Transcript Assessment of the Neurological System

Assessment of the
Neurological System
Christine M. Wilson
Viterbo University
Objectives
 Structure and Function
 Developmental considerations
 Neurological assessments
 Subjective data
 Objective data
Structure and Function
 Central Nervous System (CNS)
 Brain and spinal cord
 Peripheral Nervous System
 Cranial nerves (12)
 Spinal nerves (31 pair)
 All branches of nerves
(nerve: bundle of fibers outside of CNS)
Central Nervous System
 Cerebral cortex
 Cerebrum’s outer layer of nerve cell bodies
 Controls thought, memory, reasoning,
sensation, and voluntary movement
 Cerebrum-two hemispheres
 Right and Left
 Each hemisphere divided into 4 lobes
Lobes
 Frontal
 Personality, behavior, emotions, intellect
 Parietal
 Primary center for sensation
 Occipital
 Primary visual receptor center
 Temporal
 Primary auditory receptor center
Communication areas
 Wernike’s area in temporal lobe is
associated with language comprehension
 Receptive aphasia
 Broca area in frontal lobe responsible for
motor speech
 Expressive aphasia
Additional CNS ‘parts’
 Basal ganglia
 Deep in cerebral hemispheres
 Control automatic “associated” body
movements
 Thalamus
 Relay station; synapses (sites of contact b/tw
neurons) for sensory pathways from spinal
cord and brain stem to cerebral cortex
 Cerebellum
 Operates below conscious level
 Motor coordination of voluntary movements,
equilibrium, muscle tone, posture
 Brain stem
 Central core of brain: midbrain, pons, medulla
 Spinal cord
 Structure occupying upper 2/3 vertebral canal
 Ascending/descending fiber tracts between
brain and spinal nerves; mediates reflexes
Pathways of CNS
 Crossed representation
 Left cerebral cortex receives sensory
information from and controls motor
function to right side of body
 Right cerebral cortex receives sensory
information from and controls motor
function to left side of body
Sensory Pathways (p.664)
 Sensory receptors in skin, mucous
membranes, muscles, tendons, viscera
 Sensation travels through peripheral nerve
to spinal canal and into spinal cord
 Spinothalmic tract: pain, temperature,
crude and light touch
 Posterior (dorsal) column: sensations of
position, vibration, fine localized touch
Motor Pathways (p.665)
 Corticospinal (pyramidal) tract
 Motor nerve fibers originating in motor cortex
 Travel to brain stem, then to spinal cord
 Mediates voluntary movement; skilled,
discrete, purposeful movements
 Extrapyramidal tracts
 All motor nerve fibers outside pyramidal tract
 Controls muscle tone, gross automatic
movements
Peripheral Nervous System
 Carries sensory messages to central
nervous system (CNS)
 Carries motor function messages from
CNS to muscles and glands
 Carries autonomic messages to internal
organs and blood vessels
Reflex Arc (p.666)
 Basic defense mechanism of nervous system;
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quick reaction to potential pain/damage
Involuntary, below LOC control
Helps body maintain balance & muscle tone
Tapping tendon stretches muscle spindles which
activates sensory nerve
Message travels from receptor into spinal canal
and synapses with motor neuron
Message leaves spinal canal and travels to
muscle
Developmental Considerations
Infants
 Neurological system not completely
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developed
Motor activity under control of spinal cord
and medulla
Neurons are not yet myelinated
Movement directed by primitive reflexes
Sensory-motor development: head to
extremity
The Aging Adult
 General atrophy with steady loss of neurons in
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brain and spinal cord
Decrease in weight and volume of brain and
nerves
General loss of muscle bulk, tone, strength,
impaired fine coordination, loss of vibratory
sense, loss of Achilles reflex
Decreased velocity of nerve conduction
Slowing of motor system and movement
Decreased cerebral blood flow
Neurological assessments
 Complete—person
with neurological
concerns/dysfunction
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Mental status
Cranial nerves
Motor system
Sensory system
Reflexes
 Screening—well
persons with no
significant subjective
findings
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Tongue blade
Tuning fork
Cotton wisps
Percussion hammer
‘familiar’ items
Subjective Data
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Headaches
Head Injury
Dizziness, vertigo
Seizures
Tremors
Weakness
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Incoordination
Numbness/tingling
Dysphagia
Dysphasia
Past history
Environmental
hazards
Objective Data
 Inspect and Palpate Motor system
 Muscles
 Size: compare bilaterally; measure if needed
 Strength: check muscle groups by push/pull
 Tone: PROME; mild resistance, flaccid,
spastic
 Involuntary movements: location, frequency,
amplitude
Cerebellar Function: Balance
 Gait
 Walk 10-20 ft.; smooth, effortless, alternating
arm swing
 Tandem walk
 Heel to toe
 Romberg Test
 Feet together, arms sides, close eyes; hold
position 20 sec.; STAND CLOSE
Coordination and Skilled Movements
 Rapid alternating movements
 Pat knees with hands, palm to back, alternating
 Finger to finger
 Person touches your finger, then his nose, then your
finger; move position of your finger; smooth, accurate
 Finger to nose
 Close eyes, extend arms, touch tip of nose with index
finger, alternating; smooth, accurate
 Heel to shin
 Supine position, place heel on opposite knee and run
it down to ankle; straight line without slipping from leg
Sensory System
 Pain: Sharp/dull
 Broken tongue blade; apply point or blunt end
 2 sec. apart; distal to core
 Temperature
 If pain sensation abnormal, apply cool/warm
 Light touch
 Cotton wisp brushed across skin; distal to core
 Vibration
 Tuning fork base to great toe/finger; distal to core
 Position (Kinesthesia)
 Move finger/toe up or down; hold by sides
Tactile Discrimination: Fine touch
 Stereognosis
 Ability to recognize items by feeling form
 Graphesthesia
 Ability to “read” number traced in palm
 Two point discrimination
 Ability to distinguish two simultaneous pin points on
skin
 Extinction
 Ability to sense both sides of body being touched
 Point Location
 Ability to locate sensation of touch
Deep Tendon Reflexes
 Measurement reveals if reflex arc is intact
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at specific spinal levels
Limb relaxed and muscle partially
stretched
Relaxed hold on reflex hammer; wrist
snap
Direct short blow onto the muscle’s
insertion tendon
Compare bilaterally
 Reflex grading scale
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4+
3+
2+
1+
0
Very brisk, hyperactive
More brisk than average
Average
Diminished, Low normal
No response
 If reflex difficult to elicit: encourage
relaxation, reposition, increase strength of
blow
Deep Tendon Reflexes
 Biceps reflex (C5-C6)
 Support forearm, place thumb on biceps
tendon, strike thumb
 Contraction of biceps and flexion of the
forearm
 Triceps Reflex (C7-C8)
 Holding under upper arm, suspend arm at 90
degrees
 Strike triceps tendon directly above elbow
 Extension of the forearm
 Brachioradialis Reflex (C5-C6)
 Hold thumbs to suspend forearms; strike 2-3
cm above the radial styloid process
 Flexion and supination of the forearm
 Quadriceps Reflex: Knee jerk (L2-L4)
 Lower legs dangle freely; strike tendon just
below the patella
 Extension of lower leg and contraction of
quadricep muscles
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Achilles Reflex (L5-S2)
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Knee flexed and hip externally rotated; hold foot in
dorsiflexion, strike the Achilles tendon directly
Plantar flexion against hand
Plantar Reflex (L4-S2)
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Begin at heel, stroke lateral side of sole upward and
inward across ball of foot (upside down ‘J’)
Plantar flexion of all toes and inversion and flexion
of the forefoot
Babinski sign
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Dorsiflexion of great toe and fanning of all toes;
NORMAL in infants until age two
NOT normal in adults/children older than two
Superficial reflexes
 Receptors are in the skin rather than the
muscles
 Abdominal reflexes (Upper T8-T10,
Lower T10-T12)
 Supine position, stroke lateral to midline
 Ipsilateral contraction and pulling of umbilicus toward
stroke
 Cremasteric Reflex (L1-L2)
 In males, stroke inner aspect of thigh; note
elevation of ipsilateral testicle
Glasgow Coma Scale
 Standardized objective assessment that defines
LOC by giving it a numeric value
 Eye opening
 Verbal Response
 Motor Response
 Reflects functional state of brain as a whole, not
any particular site in brain
 Fully alert, optimal functioning—score 15
 Comatose—score 7 or less
 Pupil size and response to light often performed