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Stuff you need to know in black. Everything else in grey
General· Compare like –to-like
· Immobilise the proximal joint
· Avoid potentially painful movements
· Examine sensation in a dermatomal order, including the fingertips
Patterns of Neurological Compromise
Descriptive
LMN
Bilateral
Symmetrical
Distal
Motor / UMN
Unilateral
Asymmetrical
Proximal
Sensory Mixed
Deficit
Level
/ Myopathy
NMJ
Peripheral Neuropathy
Peripheral Merve lesion (s)
Plexopathy
Radiculopathy
Cauda equina
Spinal cord lesion/Myelopathy
Brainstem lesion
Cortical lesion
Cerebellar Syndrome
Causes
Common
Infection
Infarction
Inflammation
Iatrogenic
Tumor
Degenerative / Alcohol, posterior circulation stroke, multiple sclerosis
Nil really
Stroke –haemorrhagic or ischaemic , posterior circulation
(PICA occlusion -> Wallenburg/lateral medullary syndrome – ipsilateral cerebellar signs, ipsilateral CRN 5, 8 and bulbar, Horner syndrome, and contralateral spinothalamic (pain/pinprick) tract signs – one of the few causes of dissociated sensory deficit)
Paraneoplastic – lung tumors (esp small cell), ovarian, breast, adenocarcinoma
Drugs – phenytoin, chemotherapy, chronic alcohol
Primary or metastatic – mass effect/oedema
Friedrich’s Ataxia
Signs - DANISH
Dysdiadokokinesis
Ataxia (Broad based gait)
Nystagmus
Intention tremor
Slurred/Staccato Speech
Hypotonia
Median Nerve Palsy – sometimes orthopaedic, sometimes neurological
Examination
Inspection
Tone
Power
Reflexes
Sensation
Function
Special / Thenar wasting (APB muscle), sparing of dorsal aspect
Scars!
Normal
On basic myotomal examination – nil on extended examination - LOAF
Lateral two lumbricals
Opponens Pollicis (opposition)
Abductor Pollicis Brevis (thumbs to ceiling)
Flexor pollicis brevis
Nil
Parasthesia (often painful) in the tips of the fingers, progressing to sensory loss if sustained (see below)
Difficulty 2’sensory deficit- picking up coin etc
Tinels- tapping recreates paraesthesia,
Phalens – wrist flexion for 1 minute recreates symptoms
Provocative test - flexion and compression recreates symptoms
Sensation
Spares palmar cutaneous branch of median nerve (branches off before tunnel)
Affects the distal course of the anterior interosseous branch (which supplies the anterior compartment of the forearm, then passes through the carpal tunnel, and innervates the digits)
Structure of the carpal tunnel
Formed by the flexor retinaculum and the carpal bones
Carpal tunnel syndrome associations
Common
Structural
Predisposition
Inflammatory
Infiltrative / Chronic compression, workplace-based positioning
Rheumatoid, acromegaly, pregnancy
Diabetes, alcohol, B12
Vasculitic
Amyloid
Treatment
Conservative
Antiinflammatories
Surgical / Rest, splints, Occupational therapy input
Local steroid injection
Decompression – palmar aponeurosis
Mononeuropathy
Common
External Compression
Internal Compression
Intrinsic lesion / Compression, diabetes, vasculitis
Trauma, prolonged compression (eg. Coma)
Entrapment (eg. Carpal tunnel), tumors
Inflammation (usually part of a polyneuropathy/ MNM
- Vasculitic (SLE, Rheumatoid, ANCA associated)
- infiltrative (Amyloid, Sarcoid)
Failure to repair (metabolic) and minor compression
- Diabetic microvascular disease, alcohol, B12
- Hereditary disposition to pressure palsies
3 nerves – basics
nerve / Median / Ulnar / Radial
Site of compression / Carpal tunnel
(Proximal – rare) / Compression at ulnar tunnel, medial to the epicondyle at the elbow / ‘Saturday night syndrome’
Compression of axillary branch 2’ passing out with arm over chair
Findings / Thenar wasting
Tinels
Phalens / Claw hand
Wasting of dorsal interossei and extensors
Paper between fingers and pull test (dorsal interossei)
Froments test- (pinch grip difficulty due to adductor pollicis weakness) / Wrist drop
Motor / Short thumb muscles +lateral 2 lumbricals
APB/LOAF (thumbs to ceiling, opposition)
(Proximal –involves anterior compartment and pronators/ flexors) / Anterior/flexor compartment, small muscles of the hand (hypothenar, dorsal interossei) / Posterior compartment – mostly wrist extensors
Sensory / Tingling in fingers / Medial side of hands dorsal and palmar (4th/5th fingers) / Sensory deficit in anatomical snuffbox