Cerebral Ventriculitis: Inflammation of CEREBRAL VENTRICLES.Cerebral Ventricles: Four CSF-filled (see CEREBROSPINAL FLUID) cavities within the cerebral hemispheres (LATERAL VENTRICLES), in the midline (THIRD VENTRICLE) and within the PONS and MEDULLA OBLONGATA (FOURTH VENTRICLE).Encephalitis: Inflammation of the BRAIN due to infection, autoimmune processes, toxins, and other conditions. Viral infections (see ENCEPHALITIS, VIRAL) are a relatively frequent cause of this condition.Hydrocephalus: Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, INTRACRANIAL HYPERTENSION; HEADACHE; lethargy; URINARY INCONTINENCE; and ATAXIA.Ventriculostomy: Surgical creation of an opening in a cerebral ventricle.Spirurida: An order of nematodes of the subclass SECERNENTEA. Characteristics include ventral or caudoventral papillae and an esophagus divided into anterior muscular and posterior glandular parts.Cerebrospinal Fluid Shunts: Tubes inserted to create communication between a cerebral ventricle and the internal jugular vein. Their emplacement permits draining of cerebrospinal fluid for relief of hydrocephalus or other condition leading to fluid accumulation in the ventricles.Cerebral Ventriculography: Radiography of the ventricular system of the brain after injection of air or other contrast medium directly into the cerebral ventricles. It is used also for x-ray computed tomography of the cerebral ventricles.Ventriculoperitoneal Shunt: Surgical creation of a communication between a cerebral ventricle and the peritoneum by means of a plastic tube to permit drainage of cerebrospinal fluid for relief of hydrocephalus. (From Dorland, 28th ed)Meningitis: Inflammation of the coverings of the brain and/or spinal cord, which consist of the PIA MATER; ARACHNOID; and DURA MATER. Infections (viral, bacterial, and fungal) are the most common causes of this condition, but subarachnoid hemorrhage (HEMORRHAGES, SUBARACHNOID), chemical irritation (chemical MENINGITIS), granulomatous conditions, neoplastic conditions (CARCINOMATOUS MENINGITIS), and other inflammatory conditions may produce this syndrome. (From Joynt, Clinical Neurology, 1994, Ch24, p6)Meningitis, Fungal: Meningitis caused by fungal agents which may occur as OPPORTUNISTIC INFECTIONS or arise in immunocompetent hosts.Brain Abscess: A circumscribed collection of purulent exudate in the brain, due to bacterial and other infections. The majority are caused by spread of infected material from a focus of suppuration elsewhere in the body, notably the PARANASAL SINUSES, middle ear (see EAR, MIDDLE); HEART (see also ENDOCARDITIS, BACTERIAL), and LUNG. Penetrating CRANIOCEREBRAL TRAUMA and NEUROSURGICAL PROCEDURES may also be associated with this condition. Clinical manifestations include HEADACHE; SEIZURES; focal neurologic deficits; and alterations of consciousness. (Adams et al., Principles of Neurology, 6th ed, pp712-6)Meningitis, Bacterial: Bacterial infections of the leptomeninges and subarachnoid space, frequently involving the cerebral cortex, cranial nerves, cerebral blood vessels, spinal cord, and nerve roots.Cerebrospinal Fluid: A watery fluid that is continuously produced in the CHOROID PLEXUS and circulates around the surface of the BRAIN; SPINAL CORD; and in the CEREBRAL VENTRICLES.Cerebral Arteries: The arterial blood vessels supplying the CEREBRUM.Tuberculosis, Meningeal: A form of bacterial meningitis caused by MYCOBACTERIUM TUBERCULOSIS or rarely MYCOBACTERIUM BOVIS. The organism seeds the meninges and forms microtuberculomas which subsequently rupture. The clinical course tends to be subacute, with progressions occurring over a period of several days or longer. Headache and meningeal irritation may be followed by SEIZURES, cranial neuropathies, focal neurologic deficits, somnolence, and eventually COMA. The illness may occur in immunocompetent individuals or as an OPPORTUNISTIC INFECTION in the ACQUIRED IMMUNODEFICIENCY SYNDROME and other immunodeficiency syndromes. (From Adams et al., Principles of Neurology, 6th ed, pp717-9)