Muscle and Nerve Diseases

Question 1

what are the components that allow muscle to convert chemical energy into mechanical?

Answer 1

Excitation-contraction coupling
The contractile mechanism
Structural components
The energy system

Question 2

what are the symptoms of muscle disease?

Answer 2

Weakness of skeletal muscle
Short of breath (respiratory muscles)
Cardiomyopathy 
Poor suck/ feeding/FTT/floppy
Cramp, pain
Myoglobinuria

Question 3

what are the signs of muscle disease?

Answer 3

Wasting/ hypertrophy
Normal or reduced tone and reflexes
Motor weakness…NOT sensory

Question 4

what investigations are done to diagnose muscle disease?

Answer 4

CK
EMG
Muscle biopsy:
-Sructure
-Biochemistry
-inflammation
Genetic testing

Question 5

name the different types of muscle disease

Answer 5

Muscular dystrophies
Channelopathies
Metabolic muscle disease
Inflammatory muscle disease
Congenital myopathies

Question 6

what are the different types of muscular dystrophies?

Answer 6

Duchenne’s MD
Becker’s MD
Facioscapulohumeral MD
Myotonic dystrophy
Limb-Girdle MD

Question 7

what is muscular dystrophy?

Answer 7

a hereditary condition marked by progressive weakening and wasting of the muscles

Question 8

what are channelopathies?

Answer 8

Disorders of Ca, Na and Cl channels

Question 9

name a few channelopathies

Answer 9

Familial hypokalemic periodic paralysis
Hyperkalemic periodic paralysis
Paramyotonia congenita
Myotonia congenita

Question 10

what are different causes of metabolic muscle disease?

Answer 10

Disorders of carbohydrate metabolism
Disorders of lipid metabolism
Mitochondrial myopathies/ cytopathies

Question 11

what are the 2 types of inflammatory muscle disease?

Answer 11

Polymyositis

Dermatomyositis

Question 12

what are the characteristics of inflammatory muscle disease?

Answer 12

Acute or subacute
Painful weak muscles
Characteristic rash of DM
Any age
Other symptoms may be involved

Question 13

what investigations are used to diagnose inflammatory muscle disease?

Answer 13

↑CK
EMG, inflammation and myopathic
Biopsy:
-PM: CD8 cells
-DM: humeral-mediated, B cells and CD4 cells

Question 14

what is the treatment of inflammatory muscle disease?

Answer 14

Immunosuppression

Question 15

what is Myasthenia Gravis?

Answer 15

Disorder of neuromuscular junction

autoimmune disease

Question 16

what is the Clinical presentation of Myasthenia Gravis?

Answer 16

Fatiguable weakness:
Limbs
Eyelids (ptosis)
Muscles of mastication (chewing)
Talking
SOB
diplopia

Question 17

what are the investigations for Myasthenia Gravis?

Answer 17

AChR ab
Anti MuSK ab
Neurophysiology:
-Repetitive stimulation
-EMG
Tensilon test
CT chest

Question 18

what is the treatment for Myasthenia Gravis?

Answer 18

Symptomatic
Acetylcholinesterase inhibitor

Immunosuppression
Prednisolone
Steroid saving agent (azathioprine)

surgery
Thymectomy

Question 19

what is Myasthenia Gravis associated with?

Answer 19

In young associated with thymic hyperplasia

In old may be associated with a malignant thymoma

Question 20

what does the peripheral nerve consist of?

Answer 20

Sensory axons:
Small fibres (pain + temperature)
Large fibres (joint position sense + vibration)

Motor axons

Question 21

what are different causes of nerve root disease?

Answer 21

Degenerative spine disease
Inflammation
Infiltration

Question 22

what can cause a lesion of an individual peripheral nerve

Answer 22

Compressive/ entrapment neuropathy

Vasculitic (mononeuritis multiplex)

Question 23

what nerves are affected in generalised peripheral neuropathy?

Answer 23

Motor/ sensory/ both

+/- autonomic features

Question 24

what are causes of generalised peripheral neuropathy?

Answer 24

Metabolic: DM, alcohol, B12
Toxic: drugs
Hereditary
Infectious: Lyme, HIV, leprosy
Malignancy: paraneoplastic
Inflammatory demyelinating:
-Acute = Guillain -Barre syndrome
Chronic= CIDP

Question 25

what are symptoms of nerve root disease?

Answer 25

Myotomal wasting and weakness Reflex change Dermatomal sensory change

Question 26

what are symptoms of individual nerve disease?

Answer 26

Wasting and weakness of innervated muscle | Specific sensory change

Question 27

what are symptoms of generalised peripheral neuropathy?

Answer 27

Sensory and motor symptoms starting distally and moving proximally

Question 28

what are investigations of nerve disease?

Answer 28

``` Blood tests Genetic analysis NCS Lumbar puncture (CSF analysis) Nerve biopsy (nb sensory nerve) ```

Question 29

what is amyotrophic lateral sclerosis?

Answer 29

rapidly progressive, invariably fatal neurological disease that attacks the motor neurones responsible for controlling voluntary muscles

Question 30

describe the onset of amyotrophic lateral sclerosis?

Answer 30

Usually limb, later bulbar and respiratory involvement

Question 31

why is there a combination of UMN and LMN signs in amyotrophic lateral sclerosis?

Answer 31

anterior horn cell is cell body of the lower motor neurone and part of the corticospinal tract

Question 32

what are the combined signs of UMN and LMN in amyotrophic lateral sclerosis?

Answer 32

LMN= muscle fasciculations, wasting, weakness UMN= increased tone, brisk reflexes No sensory involvement

Question 33

what is the prognosis of amyotrophic lateral sclerosis?

Answer 33

3-5 years from symptom onset 2-3 years from diagnosis 50% die within 14 months of diagnosis

Question 34

how do you diagnose amyotrophic lateral sclerosis?

Answer 34

Unique combination of UMN and LMN signs | EMG

Question 35

how do you treat amyotrophic lateral sclerosis?

Answer 35

``` Supportive only (PEG, NIV) riluzole ```