1. ACCELEROMETRY DURING ABLATIVE THALAMIC SURGERY FOR PARKINSONIAN TREMOR Authors: J. Ciurea V. Nestianu*, Ileana Simoca, Dept. of Neurosurgery, University Hospital “ Bagdasar Arseni”, Bucharest, Romania * Dept. of Neurophysiology, University of Medicine Craiova, Romania

2. OBJECTIVE Tremor assessment during thalamotomy for Parkinson disease under the effects of electrical stimulation Comparison accelerometer vs. neurologist assessment

3. PATIENTS AND METHOD Total number of patients: 8 Stereotactic target –Vim Gender: 5 men and 3 women. Age –The mean age was 52 years –Range between 32 to 68 years. All patients exhausted drug therapy or did not respond or tolerate it.

4. PATIENTS AND METHOD The following parameters were recorded during electrical stimulation of the target : Frequency (Hz) Amplitude Occurrence of tremor Comparison with neurological direct observation. The lowest stimulation tremor suppression electrical threshold was used to select the optimal lesion site.

5. RESULTS Improvement: –United Parkinsonian Disease Rating Scale – Schwalb & England Scale – Hohen & Yahr Score. Tremor: Rest Positional Intention

6. DEEP BRAIN ELECTRICAL STIMULATION AND TREMOR Monitoring: –EMG + standardized clinical tool - only groups of muscle and movements can affect the position of the electrode –Acceleromerter + vectorial components of movement - the amplitude is a derivate and depends of frequency –Optical – photocouple - diode and receiver +simple - only frequency, interference with other sources –Piezo +sensitive -frequency response dependent on “crystal resonance” –Video + state of art -three simultaneous cameras and a analysis soft, retrospective

7. DEEP BRAIN ELECTRICAL STIMULATION AND TREMOR The 2 - 100 Hz stimulation

8. EFFECT OF STIMULATION

9. WATERFALL PRESENTATION OF ELECTRICAL STIMULATION EFFECTS

12. Accelerometer vs. Observer

13. Accelerometer sy. identification - earlier than clinical observer

14. CONCLUSION –IS TREMOR MONITORING NECESSARY? –IS TREMOR MONITORING USEFUL? TREMOR MONITORING IS AN OBJECTIVE AND EFFICIENT METHOD.