Macleod's examination of the upper limbs motor function

Summary

This video script provides a comprehensive guide to conducting an upper limb neurological examination. It covers key steps such as inspecting for asymmetry, deformities, and muscle tone, as well as testing deep tendon reflexes, power, coordination, and dexterity. The script also explains how to test for pathological signs like spasticity, rigidity, and dysdiadochokinesia, alongside specialized assessments for reflexes like the Hoffmann reflex. The examination further includes testing for apraxia, cerebellar function, and sensory impairment, all aimed at detecting neurological conditions.

Takeaways

• 🩺 The examination begins by inspecting for asymmetry, deformities, muscle wasting, hypertrophy, fasciculations, and involuntary movements.
• 💪 Muscle tone is assessed by moving the joint passively, with tone abnormalities including spasticity and rigidity.
• 🔨 Reflexes like the biceps, supinator, and triceps jerks are tested to evaluate nerve root function, using specific positioning and reinforcement if reflexes seem absent.
• 🦶 The Hoffman reflex is checked by flexing the distal phalanx of the middle finger and observing for a pathological thumb response.
• ✊ Power in the upper limbs is assessed by testing resistance in movements such as abduction, adduction, elbow flexion, and finger abduction.
• 🤲 Grip strength is tested by having the patient resist the examiner's pull on their fingers, which helps assess overall muscle strength.
• 👃 Coordination tests include the finger-nose test, observing for past-pointing or tremors to check for cerebellar disease.
• ✋ Rapid alternating movements are tested to identify dysdiadochokinesia, which could indicate cerebellar disorders.
• ☕ Dyspraxia is assessed through imitation tasks like pretending to drink tea, testing motor coordination in the absence of weakness.
• 📝 The patient is asked to copy shapes and write sentences, with difficulties suggesting issues like constructional apraxia or dysgraphia.

Q & A

What should the examiner look for during the initial inspection of the upper limb?

The examiner should look for asymmetry, deformities like clawing of the hands, muscle wasting, hypertrophy, fasciculations, and involuntary movements. These observations help detect underlying neuromuscular issues.

How can fasciculations be elicited during the examination?

Fasciculations can be elicited by flicking the skin over the muscle. If fasciculations are present, they are often visible after this stimulation.

How is muscle tone tested in the upper limb?

Muscle tone is tested by passively moving the patient's arm in various directions. The examiner holds the patient's hand and supports the elbow, rotating the forearm and flexing or extending the wrist, elbow, and shoulder. The resistance felt during these movements helps assess muscle tone.

What are the two types of hypertonia mentioned in the script?

The two types of hypertonia mentioned are spasticity and rigidity, both of which are associated with different neurological conditions.

What nerve root does the biceps jerk reflex test, and how is it performed?

The biceps jerk reflex tests the C5 nerve root. It is performed by palpating the biceps tendon and tapping it with a reflex hammer, observing for a contraction.

How is the supinator or brachioradialis reflex tested?

The supinator reflex is tested by placing the patient's forearm in the mid-prone position and tapping the tendon over the distal radius with a reflex hammer. This tests the C6 nerve root.

What technique should be used if a reflex appears absent?

If a reflex appears absent, the examiner can use reinforcement techniques, such as asking the patient to clench their teeth or make a fist with the other hand, to help elicit the reflex.

How is grip strength assessed during the examination?

Grip strength is assessed by asking the patient to grip the examiner’s fingers and resist as the examiner attempts to pull them away. This test evaluates the strength of the finger flexors and the overall grip.

What is the purpose of the finger-nose test, and what are the signs of cerebellar disease?

The finger-nose test assesses coordination. The patient is asked to touch their nose and then the examiner’s finger repeatedly. Signs of cerebellar disease include past pointing (missing the target) and intention tremor, which become evident during this test.

What does dysdiadochokinesia indicate, and how is it tested?

Dysdiadochokinesia is the inability to perform rapid alternating movements, which is typical of cerebellar dysfunction. It is tested by asking the patient to alternate hand movements between pronation and supination rapidly. Impaired performance suggests cerebellar involvement.