A case of postural and kinetic tremor caused by diffuse axonal injury]

We reported a 25-year-old woman with postural and kinetic tremor caused by diffuse axonal injury. The patient demonstrated consciousness disturbance, left oculomotor palsy and tetraparesis because of an automobile accident. T2-weighted and FLAIR MRI showed features of diffuse axonal injury. Hyperintense lesions appeared in the corpus callosum, fornix, dorsal portion of midbrain, right cerebral peduncle, and bilateral internal capsules. About 3 weeks later, head tremor and left hemiparesis appeared with improvement of consciousness. Administration of trihexyphenidyl decreased the tremor. Ten weeks after the accident, a coarse tremor in the head and right upper extremity developed after withdrawal of trihexyphenidyl. Tremor in the right upper limb predominantly occurred while maintaining an upright posture and with intended movements. Re-administration of trihexyphenidyl decreased the tremors. The dentatothalamic pathway is one of the lesions responsible for posttraumatic tremor. Our patient demonstrated lesions of diffuse axonal injury involving the dentatothalamic pathway. We considered that these lesions were associated with postural and kinetic tremor in our case. The tremor occurred at least 3 weeks after the accident. This finding suggested that the tremor was caused by transsynaptic alternations of thalamus or the extrapyramidal system secondary to involvement of the dentatothalamic pathway.