Brain 123I-FP-CIT SPECT of a Holmes Tremor Due to Midbrain Pilocytic Astrocytoma.

A 24-year-old woman with an unresectable right mesencephalic pilocytic astrocytoma was treated with stereotaxic radiation therapy. Three months after a radiation therapy-induced bleeding, she presented a severe disabling low frequency rest and kinetic tremor involving the left upper limb, associated with dystonia, and a Holmes tremor was suspected. Thereby, we performed a I-FP-CIT SPECT (DATSCAN) that revealed a normal distribution of radiotracer over the left striatum, whereas no binding was seen in the right caudate and putamen. This pattern was consistent with a right severe nigrostriatal dopaminergic denervation due to an ipsilateral red nucleus injury.