Midbrain tremor: a tremor resistant to treatment

Midbrain tremor is a resting, postural, action and intentional tremor of the upper extremity. Partial response to pharmacological agents makes the treatment of this tremor difficult. We report, herein, three cases of patients with midbrain tremors involving their midbrain and thalamic area in ischemic and hemorrhagic strokes. In the first case, the patient presented with a midbrain tremor of the right upper extremity involving left midbrain and thalamic area. After MRI examination, he was placed on benztropine, amantadine, pramipexole and eventually levodopa for treatment, all of which were unsuccessful in improving his tremor. In the second case, the patient presented with a midbrain tremor of the right upper extremity after an hemorrhagic stroke. After viewing CT and MRI scans, the patient was placed on amantadine, pramipexole and eventually levodopa, all of which made no contributions to his tremor. The patient in the third case presented with a blunt trauma to the head which led to the development of a midbrain tremor of his left arm. CT and MRI scans showed abnormalities in the right side of the midbrain and pons. He was initially started on amantadine, with no improvement of his tremor. However, he was eventually placed on trihexyphenidyl which contributed to a 70% improvement in his tremor. In the event of midbrain tremor, treatment should be assessed on a case by case basis, and all options should be considered after a risk–benefit assessment.