Neurological Glossary

Saccade

Discrete

Saccular aneurysm

Spherical outpouching from one side of an artery that occurs at an arterial bifurcation point and reflects weakness of all layers of the vessel wall

SAFO

Silicone Ankle Foot Orthosis

Sagittal

Vertical plane passing through the standing body from front to back

Sagittal sulcus (longitudinal fissure)

Long

Salivatory nuclei

Small nuclei in the pontine tegmentum that provide parasympathetic preganglionic innervation to ganglia associated with the lacrimal and salivary glands to control salivation and tearing

Saving Reaction

Physical ability to save oneself when balance is lost

Scanning speech (ataxic dysarthria)

Abnormal staccato-like speech due to a lesion of the cerebellum or cerebellar pathways

Scaphocephaly (dolichocephaly)

Premature closure of the sagittal suture

Schizencephaly

Developmental birth defect characterized by abnormal slits or clefts in the cerebral hemispheres extending from the cortical surface to the underlying ventricle

Schwann cell

Glial cell of the PNS that forms the insulating myelin sheath of peripheral axons

Schwannoma

WHO grade I benign peripheral nerve sheath tumour occurring commonly in the cerebellopontine angle (cranial nerve VII) or in the bony foramina around the spinal cord (spinal nerve root); characterized histologically by Antoni A and Antoni B tissue and Verocay bodies (zones of nuclear palisading)

Scintillating scotoma

Visual migraine aura consisting of shimmering lights followed by a dark spot or partial loss of vision that may move across the visual field

Scoliosis

An abnormal sideways curvature/twist of the spine

Scotoma

Island-like gap or blind spot in the visual field

Secondary progressive

Clinical course of multiple sclerosis that initially is relapsing-remitting and then becomes progressive at a variable rate

Secondary symptoms

Symptoms referable to secondary effects of a lesion e.g.

Seizure

Discrete event due to sudden

Selective Dorsal Rhizotomy

A neurosurgical technique used in the treatment of spasticity in the lower limbs

Sella turcica

Saddlelike prominence on the upper surface of the sphenoid bone of the skull

Sensory

Referring to part of nervous system which receives and interprets signals through senses

Sensory trick

Specific trigger a patient uses to relieve dystonia

Septal nuclei

Neuronal structures in the rostral forebrain adjacent to the septum pellucidum that communicate with the hippocampus

Septum pellucidum

Membrane extending ventrally from the body of the corpus callosum that separates the two lateral ventricles from each other

Setting sun sign

Forced depression of the eyes due to pressure on the dorsal midbrain in the setting of hydrocephalus

Shadow plaque

Foci of myelin preservation at the periphery of active multiple sclerosis plaques thought to represent partial remyelination

Sharp wave

EEG pattern consisting of a transient electrical discharge with a pointed peak and a duration of 70-200 milliseconds that stands out from ongoing background activity; has a strong association with epilepsy

Shy-Drager syndrome

Older term for a variant of multisystems atrophy characterized by preferential degeneration of the intermediolateral cell column of the spinal cord and substantia nigra producing symmetric parkinsonism and autonomic failure

Sialorrhea

Drooling; increased salivation

Simple tic

Tic involving a limited number of muscles; simple vocal tics are meaningless noises such as grunting or throat clearing; simple motor tics are focal movements such as eye blinking or facial grimacing

Single fibre electromyography

Electrodiagnostic test in which potentials of muscle fibres innervated by a single axon are recorded; normal response is for fibres to be activated with consistent latencies whereas in neuromuscular junction disorders

Sjogren's syndrome

An autoimmune disorder that prohibits production of tears and saliva

Skew deviation

Hypertropia in which the eyes move vertically in opposite directions due to acquired supranuclear or vestibulo-ocular disruption

Sleep latency

Speed of falling asleep

Sleep paralysis

Temporary (seconds to minutes) inability to move or talk that occurs during sleep-to-wake or wake-to-sleep transitions; one of the symptoms of narcolepsy

Slow wave sleep

see non-REM sleep

Smooth pursuit

Smooth following eye movements that maintain fixation

Solitary nucleus and tract

Sensory nucleus of the medulla that receives afferent taste information from nerves VII

Soma

Cell body

Somatosensory evoked potentials (SSEP)

Series of waves that reflect sequential activation of neural structures along the somatosensory pathways following electrical stimulation of peripheral nerves (typically elicited by stimulation of the median nerve at the wrist

Somesthesia

Sensation

Somnambulism (sleep walking)

Arising from bed during a period when there is a simultaneous occurrence of incomplete wakefulness and nonREM sleep; typically occurs in the first third of the night during deep sleep

Soporific

Causing or tending to induce sleep

Spastic

A term with two meanings:

• Popularly used to indicate any child or adult suffering from cerebral palsy and diplegia. This is detected by the particular sort of increased resistance to passive movement of the parts of the limb.
• Medically speaking it is used to describe a specific type of stiffness commonly seen in the limbs of hemiplegia.

Spastic Cerebral Palsy

The most common form of cerebral palsy where some muscles become very stiff and weak

Spasticity

The state of being spastic

Spatial

Relationship of one thing to another in space

Spatial Perception

The appreciation of size

Spatial skills

Ability to judge depth

Spatio-temporal

Having both spatial extension and temporal duration

Speech and Language Therapy

Rehabilitation specialism directed to the treatment of people with speech and language difficulties

Speech therapist / speech and language therapist (SALT)

A therapist who specialises in the rehabilitation of people with speech and language difficulties

Social worker (care manager)

Professionally qualified employee of local Social Services Department who gives advice and practical help with social problems. They also assess the eligibility of a person for community care services.

Spike

EEG pattern consisting of a transient electrical discharge with a pointed peak and a duration of less than 70 milliseconds that stands out from ongoing background activity; has a strong association with epilepsy

Spike-and-wave complex

Generalized synchronous pattern seen on electroencephalogram

Spina bifida

Failure of bone fusion in the posterior midline of the vertebral column resulting in a bony cleft through which the meninges and varying quantities of spinal cord tissue protrude

Spina bifida occulta

Closed spinal dysraphism characterized by posterior vertebral defect and various overlying cutaneous anomalies (e.g.

Spinal dysraphism

Failure of bone fusion in the posterior vertebral column; classified as open (not covered by skin) or closed (covered by skin)

Spinocerebellar ataxia

Group of hereditary neurodegenerative disorders caused by expansion of a CAG triplet repeat and characterized by progressive ataxia and variable other features such as neuropathy and hearing or visual loss

Spinal accessory nerve (cranial nerve XI)

Motor nerve originating partly from the medulla (nucleus ambiguus'innervating laryngeal muscles) and partly from the spinal cord (accessory nucleus in the ventral horn of the cervical cord'innervating the sternocleidomastoid and trapezius muslces); lesion results in weakness in turning the head to the opposite side and elevating the shoulder

Spinocerebellar tract

Fibre tract originating in the spinal cord and carrying proprioceptive input to the ipsilateral cerebellum

Spinothalamic tract

Axonal tract carrying information on pain and temperature that arises from the posterior nerve roots

Splenium

Thickened posterior border of the corpus callosum

Splints

Interchangeable term with braces and orthoses. Used to support or correct upper and lower limbs

Spondylosis

Degenerative disease of the vertebral column that can result in spinal cord compression

Spongiform encephalopathy

Progressive neurodegenerative disorder associated with various prion agents that produce spongy changes in the brain (e.g.

Spreading cortical depression

Brief wave of intense cortical activation followed by a marked decrease in neuronal activity and reduced blood flow that starts in the occipital cortex and spreads anteriorally at a rate of 2-6 mm/min; thought to underline migraine aura

Standing Frame

A piece of equipment to allow a child to be more upright allowing greater freedom of the trunk and arms.

Status epilepticus

Medical emergency defined as more than 30 minutes of either continuous seizure activity or two or more sequential seizures without full recovery of consciousness in between

Status migrainosus

Migraine attack that persists for > 72 hours and often leads to hospitalization

Stereognosis

Ability to recognize objects by touch

Stereotypy

Repetitive stereotyped movements commonly seen in tardive dyskinesia

STNR

Symmetrical tonic neck reaction. Very rare and usually pathological in origin. When the legs are extended the flexor tone in the arms dominate. When the arms are extended the flexor tone in the legs dominate or vice versa for both patterns

Stocking-glove

Typical distribution on the body where symptoms/signs of peripheral neuropathy are evident (toes to knee and fingers to wrist)

Strabismus

misalignment of the eyes that is either developmental (due to a miscalibration of the binocular vergence system in the cerebral cortex at some point in infancy or childhood) or acquired (due to a palsy of a cranial nerve or extraocular muscle)

Stress incontinence

Partial loss of bladder control

Stria medullaris

White matter tract connecting the anterior hypothalamus and septal nuclei in the medial basal forebrain with the habenula

Stria terminalis

White matter tract containing amygdaloid efferents to the septal nuclei in the medial basal forebrain and nuclei of the anterior hypothalamus

Striate cortex

The part of the occipital lobe of the cerebral cortex that is the primary receptive area for vision

Striatonigral degeneration (SND)

Older term for a variant of multisystems atrophy characterized by degeneration of the striatum and the substantia nigra producing symmetric parkinsonism that does not respond to levodopa or dopamine agonists

Striatum

Part of the basal ganglia consisting of the caudate and putamen separated by fibres of the anterior limb of the internal capsule

Stroke

Sudden loss of neurological function caused by a blockage or rupture of a blood vessel to the brain or spinal cord; includes infarction and haemorrhage subtypes

Stroke unit

Hospital facility for the effective management of patients with acute stroke by a multi-disciplinary team of specialists

Stupor

Condition of unresponsiveness from which the patient can only be aroused by vigorous and repeated stimuli; once stimulus ceases

Subacute

Developing over days to weeks; suggests an expanding lesion (e.g

Subarachnoid haemorrhage

Bleeding between the brain and one of the covering membranes

Subarachnoid space

Actual space separating the pia and arachnoid that surround the brain and spinal cord; contains cerebrospinal fluid

Subclinical seizure

Electrographic seizure without clinical manifestations

Subcortical

Portion of the brain immediately below the cerebral cortex; includes corona radiata

Subcortical leukoencephalopathy

see Binswanger's disease

Subdural haemorrhage

Collection of blood in the subdural space following trauma to small bridging veins or in elderly patients with cerebral atrophy or those with clotting abnormalities

Subdural space

Potential space between the dura and arachnoid that can be filled with blood

Subhyaloid hemorrhage

Accumulation of blood near the optic disc seen on fundoscopic exam in subarachnoid haemorrhage

Subiculum

Division of the parahippocampal gyrus adjacent to the hippocampal fissure that is the major source of efferent fibres from the hippocampal formation to rostral structures in the basal forebrain

Subluxed

Tendency towards a joint shifting out of position

Substantia gelatinosa

Narrow

Substantia nigra

Nucleus in the midbrain tegmentum that is divided into the pars compacta

Subthalamic nucleus (subthalamus)

Nucleus in the ventral diencephalon that modulates the output of the basal ganglia from the internal segment of the globus pallidus to the thalamus

Sulcus

Groove in the cerebral cortex separating two gyri

Superior

Nearer the head

Superior cerebellar peduncle (brachium conjunctivum)

Principle efferent fibre bundle from the cerebellum; fibres decussate in the midbrain and end primarily in the red nucleus and dorsal thalamus; lesions of the caudal SCP before the decussation result in ipsilateral deficits in motor coordination whereas lesions rostral to the decussation result in contralateral deficits; afferent fibers from the ventral spinocerebellar tract travel in the SCP to bring proprioceptive information from the lower body to the cerebellum

Superior colliculus

Paired structures on the dorsal surface of the rostral midbrain that receive unconscious visual input directly from the retina and help orient the head and eyes to all types of sensory stimuli

Superior sagittal sinus

Venous structure occupying the convex margin of the falx cerebri and draining the upper part of the cerebral hemispheres

Supine

Lying on back

Supranuclear

Central connections rostral to the cranial nerve nuclei

Suprasellar

above the sella turcica

Supratentorial

Above the tentorium cerebelli

Suture

Junction between two bones of the skull: coronal separates the 2 frontal bones from the parietal bones; metopic separates the frontal bones; sagittal separates the 2 parietal bones; lambdoid separates the occipital bone from the 2 parietal bones

Sylvian fissure (lateral fissure or lateral sulcus)

Prominent long

Sympathetic nervous system

Part of the autonomic nervous system concerned with preparing the body for fear

Symptomatic epilepsy

Epilepsy that is due to a known cause (e.g.

Syncope

Temporary loss of consciousness due to a lack of blood flow to the brain

Syndrome of inappropriate ADH secretion (SIADH)

Disorder of osmoregulation involving excessive release of arginine vasopressin (antidiuretic hormone)

Synesthesia

Condition associated with involuntary perceptual experiences that are elicited by stimuli that would not be expected to elicit such a response'a crossing of sensory modalities

Synucleinopathies

Group of neurodegenerative diseases characterized by neuronal or glial inclusions composed of alpha-synuclein; includes idiopathic Parkinson disease and diffuse Lewy body disease

Syringobulbia

Central cavitation (cystic lesion) within the spinal cord (syringomyelia) that extends up to the medulla and pons

Syringomyelia

Central cavitation (cystic lesion) of the spinal cord