[Deep brain stimulation: 12 years' experience and 150 patients treated with a follow-up of over a year]

Deep brain stimulation (DBS) is a widely accepted clinical technique. The main motor symptoms are significantly reduced. The success of the technique depends on the experience of the neurosurgeon, neurologist and neurophysiologist who carry it out. The presentation of extensive series is needed to confirm and further currently held knowledge.

To demonstrate the clinical benefits of a long series of patients treated by a single group with a minimum follow-up of one year and to report new neurophysiological data.

The study examined a total of 250 patients with different diagnoses: most of them with Parkinson's disease, tremor and dystonia. The nuclei that were chosen were located by magnetic resonance imaging, computerised axial tomography and neurophysiological registers. Neurophysiological exclusion criteria, such as reflex control of heart rate, sympathetic skin response and auditory startle reflex, are employed in order to exclude patients with Parkinson-plus.

The motor sub-scale (part III) of the Unified Parkinson's Disease Rating Scale improves by 64% in the off-medication status with sub-thalamic stimulation at one year after surgery. One year after DBS, patients with dystonia show a significant decrease on the Burke-Fahn-Marsden dystonia scale. The improvement on the scales continues, with a mean descent of 65% in the second year after surgery.

DBS is a suitable technique for the treatment of movement disorders. The neuronal activity of the sub-thalamus and the internal globus pallidus presents its own characteristics that reflect the motor symptoms of the patients. Surface electromyography proves to be useful for quantifying the patients' improvement.