Limb neurology

1. Limb neurology

2. Learning Objectives To examine the nerves of the Upper limb To examine the nerves of the Lower limb

3. Upper limbs

4. Introduction and inspection Proper introduction Wash hands Inspection Scars Skin changes Asymmetry Wasting, fasciculations

5. Pronator drift � ask the patient to hold both arms up, palms facing upwards and close their eyes. With weakness, the arm with fall and pronate. Also in this position ask the patient to keep the arms still, and warn them you will push down sharply on their arms. If they overshoot when trying to return back to the normal position � suspect cerebellar disease.Pronator drift � ask the patient to hold both arms up, palms facing upwards and close their eyes. With weakness, the arm with fall and pronate. Also in this position ask the patient to keep the arms still, and warn them you will push down sharply on their arms. If they overshoot when trying to return back to the normal position � suspect cerebellar disease.

6. Tone - Don�t bother with shoulder - Extend and flex the elbow. Fast phase in extension - Extend and flex the wrist - Supinate and pronate the wrist. Fast phase in supination. Tone can be high or low. High tone is divided into spasticity or rigidity. Spasticity is defined as a velocity dependent increase in tone. This is why we perform the fast and slow movements. The movement however must be done to counteract the pyramidal distribution of weakness associated with upper motor neurone weakness. If you think about the patient with a stroke, they are flexed at the elbow, wrist and hyperpronated. Undoing this (i.e. Extending the elbow, wrist and supinating the wrist) will bring out spasticity and feel like a �clasp knife� i.e. Feel stiff then give way like a Swiss army. Ridigity is not velocity dependent and is therefore stiff throughout the whole movement. It is associated with extrapyradimal weakness e.g. Parkinson�s. Cogwheeling is the combination of rigidity + resting tremor and is most prominent whilst circumducting the wrist.Tone can be high or low. High tone is divided into spasticity or rigidity. Spasticity is defined as a velocity dependent increase in tone. This is why we perform the fast and slow movements. The movement however must be done to counteract the pyramidal distribution of weakness associated with upper motor neurone weakness. If you think about the patient with a stroke, they are flexed at the elbow, wrist and hyperpronated. Undoing this (i.e. Extending the elbow, wrist and supinating the wrist) will bring out spasticity and feel like a �clasp knife� i.e. Feel stiff then give way like a Swiss army. Ridigity is not velocity dependent and is therefore stiff throughout the whole movement. It is associated with extrapyradimal weakness e.g. Parkinson�s. Cogwheeling is the combination of rigidity + resting tremor and is most prominent whilst circumducting the wrist.

7. Power Minimum movements � - Shoulder abduction/adduction - Elbow extension, flexion - Wrist extension, flexion - Finger abduction - Thumb abduction Grade muscles strength from 0 � 5 The movements you want to test are dependent on the pathology you suspect. Stroke� the most sensitive signs are weakness of wrist extension, finger abduction and thumb abduction. If you suspect nerve palsy then you are going to pay more attention to test that nerve more carefully... Median nerve � forearm flexors (most of them), LOAF muscles (Lateral 2 lumbricals, Opponens pollicis, Abductor pollicis, Flexor digitorum brevis) of the thenar eminence. Motor test = thumb abduction (testing abductor pollicis), sensation = lateral 3.5 fingers Ulnar nerve � some forearm flexors, muscles of the hand except the LOAF muscles. Motor test � finger abduction, sensation � medial 1.5 fingers Radial nerve � exensors of the arm and forearm. Motor wrist extension, sensation � thumb webspace. Axilllary nerve � Motor � external rotation (teres minor), Sensation - army badge patch of anaesthesia Muscle strength is graded out of 5: 0 � no movement 1 � flicker of muscle contraction 2 � move with gravity taken away 3- move against gravity but not resistance 4 � move against some resistance 5 � full power. If you discover weakness a thorough neurological exam should make clear the distribution of the weakness and therefore help you locate the lesion. Commonly, in the upper limb it might be: - Pyramidal (i.e. Flexors stronger than extensors but both weak) - Peripheral nerve � radial, ulnar or median - Distal or proximal (i.e. Related to distance down the arm, not to a nerve or root) - Related to a specific cord, division, trunk of the brachial plexus - Root � affecting the myotome The movements you want to test are dependent on the pathology you suspect. Stroke� the most sensitive signs are weakness of wrist extension, finger abduction and thumb abduction. If you suspect nerve palsy then you are going to pay more attention to test that nerve more carefully... Median nerve � forearm flexors (most of them), LOAF muscles (Lateral 2 lumbricals, Opponens pollicis, Abductor pollicis, Flexor digitorum brevis) of the thenar eminence. Motor test = thumb abduction (testing abductor pollicis), sensation = lateral 3.5 fingers Ulnar nerve � some forearm flexors, muscles of the hand except the LOAF muscles. Motor test � finger abduction, sensation � medial 1.5 fingers Radial nerve � exensors of the arm and forearm. Motor wrist extension, sensation � thumb webspace. Axilllary nerve � Motor � external rotation (teres minor), Sensation - army badge patch of anaesthesia Muscle strength is graded out of 5: 0 � no movement 1 � flicker of muscle contraction 2 � move with gravity taken away 3- move against gravity but not resistance 4 � move against some resistance 5 � full power. If you discover weakness a thorough neurological exam should make clear the distribution of the weakness and therefore help you locate the lesion. Commonly, in the upper limb it might be: - Pyramidal (i.e. Flexors stronger than extensors but both weak) - Peripheral nerve � radial, ulnar or median - Distal or proximal (i.e. Related to distance down the arm, not to a nerve or root) - Related to a specific cord, division, trunk of the brachial plexus - Root � affecting the myotome

8. Case Patient presents on Sunday morning, unable to lift his wrist Diagnosis? Wrist drop = radial nerve palsy. Often called Saturday night palsy (but should strictly be Sunday morning if they�ve slept all night) and is caused by someone stretching the nerve along the radial groove. Wrist flexion will be impaired, along with decreased sensation in the thumb webspace. Usually self resolves.Wrist drop = radial nerve palsy. Often called Saturday night palsy (but should strictly be Sunday morning if they�ve slept all night) and is caused by someone stretching the nerve along the radial groove. Wrist flexion will be impaired, along with decreased sensation in the thumb webspace. Usually self resolves.

9. Patient presents with hand weakness Further examination reveals neck crepitus Diagnosis? Cervical spondylosis � osteoporosis is often the cause with age cause compression of the nerve roots. Pain is often a feature but later a patient might develop weakness in the hand depending on which root is being compressed. In this case it is likely T1 might be affected as the small muscles in the hand are affected. Cervical spondylosis � osteoporosis is often the cause with age cause compression of the nerve roots. Pain is often a feature but later a patient might develop weakness in the hand depending on which root is being compressed. In this case it is likely T1 might be affected as the small muscles in the hand are affected.

10. Case Patient presents with pain on the lateral forearm. Make worse against forced extension of the middle finger Diagnosis? Tennis elbow or lateral epicondylitis. All pain is not neurological! The forced finger extension causing pain is almost pathogmonic of tennis elbow and is due to the attachment of the forearm extensors to the lateral epicondyle. Rest, analgesia, steroid injections are usually the treatment.Tennis elbow or lateral epicondylitis. All pain is not neurological! The forced finger extension causing pain is almost pathogmonic of tennis elbow and is due to the attachment of the forearm extensors to the lateral epicondyle. Rest, analgesia, steroid injections are usually the treatment.

11. Reflexes Biceps Supinator Triceps Biceps tests C5/6 Supinator test C5/6 Triceps test C7/8 It is important to do it in this order to show the examiner you know the anatomy. Reflexes are graded as the following: 0 = absent + = present with reinforcement ++ = normal +++ = hyperreflexia without clonus ++++ = hyperreflexia with clonus If you cant get the reflexes, try reinforcement maneouvres (called Jendrassik maneouvre). This is done by getting the patient to clench their teeth just before you strike the hammer. Biceps tests C5/6 Supinator test C5/6 Triceps test C7/8 It is important to do it in this order to show the examiner you know the anatomy. Reflexes are graded as the following: 0 = absent + = present with reinforcement ++ = normal +++ = hyperreflexia without clonus ++++ = hyperreflexia with clonus If you cant get the reflexes, try reinforcement maneouvres (called Jendrassik maneouvre). This is done by getting the patient to clench their teeth just before you strike the hammer.

12. Patient presents with sudden onset right sided weakness in A + E Power � 0/5 in all movements Coordination � unable to do Sensation � numb in the whole limb Reflexes � Absent. Diagnosis?

13. Coordination Finger nose Dysdiadochokinesia With finger point you must make sure they are outstretched when they are reaching for your finger. Past pointing (called dysmetria) and intention tremor are seen when as the cerebellum fails to smooth out the fine adjustments needed to touch your finger tip. DANISH is the mnemonic to remember the signs of cerebellar lesions � - Dysdiadochokinesia (trouble in rapid alternating movement) - Ataxia (wide based gait, looks drunk) - Nystagmus - Intention tremor with past pointing - Slurred speech - Hypotonia With finger point you must make sure they are outstretched when they are reaching for your finger. Past pointing (called dysmetria) and intention tremor are seen when as the cerebellum fails to smooth out the fine adjustments needed to touch your finger tip. DANISH is the mnemonic to remember the signs of cerebellar lesions � - Dysdiadochokinesia (trouble in rapid alternating movement) - Ataxia (wide based gait, looks drunk) - Nystagmus - Intention tremor with past pointing - Slurred speech - Hypotonia

14. Sensation Light touch in the dermatomes Proprioception Vibration sense Dermatomes are roughly: C5 � lateral upper arm C6 � thumb C7 � middle finger C8 � little finger/medial forearm T1 � medial forearm/medial elbow T2 � medial upper arm Myotomes are: C5 � shoulder abduction C6 � elbow flexion, radial extensors of the wrist C7 � triceps, ulnar extensors of the wrist, finger extensors C8 � finger flexors T1 � small muscles of the hand Dermatomes are roughly: C5 � lateral upper arm C6 � thumb C7 � middle finger C8 � little finger/medial forearm T1 � medial forearm/medial elbow T2 � medial upper arm Myotomes are: C5 � shoulder abduction C6 � elbow flexion, radial extensors of the wrist C7 � triceps, ulnar extensors of the wrist, finger extensors C8 � finger flexors T1 � small muscles of the hand

15. Case Patient presents with loss of pain and temperature sensation in both arms Fine touch and proprioception are normal All else normal

16. Syringomyelia The spinothalamic tract fibres cross at or a few levels above the site they enter the spinal cord. They cross the midline just anterior to the canal (arrowed) which contains all of the CSF and where the syrinx. The forward pressure on these nerves causes them to dysfunction whereas there is no such pressure on the light touch and proprioception tracts (dorsal columns). This means there is a dissociated sensation loss. The spinothalamic tract fibres cross at or a few levels above the site they enter the spinal cord. They cross the midline just anterior to the canal (arrowed) which contains all of the CSF and where the syrinx. The forward pressure on these nerves causes them to dysfunction whereas there is no such pressure on the light touch and proprioception tracts (dorsal columns). This means there is a dissociated sensation loss.

17. Patient presents with... Wrist drop in Left hand Weakness of intrinsic muscles of Right hand Foot drop of right foot HbA1c of 18% Mononeuritis multiplex � a rare condition where multiple discrete nerve palsies are present at the same time. Commoner in diabetics but can also be caused by: Acute � polyarteritis nodosa, DM Chronic � SLE, Rheumatoid arthritis, Sarcoidosis, Acromegaly, Hypothyroidism, leprosy Mononeuritis multiplex � a rare condition where multiple discrete nerve palsies are present at the same time. Commoner in diabetics but can also be caused by: Acute � polyarteritis nodosa, DM Chronic � SLE, Rheumatoid arthritis, Sarcoidosis, Acromegaly, Hypothyroidism, leprosy

18. Summary Inspect Pronator drift with cerebellar test Tone � high or low Power � out of 5 Reflexes � high or low Coordination � cerebellar disease? Sensation � distribution

19. Lower limbs

20. Gait Antalgic � short stance phase Circumducting � in stroke Trendelenburg � hip abductor weakness Duchenne�s sign Scissoring � bilateral spasticity Festinating � Parkinson�s Ataxic � cerebellar or sensory High stepping � foot drop Waddling � proximal myopathy �Glued to the floor� � dyspraxic gait

21. Inspection Scars Wasting, fasciculations Ulcers, joint deformity Feet � high arches? Wasting is most prominent on the quadriceps through disuse as it is the largest muscle and often the first to go. Ulcers are not only caused by neurological symptoms, sometimes they are venous or arterial but joint deformity with lots of callosities/ulcer in the weight bearing regions could mean a neuropathy. Charcot joints are grossly deformed joints caused by lack of sensation to the joint and therefore unawareness of abnormal pressures and positions making the joing wear down. High arches of the foot (pes cavus) can be a sign of neurological disease. Classically associated with Charcot Marie Tooth disease (or better called Common Peroneal Nerve Atropy) which causes a foot drop, clawing of the toes and high arches. Wasting is most prominent on the quadriceps through disuse as it is the largest muscle and often the first to go. Ulcers are not only caused by neurological symptoms, sometimes they are venous or arterial but joint deformity with lots of callosities/ulcer in the weight bearing regions could mean a neuropathy. Charcot joints are grossly deformed joints caused by lack of sensation to the joint and therefore unawareness of abnormal pressures and positions making the joing wear down. High arches of the foot (pes cavus) can be a sign of neurological disease. Classically associated with Charcot Marie Tooth disease (or better called Common Peroneal Nerve Atropy) which causes a foot drop, clawing of the toes and high arches.

22. Tone Leg roll Knee lift Clonus Lie the patient down and roll the leg. If the foot flops from side to side this is normal tone. When lifting the knee, do it quickly and see if the heel of the foot leaves the bed. If so, it might mean increased tone. Clonus is done by relaxing the ankle and rapidly dorsiflexing it. Those with increased tone may have clonus which is counted in beats. More than 2 is pathological. Lie the patient down and roll the leg. If the foot flops from side to side this is normal tone. When lifting the knee, do it quickly and see if the heel of the foot leaves the bed. If so, it might mean increased tone. Clonus is done by relaxing the ankle and rapidly dorsiflexing it. Those with increased tone may have clonus which is counted in beats. More than 2 is pathological.

23. Power Hip flexion Knee flexion/extension Ankle dorsiflexion/plantarflexion Toe extension Myotomes:hip joint flexors L1,2,3 extensors L4,5,S1 adductors L1,2,3 abductors L4,5,S1 med. rotators L1,2,3 lat. rotators L4,5,S1 knee joint: extensors L3,4 flexors L5,S1 ankle: dorsi-flexors L4,5 plantar-flexors S1,2 subtalar invertors L4,5; evertors L5,S1 foot: toe extensors L5,S1 toe long flexors S2 extension of big toe L5 The ones to really know are ankle dorsiflexion (L4-5) and Plantar flexion (S1-2). They cannot be adequately tested with your arm because they are designed to take the force of the patients body weight therefore a subtle weakness will not be picked up without asking the patient to walk on their toes and heels. Myotomes:hip joint flexors L1,2,3 extensors L4,5,S1 adductors L1,2,3 abductors L4,5,S1 med. rotators L1,2,3 lat. rotators L4,5,S1 knee joint: extensors L3,4 flexors L5,S1 ankle: dorsi-flexors L4,5 plantar-flexors S1,2 subtalar invertors L4,5; evertors L5,S1 foot: toe extensors L5,S1 toe long flexors S2 extension of big toe L5 The ones to really know are ankle dorsiflexion (L4-5) and Plantar flexion (S1-2). They cannot be adequately tested with your arm because they are designed to take the force of the patients body weight therefore a subtle weakness will not be picked up without asking the patient to walk on their toes and heels.

24. Reflexes Knee Ankle Plantars Knee jerks � L3/4 Ankle � (L5) S1 Plantars � normally down going. If upgoing, good sign of upper motor neurone lesion. You must look at the first movement of the great toe, sometimes patients withdraw because it is uncomfortable but the first movement in a normal person is down. Knee jerks � L3/4 Ankle � (L5) S1 Plantars � normally down going. If upgoing, good sign of upper motor neurone lesion. You must look at the first movement of the great toe, sometimes patients withdraw because it is uncomfortable but the first movement in a normal person is down.

25. Patient presents with leg weakness Examination reveals � Absent knee reflexes Upward going plantars Causes?

26. Absent knee jerks + extensor plantars 1. Mixed Cervical and Lumbar disc disease 2. Conus medullaris lesion MAST: Motor Neurone Disease Freidrich�s ataxia Subacute combined degeneration of the cord Tabes dorsalis The strange mix of upper and lower motor lesions is caused by very few diseases. In the conus medullaris lesion there is a mixed picture because of the close proximity of the upper motor neurones in the end of the cord, and the peripheral nerves leaving the cord travelling down the cauda equina. Freidrich�s ataxia is the most common inherited ataxia and is a genetic disease characterised by trinucleotide repeats. It is transmitted in an autosomal recessive fashion. It clinically presents with ataxia, claw foot or kyphoscoliosis. Subacute combined degeneration of the spinal cord is due to chronic B12 deficiency. Tabes dorsalis is due to syphilis infection. The strange mix of upper and lower motor lesions is caused by very few diseases. In the conus medullaris lesion there is a mixed picture because of the close proximity of the upper motor neurones in the end of the cord, and the peripheral nerves leaving the cord travelling down the cauda equina. Freidrich�s ataxia is the most common inherited ataxia and is a genetic disease characterised by trinucleotide repeats. It is transmitted in an autosomal recessive fashion. It clinically presents with ataxia, claw foot or kyphoscoliosis. Subacute combined degeneration of the spinal cord is due to chronic B12 deficiency. Tabes dorsalis is due to syphilis infection.

27. Coordination Knee � ankle � hand cycle Tap with the sole of the foot on your hand

28. Sensation Dermatomal distribution � - L3 to the knee - L4 to the floor - L5 the big toe - S1 is the sole - S2 is back of the leg - S3,4,5 � anal/perineal area Proprioception and vibration

29. A few cases to finish...

30. 86 year old presents with difficulty urinating... Now has leg weakness O/E � bilateral upper motor neurone weakness Diagnosis? Prostate Ca � most commonly spreads to the spine and can seed leading cord compression. Prostate Ca � most commonly spreads to the spine and can seed leading cord compression.

31. 56 year old presents with difficulty urinating Incontinent Ataxic Confused Diagnosis? Normal pressure hydrocephalus classicalled presents with the triad of Adam (urinary incontinence, gait disturbance and dementia). Can be remembered as �Wet, wobbly and wacky�. It is a type of communicating hydrocephalus with a normal CSF pressure on LP. A ventriculoabdominal shunt may be put in place to reduce the CSF levelsNormal pressure hydrocephalus classicalled presents with the triad of Adam (urinary incontinence, gait disturbance and dementia). Can be remembered as �Wet, wobbly and wacky�. It is a type of communicating hydrocephalus with a normal CSF pressure on LP. A ventriculoabdominal shunt may be put in place to reduce the CSF levels

32. Patient presents with back pain... Red flag symptoms that must be asked? Was it traumatic (is this a fracture?) Is the pain unrelenting and progressive? Does it wake you up at night? Do you have urinary disturbance? Faecal disturbance? Is there leg pain? If so, does it affect both legs? Is there saddle anaesthesia? Was it traumatic (is this a fracture?) Is the pain unrelenting and progressive? Does it wake you up at night? Do you have urinary disturbance? Faecal disturbance? Is there leg pain? If so, does it affect both legs? Is there saddle anaesthesia?

33. Continued... Turns out the patient did have an accident... Now has loss of touch on the right but loss of pain on the left... Diagnosis?

34. Brown Sequard syndrome (or cord hemisection) describes the loss of sensation of touch and vibration ipsilateral to the lesion, and pain/temperature contralateral to the lesion. This is due to the location of the fibre decussation. The spintothalamic tract (pain and temp) cross at the level or just a few levels above the entry point into the cord. Cutting the tract will therefore give you contralateral signs. The converse is true with the posterior columns which cross in the medulla.Brown Sequard syndrome (or cord hemisection) describes the loss of sensation of touch and vibration ipsilateral to the lesion, and pain/temperature contralateral to the lesion. This is due to the location of the fibre decussation. The spintothalamic tract (pain and temp) cross at the level or just a few levels above the entry point into the cord. Cutting the tract will therefore give you contralateral signs. The converse is true with the posterior columns which cross in the medulla.

35. Summary Gait Inspect Tone, Power, Coordination, Reflexes and sensation Some pathology

36. Thanks Any questions email me on dp305@ic.ac.uk Good luck with exams!