THIRUVANANTHAPURAM: Stroke, which causes abrupt affliction of the brain, is the second commonest disease found across the world resulting in death or paralysis. The causes for a sudden blockage of arteries may come from the heart, carotid artery or intracranial diseases.
By and large up to 50% of stroke results from blood clots and atheromatous debris emanating from the carotid artery. Sudden entry of fat particles into brain arteries obstructs them from supplying oxygen and nutrients resulting in stroke symptoms.
There may be a short duration of unconsciousness, weakness to arms and legs, blindness or even permanent paralysis depending upon the pattern and its mechanism. Elderly age, hypertension, smoking, diabetes and high cholesterol in the blood are some of the risk factors. Further checkup of symptoms helps to commence medications and plan definitive treatment options to prevent permanent brain damage.
Risk Factors
Stroke incidence is found more in males. Other risk factors that lead to carotid artery disease are smoking, hypertension, Diabetes and hyperlipidaemia. Carotid artery disease is well known to produce warning symptoms in the form of sudden but transient disturbance, one-sided paralysis or speech disturbance.
Immediate Assessment
Usually, neurologists examine the neurological system and order CT scan or MRI to ascertain if bleeding inside the brain or obstruction of blood flow has occurred to decide the line of management. Bleeding inside the brain calls for necessary medications and control of blood pressure. However, if bleeding is ruled out, immediate injection of clot lyses and are removed by passing very small tubes into arteries to restart passage of blood again. This procedure can be done only if and when patients report within 3-4 ½ hours for the procedure to be successful.
Specific Investigations
Blood tests need to be done to diagnose and quantify risk factors. The duplex scan will give important clues about carotid status, gradient across plaque and ICA flow.
ECG, ECHO will verify cardiac status.CT Scan is critical imaging modality to visualise presence or otherwise of infarcts, and extracranial carotid artery anatomy.MRI will also delineate similarly.
Medical Management
Symptomatic carotid stenosis: 70% medical management is required at least 2 weeks prior to definitive treatment. Asymptomatic carotid stenosis: 80% of patients from this category needs initial medical treatment and only if the further progress of lesion occurs intervention is required.
Best medical management consists of tight control of diabetes and hypertension and stopping smoking habit forthwith, specific medications include Vascular Pleosynergistic drugs namely antiplatelets, statins and ACE inhibitor/B blockers.
Definitive Treatment
Definitive therapy includes Carotid Endarterectomy and Carotid Artery Stenting. Both are complementary procedures with their own indications and merits. Both provide good results in appropriate clinical setting and help to prevent stroke. Former placing a stent through a key whole procedure from grain and the latter an open operation using a 6-8cm long incision in the neck. Current evidence suggests superior benefits and much less adverse neurological events when Carotid endarterectomy is performed as shown in ICSS and CREST studies held over past 2 decades.
Patients would require individualised diet control, exercises and medications further to stabilise the procedure performed as well as to control or obviate generalised atherosclerotic process at other vulnerable arteries of the body.
Screening Tests
In view of serious aftereffects of stroke, screening for subjects above the age of 65 years, particularly those with diabetes and hypertension is advisable.
Blood tests and duplex scan to study the status of carotid arteries are advised to find out any possibility of stroke in subjects above 65 years having diabetes and hypertension. Therefore check-up by our Neurologists would help prevent devastating stroke and sequelae by timely treatment if found required.
Dr M Unnikrishnan is the head of department, Vascular Surgery, SUT Hospital, Pattom
(The views expressed by the author are his own).