Upper Limb Neurological OSCE Examination

1. Introduction
2. General Inspection
3. Tone
4. Pronator Drift
5. Power
6. Reflexes
7. Coordination
8. Sensation
9. Completing the Examination
10. Quiz

Wash your hands and don personal protective equipment if appropriate.

Introduce yourself to the patient and ensure to mention your grade e.g. 3rd year medical student/junior doctor/consultant.

Confirm the patient’s details taking 3 points of identification usually; full name, date of birth and NHS/hospital number.

Obtain consent for the examination, ensuring to explain what the examination will entail. A good explanation is something like “I’d like to examine the nerves and muscles of your arms, which will involve me looking at your arms, moving them, testing how strong they are, tapping a few tendons and checking your sensation – is that alright?”

Position the patient sitting on the edge of the bed or in a chair, where you have access to both arms.

Expose both upper limbs fully, including the shoulders, so that you can compare the two sides and inspect for muscle wasting.

Ask the patient if they are in any pain anywhere before you begin, as much of the examination involves moving the limbs.

Begin with a brief inspection of the patient and the bedside. Look for clues to a neurological diagnosis such as walking aids, a wheelchair, splints, wrist supports, or aids for daily living that hint at chronic disability.

Observe the patient’s posture and any abnormal movements at rest. A resting tremor that is worse at rest and improves with movement suggests Parkinson’s disease, whereas an action or intention tremor that worsens on reaching for a target points towards a cerebellar problem.

Inspect the arms and hands carefully for:

• Muscle wasting – loss of muscle bulk suggests a lower motor neurone lesion or disuse. Focal wasting of the small muscles of the hand (the ‘guttering’ between the metacarpals) is a classic sign of a T1 root or ulnar/median nerve problem.
• Fasciculations – fine, irregular twitches visible under the skin. These result from spontaneous motor-unit discharge and may be benign in isolation. Accompanying weakness, wasting or reflex abnormalities make a lower motor neurone disorder more concerning; progressive weakness warrants assessment.
• Tremor or other involuntary movements such as chorea, myoclonus or dystonia.
• Pseudoathetosis – slow, writhing finger movements seen when the patient holds the hands outstretched with the eyes closed. Rather than a movement disorder, this reflects a loss of proprioception (the brain cannot tell where the fingers are without vision) and points to a dorsal column or sensory nerve problem.
• Scars – over the wrist (carpal tunnel decompression), elbow (ulnar nerve transposition) or neck/spine (previous decompression surgery).
• Skin changes and abnormal posturing – a flexed, adducted upper limb may indicate a previous stroke with spasticity.

It is good practice to ask the patient to hold their hands out and briefly assess for symmetry before moving on. If you suspect a fine tremor that is hard to see, rest a sheet of paper across the dorsum of the outstretched hands – the paper amplifies and makes visible an otherwise subtle postural tremor, such as that of essential tremor or thyrotoxicosis. Remember to look at the palmar and dorsal surfaces of both hands, as wasting and scars can be missed on a single view.

Tone is the resting resistance of a muscle to passive stretch. To assess it, ask the patient to relax and let you take the full weight of the arm. Support the limb and move the shoulder, elbow and wrist through their full range of movement at varying speeds, comparing the two sides.

There are three abnormal patterns to recognise:

• Spasticity – a velocity-dependent increase in tone, meaning the faster you move the limb the greater the resistance. There may be a sudden ‘give’ partway through the movement (the ‘clasp-knife’ phenomenon). Spasticity affects the flexors preferentially in the upper limb and indicates an upper motor neurone lesion such as a stroke or spinal cord injury.
• Rigidity – an increase in tone that is constant throughout the range of movement and independent of speed. ‘Lead-pipe’ rigidity is smooth throughout, whereas ‘cogwheel’ rigidity has a ratchet-like quality caused by a superimposed tremor. Rigidity is a feature of extrapyramidal disease, classically Parkinson’s disease.
• Hypotonia – reduced tone, where the limb feels floppy. This suggests a lower motor neurone lesion or, in the acute phase, a cerebellar lesion.

It can help to distract the patient by asking them to count or name the days of the week while you move the limb, as voluntary ‘help’ from the patient can mask the true resting tone.

Pronator drift is a sensitive test for a subtle upper motor neurone lesion. Ask the patient to hold both arms out straight in front of them with the palms facing upwards (supinated) and the eyes closed. Observe for around 20–30 seconds.

In a positive test, the affected arm slowly pronates (the palm turns to face downwards) and drifts downwards. This occurs because, in a pyramidal lesion, the supinator muscles are weaker than the opposing pronator muscles, so the forearm turns palm-down as the weak arm drifts, particularly when visual compensation is reduced by closing the eyes. A positive result supports upper motor neurone weakness. A cerebral corticospinal lesion above the motor crossing is opposite the affected arm; a spinal corticospinal lesion below the crossing is on the same side. Interpret the sign with the rest of the neurological examination.

If the arm instead drifts upwards, or the hand makes searching, writhing movements, this suggests a loss of proprioception (sensory ataxia) rather than weakness. An arm that overshoots when you tap it down and then springs back is part of the cerebellar ‘rebound’ phenomenon, discussed under coordination.

Power should be tested at each major joint, comparing left with right and testing the patient against your own resistance. Always fix the joint proximal to the one you are testing and ask the patient to resist you maximally. Power is graded using the Medical Research Council (MRC) scale:

• 0 – no muscle contraction
• 1 – a flicker of contraction
• 2 – movement possible only with gravity eliminated
• 3 – movement against gravity but not against resistance
• 4 – movement against resistance but reduced
• 5 – normal power

Each movement corresponds to a myotome (the muscles supplied by a single nerve root) and to one or more peripheral nerves. Knowing both allows you to distinguish a root lesion from a peripheral nerve lesion. Assess the following:

• Shoulder abduction (deltoid) – C5, axillary nerve. “Push your elbows up like wings and don’t let me push them down.”
• Shoulder adduction – C6/C7.
• Elbow flexion (biceps) – C5/C6, musculocutaneous nerve.
• Elbow extension (triceps) – C7, radial nerve.
• Wrist extension – C6, radial nerve. Weakness here with a preserved triceps suggests a radial nerve palsy (‘wrist drop’).
• Wrist flexion – C7.
• Finger extension – C7, posterior interosseous (radial) nerve.
• Finger abduction – T1, ulnar nerve. Weakness suggests an ulnar nerve or T1 lesion.
• Thumb abduction – T1, median nerve. Weakness with thenar wasting suggests carpal tunnel syndrome.

The pattern of weakness is more informative than the absolute grade. A pyramidal pattern of weakness – in which the upper limb extensors are weaker than the flexors – points to an upper motor neurone lesion. Weakness confined to a single myotome suggests a radiculopathy (nerve root compression), whereas weakness in the territory of one peripheral nerve suggests a mononeuropathy. Symmetrical proximal weakness suggests a myopathy, while distal weakness with sensory loss suggests a peripheral neuropathy.

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