Lower Limb Neurological examination Flashcards
What are the different stages involved in the examination?
- Introduction
- Inspection
- Tone
- Power
- Reflexes
- Sensation
- Co-ordination
- Conclusion
What is involved in the Introduction ?
Introduction:
Organise the equipment you need: tendon hammer, cotton wool, disposable neurological pins, 128Hz tuning fork
Wash your hands with water or alcohol gel
Approach the patient from his right-hand side
Introduce yourself to the patient
Check identity by asking name and date of birth
Explain procedure to the patient
Obtain verbal consent for examination
Ask patient if he is in any pain or discomfort
What is involved in the Inspection ?
Examination of any part of the body should start with inspection.
GAIT: The patient’s gait should be observed and assessed as they walk into the room; already you are looking for “clues”. Assess the gait and assist the patient onto the examination couch. (If patient is not observed coming into the room, ask them to stand and walk to observe their gait at an appropriate point in the examination e.g. at end of motor system or at end of full examination.) The legs should be as fully exposed as possible. Always compare right with left.
Observe the posture of the limbs, look for any asymmetry
Observe the size and shape of the muscles
Observe any scars or bruising
Note any abnormal movements
Look for muscle fasciculation
What is involved in the Tone ?
Assessment of tone;
Ask the patient to relax their leg and allow you to move it
Internally and externally rotate the leg, then briskly lift the patient’s
knee off the bed
Observe whether foot lifts off the bed
What is involved in the Power ?
Power is assessed by active movements against resistance of each joint in turn. Below is a screening examination ensuring testing of all root levels L1 to S2. It is not a full assessment of each muscle group.
- Hip flexion [iliopsoas L1/2] – “lift your leg up, don’t let me push it down”
- Hip extension [gluteus maximus L4/L5/S1] – with your hands under the
heels “press your feet into the couch” - Knee flexion [ hamstring L5/S1] – “bend your knee and try to pull your
heel towards your bottom” - Knee extension [quadriceps L3/4]–with the knee starting from a flexed position, “try to straighten your leg out”
- Ankle dorsiflexion [tibialis anterior L4/5]- “pull your foot up towards you,
don’t let me straighten it” - Great toe dorsiflexion [extensor hallucis longus L5] –“curl your big toe up towards you, don’t let me push it down”
- Ankle plantar flexion [gastrocnemius S1/2] – “point your foot, don’t let me push it back”
What is involved in the Reflexes ?
- Elicit the 2 lower limb tendon reflexes and assess for clonus
- Elicit the plantar response
The tendon hammer should be held at the end distant from the rubber head, and you should aim to deliver a brisk, staccato type stimulus.
The patient should lie in a comfortable position with the legs relaxed
Ensure the muscle being tested is exposed
Knee Jerk L3/4
With your non-dominant hand lift the knee up slightly, ensure you have the weight of the patient’s leg i.e. the patient is relaxed
Strike the patella tendon with a brisk, staccato tap from the tendon hammer
Observe the response of the quadriceps muscle
Compare the response with that of the opposite side
Ankle Jerk S1
Flex the leg at the knee out to the side
Hold the foot in gentle dorsiflexion
Strike the Achilles tendon with a brisk staccato tap from the tendon
hammer
Observe the response in the calf muscle
Compare the response with that of the opposite side
Clonus should be elicited with the leg in the same position as for the ankle jerk. Briskly dorsiflex the foot and hold it in this position. If clonus is present there will be repetitive “beating” of the foot.
Plantar response
Holding the ankle
Apply a firm tactile stimulus to the lateral border of the sole of the foot
Observe the response of the toes
The normal response is a flexor plantar response
Reinforcement
If the reflex appears absent, try a second time. If it has not been elicited on the second attempt, try a reinforcement manoeuvre e.g. clenching teeth (for upper limb reflexes) or gripping hands together (for lower limb reflexes).
What is involved in the Sensation ?
Before formal testing, ask the patient if they have noticed any altered sensation, numbness or paraesthesia.
There are several different sensory modalities. The clinically important ones are pin-prick, proprioception (joint position), vibration, light touch, temperature and 2 point discrimination.
Pain or Pinprick (Spinothalamic tract)
Use a disposable neurological pin
Establish a baseline for sharpness on the sternum
Ask the patient to close their eyes and report if the sensation is sharp or blunt
Examine the legs bearing in mind the segmental distribution of the spinal nerves
Dispose of pin in yellow sharps box
Proprioception (Dorsal Columns)
Test this in the distal aspect of the limb first
Educate the patient by holding the distal phalanx of the great toe,
moving the toe and establishing toe up and toe down positions
Ask the patient to close his eyes, and report if the toe is up or down
Holding the toe along the medial and lateral borders move the
patient’s toe
If there is any abnormality, test again at the next more proximal joint.
Vibration Sense
Using a vibrating tuning fork, educate the patient by holding the base
against the sternum to allow them to identify the sensation
Ask the patient to close their eyes
Hold the vibrating tuning fork against a distal bony prominence e.g. the
first metatarsal phalangeal joint
Ask the patient to identify the vibration
If any abnormality repeat the process at a more proximal bony
prominence eg medial malleolus
Light touch
Ask the patient to close their eyes and respond verbally to each touch
Touch the skin with a small piece of cotton wool, do not stroke
Ensure irregular time intervals to prevent prediction of the stimulus
Examine the legs bearing in mind the dermatomal distribution of the
spinal nerves
If an area of numbness is identified, map its distribution
Dispose of cotton wool in clinical waste bins
Temperature
(Not routinely done. Pain/pin prick sensation travels in the spinothalamic tracts but if an abnormality is detected, additional testing of the spinothalamic tracts can be done using something cold (e.g. metal tuning fork/cold spray) to test further.)
Using the cold stimulus establish a baseline for coldness on the sternum
Ask the patient to report if it is as cold on their arms
Map out any area of decreased temperature sensation
What is involved in the Co-ordination ?
- Heel-shin
Ensure the patient is lying flat with both legs straight. Ask him to lift the leg and place the heel onto the opposite knee. Then ask him to slide the heel along the shin until he reaches the ankle. (Ask patient to lift off heel and replace on knee. Do not slide up.) Ask him to repeat this cycle 2 or 3 times. Repeat on the opposite side.
Ask patient to come off the couch and assess their gait as they walk across the room, turn and come back to you. Be prepared to support or catch your patient if necessary.
- Heel to toe
Ask the patient to walk across the room, taking small steps, whilst placing his toe of one foot against the heel of the other foot. You may have to demonstrate and ask him to copy you. Ask him to turn and walk back to the starting position again heel to toe - Romberg’stest
An additional test looking for sensory ataxia - the patient has a tendency to be unsteady because of a lack of proprioception.
Ask the patient to stand with their feet together. Check he has “got his balance”. Stand close beside him and extend your arms to the front and back of the patient, ready to catch any fall. Then, once he is steady, ask him to close his eyes. A normal subject will maintain his balance. Someone with sensory ataxia will sway and may fall over.
What is involved in the Conclusion ?
Thank patient; Wash your hands; Summarise your findings
How is power assessed?
The MRC scale of muscle strength uses a score of 0 to 5 to grade the power of a particular muscle group in relation to the movement of a single joint.
Grade 0: No movement is observed.
Grade 1: Only a trace or flicker of movement is seen or felt in the muscle or fasciculations are observed in the muscle
Grade 2: Muscle can move only if the resistance of gravity is removed. As an example, the elbow can be fully flexed only if the arm is maintained in a horizontal plane.
Grade 3: Muscle strength is further reduced such that the joint can be moved only against gravity with the examiner’s resistance completely removed. As an example, the elbow can be moved from full extension to full flexion starting with the arm hanging down at the side.
Grade 4: Muscle strength is reduced but muscle contraction can still move joint against resistance.
Grade 5: Muscle contracts normally against full resistance.
Describe the gait in “foot drop”. What neurological lesion results in “foot drop”?
Foot drop (weakness of the dorsiflexion muscles in the foot) is common, causes difficulty in walking, and greatly increases risk of falling. Spontaneous unilateral foot drop usually has a peripheral cause. The lesion can be in the L5 nerve root, sciatic nerve, common peroneal nerve, deep peroneal nerve, or superficial peroneal nerve (figure⇓). The extent of the sensory or motor deficit depends on the location (or level), severity, and duration of the injury or compression.
Define the terms 1. hemiplegia 2. paraplegia 3. quadriplegia
There are many different causes of paralysis—and each one may result in a different kind of paralysis, such as quadriplegia (paralysis of arms and legs), paraplegia (being paralyzed from the waist down), monoplegia (paralysis in one limb), or hemiplegia (being paralyzed on one side of the body).
In a patient with hemiplegia describe the difference in posture between the upper limb and lower limb. Why does this occur? What is this pattern of weakness called?
An individual living with hemiparesis experiences a weak paralysis on one side of the body, while hemiplegia may cause the person to experience full paralysis on one side of their body, as well as difficulty breathing or speaking.
Can see hemiplegic gait with swinging leg?
Define the term proximal myopathy. What actions would the patient have difficulty with? Which diseases is this associated with?
Proximal myopathy presents as symmetrical weakness of proximal upper and/or lower limbs. There is a broad range of underlying causes including drugs, alcohol, thyroid disease, osteomalacia, idiopathic inflammatory myopathies (IIM), hereditary myopathies, malignancy, infections and sarcoidosis.
Define 1. Upper motor neurone 2. Lower motor neurone
Upper motor neurons are first-order neurons which are responsible for carrying the electrical impulses that initiate and modulate movement. Various descending UMN tracts are responsible for the coordination of movement. The major UMN tract that initiates voluntary movement is the pyramidal tract.
The lower motor neuron is responsible for transmitting the signal from the upper motor neuron to the effector muscle to perform a movement. There are three broad types of lower motor neurons: somatic motor neurons, special visceral efferent (branchial) motor neurons, and general visceral motor neurons.
Complete the table to contrast established upper and lower motor neurone lesions.
See table?
Draw a diagram of the dermatomes of the lower limb.
See image
