–Dr. Rudrajit Kanjilal, Neuro-surgeon at CMRI
Moyamoya disease is a well recognized phenomenon since 1940’s, though it is a relatively uncommon cerebrovascular disorder which at times occur due to familial reason or genetic mutation. Originally, it was thought that the disease was region specific, specially Japan and other Asian countries, since it was first discovered in Japan. However, now we have seen that all races are equally prone to developing this disease. Arguably, its occurance is higher in Asian countries than in Europe or North America. The name of the disorder “Moyamoya” has been derived from Japanese language which means “puff of smoke”. This exactly describes the appearance of the bunch of tangled tiny vessels formed at the base of the brain. In Japan it is a genetic, familial disease, while in India, it is sporadic, we don’t see a familial trend in Indian subcontinent. It is idiopathic and mostly happen due to genetic mutation, but the incidence is not very rare.
Causes and Symptoms:
Moyamoya disease is basically a situation where chronic progressive Ischemic changes occur within the brain i.e progressive fibrosis and blockage of the distal internal carotid arteries, middle cerebral and anti –cerebral arteries. Progressive fibrosis is basically development of large conglomerate masses of dense fibrosis i.e. damaged connective tissues. Therefore, the intertwined tiny vessels are created around the blocked arteries which act as alternate blood circulation, thus forming a “puff of smoke” like appearance when the angiography is done. These “puff of smoke” are actually blood clots which are formed in effort to compensate the inadequate flow of oxygen-rich blood in the brain. If not diagonised on time, the disorder progressively worsens over time leading to stroke of the patient. It occurs usually in the second decade of life and patients suffer from progressive cerebral ischemia. Hence, mostly children and some adults are affected by it. Some children are at the risk of suffering from pediatric stroke as well. Moyamoya disease is mostly collateral. The patients suffer from progressive chronic headache, sometimes seizures, recurrent neurological deficits like hemiparesis and also perhaps complete paralysis. Several patients have total visual loss and become blind.
Diagnosis and Treatment:
Digital substraction angiogram is the first step towards identifying the disorder . CT scan and MRI are also prescribed. SPECT (single photon emission computerized tomography) is used to detect the reduced blood and oxygen supply to areas of the brain affected by Moyamoya disease. Surgery is the best option for maximum chance of curing the disorder.
Dr. Rudradev Kanjilal, Senior Neuro-surgeon at CMRI has treated one of the rare cases of Moyamoya in the city. Somedays ago, a patient was orginially admitted under his colleague at BM Birla Heart Research Institute. There was a clinical suspicion that he might be harbouring the dreaded Moyamoya disease. The patient was blind and had a history of multiple admissions in different hospitals and nursing homes in a neighbouring country. In addition to that, he had medical setback of limb paralysis as well as chronic bursting headache like migrane which eventually made him blind. Dr. Kanjilal’s neurological colleague wanted to do digital substraction angiogram: the go-standard investigation on the patient, which ultimately identified the diagnosis of Moyamoya disease. The patient was also diabetic and hypertensive. He was only 27 years, so the team of best neuro-surgeons decided to go for surgical intervention.Surgical revascularization procedure was the only way to save the patient. The surgical procedure of choice is called EDAMS. This was one of a kind operation done for the first time at CMRI. EDAMS is actually an indirect method, usage of a combination of two procedures called encephalo-duro-arterio-synangiosis (EDAS) and encephalo-myo-synangiosis (EMS) .
Owing to no perception of light and complete prior blindlness, initially, Dr. Kanjilal was not keen on operation. However, post consultation with the relatives of the patient, the doctors decided to opt for the operation. They used the above mentioned EDAMS process microscope and the patient did quite well. The entire operation took about 3 hrs as an indirect revascularization of the brain was also conducted by undergoing STAMCA bypass. STAMCA is actually known as superficial temporal artery-middle cerebral artery which is done through direct revascularization method leading to immediate improvement of symptoms.
After having a good recovery, the patient immediately regained consciousness and was able to walk on the 3rd day, post operation. Then, thereafter, he was dischaged and went back home to his original country. Within three months he regained vision, he had perception of light and could count fingers three feet away. As a part of the eventual check-up, Dr. Kanjilal had then asked him to come out and follow him . The patient had developed functional vision and he could easily follow the doctor.The team of opthamologists reviwed him, and they concluded that he didn’t have peripheral vision but he had developed macular vision. In layman’s term, the centre spot of retina had macular vision which is responsible for the clearest vision. The macular vision has to work so that one can do without peripheral vision which is depended upon macular vision itself. Due to revascular operation the macular blood supply was revived, restoring his vision and this process is neurologically explainable. The disease is bilateral. The right side of the brain was damaged but the left side had reasonably good blood supply. Hence, when the artery blockage was removed, the blood flow regained its access to the right side. Presently, the patient is keeping well and will be back again to B M Birla within next 6 months for his routine check-up. And therefore, it can be aptly said that ‘all well that ends well’.