• Who is not satisfied with his/her level of control of Parkinson's disease.
• Exhibits Parkinson's disease symptoms causing a decline in the quality of life
• Has had an adequate and reasonable trial of medications is a candidate for surgery.

Diseases like diabetes, hypertension or cardiac problems are not a contraindication for surgery. However active infection or blood clotting disorders are contraindications for surgery.

Thalamotomy is an operation by which the tremor generating cells located within the thalamic nuclei of brain are selectively destroyed to control tremors.

Deep brain stimulation (DBS) involves implantation of electrode deep within the brain. In recent times, Subthalamic Nucleus stimulation has emerged as the favoured site for DBS. This electrode is permanently left in place and connected to a small implantable pulse generator (IPG) (Fig. 3). This remotely programmed pacemaker emits minute pulses of energy through the electrode to block the abnormal activity in the brain that cause the symptoms of Parkinson's disease. Precise targeting improves effectiveness and reduces complications. Additional advantages are that these newer techniques do not require purposeful destruction of the brain. In addition, the stimulation is adjustable and can be tailored to the individual patient. Subthalamic DBS is the most effective in terms of the range of symptoms that respond and the ability of patients to reduce medications. It is better for gait and balance problems than most any other form of treatment.

Parkinson's disease surgeries are done without general anaesthesia, with patient fully awake. It involves fixation of stereotactic frame to the patient's head under local anesthesia (Fig. 4). This frame is used to locate the brain targets with the help of CT and MRI scans. The coordinates (reference points) that are obtained from this scans are then transferred to the theater computers and final read outs are obtained. These points are then set on the stereotactic arc system and a fine electrode is introduced into the brain, through a small hole drilled into the skull. Electric current is passed through the electrode to check its position in relation to the vital structures surrounding the target area. Neurologist present in the operation theater constantly assesses the clinical improvement in the symptoms like tremor and rigidity vis a vis side effects. Once it is confirmed that the electrode is in the right place, either destruction of small group of cells is done or a permanent electrode is implanted.

Jaslok Hospital and Research Centre, has an ongoing research project for surgical treatment of movement disorders with special emphasis on Parkinson's disease. It has the facilities of having a state of the art MRI compatible stereotactic equipment complimented with high strength and latest MRI and CT scanner to obtain high quality of images; a pre requisite for performing any stereotactic surgery. The surgical target is located using the finest possible electrodes. Jaslok Hospital is one of the few centers in the world where the Neurologist actually attends the surgery to guide the surgeon for accurate target localization. The surgical team has a strong support from a well-established movement disorder program, for guiding the medical therapy, which forms an integral part of the management of Parkinson's disease patients.

The surgical team has an experience of performing more than 80 surgeries for Parkinson's disease during a span of two and a half years. The results of these surgeries have been scientifically evaluated and published.

We started performing pallidotomy from 1997. We have recently analysed 30 patients after one year follow up. The patients were evaluated using standard scoring system for evaluation of Parkinson's disease. This included, UPDRS (Unified Parkinson's Disease Rating Score), ADL (Schwab and England Activities of Daily Living) and Hoehn and Yahr scoring systems. At one year follow up there was more than 50% (p < 0.005) improvement in the motor scores (comprising of tremor, rigidity and bradykinesia) on the contralateral (opposite) side of Pallidotomy (Fig. 5). The dyskinesia and off phase dystonia disappeared in all patients. Pallidotomy was found to be very effective in relieving off period pain and pain associated with dyskinesias in these patients.

This surgery was started in October '99. Till date we have performed 35 cases of Deep Brain Stimulation out of which there are 32 cases of subthalamic nucleus stimulation. Twenty-five patients have been analysed for the following results. The improvement in the total "off" phase UPDRS score was approximately 60% and 70% respectively at six months and one year follow up (Fig. 6). The scores for activities of daily living improved by 43% and 62% at six months and one year follow up respectively (Fig. 7).

The patients had become independent and were able to resume back their work. The levodopa requirement of these patients was reduced by 10%-80% with an average reduction of more than 50%. Three patients were able to stop all Levodopa medication. This drug reduction helped in alleviating all the levodopa related side effects (dyskinesia, hallucinations, etc.).