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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Rachischisis

Fissure of the spinal cord resulting in exposure of the incompletely folded cord along the back

    Radiculopathy

    Symptoms and signs associated with spinal nerve root compression

      Ramsy-Hunt syndrome

      Facial paralysis

        Raphe nuclei

        Nuclei located within the medial portion of the reticular formation in the brainstem that secrete serotonin

          Raymond syndrome

          Ipsilateral lateral rectus palsy and contralateral hemiplegia sparing the face due to a ventral pontinelesion affecting the abducens nerve fascicles and corticospinal tract (but sparing the facial nerve)

            Recurrent-remittent

            Episodic attacks of symptoms with rapid recovery to normal health; implies repeating episodes of a single process (e.g.

              Red desaturation

              Finding of dimmer perception of the colour red in an eye affected by optic nerve disease such as optic neuritis; sign of subtle asymmetry in optic nerve function since colour desaturation may occur despite normal visual acuity

                Red nucleus

                Oval nucleus centrally placed in the upper midbrain reticular formation that receives fibres from the deep cerebellar nuclei and cerebral cortex and projects to the cerebellum

                  Rehabilitation

                  The process of regaining function through active treatment

                    Relapsing-remitting

                    Clinical course of multiple sclerosis characterized by episodic attacks of symptoms with recovery to normal health

                      REM behaviour disorder

                      Disorder occurring during REM sleep in which the normal motor atonia is partially or completely absent such that dreams can be acted out with punching

                        REM sleep (rapid eye movement sleep)

                        Sleep stage in which vivid dreaming occurs; identified by the occurrence of rapid eye movements under closed eyelids

                          Repetitive nerve stimulation

                          Nerve conduction study in which a brief series of shocks is applied to a motor nerve before and after brief exercise of a muscle supplied by that nerve; useful for evaluating disorders of neuromuscular transmission such as myasthenia gravis (decremental response see) and Lambert Eaton myasthenic syndrome (incremental response seen).

                            Respite care

                            Care given to someone for a short period

                              Resting tremor

                              Medium-frequency (3-6 Hz) tremor that occurs maximally with the affected body at rest rather than with holding a sustained posture or making an intentional movement; common in Parkinson disease

                                Restless legs syndrome

                                Sleep disorder characterized by tingling

                                  Reticular activating system (RAS)

                                  The activating mechanisms that lie in or near the central gray matter of the diencephalon

                                    Reticular formation

                                    Heterogeneous collection of neurons scattered throughout the brainstem tegmentum that either modulate forebrain and spinal cord activity or coordinate the firing patterns of lower motor neurons engaged in reflexive or stereotypical somatic motor and visceral motor activities

                                      Reticulospinal tract

                                      Descending pathway from the reticular formation of the brainstem to spinal inter- and motor neurons that control anti-gravity posture and locomotion

                                        Retina

                                        Light-sensitive neuronal layer lining the back of the eye that sends impulses through the optic nerve that are translated into a visual image; part of the central nervous system

                                          Retropulsion

                                          A tendency to walk backward involuntarily that can occur in Parkinson disease

                                            RGO

                                            Lower body and leg splints to help walking

                                              Rhombencephalon

                                              Hindbrain; includes the pons

                                                Righting reflex

                                                Ability to make postural adjustments in response to perturbations

                                                  Rigidity

                                                  Extreme stiffness of muscles continuous resistance to passive motion

                                                    Ring-enhancement

                                                    CT or MRI contrast enhancement surrounding a lesion that has blood-brain barrier breakdown

                                                      Risk factors

                                                      The possible underlying causes (for the stroke) such as smoking

                                                        Rollators

                                                        Walking Aids

                                                          Romberg test

                                                          Inability to maintain upright posture when feet together and eyes closed; indicates impaired proprioception

                                                            Rooting reflex

                                                            Normal neonatal reflex consisting of turning the head towards a stimulus presented to the side of the mouth

                                                              Rostral

                                                              Toward the head or nose

                                                                Rostrocaudal

                                                                meaning from the nose to the tail; used to describe the sequence of symptoms referable to progressively lower parts of the brainstem characteristic of transtentorial herniation

                                                                  Rubral tremor

                                                                  Low-frequency (<4.5 Hz) tremor often of irregular

                                                                    Ruffini corpuscles

                                                                    Thermoreceptors in the skin

                                                                      Rx

                                                                      Treatment