Muscle weakness

Question 1

What is the movement pathway?

Answer 1

Motor cortex
Medulla/spinal cord
Anterior horn
Motor neurone
Neuromuscular junction
Muscle

Question 2

What can affect the motor cortex?

Answer 2

Stroke, tumour, MS

Question 3

What can affect the medulla/SC?

Answer 3

Stroke, tumour, MS

Question 4

What can affect the anterior horn?

Answer 4

MND

Question 5

What can affect the motor neurone?

Answer 5

MND, neuropathy

Question 6

What can affect the NMJ?

Answer 6

Myasthenia Gravis

Question 7

What can affect the muscle?

Answer 7

Myopathy

Question 8

If their are bulbar sx what is this suggestive of?

Answer 8

MND, MG

Question 9

If there are opthalmoplegia?

Answer 9

MG, mitochondrial

Question 10

If there is facial involvement?

Answer 10

MG

Question 11

If there is fatigue-ability?

Answer 11

NMJ

Question 12

If there is relapse remission

Answer 12

inflammatory

Question 13

if it is fixed?

Answer 13

Stroke

Question 14

Describe peripheral neuropathy

Answer 14

Chronic and slowly progressive

Starts in the legs and longer nerves (length dependent)

Weakness, numbness, LMN

Question 15

Commonest cause of a peripheral neuropathy?

Answer 15

Diabetes

Question 16

Other causes of peripheral neuropathy?

Answer 16

Vitamin deficiency e.g. B12 /Folate
Toxins:
- Alcohol
- Chemotherapy
- Amiodarone
- Lead
- Aluminium
Metabolic disorders:
- Thyroid, uraemia
HIV
Paraneoplastic Syndromes
Hereditary neuropathies:
- Charcot Marie Tooth/ Hereditary sensory and motor neuropathy
- Hereditary liability to pressure palsies

Question 17

Causes of mononeuritis multiplex

Answer 17

vasculitides

connective tissue disorders - sarcoid

Question 18

Causes of mononeuropathy

Answer 18

Median nerve entrapment at the wrist most common ( Carpal Tunnel Syndrome)

Ulnar nerve at elbow common (handlebar palsy)

Radial nerve in axilla common (wrist drop)

Common peroneal nerve in leg

Question 19

Investigations for a neuropathy

Answer 19

History and examination
\+/-Neuropathy screen
\+/-Vasculitic screen
\+/-EMG/NCS
\+/-CSF study
\+/-nerve biopsy

Question 20

Bloods for neuropathy screen

Answer 20

FBC ESR
U+E, glucose, TFT, CRP, Serum electorophoresis
B12 Folate
Anti Gliadin
(TPHA, HIV)

Question 21

Bloods for a vasculitic screen

Answer 21

FBC, ESR
U+ECr, CRP
ANA, ENA, ANCA, anti dsDNA, RhF, Complement, Cryoglobulins

Question 22

Tx for neuropathies

Answer 22

20% no tx (neuropathic analgesia e.g. gabapentin, pregablin)

Treat/remove underlying cause e.g. gluten, sugar

Steroids in inflammatory

Question 23

Myasthenia gravis cause

Answer 23

NMJ, antibodies attack the Ach binding sites therefore no muscle activation

Question 24

Other sx of MG

Answer 24

THYMUS DYSFUNCTION

• *fatigueable weakness:
• Neck and face (head drop, ptosis)
• extraoccular (complex diplopia)
• Bulbar (speech, swallow) particularly elderly
• Breathing

Question 25

MG ix

Answer 25

AChR antibodies
EMG
Repetitve stimulation looks at NMJ
CT thorax
Tensilon test

Question 26

MG treatment

Answer 26

Acetylcholine esterase inhibitors (pyridostigmine) – symptomatic
Immunosuppresants
Steroids (start slowly)
Azathioprine/Methotrexate/mycophenolate
Thymectomy
Monitor FORCED VITAL CAPACITY and bulbar function

Question 27

What is a myasthenic crisis?

Answer 27

• severe weakness including resp and bulbar muscles
• high risk of death
• urgent review by neurologists and anaesthetic review

Question 28

Uncommon muscle disorders

Answer 28

Most genenetic  muscular dystrophies
- Duchenne, Becker, FSH, LGD 
Inflammatory muscle disease
- Polymyositis, Dermatomyositis
Mitochondrial disorders

Question 29

Muscle investigation

Answer 29

CK
EMG
ESR/CRP

+/-Genetics (DMD/Becker)
+/-biopsy

Question 30

Muscle disorder treatment

Answer 30

Remove causal agent
Supportive: MDT
- OT (aids adaptations)
- Physio (prevent contracture)
- Back
- Renal
- Diet
Immunosuppress if inflammatory
Steroids/gene therapies