Neurologist

A non-invasive study that uses sound waves to show the flow in a blood vessel and can be used to determine the degree of narrowing (percent stenosis) of the vessel. A wand is placed on the skin over the vessel that is to be imaged. This study has no risks and is not painful.

Diagnostic test that produces three-dimensional images of body structures using powerful magnets and computer technology rather than X-rays.

An opening into the ventricles of the brain, achieved by inserting a small, thin, hollow catheter. Serves as a means to relieve pressure from the brain and spinal cord.

acalculia "inability to calculate" or difficulty with arithmetic; may be the result of damage to the angular gyrus in the hemisphere dominant for speech and language

Adie’s tonic pupil irregularly dilated pupil exhibiting minimal or no reaction to light, slow reaction to accommodation, and hypersensitivity to pilocarpine; typically idiopathic and most often seen in young women

amygdala telencephalic gray matter structure located in the anterior portion of the medial temporal lobe involved in emotion, cognition and the regulation of autonomic processes; part of the limbic system

ascending tract of Deiters direct pathway (lying just lateral to the medial longitudinal fasciculus) from the vestibular nuclei to the ipsilateral medial rectus subnucleus; clinical significance of this pathway is unclear

astrocytes CNS glia that function to orient neuroblast migration in the cerebral and cerebellar hemispheres, provide mechanical support, react to injury, insulate synaptic surfaces, provide a source and sink for extracellular potassium, and uptake neurotransmitters to terminate their synaptic action astrocytoma most common central nervous system tumor derived from astrocytes astrocytosis reaction of astrocytes to neuronal injury characterized by an increase in the number and size of astrocytes (primary reaction) and cytoplasmic changes including increased glial filaments and glassy eosinophilic cytoplasm followed by formation of a dense gliotic scar (secondary reaction)

axonal spheroid stereotypic axonal response to injury consisting of marked swelling due to accumulation of materials undergoing axonal transport

The barrier that exists between the blood and the cerebrospinal fluid, which prevents the passage of various substances from the bloodstream to the brain.

Extrusion of the central portion of an intervertebral disc through the outer cartilaginous ring. The material can compress the spinal cord or nerves in or exiting the spinal canal.

Gland at base of the brain that secretes hormones into the blood stream. Those hormones then regulate other glands including the thyroid, adrenals and gonads. The "Master Gland".

The cavities or chambers within the brain that contain the cerebrospinal fluid. There are two lateral ventricles and midline third and fourth ventricles.

Operative method of strengthening and limiting motion of the spinal column that can be performed with a variety of metal instruments and bone grafts or bone grafts alone.

adrenoleukodystrophy typically X-linked recessive demyelinative disease ± adrenal dysfunction due to accumulation of very long chain fatty acids

amaurosis fugax temporary loss of vision in one eye due to impairment of blood supply through the internal carotid artery or the ophthalmic artery

anterior commissure one of the three major groups of commissural fibers that courses through the basal ganglia and cross the midline in the anterior forebrain to interconnect the olfactory bulbs, amygdala, and hippocampal areas, among others

asomatognosia inability to recognize part of one’s own body, seen with nondominant parietal lobe (or less commonly premotor cortex) lesions

axon long, slender projection from the neruonal cell body that is specialized for the conduction of information encoded in the form of action potentials

Often used as equivalent to stroke, this is a condition in which there is bleeding into an organ or blood flow to an organ has ceased.