Stroke Management and Surgery
Neurovascular diseases produce characteristic and not very often uncharacteristic clinical picture. The signs and symptoms occur as a result of altered blood flow to the brain and spinal cord. Blood flow may be affected by
1 progressive narrowing or sudden blockage of the blood vessel leading to reduction or abrupt stoppage of blood flow
2 sudden rupture due to acquired or sometimes born birth defects of blood vessels leading to brain haemorrhage
The outcome of this phenomenon is the well known term stroke which by itself is the result of many vascular diseases and risk factors. Strokes can be ischemic or haemorrhagic. Although numerous diseases can cause brain ischemia or haemorrhage the more prevalent ones which can produce stroke are
Occlusive vascular diseases
- carotid artery stenosis
- intracranial arterial stenosis
- Moyamoya disease
- Vertebral artery dissection
- Vertebral artery stenosis
Haemorrhagic vascular diseases
- Cerebral aneurysms
- Cerebral vascular malformations
- Spinal arteriovenous malformations
Many of the above mentioned can exclusively result in both ischemic and haemorrhagic symptoms. In addition there are numerous other uncommon diseases resulting in different clinical pictures.
Certain systemic diseases are strong independent risk factors responsible for the occurrence of stroke. Systemic hypertension , diabetes mellitus, dyslipidemia produce changes in blood vessels which lead to cessation of blood flow or bloodc vessel rupture. Smoking also has been shown to be an independent risk factor predisposing individuals to atherogenic and thrombotic problems resulting in ischemia or brain haemorrhage.
CLINICAL PICTURE
Symptoms of these diseases may come insidiously or there may be an abrupt or catastrophic onset necessitating emergency treatment to counter disability and death. Symptoms in these cases may be
- disturbance of gait and balance
- incoordination of movements and dizziness
- confusion or cognitive disturbance
- inability to understand or speak
- weakness or numbness of face or limbs especially one half of the body
- disturbances of vision especially seeing through one eye
- hearing difficulty or ringing in ear
- sudden severe headache and vomiting with dizziness
- neck stiffness
- sudden loss of consciousness
- seizures
- collapse
DIAGNOSIS
Diagnosis is achieved after reviewing the medical history and examination of the patient followed by laboratory and radiological tests
Physical exam: Tests are performed to assess the complaints or symptoms and additionally elicit signs by checking the nervous system in detail.
CT Scan brain: It is done to quickly determine whether there has been a blocked or a ruptured blood vessel.
MRI Bain: It is done using radio frequency waves and magnetic field to generate detailed anatomical views of the brain and to stand out the disease.
Carotid Doppler: It uses ultrasound waves to check the carotid arteries in the neck. Carotid arteries supply blood to the brain. The main purpose is to find out any obstruction to the blood flow due to plaque build up.
Four vessel neck and Brian angiography: This is primarily done in an almost non-invasive manner through CT scan or MRI scan and by injecting a dye in one of the peripheral arm veins. After a small incision in the groin a catheter is inserted in an artery and guided into the major brain vessels in the neck and beyond. It is done to obtain diagnostic clarity or when certain treatments are performed.
Blood test: These are ordered to determine the time it takes for blood to clot or to find out whether you have an infection or to monitor blood sugar .
TREATMENT
Medication: tissue plasminogen activator(tPA) a clot losing medicine to restore blood flow to the brain is given. In addition blood thinning medications on long term basis may also be prescribed.
Intra-arterial thrombolysis: a catheter is passed through the groin and guided up to the clot and a clot busting medicine is directly delivered to that area.
Mechanical clot removal in cerebral ischemia (MERCI): a catheter carrying a small device is threaded through the carotid artery to physically remove the clot and restore blood flow.
Carotid endarterectomy: it is a surgical procedure to remove the clot through an incision in the neck.
Carotid angioplasty/stinting: this is done with the help of a catheter wherein the catheter is guided to the blockage site in the carotid artery. Once in place the balloon at the catheter tip is inflated to widen the artery and restore blood flow or a hollow tube called stent is placed to keep the vessel open.
Cerebral artery bypass: it is a surgical procedure to bypass the blockage by bringing in a small blood vessel from another body site and connecting it to the blood vessel beyond obstruction.
Stereotactic radiosurgery: it delivers a single high dose of radiation to close off blood vessels over a period of time. It is used to treat AVM and cavernous malformations.
Endovascular embolisation: a glue like material to block abnormal arteries is injected to occlude the abnormal blood vessels.
Endovascular coiling: coils are released via a catheter into the aneurysms to occlude them.
Surgical clipping: a clip is surgically applied on an aneurysm to exclude it from the active circulation.
Surgical excision of AVMs and cavernous malformations: the abnormal bunch of vessels is removed surgically to prevent future sequels