The Peripheral Neurological Examination

Introduction

  • Introduce yourself to the patient
  • Wash your hands
  • Briefly explain to the patient what the examination involves

It is good practice to work systematically through the upper limb and lower limb separately; be prepared to be instructed to move on quickly to certain sections by any examiner.


General Observation

  • Ask the patient to walk around 10m, turn around, and walk back, assessing their gait (see appendix 1)
    • Assess for any unsteadiness of the feet and tandem (heel-to-toe) walking
    • Assess the lateral distance between the feet
    • Look for any signs of foot-drop present
    • Check for normal arm swing
    • Assess how well the patient can turn around

Remember to assess the patient’s posture at standing

  • Perform Romberg’s test, assessing for impaired proprioception or vestibular dysfunction
    • Ask the patient to stand with their feet together and eyes closed
    • If positive, the patient becomes more unsteady when the eyes are closed
  • Look in both upper and lower limbs for signs of:
    • Muscle wasting ± fasciculation
    • Asymmetry
    • Abnormal resting posture
    • Abnormal movements

Upper Limb

  • Pronator Drift – ask patient to close their eyes with their hands in a supine position. Observe for any involuntary pronation of the hands (occurs in UMN lesions)
  • Tone – ask the patient to relax their upper limbs and check the tone, assessing at the wrist for flexion-extension and pronation-supination. Compare both sides
    • Increased tone: ‘Clasp-knife’ rigidity or clonus (pyramidal lesions) or ‘cog-wheel’ rigidity or ‘lead pipe’ rigidity (extrapyramidal lesions)
    • Decreased tone: Lower motor neurone lesions
  • Power – secure each joint in turn, comparing both sides, and assess the power in each muscle group, starting proximally and moving distally
    • Assess using the MRC scale for assessment of muscle power (see appendix 2)
    • Assess for:
      • Shoulder: Abduction
      • Elbow: Flexion-Extension
      • Wrist: Extension
      • Fingers: Flexion-Extension, Abduction-Adduction
      • Thumb: Abduction-Adduction
  • Co-ordination – Assessing the patient’s ability to perform smooth and accurate movements
    • Finger-nose test: Placing your finger about 50cm away from the patient, ask them to touch their own nose and then touch your finger, and repeat. Do for both sides
    • Dysdiadochokinesia test: Ask patient to rapidly alternate pronation-supination on one hand in the opposite palm.
      • If irregular in amplitude and speed, can indicate cerebellar disease
  • Reflexes – Elicit the reflexes at the bicep tendon, brachioradialis tendon, and triceps tendon using the tendon hammer
    • If difficulty in eliciting reflexes, ask patient to clench their jaw (distracts the patient and may reduce any unconscious increased tone by the patient)
  • Sensation – can be assessed by pin prick, light touch, proprioception, and vibration modalities
    • Pin prick – using a neurotip, ask the patient to close their eyes and say when they can feel the neurotip, either sharp or blunt side. Assess dermatomes C4-T1 on both sides
    • Light touch – using a cotton wool ball, ask the patient to close their eyes and say when they can feel the cotton wool ball. Assess dermatomes C4-T1 on both sides
  • Proprioception – ask the patient to close their eyes, stabilise the distal interphalangeal joint of the index finger, and ask the patient to indicate the direction the distal phalanx is being moved as you move the phalanx. Compare both sides
    • If proprioception not present, move to next proximal joint
  • Vibration – assess using 128Hz tuning fork, asking the patient to close their eyes and placing the vibrating tuning fork on the index finger. Ask the patient to say if they can feel it vibrating and to state when you stop the vibration
    • If vibration sense not present, move to more proximal bony prominence

Lower Limb

  • Tone – ask the patient to relax their lower limbs and check the tone, assessing on both sides at the:
    • Hip for internal-external rotation (rolling the legs)
    • Knee for flexion-extension
    • Ankle for plantar-dorsiflexion

Test for clonus on both sides at the ankle by slowly circumflexing at the joint, then sudden dorsiflexion at the ankle (to stretch the muscle). Look for sustained rhythmic unidirectional contractions, seen in UMN lesions

  • Power – secure each joint in turn, comparing both sides, and assess the power in each muscle group, starting proximally and moving distally
    • Assess using the MRC scale for assessment of muscle power (see appendix 2)
    • Assess for:
      • Hip: Flexion-Extension
      • Knee: Flexion-Extension
      • Ankle: Dorsiflexion-Plantarflexion
      • Big Toe: Extension
  • Co-ordination – Assessing the patient’s ability to perform smooth and accurate movements
    • Heel-shin test: Ask the patient to place one heel on the other knee and slowly slide the heel down the shin, then lift the heel off the shin, and repeat. Do for both sides
    • Tapping test: Rapidly tap their foot against your hand (placed slightly away from the patient), requiring them to fully plantarflex their ankle repeatedly
      • Impairment may indicate cerebellar disease
  • Reflexes
    • Elicit the reflexes at the patella tendon and calcaneal tendon (ankle jerk) using the tendon hammer
    • Test the plantar reflexes
      • Scratch the sole of the foot with a slightly sharp object (avoid using the end of the tendon hammer)
      • Move from the heel, along the lateral side of the foot, then arc towards the big toe
      • Look for plantar response in the big toe
    • A positive Babinski sign is the big toe extending and abducting, indicating an UMN lesion
  • Sensation – can be assessed by pin prick, light touch, proprioception, and vibration modalities
    • Pin prick – using a neurotip, ask the patient to close their eyes and say when they can feel the neurotip, either sharp or blunt side. Assess dermatomes L1-S2 on both sides
    • Light touch – using a cotton wool ball, ask the patient to close their eyes and say when they can feel the cotton wool ball. Assess dermatomes L1-S2 on both sides
  • Proprioception – ask the patient to close their eyes, stabilise the distal interphalangeal joint of the big toe, and ask the patient to indicate the direction the distal phalanx is being moved as you move the phalanx. Compare both sides
    • If proprioception not present, move to next proximal joint
  • Vibration – assess using 128Hz tuning fork, asking the patient to close their eyes and placing the vibrating tuning fork on the big toe. Ask the patient to say if they can feel it vibrating and to state when you stop the vibration
    • If vibration sense not present, move to more proximal bony prominence

Completing the Examination

Remember, if you have forgotten something important, you can go back and complete this.

To finish the examination, stand back from the patient and state to the examiner that to complete your examination, you would like to perform a:

  • Cranial nerve examination
  • Rectal examination
    • Checking anal tone if suspected spinal cord injury

Appendix 1: Gait Abnormalities

Type of Gait Disorder Description Causes
Cerebellar Ataxia
  • Unsteady during walking, adopt broad-based gait to compensate
  • Worsened with tandem walking
  • May have associated nystagmus, dysarthria, and cerebellar signs in the limbs
  • Multiple Sclerosis
  • Vascular cerebellar disease
  • Chronic alcohol abuse
  • Paraneoplastic syndrome
Hemiparetic
  • Leg moves stiffly and is swung out in a semicircle to avoid scraping the foot on the floor
  • Characteristic flexion of the upper limb and extension of the lower limb
  • Cortical or internal capsule strokes
  • Cerebral hemisphere tumours or traumatic lesions
Spastic
  • Legs move slowly and stiffly, with the hips adducted and feet plantarflexed (causing a ‘scissor gait’)
  • Spinal cord compression
  • Cerebral palsy, Multiple Sclerosis (MS),  or Motor Neurone Disease (MND)
  • Subacute combined degeneration of the spinal cord
Parkinsonian
  • Stooped and flexed posture with a loss of arm swing, worse on one side
  • Difficulty in initiating movement and turning occurs in multiple small steps (‘en bloc’)
  • Festinant gait, whereby the patient leans forward and increases in pace, as though to catch up on themselves
  • Idiopathic Parkinson’s Disease (IDP)
  • Drug-induced Parkinsonism (e.g. anti-psychotics, anti-emetics)
  • Vascular pseudoparkinsonism, infection, or Wilsons disease
Sensory Ataxia
  • Broad-based unsteady gait, often stamping
  • Occurs due to impaired proprioception
  • Romberg’s test is positive
  • Posterior spinal cord lesions (Multiple Sclerosis, Vitamin B12 deficiency, Tumours, or Tabes Dorsalis)
  • Peripheral nephropathies (Diabetes Mellitus, alcohol excess, Guillain-Barré Syndrome, medication (e.g. isoniazid), or Hereditary (e.g. Charcot Marie Tooth disease))
High-stepping
  • Leg is lifted high off the ground to ensure toes clear the ground
  • Weakness of the anterior leg muscles, causing patient unable to dorsiflex the foot
  • Slapping of the foot as it strikes the floor
  • Common peroneal nerve palsy (e.g. fibular head fracture)
  • Hereditary (e.g. Charcot Marie Tooth disease)
  • Anterior horn cell disease (e.g. Polio)
Myopathic
  • Weight is alternately placed on each leg, with the opposite side of the trunk tilting towards the weight-bearing side
  • Caused by weakness in the proximal muscles of the lower limb girdle
  • Muscular dystrophies (e.g. Duchenne’s)
  • Endocrine or metabolic myopathies
  • Polymyositis or dermatomyositis

 


Appendix 2: MRC Power Scale

Grade Response
0 No movement
1 Flicker of muscle as the patient tries to move
2 Movement, but not against gravity
3 Movement, but not against resistance
4 Movement, but not to full strength
5 Full strength

 


Appendix 3: Clinical Features of Patients with Limb Weakness

Site of Lesion Wasting Tone Pattern of Weakness Reflexes Plantar Response
Upper Motor Neurone None Increased Pyramidal Increased Extensor
Lower Motor Neurone Present Decreased Myotomal Decreased Flexor
Neuromuscular Junction Rarely Normal Bilaterally and proximal limb girdle Normal Flexor
Muscle Variable Decreased Bilaterally and proximal limb girdle Decreased Flexor

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