The cerebellopontine angle (CPA) ( la, angulus cerebellopontinus) is located between the

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

and the

pons The pons (from Latin , "bridge") is part of the brainstem that in humans and other bipeds lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum. The pons is also called the pons Varolii ("bridge of Va ...

. The cerebellopontine angle is the site of the cerebellopontine angle cistern one of the subarachnoid cisterns that contains

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

, arachnoid tissue,

cranial nerves Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and f ...

, and associated vessels. The cerebellopontine angle is also the site of a set of

neurological Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal ...

disorders known as the cerebellopontine angle syndrome.

Structure

The cerebellopontine angle is formed by the cerebellopontine fissure. This fissure is made when the cerebellum folds over to the pons, creating a sharply defined angle between them. The angle formed in turn creates a subarachnoid cistern, the cerebellopontine angle cistern. The

pia mater Pia mater ( or ),Entry "pia mater"
in
arachnoid mater The arachnoid mater (or simply arachnoid) is one of the three meninges, the protective membranes that cover the brain and spinal cord. It is so named because of its resemblance to a spider web. The arachnoid mater is a derivative of the neural c ...

continues across the divide so that the subarachnoid space is dilated at this area, forming the cerebellopontine angle cistern. The

anterior inferior cerebellar artery The anterior inferior cerebellar artery (AICA) is one of three pairs of arteries that supplies blood to the cerebellum. It arises from the basilar artery on each side at the level of the junction between the medulla oblongata and the pons in the ...

(AICA) is the principal vessel of the cerebellopontine angle. It also contains two

– the

vestibulocochlear nerve The vestibulocochlear nerve or auditory vestibular nerve, also known as the eighth cranial nerve, cranial nerve VIII, or simply CN VIII, is a cranial nerve that transmits sound and equilibrium (balance) information from the inner ear to the bra ...

and the

facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...

; the cerebellar flocculus and the lateral recess of the

fourth ventricle The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ve ...

Clinical significance

Tumours can arise in the cerebellopontine angle. Four out of five of these tumours are

vestibular schwannoma A vestibular schwannoma (VS), also called acoustic neuroma, is a benign tumor that develops on the vestibulocochlear nerve that passes from the inner ear to the brain. The tumor originates when Schwann cells that form the insulating myelin sheath o ...

s (commonly known as ''acoustic neuromas''). Others found include: * Arachnoid cyst *

Facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...

tumour *

Lipoma A lipoma is a benign tumor made of fat tissue. They are generally soft to the touch, movable, and painless. They usually occur just under the skin, but occasionally may be deeper. Most are less than in size. Common locations include upper back, ...

Meningioma Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing o ...

Schwannoma A schwannoma (or neurilemmoma) is a usually benign nerve sheath tumor composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral nerves. Schwannomas are homogeneous tumors, consisting only of Schwann cells ...

of other cranial nerves (e.g. CN V >VII>IX, X, XI) *

Metastasis Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...

Intracranial epidermoid cyst Intracranial epidermoid cysts develop in the early embryonic phases. The cysts develop when epithelial cells are confined with cells that form the brain. Signs and symptoms Review of past cases, patients often do not exhibit many symptoms or obtai ...

References

External links

* https://web.archive.org/web/20110720103743/http://www.path.utah.edu/casepath/PM%20Cases/PMCase7/PMCase7Part4.htm Neuroanatomy {{neuroanatomy-stub