abnormal muscle response (AMR) were recorded from the O. oris before and after treatment. Results: BTX injections produced marked to moderate improvement in the O. oculi of all 21 patients and in the O. oris of 17 (81%). The rectified areas of SR1 and SR2 were smaller after treatment. In particular, the AMR area showed a reduction (p = 0.02). Conclusions: The significant lessening of spasms in the O. oris after BTX injection to the O. oculi and the concomitant reduction in excitability of O. oris neurons are consistent with the hypothesis that in HFS, skin or muscle afferent volleys via the trigeminal nerve enhance the excitability of facial nerve motoneurons.

[1]  S. Kameyama,et al.  Lateral spread response elicited by double stimulation in patients with hemifacial spasm , 2002, Muscle & nerve.

[2]  J. Jankovic,et al.  Hemifacial spasm: Clinical findings and treatment , 1998, Muscle & nerve.

[3]  J. Willer,et al.  Electrophysiological determination of the site involved in generating abnormal muscle responses in hemifacial spasm , 1998, Muscle & nerve.

[4]  T. Kawase,et al.  Electrophysiological investigation of hemifacial spasm after microvascular decompression: F waves of the facial muscles, blink reflexes, and abnormal muscle responses. , 1997, Journal of neurosurgery.

[5]  W A Wesselink,et al.  Effect of anode-cathode configuration on paresthesia coverage in spinal cord stimulation. , 1997, Neurosurgery.

[6]  T. Ohira,et al.  Abnormal muscle response (lateral spread) and F-wave in patients with hemifacial spasm , 1996, Journal of the Neurological Sciences.

[7]  P. V. D. Van den Bergh,et al.  Five‐year experience in the treatment of focal movement disorders with low‐dose dysportTM botulinum toxin , 1995, Muscle & nerve.

[8]  A. Møller,et al.  Pathophysiology of hemifacial spasm. , 1994, European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery.

[9]  E. Fine,et al.  The history of the blink reflex , 1992, Neurology.

[10]  J. Jankovic,et al.  Clinical correlates of response to botulinum toxin injections. , 1991, Archives of neurology.

[11]  M. Brin,et al.  Distant effects of locally injected botulinum toxin: A double‐blind study of single fiber EMG changes , 1991, Muscle & nerve.

[12]  A. Møller.  Interaction between the blink reflex and the abnormal muscle response in patients with hemifacial spasm: Results of intraoperative recordings , 1991, Journal of the Neurological Sciences.

[13]  A. Møller,et al.  Physiological abnormalities in hemifacial spasm studied during microvascular decompression operations , 1986, Experimental Neurology.

[14]  A. Møller,et al.  Blink reflex in patients with hemifacial spasm Observations during microvascular decompression operations , 1986, Journal of the Neurological Sciences.

[15]  Á. Esteban,et al.  Primary hemifacial spasm: a neurophysiological study. , 1986, Journal of neurology, neurosurgery, and psychiatry.

[16]  V. Nielsen.  Electrophysiology of the facial nerve in hemifacial spasm: Ectopic/ephaptic excitation , 1985, Muscle & nerve.

[17]  A. Møller,et al.  On the origin of synkinesis in hemifacial spasm: results of intracranial recordings. , 1984, Journal of neurosurgery.

[18]  T. Fukushima,et al.  Observations on synkinesis in patients with hemifacial spasm. Effect of microvascular decompression and etiological considerations. , 1984, Journal of neurosurgery.

[19]  E. Laws,et al.  Microvascular decompression of the facial nerve for hemifacial spasm , 1981, Neurology.

[20]  T. Ohira,et al.  Electrophysiological investigation of hemifacial spasm: F-waves of the facial muscles , 2005, Acta Neurochirurgica.

[21]  A. Straube,et al.  Time course of distant effects of local injections of botulinum toxin , 1993, Movement disorders : official journal of the Movement Disorder Society.

[22]  L. Simpson.  Molecular pharmacology of botulinum toxin and tetanus toxin. , 1986, Annual review of pharmacology and toxicology.

[23]  J. Kimura.  Clinical uses of the electrically elicited blink reflex. , 1983, Advances in neurology.