The brain is a wonderful and intricately designed organ with a multitude of functions transcending mindfulness and awareness. When this organ, nourished by an intricate blood vessel network supplying oxygenated blood, has a sudden blocked blood vessel, an acute ischemic stroke develops. Vast numbers of neurons, synapses, and nerve fibres are irretrievably lost every moment till treatment happens.
Stroke, simply put, is a ‘brain attack’, reflexively drawing an analogy to its counterpart, the heart attack. Ischemic stroke occurs when a region of the brain has been deprived of vital oxygen and nutrient supply owing to a clot in an artery supplying the brain. The adult human brain is made up of 130 billion neurons. Every 30 seconds of a sustained large-artery block kills a million neurons and destroys 6 kilometres of carefully crafted nerve networks. The consequences of untreated stroke include varying degrees of hand and/or leg paralysis, speech impairment. It also affects memory and consciousness and creates behavioral disturbances. Strokes affecting the brainstem which regulates aspects such as breathing and heart functions, could lead to death.
The critical time to treat these strokes is within six hours of onset. Cases of stroke reaching a hospital in six to 12 hours, mandate advanced CT or MRI tests to help quantify the parts of the brain that can be salvaged through treatment. A paradigm shift occurred in the management of strokes due to clots in large blood vessels after the New England Journal of Medicine published the MR CLEAN (Multicenter Randomised Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) in January 2015. In patients with strokes who seek help within six hours of onset of symptoms, the trial compared treatment outcomes of a stent device to pull out the clot (mechanical thrombectomy) versus conventional injection of a clot-dissolving agent into a vein. There was an overwhelming 13.5 percentage positive difference in the functional outcome of patients treated by mechanical thrombectomy. This study confidently characterised two eras in stroke management in large arteries supplying the brain: one before and one after the study.
The technique for clot extraction involves performing a special dye study of the arteries of the brain called cerebral angiogram using an artery in the groin as access. The clot location identified, special tubes (catheters) are used to reach the clot region and then through these micro-catheters the clot remover-stent is deployed. The stent enmeshes the clot within it and is then pulled out of the body. However, there is a limit to how far these micro-catheters can be advanced into the brain blood vessels, dictated by the size of the smaller blood vessels; here clots are still treated by clot dissolving drugs.
In the western context, special teams are set up to manage strokes with the multidisciplinary involvement of trained emergency doctors, stroke neurologists, neurosurgeons and radiologists. Hospitals brought down the time from patient arrival at hospital to initiation of treatment to one hour from the recommended two hours. From a mere 30-50 per cent chance of clot dissolution with drugs, a rate of more than 80 per cent of clot removal success has been accepted with mechanical thrombectomy. To spread awareness, the American Stroke Association recruited celebrities who experienced stroke and were successfully treated, as brand ambassadors, placed notices at important public locations to highlight stroke symptoms and contact numbers for treatment. The acronym ELVO (or Emergent Large Vessel Occlusion) created awareness about a treatable neurological disease. There was all-round cheer with treatment outcomes: patients and relatives saw dramatic improvements, the insurance companies benefited as it reduced patient stay in hospital, cost of rehabilitation and ICU care.
The Indian scene
It was estimated that in India in 2015 there would have been 1.65 million new stroke cases, with 80 per cent of them being ischemic strokes — one case of stroke in every 40 seconds. Unfortunately, only 0.5 per cent of these patients receive standard care. It points to lack of awareness of symptoms of stroke among the general population, inadequate infrastructure in primary hospitals to evaluate and non-referral of such cases to comprehensive stroke treatment centres. Emergency ambulance systems for patient transfer are crucial. The chaotic traffic in our cities can be combated utilising free-source traffic apps on smartphones of ambulance personnel. Certification of hospitals as comprehensive stroke treatment centres is vital. The catheters and clot retrieval devices are not manufactured in India and are imported. A full clot retrieval system is expensive and medical device companies need to work out a pricing model in line with local affordability. Medical insurance does reimburse treatment costs — the cost benefit of an individual restored to baseline or close to it potentially outweighs the costs of nursing an untreated person for prolonged time with rehabilitation.
The increased life expectancy in India and a growing middle class have brought lifestyle and age related risk factors such as heart disease, diabetes, hypertension, high cholesterol and smoking. Strokes can occur in anyone and at any time. Acute ischemic stroke is a highly treatable neuro-emergency. With apologies to Benjamin Franklin — time is, brain.
(The author is Senior Consultant Neurosurgeon at the M.S. Ramaiah Medical College and Memorial Hospital, Bangalore. E-mail: sunilvf@gmail.com
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