Neoplastic meningitis

Neoplastic or malignant meningitis, also called carcinomatous meningitis, leptomeningeal carcinoma, leptomeningeal carcinomatosis, leptomeningeal metastasis, meningeal carcinomatosis, meningeal metastasis, and meningitis carcinomatosa, is the development of meningitis due to infiltration of the subarachnoid space by cancerous cells. Malignant cells come from primary cancer such as breast cancer or from a primary brain tumor like medulloblastoma. Neoplastic Meningitis (NM) was first reported in the 1870s with the most common cause being breast cancer, lung cancer, and malignant melanoma. Neoplastic or malignant meningitis, also called carcinomatous meningitis, leptomeningeal carcinoma, leptomeningeal carcinomatosis, leptomeningeal metastasis, meningeal carcinomatosis, meningeal metastasis, and meningitis carcinomatosa, is the development of meningitis due to infiltration of the subarachnoid space by cancerous cells. Malignant cells come from primary cancer such as breast cancer or from a primary brain tumor like medulloblastoma. Neoplastic Meningitis (NM) was first reported in the 1870s with the most common cause being breast cancer, lung cancer, and malignant melanoma. 3 affected domains of neurological function: Signs reported Other symptoms that are less common are dementia, autonomic dysfunction, cranial nerve abnormalities, spinal symptoms such as limb weakness and paresthesia, and bowel and bladder dysfunction. Diplopia is the most common symptom of cranial nerve dysfunction. Trigeminal sensory or motor loss, cochlear dysfunction, and optic neuropathy are also common findings. Spinal signs and symptoms include weakness, dermatomal or segmental sensory loss, and pain in the neck, back, or following radicular patterns. NM diffused infiltration of tumor cells into the subarachnoid space may be associated with increased intracranial pressure, signs ofmeningeal irritation, and damage to the cranial and spinal nerve roots. NM is a secondary cancer meaning that it is the result of neoplastic cells that have metastasized from a primary cancer site. These cancers develop an enzyme that is able to break down blood vessels at a microscopic level. These cells enter the blood vessels and travel across the body. Once the brain is reached, they break down the blood–brain barrier to enter the Cerebrospinal Fluid (CSF). There the cancerous cells seed and disseminate into the leptomeninges which are composed of the arachnoid and the pia. The CSF continues to carry neoplastic cells through the brain tracts and spreads the cancerous cells. Since NM is a result of primary cancer metastasis and can develop from primary brain tumors or parenchymal metastasis when tumor cells are lodged in small central nervous system (CNS) vasculature, causing local ischemia and vessel damage which result in tumor spillage into the Virchow-Robin spaces and providing access to the subarachnoid space. Infiltration happens most often at the base of the brain, dorsal surface, and especially at the cauda equina (bundle of nerves occupying spinal column)which is largely due to the effect of gravity. Once in the CSF, malignant cells can extend along the membrane surfaces or spread freely in the CSF and attach to other locations. These cells have the ability to penetrate the pial membrane and invade the spinal cord and cranial nerves. Infiltration from the subarachnoid space into the spinal cord occurs primarily along the perivascular tissues that surround blood vessels at the brain entrance. Infiltration from the anterior median fissure, a 3mm deep furrow on the anterior side of the spinal cord, to the anterior horn of the spinal cord, the ventral grey matter of the spinal cord, is found along the central artery. Direct infiltration of the nerve roots is also observed, mostly from the dorsal roots (the afferent sensory root of the spinal nerve) than the ventral roots (the efferent motor root of a spinal nerve).