P-MD009. A neurophysiological characteristic of holme’s tremor with thalamic lesion

Abstract

Introduction. Holme’s tremor (HT) is defined as a slow frequency tremor with irregular amplitude that mostly occurs at rest and worsens with voluntary movements. Dystonia can be occurred with HT and almost all patients had thalamic lesions. The neurophysiological characteristics of HT are limited. The objective of this case report is to highlight the neurophysiological finding of HT with co-occurrence of dystonia from the thalamic lesion. Results. We reported a 46-year-old female patient with 13-year-history of left cerebellar infarction with bilateral vertebral artery dissection post left cerebellar hemispherectomy with full recovery. Recently she presented with left hemiparesis, hemiataxia and left hemianesthesia, diagnosed as the right thalamic hemorrhage. Seven months later, she developed irregular jerky movement of the left hand as well as dystonic posture. The neurophysiological test was done to distinguish among HT, myorhythmia and dystonic tremor. The one-axis accelerometer (ACC) was put on the left thumb and surface EMG was placed on the abductor pollicis brevis (APB), the flexor digitorum superficialis of the left index (FDS 2) and the left extensor indicis proprius (EIP). The ACC and EMG data showed regular sinusoidal movement of left hand at the peak frequency of 3 Hz with synchronous contractions of the antagonist pairs at rest. The similar pattern with larger amplitude of movement was demonstrated during postural holding at several positions. These findings were consistent with the definition of HT with concomitant dystonia rather than myorhythmia or dystonic tremor. The functional imaging also revealed hypometabolism of right thalamus, cerebral peduncle, medulla and left cerebellum. Botulinum toxin injection was done with good benefit. Conclusion. The neurophysiological test is capable to differentiate HT from mimics. Sinusoidal rhythmic slow oscillation with co-contraction of the antagonist pairs at rest with worsening at voluntary movements might indicate HT with concomitant dystonia.