What are the branches of the basilar artery?

Blood circulation is very important for the human body. Once there is a problem with blood circulation, it may cause many diseases. For example, the well-known diseases such as gills and atherosclerosis may be related to blood circulation. There are many arteries in the human body. Arteries have different structures and branches, including the basilar artery. Let's learn about the branches of the basilar artery.

Branches of the basilar artery:

The basilar artery is the main blood vessel in the brain. After the left and right vertebral arteries enter the cranial cavity through the foramen magnum, they rise along the anterolateral surface of the medulla oblongata and merge at the midline of the lower edge of the pons. Often called the vertebral-basilar arterial system. The branches of this system within the cranial cavity supply blood to the spinal cord, brainstem (medulla oblongata, pons, midbrain), cerebellum, and posterior diencephalon. At the end of this system, it divides into two posterior cerebral arteries, which supply part of the temporal and occipital lobes of the cerebral hemispheres.

Basilar artery is an unpaired artery formed by the merging of two vertebral arteries. It runs underneath the pons and divides into two posterior cerebral arteries, supplying the pons, cerebellum, posterior part of the brain, and inner ear.

The basilar artery refers to the blood flow to the brain which is supplied by four arteries, namely two internal carotid arteries and two vertebral arteries. The former is often called the anterior circulation, while the latter is called the posterior circulation. The basilar artery system consists of the vertebral artery trunk, the basilar artery trunk, and their branches. Most of the vertebral arteries originate from the subclavian artery, while a few may originate from the aorta. They ascend in the transverse foramen of the C6-C1 cervical vertebrae, bypass the atlantocele from the back and enter the skull through the foramen magnum. Within the skull, the vertebral artery is located on the ventral surface of the lower part of the medulla oblongata. Two vertebral arteries merge into the basilar artery on the caudal side of the pons. The branches of the vertebral artery include the posterior spinal artery, anterior spinal artery and posterior inferior cerebellar artery. In addition, there are meningeal branches that supply the meninges of the posterior cranial fossa (including the tentorium cerebelli). The vertebral artery is generally divided into three segments, namely the intravertebral segment, the atria and the intracranial segment.

Basilar artery occlusive syndrome

Compared with anterior circulation stroke, posterior circulation stroke has a longer prodromal period, which may last for days or months. The most common prodromal symptoms include dizziness and nausea, followed by headache and neck pain. Dizziness and vertigo are the most common early symptoms of BAO, but they are nonspecific and need to be differentiated from peripheral vertigo.

The head impulse-nystagmus-torsion (HINTS) examination is a sensitive assessment tool that helps differentiate central from peripheral vertigo. The ABCD2 score can also help identify higher-risk patients. The probability of a vertigo patient with a score > 6 or 7 being diagnosed with stroke is approximately 27%. The lower the score, the lower the possibility of stroke.

Patients with vertigo who also had at least one other neurological symptom were more likely to be diagnosed with stroke than those with isolated vertigo. Oculomotor paralysis, oropharyngeal dysfunction, ataxia, and limb weakness are the most common symptoms. Other symptoms include abnormal eye movements, asymmetric pupils, respiratory disturbances, dysmetria, and altered level of consciousness. Symptoms vary in severity, from isolated cranial nerve palsies to quadriplegia, locked-in syndrome, and even coma.

One of the most lethal manifestations of BAO is occlusion of the mid-basilar artery, resulting in bilateral pontine ischemia; these patients present with a fully conscious "comatose" state, quadriplegia, and only vertical eye movements. This "locked-in syndrome" has an acute mortality rate of about 75%. Occlusion of the distal tip of the BA can result in another serious syndrome because both the SCA and PCA arise from this site. This “tip of the basilar artery syndrome” may lead to ischemia of the midbrain, thalamus, inferior temporal lobe, and occipital lobe.