Occipital Nerve Stimulation for Refractory Pain after Occipitocervical Fusion.

Occipital nerve stimulation (ONS) is electric stimulation of the distal branches of the greater occipital nerve by cylindrical or paddle leads implanted in subcutaneous occipital tissue. This surgical option has emerged as a promising treatment for different types of disabling medical refractory headache and recently also for residual occipital and nuchal pain after previous occipitocervical fusion. The mechanisms of action have not yet been clearly explained: electrical stimulation of the occipital nerve has both peripheral and central effects on the nervous system, which may modulate nociception. ONS is a well-tolerated and safe procedure in comparison with other invasive modalities of treatment. Lead migration/dislodgement is a common complication, but use of new surgical techniques and leads may reduce the rate of this complication.

Minimally invasive motor cortex stimulation for Parkinson's disease.

Extra/intradural strip electrode implantation on motor cortex may be possible minimally invasive neurosurgical method for therapeutic neuromodulation in Parkinson's disease (PD). The aim of this review is to assess motor cortex stimulation (MCS) efficacy and safety in advanced PD. Sixteen published articles were included with a total of 130 PD patients treated. In almost all results are from prospective observational open labeled study, only in two studies blinded assessment was carried out. Negative results are reported in three studies. Significant improvement in motor symptoms with remarkable effect on axial symptoms, L-dopa-induced dyskinesia and quality of life are outlined in thirteen studies. Surgical technique involved implant of four-contact strip electrode over M1 in epidural space with exception of few cases in which implant was carried out in subdural space. Surgical procedure was performed contralateral to most affected side with exception of five patients in which it was carried at dominant hemisphere; in four patients electrode implant was bilateral but stimulation was carried out simultaneously on both sides only in two cases. Complications and adverse events occurred very rarely for extradural MCS whereas with higher rate for subdural MCS. Based on review of current literature extra/intradural MCS represents an alternative to deep brain stimulation (DBS) to surgically treat PD patients who are not candidate for DBS. MCS is a minimally invasive neuromodulation procedure with low morbidity-mortality that can relieve all three major symptoms of PD on both sides simultaneously and bilaterally; it has significant effectiveness on axial symptoms, gait disturbances and therapy complications.