Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MD2 Neuro > Neuromuscular Disease > Flashcards

Neuromuscular Disease Flashcards

(72 cards)

Start Studying
1
Q

Associated features of neuromuscular disease

A

MOTOR: muscle weakness/wasting (diploplia, dyspnoea, dysphagia), stiffness, cramps, fasciculation, clumsiness, poor balance, falls

SENSORY: numbness, burning, tingling

NON-SPECIFIC: fatigue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Give 3 examples of conditions causing diplopia and ptosis

A

Myasthenia gravis

Ocular nerve palsy

Thyroid eye disease (although more commonly proptosis, not ptosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give 2 examples of conditions causing dysphagia and dysarthria

A

Myasthenia gravis

MND

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Clinical features of MND

A

Muscle wasting including tongue

Fasciculations

Tone

Generalised weakness (no pattern)

Reflexes preserved until late or exaggerated

Plantars may be upgoing

No sensory loss (may have sensory symptoms but on testing no signs)

Cranial nerves (except bulbar) spared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is MND diagnosed?

A

On the basis of symptoms and signs, consistent laboratory findings (EMG) and the exclusion of other diagnoses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is MND?

A

Gradually progressive disorder with evidence of upper and lower motor neuron involvement and intact sensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Prognosis of MND

A

Life expectancy bulbar onset: 6-12 months

Life expectancy limb onset: 2-5 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are neuromuscular disorders?

A

Conditions that affect:

a) peripheral nervous system (motor and/or sensory nerves, including anterior horn and dorsal root ganglion cell disorders)
b) neuromuscular junction
c) muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the important features on Hx in neuromuscular disease?

A

Time course: are symptoms acute or chronic?

FHx of similar complaints (e.g. hereditary neuropathies, muscular dystrophy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What symptoms are typically seen in carpal tunnel syndrome?

A

Affecting median nerve supplied digits (thumb, index and middle fingers)

Worse at night; have to shake hand to stop symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a unilateral foot drop indicative of?

A

L5 radiculopathy or peroneal neuropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the best diagnostic test for carpal tunnel syndrome?

A

Nerve conduction studies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the distribution of symptoms and signs in neuromuscular disease?

A

Generalised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Distinguish between anterior horn cell diseases, neuropathy, myaesthenia gravis and myopathy in terms of muscle wasting, fasciculations, weakness, reflexes and sensation

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ix for suspected NM problem

A

Electrophysiology: distinguishes neuropathy from myopathy, axonal from demyelinating, sensory vs motor, NMJ disorder

Laboratory: FBE, ESR, vit B12, CXR, BSL, HbA1c, UEC, TFT, LFT, PEP (protein electrophoresis), anti-NF, ANCA, ENA, HIV, CK, heavy metal screen, VDRL (for syphilis), genetic tests

LP

Muscle biopsy, muscle MRI

And for difficult cases, consider: nerve biopsy, MRI of nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

55 year old previously well building surveyor, on no medications, 6/12 ago noticed cramps in both legs worse after exercise

Increasing leg weakness over past 3/12 months with L foot drop; had noticed twitching in the muscles of both legs but no sensory complaints

No FHx of weakness

What are the clinical features of MND?

A

Non-specific cramps after exercise

Fasciculations (usually presents with weakness not twitching; remember twitchig is common normally, esp in calves)

Subacute progressive problem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

55 year old previously well building surveyor, on no medications, 6/12 ago noticed cramps in both legs worse after exercise

Increasing leg weakness over past 3/12 months with L foot drop; had noticed twitching in the muscles of both legs but no sensory complaints

O/E: cranial nerve examination normal, no tongue wasting or fasciculations, few scattered fasciculations in UL muscles (deltoid and periscapular), no muscle wasting or weakness, brisk reflexes, no sensory loss, thin leg muscles, fasciculations in thighs only after exercise, weakness of hi flexion 4/5 and ankle dorsiflexion 3/5, plantars downgoing, normal sensation

What is the significance of the brisk reflexes?

Ix?

A

Brisk reflexes are an UMN sign and suggests amyotrophic lateral sclerosis (commonly upper AND lower MND)

Ix: CK, NCS/EMG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

55 year old previously well building surveyor, on no medications, 6/12 ago noticed cramps in both legs worse after exercise

Increasing leg weakness over past 3/12 months with L foot drop; had noticed twitching in the muscles of both legs but no sensory complaints

CK 859 (N is 50-200)

NCS/EMG: normal nerve conduction in motor and sensory nerves, but evidence of active and chronic denervation on needle EMG and fasciculations

Why is CK elevated in MND?

A

Due to the trophic effect of nerves on muscle; if this trophic effect is removed due to the death of the neuron, the CK will rise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the most common MND?

A

Amyotrophic lateral sclerosis (disorder of upper and lower motor neurons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What clinical syndrome is amyotrophic lateral sclerosis associated with in some patients?

A

Fronto-temporal dementia (FTLD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the peak age of onset for FTLD?

A

55-70 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does FTLD arise?

A

90% sporadic

10% familial (in some families linked to a mutation of the SOD1 gene on Ch 21; recently discovered link in some families to mutations in the gene responsible for the production of the protein TDP 43 and in others to C9orf72)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is MND diagnosed?

A

Based on characteristic symptoms and signs: gradually progressive disorder with evidence of upper and lower motor neuron involvement and intact sensation

Consistent laboratory findings: EMG

But ultimately, Dx of EXCLUSION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the most common mimic for MND?

A

Widespread radiculopathies of the spine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the prognosis for MND?
Terminal illness in most cases Course depends on presentation: average life expectancy bulbar onset is 6-12/12, average life expectancy with limb onset is 2-5 years
26
Common clinical manifestations of MND
Can affect all skeletal muscles causing weakness, dysphagia, anarthria, dyspnoea and respiratory failure
27
What is hereditary spastic paraplegia?
Inherited disorder caused by mutations in the spastin gene (although many other mutations exist)
28
What is adrenomyeloneuropathy?
X-linked disorder which results in the deposition of excess LCFAs in the CNS
29
What is primary lateral sclerosis?
Similar to ALS but with no LMN signs Best prognosis but very difficult to diagnose (no EMG markers) Clinical features include progressive UMN weakness
30
35 year old previously well lawyer, on no medications, 6/12 ago began noticing episodic diplopia which was worse towards the end of the day, now increasing exertional dyspnoea over past 1/12 but no sensory complaints No FHx of weakness O/E: mild ptosis (L\>R) with failure to adduct the L eye, speech becomes slurred during latter part of Hx taking, proximal weakness in shoulder girdle muscles not evident initially but appears with repetitive trials List 2 post-synaptic and 2 pre-synaptic disorders of NMJs
Post-synaptic: myasthenia gravia (Abs against ACh receptors), MuSK myasthenia (Abs against MuSK) Pre-synaptic: Lambert Eaton Myasthenic Syndrome (LEMS; Abs against Ca2+ channels), botulism
31
What neoplasm is associated with LEMS? What is the mechanism?
Small cell lung Ca (it is a paraneoplastic syndrome)
32
In what patient populations is botulism seen? How does it present?
IVDUs (abscess with botulinum spores) Presents with acute neuromuscular weakness which usually starts at the top and works down; neurological emergency (must be recognised early)
33
How long does it take for botulinum toxin to break down?
~6/12
34
How is botulism treated?
Anti-botulinum toxin, THEN debride Metronidazole
35
List 6 clinical features that should make you suspect myasthenia gravis
Hx of fatigueability Early involvement of EOMs and lid-opening muscles Dysarthria No muscle wasting Weakness increasing with repetitive exercise Reflexes and sensation unaffected
36
Describe the pathophysiology of myasthenia gravis
AutoAbs which cross react with ACh receptors at NMJs High association with thymic hyperplasia or thymoma
37
Describe the pathophysiology of MuSK myasthenia?
Abs binding to MuSK cause the subunits of the ACh receptor to deaggregate and lose function
38
Ix for Dx of myasthenia gravis and MuSK myasthenia, and expected findings
Tensilon test: short acting ACh-ase antagonist Blood test for autoAbs to ACh receptor, MuSK (positive in 50% of cases of pure ocular myasthenia gravis, positive in 90% of cases of generalised myasthenia gravis, 70% of seronegative cases positive for anti-MuSK Abs) CT chest: look for thymoma EMG studies: repetitive stimulation, single fibre EMG, post-exercise facilitation (post-tetanic potentiation)
39
What is the relationship between thymoma and myasthenia gravis?
Poorer; even if thymus is normal, removal improves prognosis if done when patient is young
40
MuSK
Muscle-specific kinase
41
How is the Tensilon test performed?
IV injection of short-acting drug (edrophonium) increases ACh concentration at the NMK and can temporarily reverse weakness due to myasthenia gravis Good idea to be blinded: use a dummy saline syringe as well
42
SEs of tensilon
Can become bradycardic
43
Distinguish between electrophysiology study findings with repetitive stimulation in myasthenia gravis vs normal
Normal: no decrement in amplitude of muscle response with repetitive nerve stimulation NMJ disorder: decrement
44
Distinguish between electrophysiology study findings with post-exercise facilitation in LEMS and normal patients
Exercise consists of 10 secs maximal contraction of the target muscle and then electrophysiological readings are taken Normal: no change in compound muscle action potentials (CMAP) post-exercise LEMS: change in amplitude (wider) of CMAP post-exercise
45
Mx of myasthenia gravis
ACh antagonists Plasma exchange IVIG Immunosuppression with steroids, azathioprine Thymectomy
46
65 year old type 2 diabetic, on no medications, complains of poor balance and feelings in soles of feet like "walking on cotton wool" O/E: poor balance on walking, wide-based gait, Romberg's positive, weakness of dorsiflexion bilaterally, absent ankle reflexes, stocking loss of pain and temperature sensation with sensory level just below both knees How are neuropathies categorised?
Inherited or acquired Acute or chronic Mononeuropathy, multifocal, generalised Motor, sensory or mixed
47
What is the most common type of neuropathy? How do they present?
Focal mononeuropathies Symptoms are consistent with anatomy of neve involved
48
What are the main categories of causes of focal mononeuropathies? Give examples of each
Compressive (most common): carpal tunnel syndrome, ulnar neuropathy Infection: leprosy Inflammatory: Bell's palsy Infiltrative: cancer, amyloid Ischaemic: diabetes (3rd nerve palsy)
49
Dx of focal mononeuropathies
NCS/EMG to localise lesion and confirm Dx
50
Presentation of focal mononeuropathies
Focal symptoms and signs
51
What is mononeuritis multiplex? Include definition, cause
Multifocal neuropathies (multiple mononeuropathies) Multiple peripheral nerves affected rather than generalised (e.g. ulnar and tibial) Cause almost always ischaemic (e.g. DM, vasculitis including Churg-Strauss syndrome) but occasionally infective (e.g. AIDS, CMV, sarcoid, leprosy)
52
How are generalised peripheral neuropathies classified?
Acute or chronic
53
What is the most common neurological defect in generalised peripheral neuropathy?
Sensorimotor: distal weakness and glove and stocking sensory loss (can be accompanied by severe pain, esp in diabetics, amyloid, etc)
54
List 3 causes of acute demyelinating polyneuropathy
Guillain-Barre syndrome AIDS seroconversion phase (can also cause GBS) Lymphoma
55
List 4 causes of acute axonal polyneuropathy
Glue sniffers neuropathy (due to N-hexane toxicity) Vasculitis Thiamine deficiency Acute intermittent porphyria
56
How does an acute polyneuropathy present?
Rapidly increasing diffuse weakness and/or sensory loss occurring over days
57
What are the 7 categories of causes of chronic axonal polyneuropathy? Provide at least one example for each
Genetic: HMSN type II Metabolic: DM, hypothyroidism Toxin: EtOH, drugs, prescription Rx, heavy metals (arsenic/As, Pb) Nutritional: thiamine, B12 deficiency, B6 excess Paraneoplastic: Anti-Hu Immune: abnormal paraprotein, Sjogren's Ischaemic: DM, vasculitis
58
What are the 3 categories of causes of chronic demyelinating polyneuropathy? Provide at least one example for each
Genetic: HMSN type I, HNPP (Hereditary neuropathy with liability to Pressure Palsy) Immune: inflammatory (e.g. CIDP - Chronic Inflammatory Demyelinating Polyneuropathy) or non-inflammatory (e.g. IgM anti-MAG neuropathy) Paraneoplastic: POEMS syndrome
59
POEMS syndrome
Polyneuropathy Organomegaly Endocrinopathy Monoclonal gammopathy Skin changes (e.g. hyperpigmentation)
60
Classic changes on nerve conduction study in axonopathy, inherited demyelinating neuropathy and acquired demyelinating neuropathy
Axonopathy: low amplitude CMAPs, normal conduction velocity Inherited demyelinating: slow conduction velocity, no block Acquired demyelinating: slow conduction velocity, conduction block
61
What disease process is shown in this histopathology specimen?
Small fibre neuropathy
62
What disease process is shown in this histopathology specimen?
Axonal neuropathy
63
What disease process is shown in this histopathology specimen?
Demyelinating disease (e.g. chronic inflammatory demyelinating polyneuropathy, CIDP)
64
18 year old previously well young man, Hx of increasing weakness over last 6/12 which is most noticeable when getting out of chairs, walking up stairs and using the hair dryer On no medications No sensory complaints, does not fluctuate during the day No FHx of weakness O/E: waddling gait, can't rise from squat without help, proximal weakness in shoulder girdle and hip girdle muscles Dx? What are the different types?
Myopathy: inherited, metabolic, ion channel mutations or acquired
65
List 6 inherited causes of myopathy
Myotonic dystrophy Facio-scapulo-humeral dystrophy Duchenne's dystrophy Becker's dystrophy Limb-girdle dystrophies PROMM (proximal myotonic myopathy)
66
List 2 metabolic causes of myopathy
Glycogen storage disease type V (McArdle) Carnitine palmitoyltransferase II deficiency (CPT II deficiency)
67
What ion channel mutations can cause myopathy?
Periodic paralyses: hypo K+, hyper K+, paramyotonia
68
What are the 3 categories of causes of acquired myopathy? Give examples of each
Drugs: alcohol, statins Endocrine/metabolic: hypothyroidism, hypokalaemia Inflammatory: polymyositis, dermatomyositis, inclusion body myositis
69
18 year old previously well young man, Hx of increasing weakness over last 6/12 which is most noticeable when getting out of chairs, walking up stairs and using the hair dryer Ix?
Electrophysiology: needle EMG for myopathy and myotonia CK: if elevated almost always indicates a myopathy (can be 500-1000 in MND) FHx (genetic testing): e.g. myotonic dystrophy has a triplet repeat at Ch 9, DMD has loss of dystrophin gene on X chromosome Muscle biopsy
70
What findings on histopathology are characteristic of muscular dystrophies?
Varying muscle fibre size Regenerating and degenerating fibres Increased fibrosis
71
What muscle membrane proteins can be visualised with special stains and for what myopathies is this technique used to aid Dx?
Dystrophin: Duchenne's, Becker's Dysferlin: limb girdle dystrophies Sarcoglycans: limb girdle dystrophies
72
What features are seen on muscle biopsy in myositis?
Inflammatory cell infiltrate with T (polymyositis, inclusion body myositis) and B (dermatomyositis) lymphocytes Degenerating and regenerating muscle cells

MD2 Neuro (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions