[Symptomatological rubral tremor caused by vertebral-basilar artery embolism]

Rubral tremor is a distinct clinical entity as described by Gorden Holmes. We have reported here a 44 years old woman with rubral tremor appearing about 2 months after an embolic attack of vertebral-basilar artery. On neurological examination there were left homonymous hemianopsia, dysarthria very mild weakness of left upper and lower limbs with clumsiness of her left lower limb and the tremor of the left upper limb. Muscle tone was increased in her left upper limb with dystonic posturing. The tremor of her left upper limb was present at rest with regular rhythm of 2.8 Hz. This tremor included the reciprocal movements such as radial and ulnar flexion of the left wrist and independent movements of different fingers. It was accentuated by postural adjustment and by guided voluntary movements and disappeared during sleep. Surface EMG demonstrated that the grouping discharge was seen not only alternatingly but also synchronously between agonists and antagonists. A brain MRI image revealed multiple lesions including right thalamus and left cerebellum. No lesions were detected in brain stem. On the basis of MRI, it was questionable whether the lesion involved the dentate nucleus in the left cerebellum although the lesion was located at the medulla near the dentate nucleus extending from the cortex. So-called rubral tremor could be generated in lesions of cerebello-rubro-thalamic system without rubral lesion itself.