Racemose neurocysticercosis refers to cysts in the subarachnoid space. Arachnoiditis is a broad term denoting inflammation of the meninges and subarachnoid space. The lumbar cistern is part of the subarachnoid space. The needle is then in the subarachnoid space. Cerebrospinal fluid (CSF) flows under the arachnoid in the subarachnoid space. Fibrous scarring can also be a complication within the subarachnoid space. They emerge in the brain and lie in the subarachnoid space. The use of chloroprocaine in the subarachnoid space has been questioned. In mammals, where a subarachnoid space is present, CSF is present in it. There are three anatomic patterns by which the tumor can spread in the subarachnoid space. This leads to hemorrhage in the subarachnoid space and sometimes in brain parenchyma. The meninges divide the spinal canal into the epidural space and the subarachnoid space. These travel in the subarachnoid space and send branches into the spinal cord. A hypodermic needle is used to access the subarachnoid space and fluid collected. CSF circulates in the subarachnoid space (between arachnoid and pia mater).