Subaraknoidinen

Subaraknoidinen is an adjective used in some languages to describe anything related to the subarachnoid space, the interval between the arachnoid mater and the pia mater surrounding the brain and spinal cord. The subarachnoid space is continuous over the entire central nervous system and is filled with cerebrospinal fluid (CSF). It contains small arteries, veins and the cisterns through which CSF circulates between the ventricular system and the surrounding structures.

Anatomy and function: The subarachnoid space extends from the base of the brain to the spinal canal. It houses the major cerebral vessels and serves as a reservoir through which CSF flows, enabling buoyancy, protection, and nutrient transport for the brain and spinal cord. CSF is produced mainly by the choroid plexus within the ventricles, circulates through the ventricular system, enters the subarachnoid space via the foramina of Magendie and Luschka, and is absorbed into venous blood through arachnoid granulations.

Clinical relevance: The subarachnoid space is central to several disorders. Subarachnoid hemorrhage, typically caused by rupture of a cerebral aneurysm or arteriovenous malformation, presents with a sudden severe headache and possible loss of consciousness; diagnosis relies on imaging and, if needed, analysis of CSF for xanthochromia. Infections such as meningitis involve inflammation of the subarachnoid space. Obstruction of CSF absorption or flow within this space can contribute to hydrocephalus. Imaging modalities like CT and MRI, along with lumbar puncture when appropriate, aid in evaluation.

Note: Subaraknoidinen as a form of the term appears in Finnish or related languages; in English, the equivalent term is subarachnoid.