Neurology 4 Flashcards
Musculocutaneous nerve function?
Motor
Sensory
Motor = Elbow flexion
Sensory = lateral part of FOREARM
Flexion weakness at elbow - what nerve affected
Flexion weakness at wrist - what nerve affected
Flexion weakness at fingers - what nerve affected
Extension of elbow/wrist/fingers - what nerve affected?
Elbow = Musculocutaneous Wrist = Median Fingers = Median/ulnar
Extension weakness = Radial
Median motor function?
Flexion of wrist and fingers ( except medial 2 fingers - Ulnar)
LOAF muscles Lateral 2 lumbricals Opponens pollicis brevis Abductor pollicis brevis Flexor pollicis brevis
Ulnar nerve function
Finger abduction and adduction
Flexion of 4,5th digit = Flexor digitorum profundus
Axillary nerve function?
Shoulder abduction
Erb palsy - waiter’s tip lesion where and presentation?
C5-6 lesion
Loss of elbow flexion and shoulder movement
Sensory loss in lateral aspect of arm
Klumpke palsy - lesion where and presentation?
C8 - T1 lesion
Supinated clawed hand + hyperextension at wrist
Flaccid foot + Knee flexion = only 1 nerve cause this - name?
Sciatic nerve
Once wallerian degeneration completes - denervated dying motor axon fibers express what?
Acetycholine - so inappropriate firing of motor in response to Ach = sign of denervation
Neurogenic changes
morphology and recruitment of muscle unit action potential
surviving motor axons - tries to re-innervate died motor
-fibers = thin and unmyelinated
Longer/Broad/Polyphasic/ high amplitude!
Reduced recruitment!
Myopathic changes
morphology and recruitment of muscle unit action potential
muscle fibers damaged + few remaining ( but are normal)
Small amplitude + normal/increased recruitment+ early
AChr antibodies a/w what?
Thymoma and thymic hyperplasia
Musk antibodies a/w what?
Generalized severe MG ( bulbar and respiratory involvement)
-young female - non white
Singe fibre EMG best for?
Ocular MG
Medications to avoid in MG?
Aminoglycosides Tetracyclines Macrolides Fluoroquinolones B-blockers
Lambert-eaton syndrome?
Triad of ;
1 - proximal weakness (upper limbs most affected) - mild improvement post exercise
2- autonomic features - dry mouth/erectile dysfunction/urinary issues
3- areflexia ( post exercise)
NO SENSORY/ NO FATIGUABILITY
Lambert-eaton syndrome a/w?
Paraneoplastic - SCLC
Non-paraneoplastic - HLA B8 DR3
Lambert-eaton treatment?
Resect tumor
3-4 diaminopyridine - block K from going out - prolonged depolarisation
Antibodies a/w Dermatomyositis and ILD?
Malignancy in ILD patients?
what Dermatomyositis antibodies associated with good response to treatment?
anti-MDA5 - rapidly progressive ILD
Anti-Jo 1 - ILD
Lower risk
Anti-MI 2
Treatment for dermatomyositis?
Prednisolone (iv methylprednisolone if severe weakness)
CYP if ILD
SLCO1B1 gene function?
uptake of statin into liver cells
Necrotizing autoimmune myopathy antibodies?
anti-SRP/anti-HMG COA
high CK
Anti-SRP a/w?
Dilated cardiomyopathy
No response to immunosuppression
Anto-HMG COA a/w?
higher levels of CK and muscle weakness severity
HIGHLY SPECIFIC FOR NECROTIZING AUTOIMMUNE MYOPATHY
-can occur without statins
Signal recognition particle is what?
Peptide involved in transport protein to endoplasmic reticulum
Commonest myopathy > 50 yrs old?
Inclusion body myositis ( distal + asymmetric weakness)
what muscle is spared in IBM quadriceps weakness?
Rectus femoris
All the vastus muscle affected-atrophy
Perimysial,endomysial inflammation and necrosis - have upregulation of what?
MHC1 - CD8 complex
Anti-synthetase syndrome is what?
Myositis with; ILD Mechanic hands and polyarthritis Fever Raynaud's
Myopathy in ;
Hypothyroidism features?
Hyperthyroidism features?
- Symmetric PAINFUL muscle cramps, weakness
- occasional HIGH CK
- Delayed reflexes
- PAINLESS muscle weakness
- NORMAL CK
- brisk reflexes
Statin induced NAM - HLA antibodies
protective?
at risk?
association with SLCO1B1 gene?
At risk - HLA DRB1 11
Protective - HLA DQA1/ DQB6
No! SLCO1B1 only for Statin myopathy
