Clinical Neurology Glossary
100 terms total — 24 showing — Last updated 15 Sep 2026
hemianopia
Loss of vision in half the visual field, typically indicating damage to the visual pathways posterior to the optic chiasm.
abulia
A neurological condition characterized by lack of will or motivation to act, distinct from depression or physical inabil...
agrammatism
Language disorder characterized by the loss of ability to construct grammatically correct sentences, typically affecting...
akathisia
A movement disorder characterized by a subjective feeling of inner restlessness and an inability to sit still.
akinesia
Complete absence or loss of voluntary movement, distinct from bradykinesia (slowness) or hypokinesia (reduced movement).
akinetic mutism
A neurological condition characterized by profound apathy and lack of spontaneous movement or speech despite preserved c...
alien hand syndrome
Neurological disorder where one hand performs purposeful movements without conscious control or intention by the patient...
allodynia
Pain response to normally non-painful stimuli, often indicating dysfunction in pain processing pathways.
aneurysm
Localized dilation or ballooning of a blood vessel wall, most critically concerning when occurring in cerebral arteries.
angiogram
A radiographic study using contrast material to visualize blood vessels in the brain and neck for diagnosing vascular ab...
anisocoria
Unequal pupil sizes, which may indicate neurological pathology or be a benign anatomical variant.
anosognosia
A neurological condition in which patients are unaware of or deny their own neurological deficits or disabilities.
aphasia
Language disorder caused by brain damage, affecting speech production or comprehension.
apraxia of speech
Motor speech disorder affecting the ability to plan and coordinate the precise movements needed for speech production.
astereognosis
Inability to identify objects by touch alone without visual input, indicating parietal lobe dysfunction.
asterixis
A tremor consisting of involuntary jerking movements caused by brief lapses in muscle tone, often described as a "flappi...
astrocytoma
A primary brain tumor arising from astrocytes, ranging from low-grade to high-grade malignant forms including glioblasto...
ataxia
Lack of muscle coordination affecting movement, balance, and speech.
athetosis
Slow, writhing, involuntary movements typically affecting the distal extremities, often seen in cerebral palsy.
aura
A subjective sensory, motor, or psychic phenomenon that precedes or accompanies a seizure, particularly in focal epileps...
Babinski sign
An abnormal plantar reflex indicating upper motor neuron dysfunction, characterized by upward movement of the great toe.
ballismus
A hyperkinetic movement disorder characterized by violent, flinging movements of the limbs.
bradykinesia
Slowness of voluntary movement, characteristic of Parkinson's disease.
bradyphrenia
Slowness of thought processes and mental responses, often seen in subcortical dementias.
cavernoma
A benign vascular malformation consisting of abnormal blood vessels with a characteristic "popcorn" appearance on MRI.