assessment of neurologic function
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8/7/2019 ASSESSMENT OF NEUROLOGIC FUNCTION
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ASSESSMENT OF NEUROLOGIC FUNCTION
Marichelle Delos Santos RM,RN,MAN
NERVOUS SYSTEM
is an organ system containing a network of specialized cells called neurons that coordinate the actions
of an animal and transmit signals between different parts of its body
NETWORK-
means neural network or a circuit of biological neurons signaling
NEURONS-
is an electrically excitable cell that processes and transmits information by electrical and chemical
Function of the Nervous System
Controls all motor, sensory, autonomic, cognitive, and behavioral activities.
Structures of the Neurologic System
Central Nervous System
Brain and spinal cord
Peripheral nervous system
Includes cranial and spinal nerves
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Autonomic and somatic systems
Neuron
Brain cells
Links the motor and sensory pathways
Monitor the bodys processes
Respond to the internal and external environment
Maintain homeostasis
Direct all psychological, biologic and physical activity through complex chemical and electrical messages
Neurotransmitters
Neurotransmitters can potentiate, terminate, or modulate a specific action or can excite or inhibit a
target cell.
Communicate messages from one neuron to another or to a specific target tissue.
Many neurologic disorders are due to imbalance in neurotransmitters.
Types:
Acetylcholine-muscle movement
Biogenic amines (thinking process)
-Dopamine -Serotonin
-Norepinephrine -Histamine
Amino acids
-GABA
-Peptides
Bones and Sutures of the Skull
3 essential components of skull:
Brain tissue-78%
Blood -12 %
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CSF-10%
Monro-Kellie Hypothesis
If volume added to the cranial vault equals the volume displaced from it, the total intracranial
volume will not change
Normal ICP: 60-150 mmH20 or 0-15 mmHg
Brain
Cerebrum
Consists of 2 hemisphere
Corpus callosum
connects two hemisphere
Cerebral cortex
outer surface of the cerebrum
Basal ganglia
located deep within cerebral hemisphere
Internal capsule
white matter consisting of bundle of nerve fibers carrying motor and sensory impulses to and from
cerebral cortex
Lobes of the Cerebrum and their Functions
Diencephalon
Embedded in the brain superior to brain stem
1.Thalamus
process sensory impulses before it reaches cerebral cortex
2.Hypothalamus
regulates endocrine and autonomic function, temperature, water metabolism, appetite, emotion, sleep-
wake cycle and thirst
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3.Epithalamus
includes pineal gland (secretes melatonin and inhibits LH), part of endocrine system, affects growth and
development.
Medial View of the Brain
BRAIN STEM
1. Midbrain
center for auditory and visual reflexes
2. Pons
contains the fiber tracts; contains nuclei that controls respiration
-contains pneumotaxic centercontrols rhythmic quality of respirations
3. Medulla
control cardiac rate, BP, respirators and swallowing
4. Reticular activating system (RAS)
influence excitatory and inhibitory control of motor neuron; regulatory system for consciousness
Cerebellum
Has two hemispheres
Coordination of skeletal muscle activity, maintenance of balance, posture and control of voluntary
movements
Spinal cord
Extends from medulla up to first lumbar vertebra
Gives rise to 31 pairs of spiral nerves (C1-C8, T1-T12, L1-L5, S1-S5, coccygeal nerve)
Center for conducting messages to and from the brain; a reflex center
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Divisions:
Ascending (Spinocerebellar)
Carry a specific sensory information to higher levels of CNS
Spinocerebellar tracts-muscle tension and body position
Spinothalamic-pain and temperature sensation
Descending (Corticospinal)
Pyramidal tracts-
from the cortex to cranial and peripheral nerves
inhibits muscle tone
Extrapyramidal tracts-
from brain stem, basal ganglia, and cerebellum
maintains muscle tone and gross body movements
Upper motor neurons
from cerebral cortex to anterior gray column of SC
spasticity and hyperactive reflexes
Lower motor neurons
final common pathways from anterior gray column up to muscles
flaccidity and loss of reflexes
Reflex arc
Reflexes-automatic action; spinal cord mediates most reflexes
Automatic or perceptible, inhibited or conditioned
Hyperreflexia-disease or injury of certain descending motor tracts
Hyporeflexia-damage or degeneration of the sensory or motor neurons
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Meninges and Related Structures
Arterial Blood Supply of the Brain
Sources of Blood supply:
1. Internal carotid arteries-anterior circulation, ipsilateral hemispheres
2. Vertebral arteries-posterior circulation, posterior fossa
Circle of Willis
act as a safety valve; arises from basilar arteries and internal carotid arteries; vascular network at the
base of the brain
is important to total brain circulation because it provides equal circulation bilaterally. If one side of the
circle of Willis is unable to supply adequate blood, the other side provides blood to the area normally
supplied by the damaged side
Cerebral arteries (2 each):
Anterior, Middle, Posterior
Jugular veins-drains the brain venous blood through dural sinuses
Cross Section of the Spinal Cord Showing the Major Spinal Tracts
Cranial Nerves
Dermatome Distribution
Peripheral Nervous system
Cranial nerves-innervate head and neck region, except the vagus nerve
Spinal nerves
Plexuses
complex cluster of nerve fibers (cervical, brachial, lumbar and sacral region)
Dermatomes
area of the skin innervated by cutaneous branches of a single spinal nerve
Somatic Nervous system
Consists of motor and sensory nerves
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Controls skeletal muscles
Produces a motor response through efficient nerve fibers from
CNS which transmit impulses to the skin and skeletal muscles
Autonomic Nervous System
Functions to regulates activities of internal organs and to maintain and restore internal homeostasis
Controls involuntary or automatic body functions
Has two subdivisions, serving same organ but have counterbalancing effects; each system can inhibit the
organ stimulated by the other
Sympathetic Nervous System
originates from lateral horns of first thoracic through the first lumbar of spinal cord (thoracolumbar)
helps the body cope with events in the external environment
Functions mainly during stress, triggering the fight or flight response
Increases heart rate and respiratory rate, pupil dilation, cold, and sweaty palms
SYMPATHETIC SYNDROMES
Parasympathetic Nervous System
Consist of the vagus nerves originating in the medulla of the brain stem and spinal nerves originating
from the sacral region of the spinal cord (craniosacral)
Activates GI system
Supports restorative, resting body function through such actions as replenishing fluids and electrolytes
Anatomy of the Autonomic Nervous System
Motor and sensory pathways of the nervous system
Motor pathways
Upper and lower motor neurons
Upper motor neuron lesion
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Lower motor neuron lesion
Coordination of movement
Sensory System Function
Receiving sensory impulses
Integrating sensory impulses
Sensory losses
DIVISIONS OF THE NERVOUS SYSTEM
NERVOUS SYTEM
Anatomical Classification Functional Classification
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CNS PNS Afferent/ Efferent/
Sensory Motor
Brain SC SN CN
Somatomotor Autonomic
Cerebrum Diencephalon Brainstem Cerebellum
Sympa Parasympa
Thalamus Pineal Body Hypothalamus Medulla Oblongata
Pons
Midbrain
NEUROLOGICAL NURSING ASSESSMENT
1. Health History
ask the client about
headache;
clumsiness;
loss of or change in function of an extremity;
seizure activity;
numbness or tingling
change in vision;
pain;
extreme fatigue;
personality changes;
and mood swings.
2. Neurological Assessment
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Involves assessment of LOC and verbal responses to specific questions; selected cranial nerves for
eye movement and visual acuity; muscle strength; movement; gait for motor function; and tactile and
pain sensation of extremities for sensory screening.
A complete nursing assessment of neurological function includes assessment of the following areas:
cerebral function, cranial nerve function, motor function, sensory function, and reflexes.
a. Cerebral function assessment includes:
a.1. Level of Consciousness is assessed by determining the clients awareness and orientation and is the
most important indicator of change in neurological status.
Consciousness Requires:
Arousal:
alertness; dependent upon reticular activating system (RAS); system of neurons in thalamus and upper
brain stem
Cognition:
complex process, involving all mental activities; controlled by cerebral hemispheres
Process that affect LOC:
Increased ICP
Stroke, hematoma, intracranial hemorrhage
Tumors
Infections
Demyelinating disorders
Systemic Conditions affecting LOC
Hypoglycemia
F/E imbalance
Accumulated waste products from liver or renal failure
Drugs affecting CNS: alcohol, analgesics, anesthetics
Seizure activity: exhausts energy metabolites
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Level of Consciousness
Alert
Lethargic-very sleepy
Stuporous
Coma
Death
Awareness
is the persons ability to perceive stimuli and body reactions and then respond with thought and action.
The clients awareness is assessed through four (4) components: orientation, memory, calculation and
fund of knowledge.
Glasgow Coma Scale
an objective tool for assessing consciousness in clients, most frequently clients with head injuries.
GLASGOW COMA SCALE (?)
A score of 15 indicates a fully oriented person. A score of 3 indicates deep coma. A score of 7 is
considered a state of coma.
GLASGOW COMA SCALE
GLASGOW COMA SCALE
GLASGOW COMA SCALE
a.2. Orientation
is the persons awareness of self in relation to person, place and time.
-Using open-ended communication techniques, instruct the client to tell me your first and last name,
tell me the month, day, year and day of the week, tell me where you are.
a.3. Mental Status
requires observation of the clients appearance, behavior, posture, mood, gestures, movements, and
facial expressions.
The nurse compares these behaviors based on the clients age, health status, educational level and
social position. Mood is assessed by observing and asking the client about moods and feelings.
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MENTAL STATUS ASSESSMENT WITH ABNORMAL FINDINGS
Unilateral neglect (lack of caring of the other side of the body); strokes involving middle cerebral artery
Poor hygiene and grooming: dementing disorders
Abnormal gait and posture: transient ischemic attacks(TIAs) , strokes, and Parkinsons disease
Emotional swings, personality changes: strokes
Aphasia-defective or absent language function: TIAs, strokes involving anterior/posterior artery; general
term for impairment of language
Dysphonia- change in tone of voice
Dysarthria- (different in speaking); is indistinctness of words in word articulation resulting from
interference with the peri pheral speech mechanisms (e.g. muscles of the tongue, palate, pharynx, or
lips) [Phipps, 1998, p. 1901]
Decreased level of consciousness
Confusion, Coma
a.4. Intellectual Function
is the ability of the brain to perform thought processes. Ability to concentrate, memory function (long
and short term memory), recall, calculation activities, and fund of knowledge.
a.5. Emotional Status
is assessed by observation of the clients affect (emotional response or mood).
Is affect appropriate for the situation?
Is affect labile (prone to rapid change)?
Is affect consistent with verbal communication
COGNITIVE FUNCTION ASSESSMENT WITH ABNORMAL FINDINGS
Disorientation to time and place: stroke of right cerebral hemisphere
Memory deficits
Emotional defense
a.6.Pupil reaction
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size, equality, and roundness of pupils are assessed. Size is measured in millimeters. Pupils are
evaluated for symmetry of size and for reaction to light. Reaction is assessed as being brisk, sluggish, or
nonreactive; consensual reaction is also noted.
a.7.Communication
both written and oral communication are assessed.
Aphasia
inability to communicate verbally, can be caused by the inability to form words or the inability
to understand written or spoken word.
To assess communication function, ask the client to follow simple command such as Close your
eyes. During the health history, ask the client about health care expectations to evaluate the clients
ability for verbal expression. Have the client write his name and address on paper to evaluate the ability
to write.
b. Cranial Nerve Function
Cranial I (Olfactory):
-Anosmia
lesions of frontal lobes
impaired blood flow to middle cerebral artery.
Cranial II (Optic)
blindness in eye: strokes of internal carotid artery, TIAs
Homonymous hemianopia - impaired vision or blindness in one side of both eyes; blockage of posterior
cerebral artery.
Impaired vision: strokes of anterior cerebral artery; brain tumors
Note:
Visual acquity-mediated by the cones of the retina
Field of vision or peri pheral vision-portion of space in which objects are visible during the fixation of
vision in one direction. The receptors for peripheral fields are the rod neurons of the retina. (Phipps,
1998, p. 1906)
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Cranial nerve III, IV, VI (Oculomotor, Trochlear, Abducens)-motor nerves that arise from the brainstem
Nystagmus - involuntary eye movement; strokes of anterior, inferior, superior, cerebellar arteries
Constricted pupils: may signify impaired blood flow to vertebralbasilar arteries.
� Ptosis (eyelid falldown); drooping of the upper eyelid over the globestrokes of
posterior inferior cerebellar artery; myasthenia gravis, palsy of CN III
Cranial nerve V (Trigeminal)largest cranial nerve with motor and sensory components
changes in facial sensations; impaired blood flow to carotid artery
Decreased sensation of face and cornea on same side of body; strokes of posterior inferior cerebral
artery
Lip and mouth numbness
Loss of facial sensation: contraction of masseter and temporal muscles, lesions CN V
Severe facial pain: trigeminal neuralgia (tic dorlourex)
Cranial VII (Facial nerve)mixed nerve concerned with facial movement and sensation of taste
1. Loss of ability to taste
2. Decreased movement of facial muscles
3. Inability to close eyes, flat nasolabial fold, paralysis of lower face, inability to wrinkle the forehead
4. Eyelid weakness; paralysis of lower face; paralysis of upper motor neuron
5. Pain, paralysis, sagging of facial muscles: affected side in Bells palsy
Cranial VIII (Acoustic)composed of a cochlear division related to hearing and a vestibular division
related to equilibrium (Phipps, 1998, p. 1909)
Decreased hearing or deafness: strokes of vertebralbasilar arteries or tumors of CN VIII
Cranial IX(Glossopharyngeal) and cranial X (Vagus)chief function of cranial nerve IX is sensory to the
pharynx and taste to the posterior third of tongue; cranial nerve X is the chief motor nerve to the soft
palatal, pharyngeal and laryngeal muscles (Phipps, 1998, p. 1909)
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Dysphagia (difficulty swallowing)
Unilateral loss of gag reflex
Cranial XI (Spinal accessory)motor nerve that supplies the sternocleidomastoid muscle and upper part
of trapezius muscles
Muscle weakness
Contralateral hemiparesis: strokes affecting middle cerebral artery and internal artery
Cranial XII (Hypoglossal)
Atrophy, fasciculations (twitches): LMN disease
Tongue deviation toward involved side of the body
c. Motor Function
c.1. Muscle size and symmetry
are assessed by palpating major muscle groups of the arms and legs and then comparing them
to the muscle groups of the opposite side of the body.
Unilateral atrophy indicates a nervous system problem.
c.2. Muscle Tone assessed during palpation of major muscle groups for size and symmetry while at
rest and during passive movement.
Muscle tone is described as normal, flaccid, spastic, or rigid.
Flaccid muscles are hypotonic, or soft and flabby.
Spastic muscles are at first resistant to passive movement, but then release resistance.
Rigid muscles may have tremors but are constantly rigid. Rigidity is a more constant state of spasticity,
with fewer periods of release of resistance.
c.3. Muscle Strength
to assess, each extremity is placed through passive movement.
The client is then asked to move the extremity, first against gravity, by lifting the extremity off
the bed, then against the resistance.
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5.Full power of contraction
4.Fair or moderate power of contraction
3.Just able to overcome force of gravity
2.Can move but cannot overcome power of gravity
1.Minimal contractile power
0.No movement
c.4. Coordination
is assessed by asking the client to perform repetitious movement. The client should close his
eyes and repeatedly, rapidly touch her own nose with alternate index fingers. Inability to perform this is
termed ataxia, incoordination of voluntary muscle action.
c.5. Balance
is evaluated by using the Rombergs Test. The client stands with the feet together; arms
extended in front and eyes closed.
c.6. Posturing
abnormal posturing occurs with injury to the motor tract.
Flexion posturing (formerly decorticate posturing) characterized by flexion of the arms, adduction
of the upper extremities, and extension of the lower extremities. Lesions of the cerebral hemispheres or
internal structures of the brain cause flexion posturing.
Extension posturing (formerly decerebrate posturing) is caused by brainstem injury and is
characterized by an arching of the back, backward flexion of the head, adduction and hyperpronation of
the arms, and extension of the feet. It represents greater dysfunction than does flexion posturing and
any change from flexion to extension posturing indicates a worsening condition
d. Sensory Function a subjective examination of sensory function, performed with the clients eyes
closed, is generally done only when a dysfunction is suspected.
d.1. Tactile Sensation
is tested by using a cotton ball to lightly touch the clients arms, hands, upper legs, and feet. Comparison
is done side to side. The client with eyes closed, indicated whether the cotton ball is felt.
d.2. Pain and temperature
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sensation of pain and temperature are transmitted along the same pathways and are evaluated using a
sharp and dull touch. A paper clip or cotton-tipped applicator is used. The clients ability to distinguish
sharp and dull is noted, comparing both sides of the body.
d.3. Vibration
is tested using a tuning fork. Strike the tuning fork on the palm, holding only the handle, then
place the end of the handle first on the clients wrists and then on the ankles and ask whether the
vibrations are felt. The clients eyes should be closed during the test.
d.4.Proprioception is the sense of joint position in space. With the clients eyes remaining closed,
move a joint of the clients finger or extremity up or down in space and ask the client to distinguish the
direction of movement of the digit or extremity as being either up or down.
d.5.Steriognosis is the ability to recognize an object by feel. Place a familiar object such as a coin or
key in the clients hand and ask what the object is. This sensation is a function of the brain, not of the
spinal pathways.
d.6. Graphesthesia is the ability to identify letters, numbers, or shapes drawn on the skin.
d.7. Integration of sensation is a higher cortical function. A two-point discrimination test is performed
by touching the client simultaneously on opposite sides of the body with a sharp object and asking the
client to ascertain the number of objects felt. The normal response is two. If only one is felt, the brain
function of integration is abnormal.
e. Reflexes:
e.1. Deep tendon ref lexes (DTR) are involuntary contractions of muscles or muscle groups responding
to brisk stretching near the insertion site of muscle.
e.2. Superficial or cutaneous ref lexes are elicited by irritating the skin on the area being assessed.
They are diminished or absent with dysfunction of the reflex arc.
The superficial reflex generally assessed is the plantar. To assess the plantar reflex, the handle of the
reflex hammer is used to stroke the outer aspect of the sole of the foot from the heel and across the ball
of the foot to just below the big toe. Plantar flexion or curling under of the toes, should occur.
Abnormal reflexes- the absence of DTR in clients is considered an abnormal finding. A fanning of the
toes and dorsiflexion of the big toe in response to the assessment of the plantar reflex is calledBabinski Ref lex. This abnormal response indicates corticospinal disease and is the most important abnormal
superficial reflex.
Techniques Eliciting Major Reflexes
Figure Used to Record Muscle Strength
Gerontological Considerations
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Important to distinguish normal aging changes from abnormal changes
Determine previous mental status for comparison. Assess mental status carefully to distinguish delirium
from dementia.
Normal changes may include:
Losses in strength and agility; changes in gait, posture and balance; slowed reaction times and
decreased reflexes; visual and hearing alterations; deceased sense of taste and smell; dulling of tactile
sensations; changes in the perception of pain; and decreased thermoregulatory ability
Diagnostic Tests
Computed tomography(CT)
Positron emission tomography (PET)
Single photon emission computed tomography (SPECT)
Magnetic resonance imaging (MRI)
Cerebral angiography
Myelography
Noninvasive carotid flow studies
Transcranial doppler
Electroencephalography (EEG)
Electromyography (EMG)
Nerve conduction studies, evoked potential studies
Lumbar puncture, Queckenstedts test, and analysis of cerebrospinal fluid
Magnetic Resonance Imaging
If you think education is expensive, try ignorance.
~Attributed to both Andy McIntyre and Derek Bok
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Neuroglia-protect and nourish neurons; mitotic - do not transmit impulses
Neuroglia Function
A strocytes Supply nutrients to neurons
Microglia Provide protection against microorganisms
Oligodendrocytes Wrap tightly around nerve f ibers to f orm myelin sheath
Ependymal cells Ciliated; line brain cavities; f orms CSF
Schwann cells Phagocytic cells that f orm myelin sheath around nerve f ibe
Satellite cells Found in the PNS; may maintain chemical balance of neur