Neurological Glossary

Neurological terms are often complicated and difficult to understand. The following glossary defines a variety of terms to help you understand neurological terminology:

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(Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy); the most common form of hereditary stroke disorder. A progressive illness

    Calcarine cortex

    Primary visual cortex located in the occipital lobe (striate area 17)


      Tiny blood vessels.

        Cardio-embolic stroke

        Stroke due to a clot that has formed in the heart and travelled to the brain.

          Carotid sinus

          Arterial baroreceptor located at the bifurcation of the external and internal carotid arteries that regulates arterial pressure and heart rate in response to changes in stretch and transmural pressure


            Referring to menses; with regard to women with epilepsy or migraine


              Sudden loss of postural tone

                Cauda equina

                ('horse's tail') collection of intradural spinal nerve roots caudal to the spinal cord that supply the lower limbs and pelvis; since this structure is part of the peripheral nervous system


                  Toward the tail


                    Portion of the basal ganglia that lies in the floor of the lateral ventricle

                      Cavernoma (cavernous malformation)

                      Vascular malformations composed primarily of large venous channels without a clear-cut arterial component

                        Cavernous sinus


                          Central chromatolysis

                          Regenerative response to axonal injury consisting of neuronal swelling

                            Central cord syndrome

                            Spinal cord injury syndrome associated with damage to the central portion of the spinal cord characterized by bilateral weakness of distal>proximal muscles in the arm>leg

                              Central herniation

                              Downward displacement of the cerebral hemispheres pushing the diencephalon and midbrain through the tentorial notch; symptoms classically follow a rostrocaudal deterioration

                                Central nervous system (CNS)

                                Brain and spinal cord

                                  Central post-stroke pain (CPSP)

                                  Also called thalamic pain or neuropathic pain syndrome; where all stimuli cause a pain reaction

                                    Central sulcus

                                    Prominent sulcus on the dorsolateral aspect of the cerebral hemispheres formed by the precentral and postcentral gyri; defines the boundary between the frontal and parietal lobes

                                      Centrally-acting drugs

                                      Medicines that act on the brain or central nervous system

                                        Centrum semiovale

                                        Expansive region of white matter in the dorsal core of the frontal and parietal lobes

                                          Cerebral amyloid angiopathy (congophilic angiopathy)

                                          Vascular disorder in which beta amyloid protein is deposited within the media and adventitia of small- to medium-sized meningeal and cortical blood vessels

                                            Cerebral aqueduct

                                            Portion of the ventricular system that lies in the dorsal midbrain and connects the third and fourth ventricles

                                              Cerebral arteriosclerosis

                                              Thickening and hardening of the arteries within the brain.

                                                Cerebral atherosclerosis

                                                Build-up of fatty deposits in the inner wall of cerebral arteries; form of cerebral arteriosclerosis

                                                  Cerebral atrophy

                                                  The shrinking of the brain or brain cells.

                                                    Cerebral autosomal dominant arteriopathy with subcortical infarcts & leukoencephalopathy (CADASIL)

                                                    Familial arterial disease of the brain caused by mutations in the Notch3 gene and consisting of recurrent subcortical strokes starting in midadult life

                                                      Cerebral cortex

                                                      The thin outer layer of the cerebrum

                                                        Cerebral haemorrhage

                                                        Bleeding from a ruptured blood vessel in the brain.

                                                          Cerebral hemisphere

                                                          Symmetrical half of the cerebrum as separated by the sagittal sulcus and containing the cerebral cortex

                                                            Cerebral Palsy

                                                            A disorder of movement and posture due to a non-progressive defect or lesion to the immature brain

                                                              Cerebral peduncle (crus cerebri)

                                                              White matter tracts (corticospinal and corticobulbar) on the ventral surface of the midbrain containing the efferent axons of cerebral cortex that project to brainstem and spinal cord

                                                                Cerebral perfusion pressure (CPP)

                                                                Mean arterial pressure (MAP) ' intracranial pressure (ICP)

                                                                  Cerebral salt wasting

                                                                  Centrally-mediated hypovolemic hyponatremia associated with negative sodium balance that occurs in approximately 30-50% of patients with subarachnoid hemorrhage despite their being given maintenance volumes of fluid. Excessive sodium loss is thought to be due to impaired sodium reabsorption in the proximal tubule and may be caused by disruption of sympathetic input to the kidneys

                                                                    Cerebral Thrombosis

                                                                    Formation of blood clot in an artery of the brain


                                                                      Inflammation of the brain

                                                                        Cerebrospinal fluid (CSF)



                                                                          The largest part of the brain

                                                                            Charcot-Bouchard aneurysm

                                                                            Aneurysmal dilation of small intraparenchymal vessels commonly seen in the brains of patients with hypertensive haemorrhage

                                                                              Charcot-Marie-Tooth Disease (CMT)

                                                                              An inherited neurological disorder damaging motor and sensory peripheral nerves and causing muscle weakness and reduced sensation in the legs

                                                                                Charcot joint

                                                                                Progressive destruction and deformity of bone and soft tissue at weight bearing joints due to severe sensory or autonomic neuropathy


                                                                                  Relating to the hand

                                                                                    Chiari malformation

                                                                                    CNS disorder characterized by cerebellar elongation and protrusion through the foramen magnum into the cervical spinal cord. Type I consists of caudal displacement of the medulla and inferior pole of the cerebellar hemispheres through the foramen magnum. Type II=type I + hydrocephalus and lumbosacral spina bifida. Type III involves herniation of the entire cerebellum through the foramen magnum with a cervical spina bifida cystica. Type IV involves cerebellar hypoplasia


                                                                                      A fatty substance made in the liver and also present in some foods




                                                                                          Involuntary movements showing features of both chorea and athetosis

                                                                                            Choroid plexus

                                                                                            Intraventricular structure that secretes cerebrospinal fluid

                                                                                              Choroid plexus papilloma

                                                                                              Histologically benign intracranial tumor of neuroectodermal origin that is most commonly located in a ventricle (lateral>fourth>third)

                                                                                                Chronic daily headache

                                                                                                Headache disorder consisting of frequent headache occurring 15 or more days per month and including headache associated with medication overuse

                                                                                                  Chronic pain

                                                                                                  Pain which persists over a long period of time and is resistant to most medical treatments

                                                                                                    Chronic paroxysmal hemicrania

                                                                                                    Indomethacin-responsive headache disorder characterized by the occurrence of multiple daily attacks lasting 5 to 30 minutes of severe unilateral head pain often associated with autonomic phenomenon (eye tearing


                                                                                                      Developing over months to years; implies gradual deterioration as occurs with degenerative diseases like Alzheimer disease

                                                                                                        Cingulate gyrus

                                                                                                        Cortical component of the limbic system located on the medial aspect of the hemisphere superior to the corpus callosum; involved in emotional and cognitive processing

                                                                                                          Cingulate herniation

                                                                                                          Horizontal displacement of a cerebral hemisphere due to an expanding lesion that forces the cingulate gyrus under the falx cerebri

                                                                                                            Circadian rhythm

                                                                                                            Innate daily fluctuation of physiological or behavioral functions

                                                                                                              Circle of Willis

                                                                                                              The main arterial trunk located at the base of the brain where the two internal carotid arteries and the basilar artery join

                                                                                                                Circulatory problems

                                                                                                                Impairment or malfunction of a part of the circulatory system

                                                                                                                  Constraint-induced Movement Therapy (CIT)

                                                                                                                  An intensive movement rehabilitation programme

                                                                                                                    Claude Syndrome

                                                                                                                    Ipsilateral oculomotor palsy and contralateral ataxia and hemichoreoathetosis due to a dorsal midbrain tegmental lesion affecting the III nerve fascicles


                                                                                                                      Thin plate of gray matter lying in the white matter between the insula and the basal ganglia that modulates cortical activity

                                                                                                                        Clay shoveler's fracture

                                                                                                                        Typically stable fracture through a spinous process due to hyperextension injury

                                                                                                                          Clinical psychologist

                                                                                                                          Health professional who assesses and treats psychological dysfunction

                                                                                                                            Clonic seizure

                                                                                                                            Generalized seizure characterized by jerking movements on both sides of the body


                                                                                                                              Rhythmic contraction relaxation tremor due to cyclic alternations of the spindle stretch reflex and the Golgi tendon organ reflex; indicative of exaggerated stretch reflexes


                                                                                                                                Anti-platelet drug used to stop clots from forming

                                                                                                                                  Cluster headache

                                                                                                                                  Primary headache syndrome characterized by intense


                                                                                                                                    Central nervous system

                                                                                                                                      CNS metastasis

                                                                                                                                      Metastatic tumours typically spread by a haematogenous route and found at the junction between gray matter and white matter where they are trapped by the acute angle branching of the microvasculature


                                                                                                                                        The function of processing information and applying knowledge.

                                                                                                                                          Cognitive functions

                                                                                                                                          Processes requiring thought and intelligence


                                                                                                                                            Ratchety movement due to superimposition of tremor on rigidity

                                                                                                                                              Coital headache

                                                                                                                                              Indomethacin-responsive headache disorder characterized by sudden


                                                                                                                                                State of unarousable unresponsiveness with closed eyes

                                                                                                                                                  Common carotid artery

                                                                                                                                                  Artery that arises from the brachiocephalic artery on the right and from the aortic arch on the left

                                                                                                                                                    Communicating hydrocephalus

                                                                                                                                                    Blockage of CSF flow outside the ventricular system

                                                                                                                                                      Community physiotherapist

                                                                                                                                                      Provides a local or domiciliary service (where patients are housebound) for adults with physical health difficulties or rehabilitation needs. Usually works as part of a team providing assessment and treatment for difficulties with mobility


                                                                                                                                                        Adapting to an impairment in order to perform a task successfully

                                                                                                                                                          Complementary (therapy)

                                                                                                                                                          Various treatments

                                                                                                                                                            Complex partial seizure

                                                                                                                                                            Partial seizure in which consciousness or awareness is impaired; epileptic discharge either originates in limbic structures (hippocampus) or spreads to them from neocortex

                                                                                                                                                              Complex tic


                                                                                                                                                                Computed Tomography (CT)

                                                                                                                                                                The X-ray technique most commonly used to examine the brain. Sometimes referred to as CAT - computed or computerised axial tomography.


                                                                                                                                                                  The ability to direct and focus one's thinking in whatever direction one would intend.


                                                                                                                                                                    Traumatic closed head injury that results in temporary impairment of neurological function


                                                                                                                                                                      Unconscious fabrication of experiences and events to cover gaps in memory. May be caused by damage to the anterior communicating artery and frontal area of the brain.

                                                                                                                                                                        Conduction aphasia

                                                                                                                                                                        Selective impairment of the ability to repeat due to a lesion of the arcuate fasciculus

                                                                                                                                                                          Conduction block

                                                                                                                                                                          Failure of impulse conduction along an anatomically intact axon; characteristic of demyelinating neuropathy

                                                                                                                                                                            Conductive Education

                                                                                                                                                                            A learning system which can enable some children with cerebral palsy to function more independently


                                                                                                                                                                              'present at birth' i.e. a condition which originates prenatally


                                                                                                                                                                                Automatic control of bladder and bowel function. Loss of one or both (incontinence) may happen for a time after stroke.


                                                                                                                                                                                  Opposite to the site of impact


                                                                                                                                                                                    Permanent shortening of muscle and tendon resulting from spastic tightening of muscles over a long period


                                                                                                                                                                                      Located on the opposite side of the body (brain)


                                                                                                                                                                                        Oedematous brain lesion containing punctuate parenchymal haemorrhages on the surface of the brain that may extend bi-directionally into the white matter and the subdural and subarachnoid spaces; occur at the site of impact (coup contusion) with direct trauma and at a site opposite to the site of impact (contracoup contusion) with acceleration/deceleration injury

                                                                                                                                                                                          Conus medullaris

                                                                                                                                                                                          Caudal-most part of the spinal cord located between the first and second lumbar vertebrae. Since this structure is part of the spinal cord but is in close proximity to spinal nerve roots


                                                                                                                                                                                            Coordinated inward movement of the eyes in order to fixate on a near object

                                                                                                                                                                                              Convergence-retraction nystagmus

                                                                                                                                                                                              Form of nystagmus consisting of jerking eye movements inward and backward; associated with dorsal midbrain lesion




                                                                                                                                                                                                  Vertical plane from head to foot and parallel to the shoulders

                                                                                                                                                                                                    Corona radiata

                                                                                                                                                                                                    Fan-like arrangement of fibres projecting from all aspects of the cerebral cortex and converging toward the thalamus where they will form the internal capsule

                                                                                                                                                                                                      Corpus callosum

                                                                                                                                                                                                      Large fibre structure that makes connections between homotopic regions of the cerebral hemispheres; bend at its anterior limit is called the genu; bend at its caudal end is called the splenium; portion between the two is called the body.

                                                                                                                                                                                                        Correct positioning

                                                                                                                                                                                                        After stroke where one side of the person is weak or paralysed


                                                                                                                                                                                                          Referring to the cerebral cortex

                                                                                                                                                                                                            Cortical blindness

                                                                                                                                                                                                            Apparent lack of visual functioning in spite of anatomically and structurally intact eyes due to bilateral lesions of the primary visual cortex

                                                                                                                                                                                                              Corticobasal degeneration

                                                                                                                                                                                                              Progressive neurological disorder characterized by nerve cell loss in the cerebral cortex and basal ganglia and producing parkinsonism

                                                                                                                                                                                                                Corticobulbar tract

                                                                                                                                                                                                                Axons originating in the posterior frontal lobe and projecting to lower motor neurons in the brainstem

                                                                                                                                                                                                                  Corticospinal tract (pyramidal tract)

                                                                                                                                                                                                                  Motor pathway responsible for voluntary movement that arises from primary motor cortex

                                                                                                                                                                                                                    Cough headache

                                                                                                                                                                                                                    Indomethacin-responsive headache disorder characterized by transient


                                                                                                                                                                                                                      Lesion at the site of impact

                                                                                                                                                                                                                        Cowdry A inclusion bodies

                                                                                                                                                                                                                        Eosinophilic nuclear inclusions surrounded by a clear halo in neurons or glial cells occurring in herpes simplex encephalitis

                                                                                                                                                                                                                          Cowdry B inclusion bodies

                                                                                                                                                                                                                          Large glassy eosinophilic nuclear inclusions occurring in herpes simplex encephalitis

                                                                                                                                                                                                                            Craft palsy

                                                                                                                                                                                                                            Dystonia occurring in the setting of a highly learned skilled task


                                                                                                                                                                                                                              Surgical removal of a section of bone (bone flap) from the skull for the purpose of operating on the underlying tissues or relieving intracranial pressure


                                                                                                                                                                                                                                Suprasellar WHO grade I tumour of children/young adults that causes significant morbidity and mortality; characterized histologically by basal palisading


                                                                                                                                                                                                                                  Surgical repair of a defect or deformity of the skull; replacement of a bone flap

                                                                                                                                                                                                                                    Craniorachischisis totalis

                                                                                                                                                                                                                                    Fatal neural tube defect consisting of total failure of neurulation; a neural plate-like structure is entirely exposed without overlying bony or dermal covering


                                                                                                                                                                                                                                      Premature closure at birth of one or more cranial sutures


                                                                                                                                                                                                                                        Surgical removal of a section of bone (bone flap) from the skull for the purpose of operating on the underlying tissues

                                                                                                                                                                                                                                          Creatine kinase

                                                                                                                                                                                                                                          Enzyme that catalyzes the conversion of creatine to phosphocreatine and is released into the blood by tissues'particularly muscle'that consume adenosine triphosphate (ATP) rapidly; elevated levels are seen in myopathy

                                                                                                                                                                                                                                            Cremasteric reflex

                                                                                                                                                                                                                                            Superficial (cutaneous) reflex elicited by stroking the superior and medial part of the thigh in a downward direction; normal response is contraction of the cremasteric muscle that pulls up the scrotum and testis on the side stroked; dependent on nerve roots L1 and L2


                                                                                                                                                                                                                                              A medical term to describe the grating

                                                                                                                                                                                                                                                Creutzfeldt-Jakob disease

                                                                                                                                                                                                                                                Fatal prion disease characterized by spongiform changes in the brain

                                                                                                                                                                                                                                                  Crossed adductor reflex

                                                                                                                                                                                                                                                  Reflex contraction of the adductor magnus caused by tapping the opposite knee; indication of hyperreflexia on the side of the adductor contraction; commonly thought to be due to stimulation of the adductor muscle on the hyperreflexive side through slight jarring of the pelvis


                                                                                                                                                                                                                                                    Relating to the leg


                                                                                                                                                                                                                                                      Occurring without known cause; in the context of epilepsy

                                                                                                                                                                                                                                                        CT/ CAT Scan

                                                                                                                                                                                                                                                        Diagnostic technique using a combination of computer and X-rays [Computed Axial Tomography] - provides cross-sectional images of tissue which are clearer and more detailed than X-rays alone with minimal exposure to radiation


                                                                                                                                                                                                                                                          The abbreviation for 'cerebro-vascular accident' meaning stroke. The term is widely used but may cause confusion.