Stereotactic surgery in India : the past, present and the future.
The achievements of Indian neurosurgeons in different fields of stereotactic surgery over the past decades have been discussed. This covers diverse areas like Parkinson's disease, abnormal movements, cerebral palsy, spasticity, pain relief, and sedative and functional neurosurgery. Recently, technological advances have made stereotactic surgery useful in many fields like deep biopsies, minimally invasive surgery and radiosurgery. Apart from these areas, there is still a big scope for revival of surgery on deep structures of the brain, as was practised earlier. This will lead to newer knowledge about brain function and also give relief to many patients. The future is bright, provided Indian neurosurgeons show a paradigm shift in their thinking and bring out new ideas. Interaction with other scientific disciplines is necessary in the future if new knowledge has to be added or new techniques have to be devised.
Arjun Sehgal, played a crucial part in the development of stereotactic surgery in India by inventing a new streotactic apparatus named after him as early as thirty years ago. There has been revival of interest in streotactic surgery in its various aspects, in our country, over the past decade. However, few questions need to be answered. Is the future exciting and full of possiblities or have we reached the end of the road? What are we going to do with our ability to reach, safely and precisely, any part of the brain?
The past was exciting and challenging. The conditions existing in the country 40 years ago were not conducive to the development of a new field. Step by step, this branch of neurosurgery found a firm footing in India.,,,,, Bold pioneers like Chintan Nambiar, a surgeon of the Stanley Medical College made lesions in the brain by a free hand technique using a template in the temporal region and had some successe. The surgeon was bold, the patients were bolder.
Following Irwing Cooper's technique, Balasubramanium and Ramamurthi in Madras procured a Cooper balloon apparatus in 1958 and started making lesions. The radiology department was resistant to the new demands. The balloons perished in the tropical climate and could not be replaced easily. Their import was almost impossible, against the bureacratic hurdles in the State and the Central Government levels. Friends going abroad used to smuggle them from the U.K and Australia. The local industrialist groups were not interested unless an order of more than 2000 was placed. Still we did not give up.
Fifteen years and 1700 procedures: The Leksells machine came to Madras in 1962. Visit of Lawrence Walsh and Denis Williams to Madras started the great saga of stereotactic surgery in Madras. During fifteen years, more than 1700 stereotactic operations were done at Madras and lesions placed in almost every important part of the brain. Sanath Bhagwati was trained in the UK at the Atkinson Morley where Ticky Walsh was the expert in stereotaxy. We must thank Sanath, for making his brother manufacture the Leksell's machine in India.
Skullbase approach to the thalamus: In the meantime in Bangalore the inimitable RM Varma, used his excellent skill in reaching the trigeminal ganglion to reach the thalamic nuclei via the base of the skull. The idea itself makes one skip a heart beat. I do not think lesser mortals would have been able to do this. I understand that Varma is still practising this technique with good results.
An Excellent Team: Apart from V Balasubramanium, S Kalyanaraman and TS Kanaka, the role of the present day giants of Indian neurology, viz. Dr G Arjundas and Dr K Jaganathan has to be written in letters of gold in this saga. Later Dr ZA Sayeed joined us specially in the treatment of epilepsy. Vriddhagirinathan the psychologist, and the neurochemist, Dr Valmikinathan, also got interested in this work. The operations were done under local and short acting anaesthesia. Every stereotactic procedure was a precise excercise in neurophysiology and the neurologists were in the operating theatre for hours on end, recording the findings and checking the results of stimulation and ablation of numerous centers in the brain.
Parkinsons Disease: More than thirty neuroscientists of India learnt the techniques, when Walsh and Williams were in Madras for three weeks. After that the enthusiasm of neuroscientists at Madras could not be contained and they enlarged the field of activity to treat various other neurological disorders.
Physiological Exercise: Macro and micro electrorecordings were done. Every lesion made in the brain was marked by a steel pellet. The postoperative x-rays with the Leksell's frame in position were used to chart the site of the lesion using the Schaltenbrand and Bailey's Stereotactic Atlas. The role of various nuclei in the brain in the causation of the abnormality could thus be studied. The lesions made in the brain were carefully checked with the physiological effects they produced in the patients, in terms of tremor, rigidity, ability to use limbs, voice volume and psychological changes.
Bilateral Lesions: , Success in curing tremors or rigidity in one half of the body brought a great demand from patients to operate on the other side and this was difficult. Our work showed that when bilateral lesions were symmetrically placed, the patients tended to deteriorate. Hence the second lesion was placed at a different site. S Kalyanaraman made bilateral lesions in some patients at one sitting. This was done by fixing the Leksells apparatus and also the Sehgal apparatus on the patient's head. This was exciting as cross stimulation and recording was possible. But the surgical results with bilateral simultaneous thalamic surgery were discouraging.
Thalamomania: We also found that akinesia and low voice volume could not be helped by surgery. Even though the Globes Pallidus was the site of early lesions made by Coopers Balloon technique, the thalamus mania took hold of us completely. We did not revert back to the pallidal lesions . The idea never struck us. What a pity ?
Reach anywhere in the brain: Parkinsonism was not the only field . If one can reach any target in the brain with safety, why not try other targets for other diseases and disabilities? Thus started the glorious era when we ventured on to the fields of relief of motor movement disorders, spasticity and rigidity in cerebral palsy, fields of aggressive behaviour in children with or without epilepsy, of stereotactic surgery for intractable temporal lobe and generalized epilepsy, pain relief in intractable pain, and relief of mental symptoms in depressive and obsessive compulsive disorders.
Abnormal Movements: Ablative lesions in various thalamic and subthalamic areas were found useful in movement disorders, specially in choreothetosis, dystonia and hemiballismus. Similar lesions were tried in intractable spasmodic torticollis, with some good results. TS Kanaka and V Balasubramaniam classified abnormal muscle tonus in cerebral palsy into various types, and proposed different combinations of lesions to deal with different types of spasticity and rigidity.,, This led to gratifying results. They combined lesions in the cerebellum, the VIM and the central median nuclei to get the best possible effect.,, This idea was carried further and lesions were made in the dentate nucleus to relieve spasticity in strokes. Each surgery was a meticulously planned neurophysiological exercise, painstaking but exciting and exhilarating.
Restlessness and aggression in children: V Balasubramaniam confirmed Narabayashi's work and found that bilateral lesions in the amygdala helped majority of children.,,,,,,,,,,,, Following the lead of Sano, Balasubramaniam et al made many lesions in the hypothalamus and found that a slightly different target gave better results than Sano's target.,,,,
Physiological observations were recorded on many parameters during these procedures, specially the neurophysiological effects of stimulation of the amygdala and the hypothalamus on blood pressure, respiration, pupillary movements, sweating and gastric secretion. It was shown that the amygdala formed a wayside station for changes in gastric secretion during hypothalamus stimulation. In patients with bilateral amygdalotomy, stimulation of the hypothalamus did not increase gastric secretion., The team also compared the results of amygdalotomy with those of primary hypothalamotomy in behaviour disorders and suggested indications for secondary hypothalamotomy. More than six hundred procedures were done to help aggressive children.
Epilepsy: It was seen that many children, who had temporal lobe seizures, ceased having seizures after amygdalotomy. This led to the postulation that partial complex seizures with proved medial temporal focus can be treated with stereotactic lesions rather than by a full temporal lobectomy.,,,,,,,, Why remove so much of the normal temporal lobe while excising the epileptogenic focus? The details of localisation of the focus by special EEG techniques and the grading of bilateral foci were well established by careful pre and post operative observations by my neurological collegues. The procedure of ablating the medial temporal focus by stereotactic technique was effective in about two thirds of the cases on a six month follow up and in about more than a third in a longer follow up. The results were published locally and internationally and papers presented at international meetings. Due to various reasons, the epilepsy surgeons have been lukewarm in furthering this. It is sad to think a time will come soon when somebody in the West would revive the idea and we would take it up.
Generalised Epilepsy: The real challenge of intractability is in generalised seizures. Hence our group led by the enthusiasm of S Kalyanaraman, made different lesions to control intractable grandmal seizures. Lesions were made in the internal capsule, the fields of Forel, central median nucleus and subthalamic areas, in the hope of minimising the attacks., Post operatively, the EEG did not change and the clinical results were found to be temporary. The last three decades have not substantially improved the treatment of intractable epilepsy, in spite of the voluminous literature on the subject. Advances in pharmocology have only marginally helped with the so-called add on drugs. Here is a rich field for the future.
Functional Neurosurgery: Surgery for psychological disorders has a chequered history. BN Balakrishna Rao performed prefrontal leucotomies in Bangalore guided by MV Govindaswami in 1940's. Follow up of more than 50 years of prefrontal leucotomies done by me in 1949 at St.Lukes Hospital in the UK had shown benefit in more than 60 percent of patients. But the disastrous results in some patients led to the gradual abandonment of this procedure. Even in those days (1949 International Congress) Bill Scoville had suggested orbital undercutting as a better procedure and I did a few in the UK in 1949.
The precision of stereotactic surgery stepped in to help psychotic patients. The two definite indications for surgery were severe depression and obsessive compulsive neurosis, in patients in whom drugs have not helped.,, The psychiatrists in south India were forward looking and referred cases for psychosurgery. I am not afraid to use this term in India as this does not invoke fear amongst our patients or our psychiatrists. In severe depression, we made stamp lesions in the subfrontal region using the diathermy. The success was remarkable. Some patients remarked on the operating table that 'a great load has been lifted off my chest'. Most patients benefitted.,, In obsessive compulsive neuroses, lesions in the cingulum at the level of the foramen of Monro were found beneficial. The cingulum was identified by ventriculography, and wax lesions of 8-10 mm size were made. To avoid the anterior cerebral artery, intra operative angiography was undertaken to correctly locate the vessels on either side. The results were good and the relief long lasting. In some patients, where the results were not as good as expected we made subsequent lesions in the subfrontal region or the cingulum as indicated. This improved the rate of success.
Drug Addiction: During this period we came across some doctors, nurses and others who had become addicted to morphine or pethidine. Arguing that such addiction could be some form of obsessive compulsion, we decided to try bilateral cingulum lesions in such patients and found to our delight that the results were excellent. 90 per cent of the patients were benefitted and there was no recurrence of the craving. Extending this analogy to chronic alcoholism, we treated a few patients with bilateral cingulumotomy., The immediate results were gratifying, but in a few months it was found that 'friends' at social functions induced them just to take a sip and majority of then reverted to alcoholism. Perhaps a socially accepted custom is difficult to cure by such surgery.
Following the paranoia created in the United States of America and later in Japan and in some European countries against psychosurgery, it fell into disrepute. The argument was that such a power in the hands of the surgeons to alter mental state is dangerous and doctors may operate to change 'good kind Americans into big bad communists' if neurosurgeons were encouraged in this area. This paranoia invading Japan made Japanese medical students 'gherao' Keiji Sano in Tokyo during the 1971 World Congress.
The cultural attitude of Indians and Indian psychiatrists did not accept this paranoid view and many cases were referred for psychosurgery.,,, To deny proved useful surgery to patients with mental illness is unethical. Luckily 'functional neurosurgery' is gradually staging a comeback in many countries of the World.
Pain relief: Four decades ago, the methods of pharmacological pain relief were crude and often ineffective in chronic cancer pain. The idea of frequent administration of metered doses of pain relieving drugs to keep pain in check was still not accepted and surgeons had to do what they could. In the forties and fifties, unilateral prefrontal leucotomy was offered for intractable pain and many of my patients had some relief. The result was more an indifference to the presence of pain rather than abolition of pain. Such unilateral procedures on the right brain did not carry with them the terror of a vegetable existence.
The other useful operation, more often performed, was dorsal cordotomy for pain arising from incurable malignancy in the lower half of the body, specially the pain of pelvic malignancy. As a matter of historical interest, Norman Dott had a unilateral cordotomy performed on himself for intractable pain for osteoarthritis of the hip. (No hip replacement was available those days). Cordotomy in the higher cervical region was more risky and of course not of use for pain arising from lesions higher up. With stereotactic surgery it was possible to offer relief from pain by making lesions in the sensory relay nucleus of the thalamus. By depth recording we located the nucleus and then decided on the site of lesion by observing the effect of stimulation of the various segments of the sensory nucleus,. Precision was possible and pain relief could be achieved. Hypothalamic lesions were also found useful in pain relief. As mentioned earlier, each procedure was a physiological exercise and new knowledge could be added.,
In some patients, we decided to add a lesion in the centro median nucleus or the anterior ventral nucleus to give more permanency to the pain relief. Usually in advanced cancer pain, the pain relief achieved lasted the short life span of the patient. We did not venture into the field of spinal stereotactic surgery, though we tried some cases by reversing the arc of the Leksell's apparatus. In the late seventies and eighties, due to various reasons, stereotactic surgery for neurological disorders gradually ebbed away.
The modern revival of interest in stereotaxy came with the possibility of combining the CT scan with stereotactic surgery. The method is being used in treating pathological lesions of the brain and in making surgical approaches to deep seated lesions of the brain to be less invasive. Stereotactic biopsies, aspirations of cysts, insertion of reservoirs and combination with neuronavigator techniques have been the other advances.
A spectacular progress has been in the field of stereotactic radiosurgery which helps in the nonsurgical treatment of small lesions. Functional neurosurgery has undergone a revival specially with the idea of making lesions in the globus pallidus with good results in akinesia. An important advance has been in the insertion of chronic indwelling electrodes to alleviate Parkinsonism syndromes and effect pain relief.
The future appears exciting and Indian neurosurgeons should be determined to play a leading role in this adventure and not merely follow the technological advances offered by the West . While we cannot beat them in advanced technology, we can certainly contribute to the advancement of knowledge and creation of new ideas.
At the International Congress of Stereotactic Surgery at Lyons in 1997, retrospection revealed that no new ideas had emerged, except the re-emergence of globus pallidal lesions. Of course there were many presentations of high cost technology, useful for the rich departments and for the benefit of the manufacturing companies. Stereotactic biopsies have marginally improved prognosis of deep lesions; minimally invasive surgery has helped to reduce discomfort and hospital stay in the developed countries. But the benefit to the common man with neurological illness seems to have been minimal. What does it matter to the millions in developing countries if the patient has to stay for a few more days in the hospital or whether his craniotomy scar is bigger than his richer western counterpart? Can we use our skills to benefit numerous patients with dystonias and other abnormal movements, spasticity and rigidity, epilepsy and behavioural and mental disorders and intractable pain as has already been proved by the pioneers?
My plea for Indian neurosurgeons is to go back to the exciting area of neurophysiology and relieve the distress of hundreds who have now no hope of therapeutic relief. We have already shown the way two decades ago. Should Indian neurosurgeons neglect this area, till our Western counterparts show interest again in these fields?
Can We Not Lead?
Yes, we can, and that also with only the equipment we have. Let us not give the excuse of lack of equipment for our tardiness in venturing into new areas. Many centres still use ventriculography in combination with CT scan for precise localisation. MRI compatible equipment though useful, is not that necessary for us to venture into the useful fields mentioned above. Those who have them, let them use them. But the majority of us will have to make do. We cannot say that "we will do sterotactic surgery only in the rich hospitals of our country".
Can we peep into the future ? Advances in science were made by sudden twists and turns and not by following a straight line. There must be a paradigm shift in our thinking and teaching. Are there areas of ignorance in neurology where we, as stereotactic surgeons, may help add new knowledge? Can we improve knowledge in the fields of neuropsychology? Would it be possible to marry stereotaxy with new area of biotechnology molecular biology, x-ray crystallography, isotope studies and information technology techniques, to determine the role of deep neural structures and circuits? Can we help by our studies to solve the mysteries of grandmal epilepsy or that of schizophrenia?
We can use very fine micro electrodes and help to study not only local physiology but the local chemistry of precise areas e.g. the role of the nucleus accumbens and the role of the cingulum and the basal ganglia in the field of drive, motivation and will. Can we help to solve the physiology of depression or the desire for addiction?
While conceding that our brain acts as an integrated whole and is influenced by environment, nutrition and genetic mode, still the ability of the stereotactic surgeons to reach precise targets has to be used, to determine normal and abnormal brain function. Non invasive techniques can be combined with stereotactic surgery. We have to think of `out of the way' solutions. We can talk to our computer engineers, molecular biologists, X-ray crystallographers and many others outside our field to get new ideas. I would also suggest interaction with University and other departments of life sciences and neurosciences, encouraging them in the use of animal models and utilising their expertise. On a more mundane field, our society can also make every effort to make available cheaper stereotactic apparatus so that more neurosurgeons in the periphery may use it.
It is precisely the role of this society to stimulate new thoughts and new approaches and see that Indian contribution to new knowledge becomes visible and palpable.