High frequency extradural motor cortex stimulation transiently improves axial symptoms in a patient with Parkinson's disease.

In a primate model of Parkinson's disease (PD), the benefit of extradural motor cortex stimulation (EMCS) was associated with high-frequency stimulation (130 Hz), whereas no significant motor improvement was achieved at 10 Hz or intermediate frequencies of stimulation. We report the case of a 72-year-old female patient affected by severe PD who underwent bilateral EMCS. In baseline med-off condition the patient was unable to arise from a chair and to stand without assistance. Stimulation at 3 and 60 Hz failed to provide any improvement of symptoms, whereas, when stimulating at 130 Hz, axial akinesia and walking improved consistently: the patient, in med-off condition, was able to arise from chair and to walk without assistance. The patient underwent two brain 99mTc- Ethylcysteinate Dimer-SPECT studies: semiquantitative and Statistical Parametric Mapping revealed that the regional cerebral perfusion was significantly increased in the supplementary motor area during stimulation at 130 Hz. After five months, the benefit of EMCS gradually disappeared.