Neuro Upper Limb Flashcards
What is the main purpose of a neuro exam
What is the most basic question related to this?
to localise where in the nervous system the problem is.
Is there an upper (i.e. brain or spinal cord) or lower (i.e. nerve roots, peripheral nerve, neuromuscular junction or muscle) motor neuron lesion?
How can you differentiate an upper motor sign from a lower motor sign in the upper limb neuro exam on inspection
UMN: No fasciculation or significant wasting (there may however be some disuse atrophy or contractures)
LMN: Wasting and fasciculation of muscles
Is pronator drift present in upper limb UMN damage?
may be present for UMN injury
There may be some drift/movement of the arm(s) if weak or deafferented, but not pronator drift in LMN injury
How does tone change in the upper limb after a UMN vs LMN injury
UMN: Increased (spasticity or rigidity)
LMN: Decreased (hypotonia) or normal
How does power change in the upper limb after a UMN vs LMN injury
UMN: Classically a “pyramidal” pattern of weakness (extensors weaker than flexors in arms, and vice versa in legs)
LMN: Different patterns of weakness, depending on the cause (e.g. classically a proximal weakness in muscle disease, a distal weakness in peripheral neuropathy)
How do reflexes change in the upper limb after a UMN vs LMN injury
UMN: Exaggerated or brisk (hyperreflexia)
LMN: Reduced or absent (hyporeflexia or areflexia)
What equipment do you need in the neuro exam (upper limb)
Tendon hammer
Neurotip
Cotton wool
Tuning fork (128Hz)
What are the main stages of the upper limb neuro exam
Gather equipment
Intro (WIPERQQ)
Inspection
Pronator Drift
Tone
Power (Shoulder, Elbow, Wrist, Hand/fingers)
Reflexes (Biceps, supinator, triceps)
Sensation (dermatomes, light touch sensation, pin-prick sensation, vibration sensation, proprioception)
Coordination
Further assessments
What clinical signs do you look for at the beginning of the upper limb neuro exam (11)
Scars: may provide clues regarding previous spinal, axillary or upper limb surgery.
Wasting of muscles
Tremor
Fasciculations
Pseudoathetosis: abnormal writhing movements (typically affecting the fingers) caused by a failure of proprioception.
Chorea: brief, semi-directed, irregular movements that are not repetitive or rhythmic but appear to flow from one muscle to the next. Patients with Huntington’s disease typically present with chorea.
Myoclonus
Tardive dyskinesia
Hypomimia: a reduced degree of facial expression associated with Parkinson’s disease.
Ptosis and frontal balding: typically associated with myotonic dystrophy.
Ophthalmoplegia
What are fasciculations
What are they associated with
small, local, involuntary muscle contraction and relaxation which may be visible under the skin.
Associated with lower motor neuron pathology (e.g. amyotrophic lateral sclerosis).
What is myoclonus
brief, involuntary, irregular twitching of a muscle or group of muscles.
All individuals experience benign myoclonus on occasion (e.g. whilst falling asleep) however persistent widespread myoclonus is associated with several specific forms of epilepsy (e.g. juvenile myoclonic epilepsy).
What is tardive dyskinesia
involuntary, repetitive body movements which can include protrusion of the tongue, lip-smacking and grimacing.
This condition can develop secondary to treatment with neuroleptic medications including antipsychotics and antiemetics.
What is Ophthalmoplegia?
What can cause it?
weakness or paralysis of one or more extraocular muscles responsible for eye movements.
Ophthalmoplegia can be caused by a wide range of neurological disorders including multiple sclerosis and myasthenia gravis.
What objects should you look for in a neuro upper limb exam
Walking aids: the ability to walk can be impacted by a wide range of neurological pathology.
Prescriptions: prescribing charts or personal prescriptions can provide useful information about the patient’s recent medications.
How do you assess pronator drift
- Ask the patient to hold their arms out in front of them with their palms facing upwards and observe for signs of pronation for 20-30 seconds.
- If no pronation occurs, ask the patient to close their eyes and observe once again for pronation (this typically accentuates the effect due to the reliance on proprioception alone).
Why is assessing pronator drift useful
Checking for pronator drift is a useful way of assessing for mild upper limb weakness and spasticity:
On assessment, if the forearm pronates, with or without downward movement, the patient is considered to have pronator drift on that side. The presence of pronator drift indicates a contralateral pyramidal tract lesion. Pronation occurs because, in the context of an UMN lesion, the supinator muscles of the forearm are typically weaker than the pronator muscles.
How do you assess tone in upper limb muscles (4)
Assess tone in the muscle groups of the shoulder, elbow and wrist on each arm, comparing each side as you go:
- Support the patient’s arm by holding their hand and elbow.
- Ask the patient to relax and allow you to fully control the movement of their arm.
- Move the muscle groups of the shoulder (circumduction), elbow (flexion/extension) and wrist (circumduction) through their full range of movements.
- Feel for abnormalities of tone as you assess each joint (e.g. spasticity, rigidity, cogwheeling, hypotonia).
How does spasticity present
velocity-dependent”, meaning the faster you move the limb, the worse it is. There is typically increased tone in the initial part of the movement which then suddenly reduces past a certain point (known as “clasp knife spasticity”).
Spasticity is also typically accompanied by weakness.
Are spasticity and rigidity the same?
No
Spasticity is associated with pyramidal tract lesions (e.g. stroke) and rigidity is associated with extrapyramidal tract lesions (e.g. Parkinson’s disease). Spasticity and rigidity both involve increased tone, so it’s important to understand how to differentiate them clinically.
How is spasticity different from rigidity
Spasticity is “velocity-dependent”
Rigidity is “velocity independent” meaning it feels the same if you move the limb rapidly or slowly.
What are the 2 key types of rigidity
Cogwheel rigidity involves a tremor superimposed on the hypertonia, resulting in intermittent increases in tone during movement of the limb. This subtype of rigidity is associated with Parkinson’s disease.
Lead pipe rigidity involves uniformly increased tone throughout the movement of the muscle. This subtype of rigidity is typically associated with neuroleptic malignant syndrome.
(Remember - Rigidity is “velocity independent” meaning it feels the same if you move the limb rapidly or slowly.)
Which myotome and muscles are assessed for shoulder abduction
Myotome assessed: C5 (axillary nerve)
Muscles assessed: deltoid (primary) and other shoulder abductors (Supraspinatus, Trapezius, and Serratus Anterior)
What muscles are involved in shoulder abduction
Supraspinatus, Deltoid, Trapezius, and Serratus Anterior.
(Super Dads Tickle Super Alpacas. Imagine our super dads reaching up with their arms stretched out above their heads, like Super Man, and tickling a really tall super alpaca)
How do you assess shoulder abduction
- Ask the patient to flex their elbows and ABduct their shoulders to 90°: “Bend your elbows and bring your arms out to the sides like a chicken.”
- Apply downward resistance on the lateral side of the upper arm whilst asking the patient to maintain their arm’s position: “Don’t let me push your shoulder down.”
Which myotomes and muscles are assessed in shoulder adduction
Myotomes assessed: C6/7 (thoracodorsal nerve)
Muscles assessed: teres major, latissimus dorsi and pectoralis major
Which myotomes and muscles are assessed in shoulder adduction
Myotomes assessed: C6/7 (thoracodorsal nerve)
Muscles assessed: teres major, latissimus dorsi and pectoralis major
How do you assess shoulder adduction
- Ask the patient to ADduct their shoulders to 45° bringing their elbows closer to their body: “Now bring your elbows a little closer to your sides.”
- Apply upward resistance on the medial side of the upper arm whilst asking the patient to maintain their arm’s position: “Don’t let me pull your arms away from your sides.”
Which myotomes and muscles are assessed in elbow flexion
Myotomes assessed: C5/6 (musculocutaneous and radial nerve)
Muscles assessed: biceps brachii, coracobrachialis and brachialis
How do you assess elbow flexion
- Ask the patient to flex their elbow: “Put your hands up like a boxer.”
- Apply resistance by pulling the forearm whilst stabilising the shoulder joint: “Don’t let me pull your arm away from you.”
How do you assess elbow flexion
- Ask the patient to flex their elbow: “Put your hands up like a boxer.”
- Apply resistance by pulling the forearm whilst stabilising the shoulder joint: “Don’t let me pull your arm away from you.”
How do you assess elbow flexion
- Ask the patient to flex their elbow: “Put your hands up like a boxer.”
- Apply resistance by pulling the forearm whilst stabilising the shoulder joint: “Don’t let me pull your arm away from you.”
Which myotomes and muscles are assessed in elbow extension
How is this assessed
Myotome assessed: C7 (radial nerve)
Muscles assessed: triceps brachii
With the patient’s elbows still in the flexed position, apply resistance by pushing the forearm towards the patient whilst stabilising the shoulder joint: “Don’t let me push your arm towards you.”
Which myotomes and muscles are assessed in wrist extension
Myotome assessed: C6 (radial nerve)
Muscles assessed: extensors of the wrist
How do you assess wrist extension
- Ask the patient to hold their arms out in front of them with their palms facing downwards: “Hold your arms out in front of you, with your palms facing the ground.”
- Ask the patient to make a fist and extend their wrist joints, keeping their wrists in this position whilst you apply resistance: “Make a fist, cock your wrists back and don’t let me pull them downwards.”
Which myotomes and muscles are assessed in wrist flexion
What instructions do you give the patient
Myotomes assessed: C6/7 (median nerve)
Muscles assessed: flexors of the wrist
With the patient still holding their arms out in front of them, now ask them to flex their wrist joints and keep them in this position whilst you apply resistance: “Ok now point your wrists downwards and don’t let me pull them up.”
Which myotomes and muscles are assessed in finger extension
What instructions do you give the patient
Myotome assessed: C7 (radial nerve)
Muscles assessed: extensor digitorum
Instructions: Ask the patient to hold their fingers out straight whilst you apply downwards resistance: “Hold your fingers out straight and don’t let me push them down.”
Which myotomes and muscles are assessed in finger abduction
What instructions do you give the patient
Myotome assessed: T1 (ulnar nerve)
Muscles assessed: First dorsal interosseous (FDI); Abductor digiti minimi (ADM)
Instructions: Ask the patient to abduct their fingers against resistance. You should assess abduction in FDI and ADM separately using the equivalent finger of your own to apply resistance: “Splay your fingers outwards and don’t let me push them together.”
Which myotomes and muscles are assessed in thumb abduction
What instructions do you give the patient
Myotomes assessed: T1 (median nerve)
Muscle assessed: abductor pollicis brevis
Instructions: Ask the patient to turn their hand over so their palm is facing upwards and to position their thumb over the midline of the palm. Advise them to keep it in this position whilst you apply downward resistance with your own thumb: “Point your thumbs to the ceiling and don’t let me push them down.”
How do the patterns of muscle weakness differ in UMN and LMN lesions
Upper motor neuron lesions cause a ‘pyramidal’ pattern of weakness that disproportionately affects upper limb extensors and lower limb flexors (i.e. upper limb extensors are weaker than flexors in an upper limb neurological assessment).
Lower motor neuron lesions cause a focal pattern of weakness, with only the muscles directly innervated by the damaged neurones affected.
Give the MRC muscle power assessment scale
0 No contraction
1 Flicker or trace of contraction
2 Active movement, with gravity eliminated
3 Active movement against gravity
4 Active movement against gravity and resistance
5 Normal power
Give general rules for assessing reflexes
Explain to the patient that you are now going to assess their reflexes by tapping gently on their arm with a tendon hammer (it is useful to show the patient the tendon hammer at this stage).
For each of the reflexes, the patient’s upper limb needs to be completely relaxed.
Make sure to hold the tendon hammer handle at its end to allow gravity to aid a good swing.
If a reflex appears absent make sure the patient is fully relaxed and then perform a reinforcement manoeuvre by asking the patient to clench their teeth together whilst you simultaneously tap the tendon.
How do you assess biceps reflex
Biceps reflex (C5/6)
1. With the patient’s arm relaxed, locate the biceps brachii tendon which is typically found at the medial aspect of the antecubital fossa.
- Place the thumb of your non-dominant hand over the tendon and then tap your thumb with the tendon hammer.
- Observe for a contraction of the biceps muscle and associated flexion of the elbow.
Which nerves/ myotomes are assessed in the biceps reflex
C5/6
How do you assess the supinator reflex
Supinator (brachioradialis) reflex (C5/6)
1. Locate the brachioradialis tendon which can be found on the posterolateral aspect of the wrist approximately 4 inches proximal to the base of the thumb.
- With two fingers positioned over the tendon, tap your fingers with the tendon hammer.
- Observe for a contraction of the brachioradialis muscle and associated flexion, pronation or supination of the forearm at the elbow.
Which dermatomes are assessed in the brachioradialis/supinator reflex
C5/6
How to assess triceps reflex
Triceps reflex (C7)
1. Position the patient’s arm so that the triceps tendon is relaxed: this is commonly achieved by resting the patient’s elbow in 90º flexion on their lap or by supporting the patient’s forearm.
- Locate the triceps tendon, which can be found superior to the olecranon process of the ulna.
- Tap the tendon with the tendon hammer and observe for a contraction of the triceps muscle.
Which dermatome is assessed in the triceps reflex
C7
What do hyperreflexia and hyporeflexia indicate
Hyperreflexia is typically associated with upper motor neuron lesions (e.g. stroke, spinal cord injury) due to the loss of inhibition from higher brain centres which normally exert a degree of suppression over the lower motor neuron reflex arc.
Hyporeflexia is typically associated with lower motor neuron lesions (e.g. brachial plexus pathology or other peripheral nerve injuries) due to loss of the efferent and afferent branches of the normal reflex arc.
What do reflexes look like in cerebellar disease
In cerebellar disease, reflexes are described as ‘pendular’, which means less brisk and slower in their rise and fall. This sign is, however, very subjective and often reflexes appear to be ‘normal’ in cerebellar disease.
What are the key points of assessing sensation
Check at least one modality each from the dorsal columns and spinothalamic tracts.
Ensure the patient has their eyes closed for the assessment.
Demonstrate normal sensation on the patient’s sternum.
Assess sensation across each of the upper limb dermatomes (see below), comparing left to right at equivalent regions as you progress.
Where should you assess each of the dermatomes in the upper limb
C5: the lateral aspect of the lower edge of the deltoid muscle (known as the “regimental badge”).
C6: the palmar side of the thumb.
C7: the palmar side of the middle finger.
C8: the palmar side of the little finger.
T1: the medial aspect antecubital fossa, proximal to the medial epicondyle of the humerus.
Which spinal columns are involved in light touch sensation
both the dorsal columns and spinothalamic tracts.
How do you assess light touch sensation
- Ask the patient to close their eyes and touch their sternum with the wisp of cotton wool to provide an example of light touch sensation.
- Ask the patient to say “yes” when they feel the sensation.
- Using the wisp of cotton wool, begin to assess light touch sensation across each of the upper limb dermatomes, comparing each side as you go by asking the patient if it feels the same.
Which spinal tracts does pin-prick sensation involve
spinothalamic tracts.
How do you assess pin-prick sensation
- Ask the patient to close their eyes and touch their sternum with the sharp end of a neuro-tip
- Ask the patient to say “yes” when they feel the sensation.
- Using the sharp end of a neuro-tip, begin to assess pin-prick sensation across each of the upper limb dermatomes, comparing each side as you go by asking the patient if it feels the same.
If loss of sensation is noted distally, test for “glove” distribution of sensory loss (associated with peripheral neuropathy) by moving distal to proximal.
How do you assess pin-prick sensation
- Ask the patient to close their eyes and touch their sternum with the sharp end of a neuro-tip
- Ask the patient to say “yes” when they feel the sensation.
- Using the sharp end of a neuro-tip, begin to assess pin-prick sensation across each of the upper limb dermatomes, comparing each side as you go by asking the patient if it feels the same.
If loss of sensation is noted distally, test for “glove” distribution of sensory loss (associated with peripheral neuropathy) by moving distal to proximal.
How do you assess pin-prick sensation
- Ask the patient to close their eyes and touch their sternum with the sharp end of a neuro-tip
- Ask the patient to say “yes” when they feel the sensation.
- Using the sharp end of a neuro-tip, begin to assess pin-prick sensation across each of the upper limb dermatomes, comparing each side as you go by asking the patient if it feels the same.
If loss of sensation is noted distally, test for “glove” distribution of sensory loss (associated with peripheral neuropathy) by moving distal to proximal.
Which spinal tracts does vibration sensation involve
dorsal columns
How do you assess vibration sensation in the upper limb
- Ask the patient to close their eyes and to let you know both when they can detect vibration and when it stops.
- Tap a 128 Hz tuning fork and place onto the patient’s sternum to check they are able to feel it vibrating. Then grasp the ends of the tuning fork to cease vibration and see if the patient is able to accurately identify that it has stopped.
- Tap the tuning fork again and place onto the interphalangeal joint of the patient’s thumb. If the patient is able to accurately identify when the vibration begins and when it stops at this point in both upper limbs, the assessment is complete.
- If vibration sensation is impaired at the interphalangeal joint of the patient’s thumb, continue to sequentially assess more proximal joints (e.g. carpometacarpal joint of the thumb → elbow joint → shoulder joint) until the patient is able to accurately identify vibration.
How do you assess proprioception in the upper limb
- Begin assessment of proprioception at the interphalangeal joint of the thumb by holding the distal phalanx of the thumb by its sides (avoid holding the nail bed as this can allow the patient to determine direction based on pressure).
- Demonstrate movement of the thumb “upwards” and “downwards” to the patient whilst they watch.
- Ask the patient to close their eyes and state if you are moving their thumb up or down.
- Move the thumb up or down 3-4 times in a random sequence to see if the patient is able to accurately identify joint position with their eyes closed.
- If the patient is unable to correctly identify the direction of movement, continue to sequentially assess more proximal joints (e.g. carpometacarpal joint of the thumb → wrist → elbow → shoulder).
Which spinal tracts does proprioception involve
dorsal columns
What are the different patterns of sensory loss in the upper limb (6)
Mononeuropathies result in a localised sensory disturbance in the area supplied by the damaged nerve.
Peripheral neuropathy typically causes symmetrical sensory deficits in a ‘glove and stocking’ distribution in the peripheral limbs. The most common causes of peripheral neuropathy are diabetes mellitus and chronic alcohol excess.
Radiculopathy occurs due to nerve root damage (e.g. compression by a herniated intervertebral disc), resulting in sensory disturbances in the associated dermatomes.
Spinal cord damage results in sensory loss both at and below the level of involvement in a dermatomal pattern due to its impact on the sensory tracts running through the cord.
Thalamic lesions (e.g. stroke) result in contralateral sensory loss.
Myopathies often involve symmetrical proximal muscle weakness.
What do you assess when assessing coordination in the upper limb
Finger-to-nose test
Dysdiadochokinesia
How do you perform the finger-to-nose test
- Position your finger so that the patient has to fully outstretch their arm to reach it.
- Ask the patient to touch their nose with the tip of their index finger and then touch your fingertip.
- Ask the patient to continue to do this finger to nose motion as fast as they are able to.
What are you screening for in the finger-to-nose test
When patients with cerebellar pathology perform this task they may exhibit both dysmetria and intention tremor:
The presence of dysmetria and intention tremor is suggestive of ipsilateral cerebellar pathology.
What is dysmetria
refers to a lack of coordination of movement. Clinically this results in the patient missing the target by over/undershooting in the finger-to-nose test
What is intention tremor
a broad, coarse, low-frequency tremor that develops as a limb reaches the endpoint of a deliberate movement.
Clinically this results in a tremor that becomes apparent as the patient’s finger approaches yours in a finger-to-nose test. Be careful not to mistake an action tremor (which occurs throughout the movement) for an intention tremor.
What is dysdiadochokinesia
Dysdiadochokinesia is a term that describes the inability to perform rapid, alternating movements, which is a feature of ipsilateral cerebellar pathology.
How do you assess dysdiadochokinesia (6)
What results may you get
- Ask the patient to place their left palm on top of their right palm.
- Then ask them to turn over their left hand and touch the back of it onto their right palm.
- Now ask them to return their left hand to the original position (left palm on right palm).
- Ask the patient to now repeat this sequence of movements as fast as they are able until you tell them to stop. It is often useful to demonstrate the sequence of movements to the patient to aid understanding.
- Observe the speed and fluency by which the patient is able to carry out this sequence of rapidly alternating movements.
- Repeat the assessment with the other hand.
Patients with cerebellar ataxia may struggle to carry out this task, with their movements appearing slow and irregular. The presence of dysdiadochokinesia suggests ipsilateral cerebellar pathology.
Give 2 further assessments to recommend at the end of the upper limb neuro exam
Full neurological examination including the cranial nerves, lower limbs and cerebellar assessment.
Neuroimaging (e.g. MRI spine and head).
