Extradural motor cortex stimulation (EMCS) for Parkinson's disease. History and first results by the study group of the Italian neurosurgical society

The preliminary results obtained by the Study Group for Treatment of Involuntary Movements by Extradural Motor Cortex Stimulation (EMCS) of the Italian Neurosurgical Society, are reported. The series includes 16 cases of very advanced Parkinson's Disease (PD), aged 46-81; 15 of them were not eligible for Deep Brain Stimulation. Ten cases have been evaluated at 3-30 months after implantation. Unilateral, sub-threshold extradural motor cortex stimulation (2-8 Volt, 100-400 μsec., 20-120 Hz) by chronically implanted electrodes, relieves, at least partially, but sometime dramatically, the whole spectrum of symptoms of advanced PD. Tremor and rigor bilaterally in all limbs and akinesia are reduced. Standing, gait, motor performance, speech and swallowing are improved. Benefit is marked as far as axial symptoms is concerned. Also the symptoms of Long Term Dopa Syndrome - dyskinesias, motor fluctuations - and other secondary effect of levodopa administration - psychiatric symptoms - are improved. Levodopa dosage may be reduced by 50%. The effect seems persistent and does not fade away with time. Improvement ranged, on the basis of the UPDRS scale, from <25% to 75%. There was only one case of complete failure. Quality of life is markedly improved in patients who were absolutely incapable of walking and unable arise out of chair. After stimulation they could walk, even if assistance was necessary. Improvement was observed also in those with disabling motor fluctuation and dyskinesias which could be abolished.