What Is the Anterior Inferior Cerebellar Artery?

Vertebrobasilar insufficiency (VBI) refers to the manifestation of a series of clinical intermittent and recurrent neurological dysfunction caused by vertebra-basal artery stenosis (or occlusion) caused by various reasons.

Basic Information

English name: vertebrobasilar insufficiency
Visiting department: Neurology
Common causes: Mainly caused by atherosclerosis

Common symptoms: Diplopia, dysarthria and dysphagia, dizziness and ataxia, bilateral dark or isotropic blindness, sudden onset, motor dysfunction, etc.

Causes of vertebrobasilar insufficiency

Atherosclerosis

As the most important factor, the most common site is the origin of the vertebral artery, followed by the second segment of the vertebral artery, and again the vertebral-basal artery junction.

2. Spontaneous dissecting aneurysms of vertebrobasilar pseudoaneurysms and complete occlusion of vertebral arteries

Often accompanied by arterial fibrous hyperplasia, which occurs in the second and third segments of the vertebral artery.

3. Penetrating neck injury, severe cervical fracture and dislocation

Direct damage to the vertebral artery can cause vertebral artery dissection aneurysms or arteriovenous fistulas, and cervical vertebral artery dissection or occlusion caused by cervical massage.

4. Cervical spine

It is common in people with severe osteoarthritis and osteoproliferation. Compression of the second segment of the vertebral artery causes insufficient blood supply to the vertebrobasilar artery related to the position of the cervical spine, or compression of the anterior oblique muscle ligament at the C6 level causes vertebral artery related to cervical rotation. Vertebro-basal artery insufficient blood supply.

5. Subclavian artery steal syndrome

Intracranial cerebral blood flow shunts can often be induced by active exercise of the left upper limb, and part of the brain stem ischemia appears.

6. emboli

Most vertebral basilar arterial emboli come from heart valves, atrial thrombi, atrial myxomas, aorta, subclavian arteries or innominate atherosclerotic plaques and emboli of systemic origin.

7. Common vertebral artery origin lesions

Including severe atherosclerotic stenosis at the origin of the vertebral artery; severe stenosis due to extra-luminal compression caused by fibrous muscle bands or proliferative anterior oblique muscle at the origin of the vertebral artery; combined with the proximal subclavian artery and Severe ulcerative lesions at the origin of the vertebral artery; subclavian artery steal syndrome.

8. Lesions of vertebral artery stenosis

Including subclavian artery stolen blood syndrome; vertebral artery stenosis on one side, stenosis, or occlusion, or dysplasia of the contralateral vertebral artery at the same time; vertebral artery on one side is narrow enough to reduce blood flow to the vertebrobasilar artery Combined with ulcers to form cerebral embolism).

Clinical manifestations of vertebrobasilar insufficiency

1.Brain stem, cerebellum and occipital lobe

The clinical features of vertebrobasilar insufficiency are intermittent and paroxysmal neurological dysfunction, which are mainly manifested by symptoms of brainstem, cerebellum and occipital lobe:

(1) Symptoms of brain stem are mainly diplopia, dysarthria, and difficulty swallowing.

(2) Cerebellar symptoms are mainly dizziness and ataxia.

(3) Occipital lobe symptoms are mainly bilateral darkening or isotropic blindness.

(4) Other symptoms may include sudden onset and motor dysfunction.

2. Extracranial vertebral artery stenosis

(1) The left side stenosis is more common, which can result in insufficient blood supply to the vertebral-basal artery. The common symptoms are dizziness, ataxia, visual impairment, and motor sensation changes. Headaches, sudden attacks, and mental decline are rare.

(2) Two characteristics of extracranial vertebral artery stenosis: the posterior circulation is isolated, that is, neither posterior communication artery supplies blood to the vertebral-basal artery; activities of the head and neck can repeatedly produce these symptoms.

3. Anterior spinal artery

After occlusion, anterior spinal cord syndrome is caused, with contralateral hemiplegia and ipsilateral tongue weakness, with loss of contralateral proprioception and vibration.

4. Posterior inferior cerebellar artery (PICA)

Proximal or vertebral arterial occlusion can produce dorsal lateral medulla syndrome (Wallenberg syndrome): ipsilateral Horner syndrome involving descending sympathetic fibers, pain in the ipsilateral and contralateral trunks involving the spinal tract and the ascending trigeminal system Changes in temperature sensation, nausea, vomiting, dizziness and nystagmus involving the vestibular nucleus, hoarseness and dysphagia involving the suspected nucleus or the ninth and Xth nerves, rare facial muscle weakness, hearing loss or eye movement disorders

5. Vertebral artery (VA)

Involvement of the level of the paracentral perforator may present the medial medulla syndrome, manifested by weakness of the contralateral limbs and ipsilateral tongue, with decreased contralateral proprioception and vibration.

6. Anterior inferior cerebellar artery (AICA)

Similar to lateral medullary syndrome during ischemia, with nausea, vomiting, vertigo, nystagmus, loss of temperature and pain on the ipsilateral and contralateral sides of the trunk, and ataxia on the ipsilateral side. Horner sign is rare; peripheral facial paralysis, deafness, tinnitus and Side stare paralysis can be distinguished from PICA (Wallenberg) syndrome.

7. Superior Cerebellar Artery (SCA)

Occlusion can cause contralateral detached sensory sensation, affecting the face, arms, torso, and legs, and may have Horner syndrome and epicondylosis, ipsilateral or contralateral hearing loss, and gaze disorders, dizziness, nausea, Vomiting, nystagmus, ipsilateral ataxia, and ipsilateral upper limb tremor.

8. Basal artery (BA)

The most common signs of bilateral VA infarction at the junction of the bridge extension are bilateral, which often develop in a stepwise manner within hours or days. Patients appear lethargic or have a significant decline in consciousness. Lesions in the lateral midbrain area may appear. In the "locked" state, progressive infarction of BA often causes death of patients.

9. Posterior cerebral artery (PCA)

Cerebral foot branch occlusion may appear BA tip syndrome (abnormal vision and eye movements and changes in consciousness); long-rotating arterial occlusion with limited vertical gaze.

Vertebro-basal artery blood supply test

Laboratory inspection

May have high blood lipid abnormalities.

2. ECG and 24-hour Holter

Excludes cardiogenic cataplexy.

3. CT, MRI (magnetic resonance imaging), PET (positron emission tomography) and TCD (transcranial Doppler ultrasound)

It can be used to detect cerebral ischemic damage, such as the location, extent of infarction, hemodynamic changes, and changes in brain metabolism.

4.CTA (CT Angiography) / MRA (Magnetic Resonance Angiography) / DSA (Digital Subtraction Angiography)

The location and extent of vascular stenosis can be identified. DSA is the most reliable and should include the aortic arch and cerebral blood vessels.

Diagnosis of Vertebro-Basal Arterial Insufficient Blood Supply

The clinical symptoms of this disease are diverse and complicated, and sometimes the diagnosis is difficult. You should carefully inquire about the history and symptoms, and conduct a comprehensive examination of cardiovascular function, nervous system, otology, audiology, and vestibular function. Cranial Doppler ultrasound, CT or MRI of the skull, vertebral angiography can further confirm the diagnosis.

Differential diagnosis of vertebrobasilar insufficiency

When diagnosing insufficient blood supply to the vertebral-basal artery, the following conditions must be identified first:

(1) Cardiogenic diseases such as arrhythmias, myocardial insufficiency, and embolism (valvular disease or subacute infective endocarditis).

(2) Potential hematological diseases with hypercoagulable states such as thrombocytosis, sickle cell disease, and macroglobulinemia.

(3) Brain diseases: Intracerebral hemorrhage, demyelinating disease and intracranial tumor.

(4) Other women who smoke, oral contraceptives or migraine.

Treatment of Vertebro-Basal Arterial Insufficient Blood Supply

(A) medical treatment

1. Changing bad lifestyle, losing weight, reducing fat, etc.

2. Early anticoagulation (warfarin), anti-polymer (aspirin) treatment.

3. Control hypertension.

4. Treat abnormal blood components, such as hyperglycemia and hyperlipidemia.

(B) surgical treatment

General anticoagulant, anti-polymer and other drug treatment failures need to consider surgery.

1. Choice of surgical treatment

Clinically, the stenosis at the beginning of the first segment of the vertebral artery is most common, and endometrial resection or bypass surgery is feasible. The third and fourth segments are followed by endometrial resection, but extracranial-intracranial arterial anastomosis is often performed. The second segment of stenosis is caused by osteophyte compression caused by atherosclerosis or cervical degeneration. The former requires endometrial resection or bypass surgery, and the latter requires resection of the articulation of the hook vertebrae.

2. Vertebral artery-common carotid artery end-to-side anastomosis

(1) Indications Subclavian artery steal syndrome; Occlusion of the vertebral artery at one side of the vertebral artery is incomplete due to stenosis, occlusion, or dysplasia on the contralateral side, resulting in insufficient vertebral-basal artery blood supply.

(2) Precautions The thymic duct or left lymphatic duct in the triangular area consisting of the jugular vein and subclavian vein should be ligated in time to prevent the formation of chylus fistula or chylous cyst; when protecting the right vertebral artery, care should be taken to protect the esophagus, The recurrent laryngeal nerve in the trachea and tracheoesophageal sulcus, so as not to cause paralysis of the ipsilateral vocal cords.

3. Vertebral artery-vein transplantation-subclavian artery (common carotid artery) bypass

4. Vertebral artery endarterectomy

(1) The choice of method usually refers to the endometrial resection of the vertebral artery. The distal end (intracranial) endometrial resection via the far lateral suboccipital approach has also been reported. It has a good effect on the prevention of ischemic stroke, but The operation is difficult, and the number of cases is about 10% of the internal carotid artery.

(2) Indications Those with narrow vertebral artery origin and symptoms of ischemic vertebrobasilar system; Asymptomatic unilateral vertebral-basal artery severe stenosis, which is about to completely occlude and cause Wallenberg syndrome; Arterial stenosis with contralateral vertebral artery and / or carotid artery stenosis causing ischemic symptoms.

5. Vertebral artery decompression

(1) Indications Narrow or occlusion of the second segment of the vertebral artery (inner transverse process hole) caused by cervical osteophytes causes insufficient blood supply to the vertebral-basal artery, especially when the neck is turned to a certain position. Symptoms of arterial insufficiency even catastrophic, and immediately recovered after leaving this position, and DSA saw vertebral artery narrow at the transverse process hole or curved at the intervertebral space.

(2) Anterior oblique muscle fiber bands can be released at the level of C6 transverse foramen in the vertebral artery. Individuals with osteophytes can perform single or multiple transforaminal osteotomy decompression through the anterior or lateral approach during the arterial stroke of the C6 to C2 transverse foramen segment and pay attention to resection of the periosteum around the vertebral artery to avoid recurrence.

6. Intracranial-extracranial approach

(1) Indications of occipital artery-inferior cerebellar arterial anastomosis : arterial stenosis or occlusion in the proximal segment of the PICA branch of the vertebral artery, with symptoms of brain stem ischemia; authors must be clamped during vertebral artery-basal aneurysm surgery To close the origin of the posterior inferior cerebellar artery, this bypass technique is required to maintain blood supply to the brain stem from the posterior inferior cerebellum.

(2) Indications for superficial temporal artery-superior cerebellar artery anastomosis : narrowing of the middle basilar artery, causing brain stem ischemia.

Vertebral-basal artery insufficiency prognosis

1. The mortality of the extracranial vertebral artery vascular reconstruction surgery is 1%, the incidence of neurological dysfunction is 2%, and the incidence of complications is high in patients with unstable neurological symptoms, progressive cerebral ischemia and stroke during development.

2. The overall disability rate of vertebrobasilar artery disease was 5%, and the mortality was 3%.