Pune recently hosted the 3rd National Conference of the Society of Stereotaxy and Functional Neurosurgery on Oct.9 and 10. I think it went off very well and we had interesting lectures, discussions and my impression was that all our guests were happy with the academic fare, the hospitality and the efficiency. I must say Dr. Vhora, as Secretary, did a fine job.
But this is only a prelude. What struck me through the Conference was the way medicine moves forward. The major thrust of stereotaxics surgery is of course the advances in the treatment of Parkinson’s and we will use this disease to speak about how medicine moved forward in the last half century.
- First there is the luck factor – It started in the 50s. Dr.Cooper, a surgeon, was operating on a Parkinson’s patient with an aneurysm. The aneurysm ruptured and he was forced to clip the vessel blind and clipped the anterior choroidal artery. Suprise surprises ! when the patient was awake the SAH was treated and the Parkinsonian tremor had disappeared. Lady luck had stepped in.
- Then the introspection – As is has been said before, many people stumble on the truth, but most just grumble a bit at the fool who left the stone in the way, and go on their way. Cooper paused to think over the chance finding why this luck had occurred. He wondered why that should be, and not getting a good explanation he decided to try his luck and see what happens in other patients of Parkinsonism if he did the same and he was reasonable successful. The surgical treatments of Parkinson’s had begun.
- The third is technology – Neurology and innovation entered. Why not make the same lesion produced by occlusion of the anterior choroidal in a different non invasive way? This gave birth to Stereotaxy. The formation of the Leskell frame the wedding of technology and a dedicated medical man so that using 3 planes, sagittal, coronal and axial and a rotating arm, we could introduce a probe through the skull to hit a predetermined area round 3 mm’s cube in the depth of the brain without incision of injuring superficial areas. As far as I know, it was the first such procedure in any discipline in medicine.
- Then we advanced by accumulating experience – Stereotaxic ablation of the ventral intermediate nucleus of the thalamus became one of the treatments of Parkinson’s in the 50s. Many surgeons all over the world started using the technique. The biggest centre in India was undoubtedly Ramamurthy’s Dept. in Madras, and before that the surgical unit in Vellore. Mumbai started a little later and by the time I had passed, things had crystallized. Stereotaxy was good for tremor predominant Parkinson’s. You required a relatively young patients whose main problem was tremor and who had predominantly unilateral disease. If that were so, he was markedly improved by the stereotactily placed lesion in the thalamus. But bilateral surgery was not desirable and if the problem was bilateral, Stereotaxic surgery was dangerous, it often worsened the patients and caused dysphonia and aphasia.
- The 4" step. Medicine make surgery redundant. Remember surgery for peptic ulcer, the commonest major surgery as I became a resident and junior consultant. So also stereotaxy. Two ideas now surfaced. First was the recognition that the nigrostriatal pathway was important for Parkinson’s disease and that dopamine was the neurotransmitter of this pathway. The second was cotzias method of getting dopamine into the brain by use of L.dopa rather than published “Reversal of the pathophysiology of Parkinson’s disease” and Stereotaxic frames were mostly dumped. There was no need for stereotaxy, or if no need at all, certainly the need decreased for the rare case, so, as Dr.Bhagwati told me he was doing one case in 3–4 months and no other neurosurgeons were interested in learning the methodology.
- Then advance occurred with the wheel turning full circle. We realized that after 5–10 years of treatment with L.dopa, lots of problems arose and we could hardly help the resistant cases anymore. With that came additional knowledge. We realized that palidotomy of Globus Pallidus Interna (GPi) not only helped a tremor but in fact helped bradykinesia, and hypertonia and freezing too and surgery returned first in Europe and US and now in the last few years in India. We saw, how, as soon as the electrode enters the GPi of thalamus, tremor disappears. Dr. Ho showed us a video of a case he had done and the dramatic change in the tremor and the hand was most impressive. But I was sitting near Dr. Ramamurthy and Dr. Bhagwati and they looked at one another and smiled. Reminds us of 35 years ago they felt. We had seen this and been impressed with the self same finding 30–40 years ago when we were young like the dozens watching today.
- But technology marches on. Medicine does not move in a circle. It’s more like a spiral so through we are coming backwards to what our forefathers were doing or thinking, we are doing it better. The lesion is more exact, the Pallidotomy replaces the thalamic lesion. We can bilateral cases putting the lesion on the more affected side.
- Then a new idea surfaces – Deep brain stimulation. A needle is put in the pallidum GPi and it is attached to a stimulator. We can stimulate the area at high speed stimulus and thereby cause a loss of function. What is the advantage of deep brain stimulation?
- We can increase or decrease the current so if the effect reduces, we can adjust the stimulating parametres to get effects again.
- The affect is not permanent. The needle can be removed, put in another area by the side to give us flexibility.
- We can keep the stimulus off when the effect is not required (sleep) and on when required.
- While pallidotomy is still a little troublesome if done bilaterally, one can do pallidotomy on one side and deep brain stimulus on the other or deep brain stimulation on both sides. And then a new idea. One can put the deep brain stimulation in the substantia nigra and get results even better than GPi lesions. During the conference, Dr.Ho put electrodes for deep brain stimulation in bilateral substantia nigra in a patient at RHC with excellence results. For non–neurologists which cases of Parkinson’s are suitable for stereotaxy today?
- The patient must have previously responded to L dopa well and there should be no dispute about the diagnosis. Parkinson’s plus syndromes which have Parkinson and some other atypical features are not desirable. Nor added dementia etc.
- The patient must have had a proper drug trial and having initially responded now the effects are not satisfactory and various methods of trying to improve medicals results have failed.
- If one of the major problems is drug (L dopa) induced dyskinesia and that is causing it difficult to trat, that is an ideal candidate because undoubtedly one advantage of surgery is that drug induced chorea/dystonia disappears and thus we can use more L dopa for further control.
- The patient must realize that drug treatment will have to continue but control will be smoother. Subsequent failure of surgical affects is also likely.
- The patient must not be too old or too infirm to benefit long term.
- The last stimulus to advance in medicine is of course competition. The best centre in the world is believed to be in France where patients come from all over the world for surgery and doctors to learn the technique. The placement of the lesion is done by Robots. From France we have surgeons who have worked there and come to India and are doing stereotaxy for Parkinson’s in Trivandrum and Mumbai etc. In Pune, the first surgery was done at PIN, but now there are fledging units at JNH, RHC and soon in Poona Hospital. My experience in case is not too impressive. One done in the US failed and has a hemiplegia. Another done in the US is not too happy, though surgeons say the result is satisfactory. Two went earlier to Mumbai and Trivandrum and were turned down. But one last week, I hadn’t sent for surgery, came back after his operation was done! He learned of the surgery, and has taken the chance himself and relations seem happy (I haven’t seen him yet). Patients of Parkinson’s are now regularly asking is not there something else when medicine is no longer useful? And in truth there is. This then is the way medicines advanced in the last half century. An idea (Brain’s) a little luck (chance), Experience (i.e hard work carefully documented) more ideas, Technology, more Technology and Competition (ego, money!) and that is the way medicine goes round and round and spirals forward.
- What of the future of Parkinson’s disease? Long ago I had read that there are stages in the advances in medicals treatment. The halfway stage is one which is difficult to do, very costly, requires expertise and is not available to all. The final stage is one which is simple, cheap and available to all and causes the disease to decline and go. The iron lung for Polio and the distribution of ventilators in all hospitals was the halfway stage for Polio. Now with the Polio vaccine we are at the end goal and target year 200 for eradication is near. Looked at this way CABG, dialysis, transplant, stereotaxy, deep brain stimulation is halfway stage. The end goal appears far away but will come with a medical therapy the nature I do not know. A neuromodulation? a neurotransmitter? a free radial scavenger? a preventive strategy? Once again the wheel of medicine will turn full circle and the museum. And then – then who knows. For was not Chloromycetin the end stages of enteric fever and DDT the end stage for malaria? And small pox vaccine the end stage of small pox.
Patients Statistics for the period JUNE’99 to AUGUST’99
|Total No. of OPD Patients||7278||7677||7601||22556|
|Total No. of Indoor Patients Admitted||1564||1594||1583||4741|
|Total No. of Free and Concessional cases in OPD (All Dept)||948||1217||1108||3273|
|Free cases treated (General Ward Patients Only) Indoor||19||28||37||84|
|Concessional cases treated (General Ward Patients Only) Indoor||31||71||41||143|
Dr. R. S. Wadia (M.D.)