To evaluate the pathophysiological mechanism of hemifacial spasm (HFS), we performed electrophysiological examinations, such as supraorbital nerve stimulation with orbicularis oris muscle recording and lateral spread tests, after suppressing the patient's central nervous system by administering intravenous diazepam.
Six patients with HFS were recruited. Supraorbital nerve stimulation with orbicularis oris muscle recording and the lateral spread test were performed, followed by intravenous application of 10 mg diazepam to achieve facial motor neuron suppression. Subsequently, we repeated the two electrophysiological experiments mentioned above at 10 and 20 minutes after the patients had received the diazepam intravenously.
Orbicularis oris muscle responses were observed in all patients after supraorbital nerve stimulation and lateral spread tests. After the diazepam injection, no orbicularis oris muscle response to supraorbital nerve stimulation was observed in one patient, and the latencies of this response were evident as a slowing tendency with time in the remaining five patients. However, the latencies of the orbicularis oris muscle responses were observed consistently in all patients in the lateral spread test.
Our results suggest that ectopic excitation/ephaptic transmission contributes to the pathophysiological mechanisms of HFS. This is because the latencies of the orbicularis oris muscle responses in the lateral spread test were observed consistently in the suppressed motor neuron in our patients.
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Holmes tremor is a rare movement phenomenon, with atypical low-frequency tremor at rest and when changing postures, often related to brainstem pathology. We report a 70-year-old female patient who was presented with dystonic head and upper limb tremor after brainstem hemorrhage. The patient had experienced a sudden onset of left hemiparesis and right facial paralysis. Brain magnetic resonance imaging showed an acute hemorrhage from the brachium pontis through the dorsal midbrain on the right side. Several months later, the patient developed resting tremor of the head and left arm, which was exacerbated by a sitting posture and intentional movement. The tremor showed a regular low-frequency (1-2 Hz) for the bilateral sternocleidomastoid and cervical paraspinal muscles at rest. The patient's symptoms did not respond to propranolol or clonazepam, but gradually improved with levodopa administration. Although various remedies were attempted, overall, the results were poor. We suggest that levodopa might be a useful remedy for Holmes tremor. The curative or relieving effect of the dopaminergic agent in Holmes tremor needs more research.
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To investigate whether or not indirect ultrasound guidance could increase the accuracy of the glenohumeral joint injection using the superior approach.
Twelve shoulders from 7 adult cadavers were anatomically dissected after a dye injection had been performed, while the cadavers were in the supine position. Before the injection, a clinician determined the injection point using the ultrasound and the more internal axial arm rotation was compared to how it was positioned in a previous study. Injection confidence scores and injection accuracy scores were rated.
The clinician's confidence score was high in 92% (11 of 12 shoulders) and the injection accuracy scores were 100% (12 of 12 shoulders). The long heads of the biceps tendons were not penetrated.
Indirect ultrasound guidance and positioning shoulder adducted at 10° and internally rotated at 60°-70° during the superior glenohumeral joint injection would be an effective method to avoid damage to the long head of biceps tendons and to produce a highly accurate injection.
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