Neurological Glossary

Abulia

Loss of will, impulse, and decision-making ability.

• Ford
• BMW
• Fiat

Acalculia

Inability to do the most simple calculations.

Acupuncture

A traditional Chinese system of healing in which symptoms are relieved by having thin metal needles inserted into selected points beneath the skin. The needles may be stimulated either by rotation or by an electric current and are then removed. If in any doubt about your condition, you should consult your doctor.

Acute stroke

The critical stage of stroke, starting at the onset of symptoms and lasting until the patient's condition is stabilised and they enter recovery

Action tremor

Tremor that appears during movement of the affected body part

Adaptations

Modifications to the built environment designed to assist access, mobility and self reliance; such as ramps, rails, roll-in showers and stair lifts.

ADL

Activities of Daily Living. The routine tasks that we all have to perform to live independently, such as washing, dressing, using the toilet, bathing, walking and climbing stairs.

Afferent

Sensory pathway proceeding toward the CNS from the peripheral receptor organs

AFO

Ankle Foot Orthosis. A brace used to stretch the Achilles tendon. This is usually made of thin, light plastic material, which the orthosis is individually moulded and will require replacement as the child grows.

Agnosia

Inability to recognise objects or sounds due to lack of perceptive capacity, although general intelligence is normal.

• Auditory agnosia, where the person's hearing is normal but he is unable to understand what words mean.
• Finger agnosia (sometimes used as a test for cerebral palsy), where a person is unable to identify individual fingers when, for example, they are touched by another person
• Tactile agnosia, where a person is unable to identify familiar objects by touch alone although he is aware that he is touching something.
• Visual agnosia, where a person is able to see but unable to express ideas in words.

Aphasia

A specific defect to brain function which leads to:

• Expressive aphasia, when a person is unable to express ideas in words.
• Receptive aphasia, when a person is unable to understand spoken language.

Agraphia

Inability to express thoughts in writing or by drawing.

Akinesia

Paucity of movement

Akinetic mutism

Disorder of consciousness characterized by periods of sleep and periods of wakefulness during which the patient lies with eyes open but is unresponsive, mute, and immobile; often due to frontal lobe damage.

Alexia

Inability to read, usually due to a lesion of dominant occipitotemporal cortex

Alien hand syndrome

Syndrome characterized by the involuntary movement of a single upper limb in conjunction with the experience of estrangement from or personification of the movements of the limb; often seen in corticobasal degeneration

Allodynia

Condition in which an ordinarily painless stimulus is experienced as being painful

Alpha motor neurons

Large motor neurons that innervate extrafusal skeletal muscle fibers

Alexia

Inability to read.

Alignment

Straight position.

Alzheimer's disease

Most common cause of dementia in older adults; a neurodegenerative disease characterized by the gradual loss of cognitive ability in association with the neuropathological findings of abnormal protein aggregates (neuritic plaques and neurofibrillary tangles) and neuron loss in the cerebral cortex

Amaurosis Fugax

A temporary loss of vision in one eye due to a blood clot blocking the flow of blood to the eye. There is complete recovery within 24 hours.

Amblyopia

Developmental abnormality in which a child fails to develop sharp visual acuity

Ambulatory

Able to walk.

Amnesia

Loss of memory.

Amyotrophic lateral sclerosis

(Lou Gehrig's disease) inexorably progressive and fatal disease of unknown cause characterized by slowly progressive degeneration of upper and lower motor neurons

Analgesia

Loss of pain sensation

Anencephaly (aprosencephaly)

CNS malformation involving failure of closure of the cephalic end of the neural tube

Aneurysm (brain aneurysm

cerebral aneurysm)

Anomia

Inability to name objects or to recognize written or spoken names of objects

Anosmia

Loss of sense

Anoxia

Lack of oxygen to the brain or other vital organs

Anterior cerebral artery

A branch of the internal carotid artery; supplies blood to the medial aspect of the cerebral cortex (leg area predominant)

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

Anterior communicating artery

Branch of the internal carotid artery that joins together the paired anterior cerebral arteries

Anterior cord syndrome

Spinal cord injury syndrome associated with damage to the anterior 2/3 of the spinal cord

Anterior cranial fossa

Portion of the internal base of the skull housing the frontal lobes

Anterior horn (ventral horn)

Gray matter in the front of the spinal cord that contains motor_neurons

Anton's syndrome

Form of cortical blindness in which the patient is unaware of/denies the visual impairment; due to a lesion of the occipital lobe extending from primary visual cortex into visual association cortex

Aphasia

Inability to use language. It can either be a problem understanding language (receptive) or speaking it (expressive). People are often affected by both sorts. See: Dysphasia.

Aphemia

Inability to speak words despite being able to make other sounds

Aphonia

Complete loss of voice

Aprasia

An inability to perform purposeful movements

Apraxia

The inability to control and co-ordinate movements or carry out complex tasks when requested

Arachnoid

Middle layer of the meninges covering the brain and spinal cord

Arachnoid granulations (arachnoid villi)

Branched tufts of arachnoid that project through the dura mater into the venous sinuses and function to return CSF to the systemic circulation

Arachnoid villi

Diverticula of the arachnoid mater in the subarachnoid space that extend into the veins and venous sinuses of the dura; a major pathway for the drainage of cerebrospinal fluid and transport across the endothelium into the blood.

AROM

Active Range of Movement.

Aromatherapy

A therapy which employs aromatic plant-derived essential oils

Arcuate fasciculus

Pathway connecting Wernicke's area in the posterior left superior temporal gyrus to Broca's area in the left inferior frontal lobe; lesion results in impaired repetition

Area postrema

Chemoreceptor trigger zone for vomiting that is located on the dorsal surface of the medulla

Argyll-Robertson pupil

Pupil exhibiting light-near dissociation due to a lesion in the midbrain periaqueductal gray matter caused by tertiary syphilis

Arousal

Abrupt change from sleep to wakefulness

Arteriovenous malformation

A tangled collection of abnormal arteries and veins Click here for more information from the National Institute for Neurological Disorders and Stroke

Arteritis

Inflammation of an artery

Arthrokinetic nystagmus

Nystagmus induced by passive rotation of the arm of a stationary subject seated in total darkness inside a rotating drum

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

Aseptic meningitis

Syndrome characterized by headache

Associated reactions

Movements of body parts other than the ones that are intended to move

Association cortex

Cortical areas involved in higher order processing of sensory information and integration of multiple sensory and sensorimotor modalities

Astasia

Inability to stand because of motor incoordination

Astasia-abasia

Functional stance and gait characterized by bizarre movements

Asteriognosis

Inability to recognise objects by touch.

Asterixis

Sudden palmar flapping movement of the hands at the wrists; indicative of metabolic encephalopathy

Astrocytes

CNS glia that function to orient neuroblast migration in the cerebral and cerebellar hemispheres

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)

Asymmetrical

Difference between two similar parts.

Ataxia

Lack of balance and uncoordinated movement.

Athetosis

Involuntary

Atonia

Loss of muscle tone

Atonic seizure (drop attack)

Generalized seizure characterized by sudden loss of muscle tone and strength; may cause the head to drop suddenly

Attention span

The length of time a person is able to concentrate on a given task.

Attention problems

Inability to sustain concentration because of competing stimuli or thoughts.

Athetosis

The term used to indicate a particular sort of uncontrollable movement and result from a particular brain lesion. It is present in the 'athetoid' type of cerebral palsy.

ATNR

Asymmetrical tonic neck reaction. When the face is turned to one side

Auditory agnosia

Failure to recognise specific sounds

Aura

Warning symptom

Automatism

Mechanical

Autonomic

Pertaining to the autonomic nervous system

Autonomic nervous system

Part of the peripheral nervous system that regulates visceral function and homeostasis independent of voluntary control.

Autoregulation

Physiological process by which blood vessels change caliber to maintain constant cerebral blood flow over a wide range of cerebral perfusion pressures.

Ax

Assessment.

Axial

Transverse plane producing a cross-section of the body or head.

Axial Skeleton

The bones of the skull

Axon

Long

Axonal degeneration

Neuropathic process resulting in degeneration of the axon and its myelin sheath; preferentially involves the distal portion of the axon.

Axonal spheroid

Stereotypic axonal response to injury consisting of marked swelling due to accumulation of materials undergoing axonal transport.