Basic Neurological Exam of Lower Limbs Flashcards
What are the main steps in the neurological exam of the lower limbs?
Prepare patient Hand hygiene Gait Inspection Tone Power Deep tendon reflexes Coordination Sensory exam Completing exam
How do you prepare the patient?
Explain reason for exam
In general what it involves
Ask about pain in legs
Advise them to inform you if exam uncomfortable or causes pain
Adequately expose legs - dignity maintained
Check if ready to proceed
How do you measure gait?
Ask patient to walk away from you and then back Observe Ease and fluidity of movement Way feet strike floor Note asymmetry Joint problems can affect gait
How do you perform an inspection?
Check lumbar region of back whilst patient standing - Scars - Deformity Ask them to lie down on bed - can raise head rest Inspect lower limbs - Posture - Muscle bulk - If muscle wasting, note pattern - Fasciculations
What is a decrease in muscle volume or bulk called?
Muscle atrophy
What is an increase in muscle volume or bulk called?
Muscle hypertrophy
What are fasciculations?
Muscle twitches due to involuntary contractions of muscle fibres
How do you assess tone?
Assess passive resistance against movement at knee and ankle Patient must relax limbs - Let me take the weight of your legs - Make your legs go loose and floppy like a rag doll At knee - Hold patient's foot with one hand - Support leg with other - Swing gently a couple of time - Suddenly flex knee with hand not holding foot At ankle - Swivel ankle gently a few times - Rapidly dorsi-flex foot Repeat on other leg Look for clonus
What is tone?
Partial contraction continuously present that helps maintain normal posture
Define hypotonia
Abnormally low tone
Define hypertonia
Abnormally high tone
What is clonus?
Rapid jerky muscle contractions
When can clonus occur?
If muscle suddenly stretched
What type of clonus considered abnormal?
Sustained clonus
More than 5 beats
How do you assess power?
Systematically check individual muscles
Ask patient to resist efforts to move particular body part
Correct positioning important so only particular muscle in question being tested
When testing strong muscles use maximum mechanical advantage so slight weakness not missed
- Normal muscle may appear weak if placed at mechanical disadvantage
Main movements at each major joint examined
One side compared with other
Start at hips
Progress distally
Provide clear and explicit instructions
- Verbal
- Non-verbal
What influences the results of a neurological exam?
Patient's: - Motivation - Pain - Changes in tome Your own muscle strength
How do you test the power of hip flexion?
Ask patient to flex hip to about 40 degrees
Ask them to keep leg in this position as you apply downward pressure just proximal to knee joint
What are the nerve roots controlling hip flexion?
L2
L3
How do you test the power of hip extension?
Ask patient to push their heel down on couch and stop you raising it
What are the nerve roots controlling hip extension?
L4
L5
S1
How do you test the power of hip abduction?
Place hands on outside of patient’s thighs
Ask them to push their knees apart
What are the nerve roots for hip abduction?
L4
L5
S1
How do you test the power of hip adduction?
Place hands on inside of patient’s thighs
Ask them to push knees together
What are the nerve roots for hip adduction?
L2
L3
L4
How do you test the power of knee flexion?
Ask patient to bend their knee
Ask them to try to move heel along couch towards their bottom
You apply resistance
What are the nerve roots for knee flexion?
L5
S1
How do you test the power of knee extension?
Ask patient to straigten leg as you apply pressure distal to knee
What are the nerve roots for knee extension?
L2
L3
L4
How do you test the power of ankle dorsiflexion?
Place your hands over dorsal aspect of patient’s foot
Ask them to push foot towards face against your resistance
What are the nerve roots for ankle dorsiflexion?
L4
L5
How do you test the power of ankle plantar flexion?
Place fist over plantar aspect of patient’s foot
Ask them to push their foot down against your resistance
What are the nerve roots for ankle plantar flexion?
S1
S2
How do you test the power of inversion of the foot?
Plantar-flex patient’s foot
Ask them to keep foot turned that way as you pull the other way
What are the nerve roots for inversion of the foot?
L4
L5
How do you test the power of eversion of the foot?
Dorsi-flex patient’s foot
Ask them to keep foot turned that way as you pull the other way
What are the nerve roots for eversion of the foot?
L5
S1
How do you test the power of great toe extension?
Ask patient to pull toe towards their face as you apply resistance
What are the nerve roots for great toe extension?
L4
L5
S1
What must muscle strength be graded against?
Patient’s maximum effort for particular muscle group
What is conventionally used to grade muscle strength?
Medical Research Council (MRO) scale
Best available grading system
Has limitations
What are the categories for the MRO scale?
0 = complete paralysis 1 = flicker or trace of contraction 2 = Active movement with gravity eliminated 3 = Active movement against gravity 4 = Active movement against gravity and resistance 5 = normal power
How else can muscle power be assessed?
Using functional testing Test groups of muscles Useful for: - Detecting mild weakness - Monitoring progression of neurological problem
How can mild upper limb weakness be tested functionally?
Ask patient to close eyes
Hold arms straight out with palms facing upwards for one minute
If reduced strength, patient’s arm starts to pronate and drift down = pronator drift
How do you test the strength of the pelvic girdle muscles functionally?
Ask patient to stand from chair or squatting position
What should you describe if muscle weakness is detected on examination?
Pattern
- Symmetric or asymmetric
- Proximal or distal
What does the suffix “-plegia” mean?
Paralysis = complete loss of strength
What does paresis mean?
Incomplete loss of strength
Define hemiplegia
Paralysis on one side of body
Define hemiparesis
Paresis on one side of body
Define monoplegia
Paralysis of one limb
Define monoparesis
Paresis of one limb
Define paraplegia
Paralysis of both lower limbs
Define paraparesis
Paresis of both lower limbs
Define quadriplegia
Paralysis of all four limbs
Define quadriparesis
Paresis of all four limbs
What happens in a deep tendon reflex?
Muscle tendon tapped with tendon hammer
Muscle normally contracts
Because of two-neuron reflex involving spinal segment innervating muscle
Provides information about integrity of central and peripheral nervous systems
Patient must be relaxed for test - anxiety makes reflexes difficult to elicit
What should you do if the tendon reflex seems to be absent?
Ask patient to curl their fingers, lock them together, and pull tight while you repeat manoeuvre
Isometric contraction of another muscle group can help increase reflex
How do you do the knee jerk test?
Patient’s knee slightly flexed
Place arm under both knees to support them
Use tendon hammer to tap patella tendon between patella and tibial tuberosity
Look for contraction of quadriceps and extension of knee
What nerve roots control the knee jerk?
L2
L3
L4
How do you do the ankle jerk test?
Externally rotate patient’s hip
Slightly flex knee
Place Achilles tendon on small amount of stretch by dorsiflexing foot at ankle
Tap over tendon to elicit ankle jerk
Look for plantar flexion at ankle and contraction of gastrocnemius muscle
Can also be tested with patient kneeling in chair
What nerve roots control the ankle jerk?
S1
S2
How do you test the plantar (Babinski) reflex?
Warn patient this test can be a little uncomfortable
Run thumb nail or blunt object along lateral aspect of patient’s sole and then across metatarsal heads
Big toe flexes down
Abnormal response: big toe extends up
- Indicates upper motor neuron lesion
Abnormal plantar reflex in absence of other neurological signs is unlikely to be of significance
What do decreased reflexes indicate?
PNS problem
What do increased reflexes indicate?
CNS problem
What is the conventional grading system for reflexes?
0 = absent 1+ or + = hypoactive 2+ or ++ = normal 3+ or +++ = hyperactive without clonus 4+ or ++++ = hyperactive with clonus
What are the nerve roots controlling the plantar reflex?
L5
S1
S2
How do you test coordination?
Tested after motor strength Reduced power can make test difficult Heel-shin test: - Lift foot to touch elevated finger - Place heel of that foot on patella of opposite leg - Run heel down shin to ankle - Repeat on other side
How do you close the examination?
Say you’re done
Offer assistance if required
What clinical signs does an upper motor neuron lesion cause?
Slight atrophy Increased (spacity) tone Hyper-reflexia +/- clonus Upgoing plantar reflex Absent fasciculations
What clinical signs does a lower motor neuron lesion cause?
Marked atrophy - up to 70-80% muscle mass Decreased (flaccidity) tone Decreased or absent reflexes Normal or absent plantar reflexes Fasciculations may be present
What might affect the results of a sensory exam?
Patient's ability to respond to your instructions Tiredness Anxiousness Unable to concentrate Unclear instructions
What sort of changes should you focus on in a sensory exam?
Major changes rather than subtle variations
What are the two main types of sensation tested in the clinical situation?
Primary sensation
Cortical sensory function
What does primary sensation testing mean?
Reflects integrity of PNS Assessing patient's response to - Pain - Touch - Vibration - Thermal stimulus - Proprioception
What does cortical sensory function testing mean?
Reflects integrity of CNS Includes - 2 point discrimination - Graphaesthesia - Stereognosis - Bilateral simultaneous stimulation
What is required for the testing of cortical sensory function?
Normal primary sensation
What are the main modalities used to test primary sensation?
Pain Light touch Thermal sensation Vibration sense Proprioception
How do you test for pain?
Use sharp instruments like Neurotips or new toothpicks
Don’t reuse
Don’t use needles
Test in unaffected area first like upper chest
Test in middle of each dermatome from L1-S2, comparing sides
How do you test for light touch?
Test with wisp of cotton wool
If unavailable, use tip of finger
Test in unaffected area like upper chest
Test in middle of each dermatome from L1-S2, comparing sides
How do you test for thermal sensation?
Don’t need to for OSCE if pain sensation normal
Use cold tuning fork
Difficult to test in routine clinical situation
How do you test for vibration sense?
Use tuning fork
Ask patient to close eyes
Place vibrating tuning fork on tip of great toe/interphalangeal joint
Ask patient what feeling they get
Alternative: deaden vibration and ask them to tell you when it stops
If reduced/absent test proximally to determine level of abnormality
How do you test for proprioception?
Tested at great toe
Place toe in neutral position
Grasp on either side between thumb and forefinger
Use other hands to stop other toes from touching
Move in plantar or dorsal direction
Ask patient to close eyes and say which way toe has been moved
If just assessing the sensory aspect, what does the exam begin with?
Gait
Inspection of the back and lower limbs
