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 three 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 (one that is worst at rest and improves with movement) suggests Parkinson’s disease (a brain condition that causes tremor, stiffness and slow movement), 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, the long bones of the palm) is a classic sign of a problem with the first thoracic (T1) nerve root or the ulnar/median nerve.
• Fasciculations – fine, irregular twitches visible under the skin. These result from motor units (a nerve cell and the muscle fibres it supplies) firing spontaneously, and may be benign in isolation. Accompanying weakness, wasting or reflex abnormalities make a lower motor neurone disorder more concerning. Progressive weakness needs further neurological assessment and investigation.
• Tremor or other involuntary movements such as chorea (jerky, dance-like movements), myoclonus (sudden, brief jerks) or dystonia (sustained muscle spasms that cause abnormal postures).
• 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 problem in the dorsal columns (the part of the spinal cord that carries touch, vibration and position sense) or in a sensory nerve.
• Scars – over the wrist (carpal tunnel decompression, surgery to release pressure on the median nerve), elbow (ulnar nerve transposition, moving the ulnar nerve to a new position) or neck/spine (previous decompression surgery).
• Skin changes and abnormal posturing – a flexed, adducted upper limb may indicate a previous stroke with spasticity (stiffness from raised muscle tone, described under Tone).

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 back of the outstretched hands. The paper amplifies and makes visible an otherwise subtle postural tremor, such as that of essential tremor (a common cause of shaky hands) or thyrotoxicosis (an overactive thyroid). 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 (disease of the deep brain circuits that help to control movement), 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. This is because 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 in a pyramidal lesion (damage to the pyramidal tracts, the main pathways that carry movement signals from the brain to the spinal cord). The supinator muscles become weaker than the opposing pronator muscles, so the forearm turns palm-down as the weak arm drifts. The effect is clearest when visual compensation is removed by closing the eyes. A positive result supports upper motor neurone weakness. A lesion of the corticospinal tract (the pathway that carries movement signals from the cerebral cortex down the spinal cord) in the brain affects the arm on the opposite side of the body, because most of its fibres cross to the opposite side in the lower brainstem. A corticospinal lesion in the spinal cord, below that crossing, affects the arm on the same side. Interpret the sign with the rest of the neurological examination.

If the arm instead drifts upwards, this can occur in cerebellar disease (where the arm may also drift outwards) or with loss of proprioception (the sense of where your limbs are in space), rather than weakness. Involuntary, searching, writhing movements of the hand with the eyes closed (pseudoathetosis) also point to loss of proprioception (sensory ataxia: clumsy, unsteady movement caused by loss of position sense). An arm that overshoots wildly when you tap it down and release it is part of the abnormal 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 (loss of muscle bulk at the base of the thumb) suggests carpal tunnel syndrome (compression of the median nerve at the wrist).

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 (disease of a single nerve). Symmetrical proximal weakness suggests a myopathy (a disease of the muscle itself), while distal weakness with sensory loss suggests a peripheral neuropathy (damage to many peripheral nerves, often causing numbness and weakness in the hands and feet).

Preview the Upper Limb Neurological OSCE Examination quiz