Gamma knife: Equipment that precisely delivers a concentrated dose of radiation to a predetermined target using gamma rays. More about stereotactic radiosurgery.
Glasgow coma scale (GCS): The most widely used system of classifying the severity of head injuries or other neurologic diseases.
Glasgow outcome scale: A widely used system of classifying outcome after head injury or other neurologic diseases.
Glia (glial cells): The major support cells of the brain. These cells are involved in the nutrition and maintenance of the nerve cells.
Glioblastoma: A rapidly growing tumor composed of primitive glial cells, mainly arising from astrocytes. More about glioblastoma multiforme (GBM).
Glioma: A tumor formed by glial cells.
Globus pallidus: Part of the basal ganglia, which are brain cells that lie deep in the brain.
Greater occipital nerve: A branch of the second cervical spinal nerve that innervates the middle portion of the occipital area (at the back of the skull) of the scalp.