Neurological Glossary

Pacinian corpuscle

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

Paediatrician

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

Palsy

Paralysis of a muscle group

Papilledema

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

Paralysis

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

Parameningeal

Adjacent to the meninges; includes nasal cavity

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

Paraplegia

Impairment of legs only

Parasagittal

Sagittal section that is lateral to the midline

Parasomnia

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

Parenchyma

tissue

Paresis

Reduced ability to activate motor neurons; weakness

Paresthesia

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

Parkinsonism

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.

Penumbra

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

Perception

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

Perimetry

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

Perineurium

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

Perseveration

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

Perimysium

Connective tissue sheath surrounding a bundle of muscle fibres

Petit mal seizure

see absence seizure

Phonophobia

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

Photophobia

Abnormal intolerance to light

Physiologic tremor

Subtle low amplitude

Physiotherapist

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

Pia

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

Pineal

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

Plegia

Inability to activate any motor neurons; paralysis

Polymyositis

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

Polysomnogram

Continuous and simultaneous recording of multiple physiological variables during sleep

Pons

Middle aspect of the brainstem

POP

Plaster of Paris casts

Porencephaly

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

Postdrome

Period following a migraine during which a person has impaired concentration

Posterior/Dorsal

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

Posture

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

Potts disease

Tuberculous involvement of the vertebral column with vertebral collapse

PMH

Past Medical History

PMLD

Profound and Multiple Learning Difficulties

Praxis

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

Prion

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

Prodrome

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

Prognosis

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

PROM

Passive range of Movement

Prone

Lying on tummy

Proprioception

Joint position sense

Proptosis (exophthalmos)

Abnormal protrusion of the eyeball

Prosencephalon

see forebrain

Prosody

Emotional content of language

Pseudoathetosis

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

Pseudorosette

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

Psychologist

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.

Ptosis

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

Putamen

Largest and most lateral component of the basal ganglia

Pyramid

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

Pyramidal tract

see corticospinal tract