Upper limb neurological examination Flashcards
what are UMN signs in inspection, pronator drift, tone, power and reflexes?
- no fasiculation or significant wasting
- pronator drift may be present
- increased tone (spasticity or rigidity)
- pyramidal pattern of weakness (extensors weaker than flexors in arms, and vice versa in legs)
- exaggerated/brisk reflexes
what are LMN signs in inspection, pronatory drift, tone, power and reflexes?
- wasting and fasiculation of muscles
- may be some drift/movement of the arms if weak or deafferented, but not pronator drift
- decreased tone or normal
- different patterns of weakness depending on cause (proximal weakness in muscle disease, distal in peripheral neuropathy)
- reduced or absent reflexes
what equipment is required?
- tendon hammer
- neurotip
- cotton wool
- tuning fork (128Hz)
what clinical signs should be looked for in general inspection?
- scars
- muscle wasting
- tremor
- fasciculations
- pseudoathetosis
- chorea
- myoclonus
- tardive dyskinesia
- hypomimia
- ptosis and frontal balding
- opthalmoplegia
what are fasciculations?
small, local, involuntary muscle contraction and relaxation which may be visible under the skin; associated with LMN pathology
what is pseudoathetosis?
abnormal writhing movements caused by failure of proprioception
what is chorea?
brief, semi-directed, irregular movements that aren’t repetitive or rhythmic but appear to flow from one muscle to the next; associated with Huntington’s
what is myoclonus?
brief, involuntary, irregular twitching of a muscle or group of muscles; persistent widespread myoclonus is associated with epilepsy
what is tardive dyskinesia?
involuntary, repetitive body movements which can include protrusion of the tongue, lip-smacking and grimacing
what is hypomimia?
reduced degree of facial expressions
what is opthalmoplegia?
weakness of paralysis of one or more extraocular muscles responsible for eye movements; caused by many disorders e.g. MS/myasthenia gravis
how is pronator drift assessment done?
- assesses mild upper limb weakness and spasticity
- ask patient to hold their arms out in front of them in supination and observe for signs of pronation for 20-30s
- if no pronation occurs, ask patient to close their eyes and observe again
- if forearm pronates, with/without downward movement, there is pronator drift on that side
what does pronator drift indicate?
a contralateral pyramidal tract lesion
how is tone assessment done?
- assess tone in muscle groups of the shoulder, elbow and wrist on each arm, comparing sides
- support arm by holding their hand and elbow
- ask patient to relax and allow you to fully control the movement
- 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 (spasticity, rigidity, cogwheeling, hypotonia)
what is spasticity? what is it associated with?
- velocity dependent; faster you move the limb, the worse it is
- increased tone in initial part of the movement which then suddenly reduces past a certain point
- accompanied by weakness
- associated with pyramidal tract lesions
what is rigidity? what is it associated with?
- velocity independent; feels the same if you move the limb rapidly or slowly
- associated with extrapyramidal tract lesions
what are the two subtypes of rigidity?
cogweel and lead pipe
what is cogwheel rigidity?
involves tremor superimposed on the hypertonia, resulting in intermittent increases in tone during movement of the limb; associated with Parkinson’s
what is lead pipe rigidity?
involves uniformly increased tone throughout the movement of the muscle; associated with neuroleptic malignant syndrome
what movements are used to assess power?
- shoulder abduction
- shoulder adduction
- elbow flexion
- elbow extension
- wrist extension
- wrist flexion
- finger extension
- finger abduction
- thumb abduction
how do you assess power?
- stabilise and isolate the relevant joint
- assess one side at a time
- compare each side
- use MRC scale
- apply resistance against each movement
what is the pattern of muscle weakness in UMN lesions?
pyramidal pattern of weakness that disproportionately affects upper limb extensors and lower limb flexors
what is the pattern of muscle weakness in LMN lesions?
focal pattern of weakness, with only the muscles directly innervated by the damaged neurones affected
what are the different scores on the MRC scale?
0/5 = no muscle contraction 1/5 = flicker or trace of contraction 2/5 = active movement without gravity 3/5 = active movement against gravity 4/5 = active movement against gravity and resistance 5/5 = normal power
what reflexes do you assess?
- biceps reflex (C5/6)
- supinator (brachioradialis) reflex (C5/6)
- triceps reflex (C7)
how do you assess the biceps reflex (C5/6)?
- with patient’s arm relaxed, locate the biceps brachii tendon at the medial aspect of the antecubital fossa
- place the thumb of your left hand over the tendon and tap your thumb with the tendon hammer
- observe for contraction of the biceps muscle and associated flexion of the elbow
how do you assess the supinator reflex (C5/6)?
- locate brachioradialis tendon on the posterolateral aspect of the wrist 4 inches proximal to the base of the thumb
- with two fingers over the tendon, tap fingers with hammer
- observe for contraction of the brachioradialis muscle and associated flexion, pronation or supination of the forearm at the elbow
how do you assess the triceps reflex (C7)?
- rest the patient’s elbow in 90deg flexion on their lap/support their forearm
- locate the triceps tendon, superior to the olecranon process of the ulna
- tap tendon with hammer and observe for contraction
how should sensation be assessed?
- check at least one modality from dorsal columns and spinothalamic tracts
- eyes closed
- demonstrate normal sensation on sternum
- assess dermatomes and compare sides
where is the C5 dermatome?
lateral aspect of the lower edge of the deltoid muscle
where is the C6 dermatome?
palmar side of the thumb
where is the C7 dermatome?
palmar side of the middle finger
where is the C8 dermatome?
palmar side of the little finger
where is the T1 dermatome?
medial aspect of the antecubital fossa, proximal to the medial epicondyle of the humerus
what types of sensation should you assess?
- light touch sensation
- pin-prick sensation
- vibration sensation
- proprioception
how is light touch assessed?
- involves both dorsal columns and spinothalamic tracts
- ask patient to close eyes and demonstrate cotton wool on sternum
- assess across each upper limb dermatomes, comparing each side as you go
how is pin-prick sensation assessed?
- involves spinothalamic tracts
- use sharp end of a neurotip and demonstrate on sternum
- assess each upper limb dermatomes, comparing each side as you go
how is vibration sensation assessed?
- involves dorsal columns
- ask patient to close eyes and to let you know when they can detect vibration and also when it stops
- tap a 128Hz tuning fork and place onto their sternum to demonstrate, then stop vibration
- repeat this and place the fork on the interphalangeal joint of their thumb
- if vibration sensation is impaired, continue to assess more proximal joints (e.g. carpometacarpal joint of thumb -> wrist -> elbow -> shoulder) until they can identify it
how is proprioception assessed?
- involves dorsal columns
- begin at the interphalangela joint of the thumb by holding its distal phalanx by its sides
- demonstrate movement of the thumb upwards and downwards to patient
- ask them to close eyes and state if you’re moving it up or down
- move thumb up or down 3-4 times in random sequence
- if they cannot identify it, assess more proximal joints until they can
how is coordination assessed?
- finger-to-nose test
2. dysdiadochokinesia
how is the finger-to-nose test performed?
- assesses coordination
- position your finger so the patient has to fully outstretch their arm to reach it
- ask patient to touch their nose with their index finger and then touch your fingertip
- do this as fast as possible and move your finger slowly
what is the result of the finger-to-nose test in cerebellar pathology?
dysmetria and intention tremor
what is dysmetria?
lack of coordination of movement; patient misses target by over/undershooting
what is intention tremor?
broad, coarse, low-frequency tremor that develops as a limb reaches the endpoint of a deliberate movement
how is dysdiadochokinesia assessed?
- ask patient to place their left palm on top of their right palm
- ask them to turn over their left hand and touch the back of it onto their right palm
- return their hand to the original position
- do this as fast as possible
- observe their speed and fluency
- repeat with other hand
what is dysdiadochokinesia?
inability to perform rapid, alternating movements
what further assessments and investigations should be suggested after this exam?
- full neuro exam
2. neuroimaging
what are the overall steps of this examination?
- general inspection
- tone
- power
- reflexes
- sensation
- coordination
