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.