Makindo Medical Notes

Lower Limb Neurological Examination (OSCE)

Performing a thorough neurological examination of the lower limbs is essential for assessing motor, sensory, and coordination functions. Below is a structured approach to conducting the examination.

Overall Plan

Neurological Examination: Steps
Wash hands, introduce yourself, and obtain consent. Inspect from the end of the bed: observe the patient and environment. Assess the face, eyes, language, and cognition. Examine the upper limbs: motor, sensory, and coordination. Examine the lower limbs: motor, sensory, and coordination. Assess gait. Thank the patient, wash hands, and present findings.

Lower Limb Examination Steps

1. Inspection

From the end of the bed, observe for any aids or equipment:

• Walking stick, crutches, foot supports, wheelchair.
• Special glasses, hearing aids.

Inspect the patient's legs for:

• Muscle Appearance:
  • Fasciculations (muscle twitching).
  • Muscle wasting (proximal and distal muscles).
• Skin and Structural Changes:
  • Scars.
  • Skin changes (e.g., trophic changes, ulcers).
  • Signs of denervation: injuries, neuropathic ulcers, Charcot joints.
  • Contractures.
  • Foot deformities: pes cavus (high arch), foot drop.
  • Deformities and abnormal postures.
  • Abnormal movements (e.g., tremors, chorea).

Inspect the patient's back for:

• Spinal scars.
• Spinal deformities: kyphosis, scoliosis.

2. Motor Examination

Gait Assessment

• Ask the patient to walk and turn. Observe:
  • Balance and coordination.
  • Stride length and rhythm.
  • Arm swing symmetry.
  • Use of walking aids.
• Assess heel-toe gait (tandem walking) to evaluate coordination.
• Ask the patient to stand on tiptoes and heels to assess calf and anterior leg muscle strength.

Romberg's Test

• Ask the patient to stand with feet together and arms by their sides.
• First with eyes open, then eyes closed.
• A positive Romberg's sign is indicated by increased unsteadiness or falling with eyes closed, suggesting proprioceptive or vestibular dysfunction.
• Safety Note: Stand close to the patient to prevent falls.

Tone Assessment

• Lift each knee briskly off the bed to assess for spasticity or flaccidity.
• Gently roll each leg to assess tone in the hip joints.
• Check for ankle clonus:
  • Support the leg and rapidly dorsiflex the foot.
  • Observe for rhythmic oscillations (clonus).

Power Assessment

Test muscle strength for key movements, grading power on the Medical Research Council (MRC) scale (0 to 5):

• Hip Flexion (L1, L2): Ask the patient to lift the thigh against resistance.
• Hip Extension (L5, S1): Ask the patient to push the thigh down against resistance.
• Knee Flexion (L5, S1): Ask the patient to bend the knee while you resist the movement.
• Knee Extension (L3, L4): Ask the patient to straighten the knee against resistance.
• Ankle Dorsiflexion (L4, L5): Ask the patient to pull the foot upwards against resistance.
• Ankle Plantarflexion (S1, S2): Ask the patient to push the foot down (like pressing a gas pedal) against resistance.
• Foot Inversion (L4, L5): Ask the patient to turn the sole of the foot inward against resistance.
• Foot Eversion (L5, S1): Ask the patient to turn the sole outward against resistance.
• Toe Movements (L5, S1): Test extension and flexion of the big toe against resistance.

Reflexes

• Knee Jerk (L3, L4): Tap the patellar tendon with the reflex hammer and observe for leg extension.
• Ankle Jerk (S1, S2): Tap the Achilles tendon and observe for plantarflexion.
• Plantar Reflex:
  • Stroke the lateral aspect of the sole from heel to little toe, then medially across the ball of the foot.
  • Normal response: flexion of toes (downgoing).
  • Abnormal response (Babinski sign): extension of the big toe and fanning of other toes (upgoing), indicating upper motor neuron lesion.
• If reflexes are absent or difficult to elicit, use reinforcement techniques:
  • Ask the patient to clench their teeth.
  • Perform the Jendrassik maneuver: ask the patient to interlock their fingers and pull apart.

Coordination

• Heel-to-Shin Test:
  • Ask the patient to run the heel of one foot down the shin of the opposite leg, from knee to ankle.
  • Repeat on both sides.
  • Observe for smoothness and accuracy of movement.
• Reassess gait if necessary to evaluate coordination during movement.

3. Sensory Examination

Explain the examination to the patient and ensure they are comfortable. Begin by checking sensation on an area known to have normal sensation (e.g., sternum) to establish a baseline.

Dermatomes of the Lower Limb

• L1: Just below the groin.
• L2: Medial aspect of mid-thigh.
• L3: Knee region.
• L4: Medial lower leg.
• L5: Dorsum of the foot to the big toe.
• S1: Lateral foot and little toe.
• S2: Back of the thigh and knee.

Modalities to Test

• Light Touch (Dorsal Columns): Use a wisp of cotton wool. Ask the patient to close their eyes and say "yes" when they feel the touch. Test each dermatome bilaterally.
• Pin-Prick (Spinothalamic Tract): Use a neurotip or sterile pin. Instruct the patient to differentiate between sharp and blunt sensations. Test each dermatome bilaterally.
• Vibration Sense (Dorsal Columns): Use a 128 Hz tuning fork:
  • Place the vibrating fork on the distal bony prominence (e.g., big toe).
  • Ask the patient to tell when they feel the vibration and when it stops (stop the fork manually).
  • If impaired, move proximally to medial malleolus, tibial tuberosity, etc.
• Proprioception (Joint Position Sense):
  • Hold the sides of the big toe, demonstrate "up" and "down" movements with the patient's eyes open.
  • Ask the patient to close their eyes and identify the direction of movement.
  • If impaired, test proximally at the ankle joint.
• Temperature (Spinothalamic Tract): If required, offer to test using cold and warm objects or specialized equipment.
• Two-Point Discrimination: If required, offer to perform using calipers to assess cortical sensory function.

Identifying Patterns of Sensory Loss

• Determine if the sensory loss follows a dermatomal pattern (indicating nerve root involvement) or a peripheral nerve distribution.
• Look for "glove and stocking" pattern suggestive of peripheral neuropathy.

4. Completion

• Thank the patient and assist them if needed.
• Wash hands.
• Summarize and present your findings.
• Offer an appropriate differential diagnosis based on the examination.
• Suggest further investigations and management plans.

Notes

• Patient Safety: Always ensure patient comfort and safety throughout the examination.
• Communication: Explain each step to the patient before performing it.
• Technique: Use appropriate reinforcement techniques if reflexes are difficult to elicit.
• Systematic Approach: Maintain a structured examination to ensure all aspects are covered.

Checklist Summary

• Wash hands before and after the examination.
• Introduce yourself and obtain informed consent.
• Inspect the environment and the patient systematically.
• Assess motor function: gait, tone, power, reflexes, coordination.
• Assess sensory function: light touch, pin-prick, vibration, proprioception, temperature.
• Identify patterns of sensory and motor loss.
• Thank the patient and offer assistance if needed.
• Present findings clearly and concisely.
• Provide differential diagnoses and suggest further investigations.

Overall Impression

A thorough lower limb neurological examination involves careful observation, methodical testing of motor and sensory functions, and accurate interpretation of findings to identify potential neurological deficits. Effective communication and patient comfort are paramount throughout the assessment.