Chapter 24 – Neuro Muscular
❖ Developmental
INFANT/CHILDREN
● Neurologic system is not completely developed at birth
⇒ Movement is directed primarily by primitive reflexes
⇒ Persistence of primitive reflexes is an indication of CNS dysfunction
⇒ Sensory and motor development proceed with gradual acquisition of myelin needed
to conduct most impulses
⇒ As myelination develops infant is able to localize stimulus more precisely and make
more accurate motor response
AGING ADULT
● Atrophy with steady loss of neuron structure in brain spinal cord
● Velocity of nerve conduction decreases making reaction time slower in some older persons
● Increased delay at synapse results in diminished sensation of touch, pain, taste, and smell
● Motor system may show general slowing down of movement, muscle strength, and agility
decrease
● Progressive decrease in cerebral blood flow and oxygen consumption may cause dizziness
and loss of balance
❖ Culture and Genetics
⮚ Strokes
▪ Racial
● 5th most common cause of death in the US
● screening of hyperlipidemia and HTN with statin treatment
▪ Geographic
● Existence of “stroke belt” – 8 states with increased stroke mortality
▪ Nationwide
● Higher for African Americans and Hispanic populations
▪ Global concern
● Research evidence indicates that 90% of stroke burden due to modifiable factors
,❖ Subjective Data
, Objective Data
Test Cranial Nerves
Cranial Nerve I – Olfactory
Do not test routinely. Only those who report loss ● Air passages are occluded with upper
of smell, head trauma. respiratory infection or sinusitis
Person’s eyes closed, occlude one nostril and ● Anosmia: decrease of loss of small
present an aromatic substance. occurs bilaterally with tobacco
Use coffee, toothpaste, orange, vanilla. smoking, allergic rhinitis, and cocaine
use
Normally a person can identify an odor on each Unilateral loss of smell in the absence of
side of the nose nasal disease in neurogenic anosmia
Cranial Nerve II – Optic
Test visual acuity and visual fields by Visual field loss
confrontation. Papilledema with increased intracranial
Using the opthalmoscope, examine the ocular pressure; optic atrophy
fundus to determine the color, size, and shape of
the optic disc
Cranial Nerve III, IV, and VI – Oculomotor, Trochlear, and Abducens
Palpebral fissures are usually equal in width or ● Ptosis (drooping) occurs with
nearly so myasthenia gravis, dysfunction of
cranial nerve III
Check pupils for size, regularity, equality, direct Increasing intracranial pressure causes a
and consensual light reaction, and sudden, unilateral, dilated, and
accommodation nonreactive pupil
Assess extraocular movements by the cardinal Strabismus (deviate gaze) or limited
position of gaze movement
Nystagmus: back and forth oscillation of eyes Nystagmus occurs with disease of
Assess any other nystagmus, noting: vestibular system, cerebellum, or
Pendular movement: oscillations move equally brainstem
left or right
Jerk: quick phase in one direction than a slow
phase in the other
Amplitude: degree of movement is fine,
medium, or coarse
Frequency: constant or fade after a few beats
Plane of movement: horizontal, vertical, rotary
or a combination
, Cranial Nerve V – Trigeminal
Motor Function. Decreased strength on one or both
Assess the muscles of mastication by palpating the sides.
temporal and masseter muscles as the person Asymmetry in jaw movement.
clenches the teeth Pain with clench of teeth.
Unilateral weakness occurs with
lesion of pons (same side) and
cancer metastases to skull.
Sensory Function. Decrease on unequal sensation.
Person’s eyes closed, test light sensation by touching a With a stroke, sensation of face and
cotton wisp to these designated areas on person’s body is lost on the opposite side of
face: forehead, cheeks, and chin. the lesion.
Ask the person to say “now” whenever the touch is Hemiparesis and aphasia often are
felt. associated.
Tests all three divisions of the nerve: 1) ophthalmic, 2)
maxillary, and 3) mandibular
Cranial Nerve VII – Facial
Motor Function. Muscle weakness is shown by flattening
Note mobility and facial symmetry as the person of the nasolabial fold, dropping of one
responds to these requests: smile, frown, close side of the face, lower eyelid sagging, and
eyes tightly (against your attempt to open them), escape of air from only one cheek that is
lift eyebrows, show teeth, and puff cheeks. pressed in.
Press the person’s puffed cheeks in and note that Loss of movement and asymmetry of
the air should escape equally from both sides. movement occur with both CNS lesions
and PNS lesions.
❖ Developmental
INFANT/CHILDREN
● Neurologic system is not completely developed at birth
⇒ Movement is directed primarily by primitive reflexes
⇒ Persistence of primitive reflexes is an indication of CNS dysfunction
⇒ Sensory and motor development proceed with gradual acquisition of myelin needed
to conduct most impulses
⇒ As myelination develops infant is able to localize stimulus more precisely and make
more accurate motor response
AGING ADULT
● Atrophy with steady loss of neuron structure in brain spinal cord
● Velocity of nerve conduction decreases making reaction time slower in some older persons
● Increased delay at synapse results in diminished sensation of touch, pain, taste, and smell
● Motor system may show general slowing down of movement, muscle strength, and agility
decrease
● Progressive decrease in cerebral blood flow and oxygen consumption may cause dizziness
and loss of balance
❖ Culture and Genetics
⮚ Strokes
▪ Racial
● 5th most common cause of death in the US
● screening of hyperlipidemia and HTN with statin treatment
▪ Geographic
● Existence of “stroke belt” – 8 states with increased stroke mortality
▪ Nationwide
● Higher for African Americans and Hispanic populations
▪ Global concern
● Research evidence indicates that 90% of stroke burden due to modifiable factors
,❖ Subjective Data
, Objective Data
Test Cranial Nerves
Cranial Nerve I – Olfactory
Do not test routinely. Only those who report loss ● Air passages are occluded with upper
of smell, head trauma. respiratory infection or sinusitis
Person’s eyes closed, occlude one nostril and ● Anosmia: decrease of loss of small
present an aromatic substance. occurs bilaterally with tobacco
Use coffee, toothpaste, orange, vanilla. smoking, allergic rhinitis, and cocaine
use
Normally a person can identify an odor on each Unilateral loss of smell in the absence of
side of the nose nasal disease in neurogenic anosmia
Cranial Nerve II – Optic
Test visual acuity and visual fields by Visual field loss
confrontation. Papilledema with increased intracranial
Using the opthalmoscope, examine the ocular pressure; optic atrophy
fundus to determine the color, size, and shape of
the optic disc
Cranial Nerve III, IV, and VI – Oculomotor, Trochlear, and Abducens
Palpebral fissures are usually equal in width or ● Ptosis (drooping) occurs with
nearly so myasthenia gravis, dysfunction of
cranial nerve III
Check pupils for size, regularity, equality, direct Increasing intracranial pressure causes a
and consensual light reaction, and sudden, unilateral, dilated, and
accommodation nonreactive pupil
Assess extraocular movements by the cardinal Strabismus (deviate gaze) or limited
position of gaze movement
Nystagmus: back and forth oscillation of eyes Nystagmus occurs with disease of
Assess any other nystagmus, noting: vestibular system, cerebellum, or
Pendular movement: oscillations move equally brainstem
left or right
Jerk: quick phase in one direction than a slow
phase in the other
Amplitude: degree of movement is fine,
medium, or coarse
Frequency: constant or fade after a few beats
Plane of movement: horizontal, vertical, rotary
or a combination
, Cranial Nerve V – Trigeminal
Motor Function. Decreased strength on one or both
Assess the muscles of mastication by palpating the sides.
temporal and masseter muscles as the person Asymmetry in jaw movement.
clenches the teeth Pain with clench of teeth.
Unilateral weakness occurs with
lesion of pons (same side) and
cancer metastases to skull.
Sensory Function. Decrease on unequal sensation.
Person’s eyes closed, test light sensation by touching a With a stroke, sensation of face and
cotton wisp to these designated areas on person’s body is lost on the opposite side of
face: forehead, cheeks, and chin. the lesion.
Ask the person to say “now” whenever the touch is Hemiparesis and aphasia often are
felt. associated.
Tests all three divisions of the nerve: 1) ophthalmic, 2)
maxillary, and 3) mandibular
Cranial Nerve VII – Facial
Motor Function. Muscle weakness is shown by flattening
Note mobility and facial symmetry as the person of the nasolabial fold, dropping of one
responds to these requests: smile, frown, close side of the face, lower eyelid sagging, and
eyes tightly (against your attempt to open them), escape of air from only one cheek that is
lift eyebrows, show teeth, and puff cheeks. pressed in.
Press the person’s puffed cheeks in and note that Loss of movement and asymmetry of
the air should escape equally from both sides. movement occur with both CNS lesions
and PNS lesions.
