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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Pacinian corpuscle

Largest of the skin receptors located deep in the dermis and responsible for sensation of vibration and deep pressure


    A doctor who specialises in the care of children and in their disorders and diseases.


      Paralysis of a muscle group


        Swelling of nerve head usually but not always due to increased ICP

          Parachute reflex

          Protective reflex of normal infants (present by 7-9 months) in which both arms go out in front in response to the head being held down and pointed toward the floor


            Loss of motor function in a body part

              Paramedian pontine reticular formation (PPRF)

              Collection of premotor neurons located in or near the abducens nucleus that drive horizontal gaze when excited by the cerebral cortex


                Adjacent to the meninges; includes nasal cavity

                  Paraphasia speech error characterized by substitutions of letters (e.g.


                    Impairment of legs only


                      Sagittal section that is lateral to the midline


                        Disorder in which abnormal behavior intrudes into the sleep process; includes somnambulism

                          Parasympathetic nervous system

                          Part of the autonomic nervous system concerned with conservation and restoration of energy; its preganglionic fibres arise from the motor nuclei of cranial nerves III

                            Paratonia (gegenhalten)

                            Increased muscle tone that increases in proportion to the speed and strength with which the examiner tries to move the joint; indicative of extensive bihemispheric or bifrontal dysfunction




                                Reduced ability to activate motor neurons; weakness


                                  Skin sensation

                                    Parinauds syndrome (dorsal midbrain syndrome)

                                    Syndrome characterized by a supranuclear palsy of vertical conjugate movements

                                      Parkinson disease

                                      Neurodegenerative disease characterized by resting tremor


                                        Complex of symptoms including resting tremor

                                          Parkinson plus syndromes

                                          Primary neurodegenerative disorders associated with complex clinical presentations including parkinsonism that reflect degeneration in various neuronal systems in addition to the substantia nigra; parkinsonian features are characterized by symmetry of signs

                                            Partial (focal) seizure

                                            Seizure that starts in a single cortical region

                                              Participation restrictions

                                              Problems an individual may experience in their own involvement in life situations (e.g.


                                                Area surrounding the dense core of irreversibly damaged cells that has preserved ionic homeostasis and reduced neuronal electrical activity but that is capable of recovery

                                                  Pelvic Tilt

                                                  Position of pelvis which can be normal or abnormal


                                                    Awareness and understanding of one's environment (e.g. awareness of touch

                                                      Perceptual neglect

                                                      Inability to distribute spatial attention to objects in the visual field

                                                        Perceptual skills

                                                        Ability to receive and distinguish information through the prime senses of vision

                                                          Periaqueductal gray

                                                          Tegmental gray matter surrounding the cerebral aqueduct within the midbrain that is important in the processing of pain


                                                            Visual field testing designed to determine the sensitivity of specific locations of peripheral and central vision


                                                              Connective tissue sheath surrounding a bundle of nerve fibers

                                                                Periodic limb movement disorder

                                                                Sleep disorder characterized by repetitive stereotyped movements during sleep

                                                                  Peripheral nerve block injections

                                                                  Injection of local anaesthetic in the vicinity of a peripheral nerve to anaesthetize the nerve's area of innervation and prevent pain signals from reaching the brain.

                                                                    Peripheral nervous system

                                                                    Nerve cell body


                                                                      A persisting tendency to repeat actions or phrases of sentence. An ability to stop one activity and transfer to another.

                                                                        Perisylvian plexus

                                                                        Referring to structures around the Sylvian fissure; includes Wernicke's area in auditory association cortex and Broca's area in front of motor cortex


                                                                          Connective tissue sheath surrounding a bundle of muscle fibres

                                                                            Petit mal seizure

                                                                            see absence seizure


                                                                              Abnormal intolerance to sound that commonly occurs in migraine and other headaches


                                                                                Abnormal intolerance to light

                                                                                  Physiologic tremor

                                                                                  Subtle low amplitude


                                                                                    A therapist who specialises in physical methods of treatment to promote healing and return to health and optimal functioning


                                                                                      Innermost layer of the meninges that is intimately applied to the surface of the brain parenchyma and spinal cord and separated from the arachnoid by the subarachnoid space

                                                                                        Picks disease

                                                                                        Form of frontotemporal dementia characterized by a slowly progressive deterioration of social skills and changes in personality in addition to impairment of intellect

                                                                                          Piedro Boots

                                                                                          Specialised footwear

                                                                                            Pincer grasp

                                                                                            Finger-thumb opposition


                                                                                              Midline body attached to the posterior part of the third ventricle and lying between the superior colliculi

                                                                                                Pituitary apoplexy

                                                                                                Spontaneous hemorrhagic infarction of a typically large and nonfunctioning pituitary adenoma presenting with headache

                                                                                                  Pituitary gland (hypophysis)

                                                                                                  Endocrine organ lying ventral to the hypothalamus and optic chiasm; includes an anterior glandular lobe made up of hormone-secreting cells and a posterior neural lobe containing the terminals of neuropeptide-secreting

                                                                                                    Placing (stepping) response

                                                                                                    Normal neonatal reflex consisting of elevating the foot and moving it forward when its dorsal surface is touched; the infant will appear to attempt to stand or walk

                                                                                                      Plantar response

                                                                                                      Superficial (cutaneous) reflex elicited by applying a stimulus to the skin of the foot or leg; flexion (curling down) of all toes (downgoing toe) is a normal response


                                                                                                        Inability to activate any motor neurons; paralysis


                                                                                                          Inflammatory muscle disease associated with primarily proximal limb weakness; considered to be an autoimmune disease of disordered cellular immunity and often associated with a specific collagen-vascular disease


                                                                                                            Continuous and simultaneous recording of multiple physiological variables during sleep


                                                                                                              Middle aspect of the brainstem


                                                                                                                Plaster of Paris casts


                                                                                                                  Cerebral hemispheric cyst that is usually the remnant of a destructive lesion (e.g.

                                                                                                                    Positive sharp wave

                                                                                                                    Spontaneous muscle activity seen on electromyography in association with denervation or irritable myopathy consisting of long action potentials with initial positive (down) wave followed by wide negative (up) wave

                                                                                                                      Positive symptom

                                                                                                                      Exaggeration of a physiological phenomenon; implies abnormal excessive (irritative) discharges in gray matter or (e.g.

                                                                                                                        Positron Emission Tomography (PET)

                                                                                                                        A sensitive medical imaging technique in which a pharmaceutical


                                                                                                                          Period following a migraine during which a person has impaired concentration


                                                                                                                            Nearer the back of the body

                                                                                                                              Posterior cerebral artery

                                                                                                                              Paired arteries that arise from the top of the basilar artery; supply blood to the posterior areas of the brain

                                                                                                                                Posterior commissure

                                                                                                                                One of the three major groups of commissural fibres that crosses the midline of the epithalamus just dorsal to the point where the cerebral aqueduct opens into the third ventricle

                                                                                                                                  Posterior communicating artery

                                                                                                                                  Branch of the internal carotid artery that joins the middle cerebral artery (anterior circulation) to the posterior cerebral artery (posterior circulation); supplies thalamus

                                                                                                                                    Posterior cord syndrome

                                                                                                                                    Spinal cord injury syndrome associated with damage to the posterior portion of the spinal cord resulting in bilateral loss of vibration /proprioception +/- bilateral weakness below the level of the lesion

                                                                                                                                      Posterior fossa

                                                                                                                                      Brainstem and cerebellum

                                                                                                                                        Posterior horn (dorsal horn)

                                                                                                                                        Gray matter in the back of the spinal cord that receives sensory information from the body through the dorsal root ganglia

                                                                                                                                          Post-herpetic neuralgia

                                                                                                                                          Condition following an acute varicella zoster infection (shingles) characterized by persistent pain (3 or more months) in the dermatomal distribution of the previous zoster rash

                                                                                                                                            Postural instability

                                                                                                                                            Loss of ability to make postural adjustments in response to perturbations

                                                                                                                                              Postural tremor

                                                                                                                                              Tremor that occurs with the maintenance of a posture or position against gravity


                                                                                                                                                Ability to stand upright automatically against gravity; controlled by the vestibulospinal

                                                                                                                                                  Potts disease

                                                                                                                                                  Tuberculous involvement of the vertebral column with vertebral collapse


                                                                                                                                                    Past Medical History


                                                                                                                                                      Profound and Multiple Learning Difficulties


                                                                                                                                                        Ability to plan

                                                                                                                                                          Prefrontal cortex

                                                                                                                                                          Cortical region of the frontal lobe lying anterior to primary and premotor cortex; mediates various executive functions

                                                                                                                                                            Premotor cortex

                                                                                                                                                            Cortical region (Brodmann's area 6) in the posterior frontal lobe anterior to the primary motor cortex involved in planning or programming of voluntary movements

                                                                                                                                                              Primary progressive

                                                                                                                                                              Clinical course of multiple sclerosis characterized from the beginning by progressive disease

                                                                                                                                                                Primary progressive aphasia

                                                                                                                                                                Progressive form of dementia characterized by global loss of language abilities and initial preservation of other cognitive functions; pathologically

                                                                                                                                                                  Primitive neuroepithelial tumor (PNET)

                                                                                                                                                                  Tumor histologically similar to the medulloblastoma but located outside the posterior fossa


                                                                                                                                                                    Proteinacious infectious agent responsible for various fatal brain diseases classified as spongiform encephalopathy


                                                                                                                                                                      Premonitory phenomena occurring hours to days before headache onset in migraine consisting of psychological


                                                                                                                                                                        Assessment of the future course and expected outcome of a patient's illness

                                                                                                                                                                          Progressive multifocal leukoencephalopathy (PML)

                                                                                                                                                                          Fatal demyelinating CNS disease of immunocompromised patients caused by reactivation of the JC papovavirus

                                                                                                                                                                            Progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome)

                                                                                                                                                                            Parkinson plus syndrome characterized by predominantly axial rigidity


                                                                                                                                                                              Passive range of Movement


                                                                                                                                                                                Lying on tummy


                                                                                                                                                                                  Joint position sense

                                                                                                                                                                                    Proptosis (exophthalmos)

                                                                                                                                                                                    Abnormal protrusion of the eyeball


                                                                                                                                                                                      see forebrain


                                                                                                                                                                                        Emotional content of language


                                                                                                                                                                                          Involuntary slow

                                                                                                                                                                                            Pseudobulbar affect

                                                                                                                                                                                            Condition in which episodes of laughing and/or crying occur with no apparent precipitating event

                                                                                                                                                                                              Pseudobulbar palsy

                                                                                                                                                                                              Syndrome characterized by dysarthria


                                                                                                                                                                                                Spoke-wheel arrangement of cells with tapered cellular processes surrounding a blood vessel


                                                                                                                                                                                                  A person qualified in the scientific study of the mind. A Clinical Psychologist is trained in the assessment and treatment of people with illness or impairment.


                                                                                                                                                                                                    Eyelid droopiness

                                                                                                                                                                                                      Pupillary light response

                                                                                                                                                                                                      Contraction of the pupil on exposure of the retina to light; dependent on proper functioning of the optic and oculomotor nerves


                                                                                                                                                                                                        Largest and most lateral component of the basal ganglia


                                                                                                                                                                                                          Prominent column of white matter on the ventromedial margin of the medulla containing axons of the corticospinal tract

                                                                                                                                                                                                            Pyramidal tract

                                                                                                                                                                                                            see corticospinal tract