Neuro Exam Flashcards
What type of deficits are produced by brainstem lesions?
Ipsilateral loss in face, contralateral loss in body
Explain the scale for grading muscle strength
0/5= no muscle contraction 1/5= slight contractive but no joint movement 2/5= active movement with gravity eliminated 3/5= complete ROM against gravity but not resistance 4/5= complete ROM against gravity with some resistance, movement at joint with some effort 5/5= complete ROM against gravity with full resistance, no movement at joint
Why are CN VI lesions the most common isolated CN palsy? When is it often seen?
D/t long peripheral course
Often seen in pts with subarachnoid hemorrhage, late syphilis and trauma
How is the cerebellum tested? What specifically is being tested?
–Finger-to-nose: dysmetria/dystaxia of voluntary movements
–Finger-to-finger: position sense, labyrinth and cerebellum function
–Heel-to-shin: tap heel on opposite patella and glide slowly along shin, look for accuracy and smoothness
–Rapid alternating movements: rapid pronation and supination of hand, deficit seen in frontal and cerebellar damage
–Saccades: tests contralateral cerebral hemisphere
What is the Romberg test?
Generally evaluated with gait and station but tests proprioception
What type of deficits are produced with thalamic lesions?
Hemisensory loss of all modalities
Differentiate between Bell’s Palsy, bilateral facial palsies and supra nuclear (central) facial palsy
Bell’s palsy: peripheral facial paralysis, caused by trauma or infection, but in most cases is idiopathic
Bilateral facial palsies: can occur in Miller:Fisher variant of Guillain-Barre syndrome
Supranuclear (central) facial palsy): spares upper face, usually associated with hemiplegia, important in determining if weakness is central or peripheral
What can lesions in CN X result in?
Dysphonia, dysphagia, dyspnea, loss of gag or cough reflex
How do you test CN I? How might CN I be affected?
Test via: with eyes closed, have patient depress each nostril and sniff to identify non-irritating, familiar odors on each side
Loss of smell can occur with smoking, chronic sinus dz, head trauma, aging, Parkinson’s dz, cocaine use
Loss of smell can indicate an ipsilateral lesion
What can CN III lesions cause?
Ptosis, pupillary dilation or asymmetry, position change of the eye (i.e. down and out)
What is clonus?
UMN sign, abnormal pattern involving rapidly alternating involuntary contractions and relaxations of skeletal muscle; test if reflexes are hyperactive
Differentiate between myopia and presbyopia
Myopia: nearsightedness (loss of distance vision)
Presbyopia: farsightedness (loss of nearby vision)
Which motor dermatomes are tested with wrist flexion? Extension?
Wrist flexion: C6-7
Wrist extension: C6-7
What are the motor dermatomes relevant to the quadriceps?
L2-4
Which muscles and motor dermatomes are tested with knee flexion? Extension?
Knee flexion: hamstrings, L4-S2
Knee extension: quadriceps: L2-L4
How is temperature tested?
Often omitted if pain is intact, test tube with hot and cold water
Which muscles and motor dermatomes are tested with hip flexion? Extension?
Hip flexion: psoas and iliaques, L2-4
Hip extension: gluteus maximus, S1
What type of deficits are produced with cortical lesions?
Intact primary sensations but loss of cortical sensations
What four umbrella sensations is the sensory system tested for?
–pain and temperature
–proprioception, 2-point tactile discrimination and vibration
–light touch
–discriminative sensations
Explain the DTR grading scale
0: no response
1: diminished, low normal
2: average, normal
2+: more brisk tha normal but no spread
3: brisk, spread to involve moments across more than 1 joint
4: hyperactive with clonus
What are the motor dermatomes relevant to the triceps?
C6-8
What sensory dermatome corresponds to the nipple? Umbilicus? Inguinal?
Nipple: T4
Umbilicus: T10
Inguinal: L1
What are the four discriminative (cortical) senses?
Stereognosis: ability to ID shapes of objects or recognize objects place in the hand
Graphesthesia: ability to ID #s written on the palm
2-point discrimination: ability to distinguish being touched by one or two points
Double simultaneous stimulation (extinction): ability to feel two locations being touched simultaneously
How do you test CN IX?
Afferent limb of the gag reflex: touch posterior pharynx with cotton applicator
Which four systems coordinate muscle movement? What specifically are their roles?
–Motor system: strength
–Cerebellar system: rhythmic movement and posture
–Vestibular system: balance, coordination of eye, heady and body movement
–Sensory system: position sense
What is the anal wink reflex?
–S4-5
–Cauda equina or lesions affecting the sacral region
–Touch areas around perirectal region and note contraction
What are the functions of CN IX?
–motor: innervates stylophayngeus muscle→elevates and widens pharynx during swallowing
–sensory: taste to posterior 1/3 of tongue, sensation to palate and pharynx, skin of external ear
–afferent limb of gag reflex
Explain peripheral pattern of weakness. What might this be a sign of?
=weak arm flexors and leg extensors
–associated with LMN dysfxn
What are the motor dermatomes relevant to the biceps?
C5-6
What can lesions of CN IV result in?
Extorsion, weakness of downward gaze, vertical diplopia, head tilting (opposite lesion)
Describe Parkinsonian gait
–symmetrical abnormal gait –anteroflexed posture –festinating –small steps –↓arm swing
Describe root sensory loss and give two examples.
=loss in different nerve distributions with a common root
Ex) C5-C7 in the arms, L4-S1 in the legs
What can lesions in CN XII cause?
Tongue deviation to the weak side and inability to push tongue to the opposite cheek
How is light touch tested?
Fine wisps of cotton
Differentiate between dysarthria and aphasia?
Dysarthria: defective articulation d/t defect in motor control of speech apparatus
Aphasia: disorder in producing or understanding language, usually d/t lesions in the dominant hemisphere
What can lesions to CN VIII cause?
Cochlear division lesions: destructive lesions can lead to sensorineural hearing loss, irritative lesions can cause tinnitus
Vestibular division lesions: disequilibrium, nystagmus
What does the H-test assess?
CN III: adduction, downward gaze, elevation
CN IV: inward rotation, downward and lateral movement
CN VI: lateral movement
How do you test CN II?
Test via pupillary light reflex (CN II and III), near response (constriction, convergence and accommodation), static finger wiggle test for visual field
Describe magnetic gait
–symmetrical abnormal gait
–small steps
–feet do not leave ground
–seen in front lobe processes and hydrocephalus
What are the functions of CN X?
Efferent limb of the gag reflex, innervates pharynx and larynx musculature, visceral afferent fibers and parasympathetic innervation to smooth muscle from the mucosal of the esophagus to mid-transverse colon and lining of the respiratory system
List the five commonly tested reflexes
–Biceps: C5 –Brachioradialis: C6 –Triceps: C7 –Patellar: L4 –Achilles: S1
How do you test CN V?
–check facial sensation in the forehead, cheek and chin
–check motor function via lateral jaw movements and jaw clenching
–check corneal (blink) reflex (CN V and VIII)
What sensory dermatome corresponds to the patella? Medial calf? Anterolateral calf? Posterolateral calf? Big toe? Little toe?
Patella: L4 Medial calf: L4 Anterolateral calf: L5 Posterolateral calf: S1 Big toe: L5 Little toe: @1
Where is the lesion located if reflexes are hyperactive? Hypoactive?
Hyperactive: CNS
Hypoactive: PNS
How might you document findings regarding the CNs on a SOAP note?
Cranial nerves are grossly intact: II-XII
Cranial nerves II-XII are intact to confrontation: testing
Explain pyramidal pattern of weakness. What might this be a sign of?
=weak arm extensors and leg flexors
–associated with UMN dysfxn
What is a functional loss?
Non-anatomical distribution
Which muscles and motor dermatomes are tested with ankle plantar flexion? Dorsiflexion?
Plantar flexion: gastrocnemius, S1
Dorsiflexion: tibialis anterior, L4-5
What sensory dermatome corresponds to the long finger? Little finger?
Long finger: C7
Little finger: C8
Describe atasia/abasia (functional) gait
–symmetrical abnormal gait
–gait all over the place
–pt does not fall but looks like they will
–usually psychogenic
What can lesions of CN III, IV and VI cause?
Diplopia and weakness of muscles innervated by that specific cranial nerve
Which motor dermatomes are tested with shoulder abduction, flexion and extension?
C5
Differentiate between delirium, dementia and depression
Depression: feeling down or hopeless, anhedonia
Delirium: common in older adults d/t hospitalization, screen via CAM dx algorithm, usually reversible
Dementia: must eliminate depression and delirium before dx, meds can slow progression but usually not reversible
What might problems with toe walking indicate? Heel walking? Tandem walking? Hopping in place?
Toe walking: distal muscle weakness
Heel walking: CST lesions or distal muscle weakness
Tandem walking: imbalance
Hopping in place: proximal and distal muscle strength, position sense, cerebellar function
Differentiate between the different levels of A&O
x1: person
x2: person, place
x3: person, place, time
x4: person, place, time, event
What can lesions to CN VII cause?
paralysis of muscles of facial expression, loss of corneal reflex, hyperacusis, crocodile tears syndrome
Differentiate between decorticate and decerebrate
Decorticate: both arms flexed, legs stiff and extension, lesion above brainstem in thalamus
Decerebrate: arms extended and legs stiff extended, lesion in midbrain
How might compressive brainstem lesions affect CN III?
Brain herniation may cause dilation and fixation of the pupil via pupilloconstrictor fibers of CN III. Somatic efferent fibers supplying the EOM can cause external strabismus (second effect)
How do you test CN X?
Listen to voice for hoarseness and nasal tone, check gag reflex, difficulty swallowing, say “ah”
If a patient is unable to rise from a chair with arms folded, what might this indicate?
Proximal muscle weakness
How do you test CN XI?
Test SCM by having pt turn head against resistance; test trapezius muscle by having pt shrug shoulders against resistance
How is proprioception tested?
Move pt’s big toe through an arc with pt’s eyes closed
What do CN VI lesions result in?
Convergent (medial) strabismus (esotropia): inability to ABDuct eye d/t LR weakness
Horizontal diplopia: maximal separation of images when looking toward the paretic LR
What are the functions of CN XI?
Cranial division: innervates muscles of the larynx
Spinal division: innervates trapezius and SCM muscle
How do you test CN VIII?
Cochlear division: hearing via whisper test or finger rub
Vestibular division: balance
Why is CN IV particularly vulnerable to head trauma?
Has a long course around the brainstem
What sensory dermatome corresponds to the auricle? Earlobe? Anterior/posterior neck? Shoulder?
Auricle: C2
Earlobe: C3
Anterior/posterior neck: C3
Shoulder C4
What is a Babinski sign?
UMN sign, abnormal when sole of foot is scratched from heel toward toes and great toe extends
Describe waddling pelvis
–asymmetrical abnormal gait
–usually myopathic dz
–hips sway or “waddle” from side to side
How do you test CN VII?
–motor: facial expression, eye and mouth closure
–sensory: taste for salty, sweet and bitter substances anterior to 2/3 of tongue
–PS: saliva and tear secretion
–general sensation: external ear
What are signs and sx of LMN dysfunction?
Wasting, fasciculation, ↓muscle tone, ↓reflexes, peripheral pattern of weakness (weak leg extensors), muscle disease; can have normal tone, reflexes and muscle bulk but erratic power
What can lesions in CN XII cause?
Tongue deviation to the weak side and inability to push tongue to the opposite cheek
What sensory dermatome corresponds to the radial aspect of the forearm?
C6
How is pain tested?
Broken bottom tip or tongue depressor
What can CN V lesions cause?
↓sensation of the face and mucous membranes, loss of corneal reflex, weakness of muscles of mastication, jaw deviation
What are important considerations regarding onset during a neuro exam? Give examples
Abrupt or sudden onset/acute onset: cerebral hemorrhages, vascular dz, infections, head trauma
Progressive onset: degenerative dz
Intermittent/relapsing episodes: demyelinating dz (i.e. MS), vascular dz
What is nystagmus? What causes it?
=rhythmic oscillation of the eyes (laterally based on fast beat)
–can be seen slightly in extreme gaze deviation and can occur in one or more planes
–can be d/t impairment of vision at an early age, disorders of the labyrinth and cerebellar systems or drug toxicity
Describe scissoring gait
–symmetrical abnormal gait
–feet crossing over with toes dragged
–often seen in cerebral palsy or MS
Which motor dermatomes are tested with hand grip? Finger abduction? Thumb opposition?
Hand grip: C7-T1
Finger abduction: C8-T1
Thumb opposition: C8-T1
What are sx of UMN dysfunction?
Hypertonia, hyperreflexia, pyramidal pattern of weakness (weak arm extensors), pronator drift
Differentiate between postural/kinetic tremors and resting/pill rolling tremors
Postural or kinetic: due to essential tremor
Resting (pill rolling): basal ganglia dz
Describe hemiplegic gait
–asymmetrical abnormal gait
–usually d/t UMN lesion, such as stroke
–circumducted gate
–↓arm swing ipsilateral to affected leg
Describe foot drop
–asymmetrical abnormal gait
–unable to keep foot up during heel walk
–can be d/t UMN or LMN lesions
What is the corneal (blink) reflex?
=protective reflex involving CN V (afferent) and VII (efferent)
Ask pt to look up and away from the examiner→touch cornea with cotton wisp→blink
How is vibration tested?
Tuning fork
Which motor dermatomes are tested with elbow flexion? Extension?
Elbow flexion: C5-6
Elbow extension: C6-8
What might a shallow knee bend in each leg during gait indicate?
Weakness of hip extensors, quadriceps or both
What are the motor dermatomes relevant to the gastrocnemius?
L5-S2
How do you test CN III?
Check for eyelid ptosis, check pupil shape and symmetry, pupillary light reflex and near reaction
Which motor dermatomes are tested with hip adduction? Abduction?
Hip adduction: L2-4
Hip abduction: L4-S1
How do you test CN XII?
Have pt protrude tongue and push into opposite cheek
Lesions to the optic nerve in what location would cause ipsilateral blindness?
Anterior to the chiasm
What is the cremasteric reflex?
–Afferent L1, efferent L2
–Stroking inner thigh causes scrotum to rise on stroked side
Describe sensory ataxic gait
–symmetrical abnormal gait
–high stoppage
–broad based
–seen with posterior column damage and peripheral neuropathy
What are important associated sx to assess during a neuro exam?
Headache, dizziness or vertigo, weakness, numbness or abnormal sensation, fainting or blacking out, seizures, tremors or involuntary movements
What are frontal lobe release reflexes?
Rooting, grasping, glabellar and palms-mental reflexes seen in infants
Explain pronator drift. What might this bee a sign of?
=arms held extended for 2 minutes drift down and supinate
–associated with UMN dysfxn
What is an abdominal reflex?
–T10-12
–Test all four quadrants
–Stroking abdomen causes umbilicus to move toward area of stimulation
What are the functions of CN XII?
Innervates all intrinsic and extrinsic tongue muscles
What are the two signs of meningitis?
Kerning’s sign: pt supine→flex thigh then straighten knee→pt will experience pain in neck
Brudzinski’s sign: pt supine→lift pt’s head→knees come up in response
