subarahnoidsesse

Subarahnoidsesse appears to be a misspelling or nonstandard variant of the subarachnoid space, a key anatomical feature of the central nervous system. The subarachnoid space is the cerebrospinal fluid–filled area between the arachnoid mater and the pia mater that surrounds the brain and spinal cord.

Anatomy and contents

The subarachnoid space envelops the entire brain and spinal cord, following their contours and extending into cisterns such as the chiasmatic, ambient, and interpeduncular cisterns. It contains cerebrospinal fluid (CSF) and blood vessels, including major arteries and veins that supply the CNS. Arachnoid trabeculae span the space, connecting the arachnoid to the pia and helping to maintain its structure.

Functions

The space plays a crucial role in cushioning the brain within the skull, providing a reservoir for CSF, and serving as a conduit for the circulation and resorption of CSF. It also houses the arterial and venous networks that supply the brain and spinal cord.

CSF circulation and reabsorption

CSF is produced primarily by choroid plexuses in the cerebral ventricles, flows from the ventricles into the subarachnoid space, circulates around the brain and spinal cord, and is eventually reabsorbed into the venous bloodstream via arachnoid granulations into the dural venous sinuses.

Clinical relevance

Subarachnoid hemorrhage, most commonly from rupture of an intracranial aneurysm or trauma, fills the subarachnoid space with blood and can be life-threatening. Symptoms include a sudden severe headache, neck stiffness, and altered consciousness. Diagnosis often begins with a CT scan; if inconclusive, a lumbar puncture may detect xanthochromia. Complications can include vasospasm and hydrocephalus. Infections such as meningitis can involve the subarachnoid space as well.

Terminology

The term subarachnoid space is sometimes referred to in broader discussions of the meninges as part of the leptomeninges, which include the arachnoid and pia mater.