Neuromuscular Disease

Question 1

acquired vs hereditary?

GBS, AIDP, polio, botulism, MG, polymyositis, toxic neuropathy

Answer 1

acquired.

Question 2

Pseudohypertrophy- define and name two common associated diseases

Answer 2

Def: increased gastrocnemius calf circumference caused by increase in fat and connective tissue, not true muscle

DMD, becker’s muscular dystrophy

Question 3

_______ appearance is focal atrophy of distal lower extremity muscles particularly seen in hereditary motor sensory neuropathies

Answer 3

stork (or champagne bottle) leg appearanc

Question 4

_____ is the inability to rise from sitting position on the floor, normally due to proximal (pelvic girdle) muscle weakness

Answer 4

Gower’s sign

Question 5

Toe walking seen in DMD, is caused by

Answer 5

fibrosis

Question 6

Duchenne muscular dystrophy is a _____ inheretence and results from abnormality in the ____ gene loci and ______ deficiency

Answer 6

X-linked recessive
Xp21 gene loci
plasma membrane protein dystrophin deficiency

– absent dystrophin or less than 3% of normal is diagnostic of DMD.

Question 7

All DMD subjects who took > or = 9 seconds to ambulate _____ feet lost ambulation within 1 year

Answer 7

30 feet

Question 8

Which part of PFTs is a prognostic factor for DMD

Answer 8

forced vital capacity (FVC) - increases during the first decade of life and plateaus during the early part of the second decade. Linerar decline of FVC between age 10 to 20 years old. FVC <40% is a contraindication to surgical spinal arthrodesis bc of increased perioperative morbidity

Question 9

In beckers muscular dystrophy, _____ is present but has abnormal molecular weight

Answer 9

dystrophin is present 20-80% of the time, but is abnormal. Also X-linked

Question 10

Which type of congenital muscular dystrophy has most intellectual retardation?

Answer 10

japan - Fukuyama type

Question 11

Which type of congenital muscular dystrophy has most hydrocephalus and fundal changes?

Answer 11

Satavuori type

Question 12

inheretence of congenital muscular dystrophy?

Answer 12

autosomal recessive , gene 9q31-33; 6q

can be sporadic or a sequel to viral or other inflammatory process

Question 13

facioscapulohumeral muscular dystrophy often affects what facial muscles?

Answer 13

orbicularis oculi, zygomaticus, and orbicularis oris.

masseter, temporalis, extraocular and pharyngeal muscles are spared usually

Question 14

inheritence of facioscapulohumeral muscular dystrophy

Answer 14

AD

gene locus 4q35

Question 15

emery-dreifuss muscular dystrophy (EMD) can present in adolescence or early adulthood with atrophy in upper arms and legs due to focal wasting of ____ and ____

Answer 15

biceps and calf muscles

Question 16

Clinical hallmark of emery-dreifuss muscular dystrophy (EMD)?

Answer 16

early presence of contractures of elbow flexors with limitation of full elbow extension. Heel cord tightness with ankle dorsiflexion weakness and toe walking may also be present

Question 17

inheritence of emery-dreifuss muscular dystrophy? (EMD)

Answer 17

X-linked recessive, gene locus Xq28

EMERIN is muscle protein deficient as opposed to dystrophin in DMD/BMD

Question 18

Inheretence of limb girdle syndromes

Answer 18

gene 15q - very similar to DMD/BMD

Question 19

Which congenital myopathy?

• AD with gene locus 19q13.1
• high incidence of malignant hyperthermia with inhalation of anesthetic agents
• predominance of type I muscle fibers (high-oxidative, low-glycolytic) and paucity of TypeII fibers resulting in relative deficiency of glycolytic enzymes
• mild relatively non-progressive weakness

Answer 19

central core myopathy

Question 20

Which congenital myopathy?

• autosomal recessive;
• predominance of Type I fiber involvement
• delayed motor development, hypotonia, nonprogressive symmetric weakness of trunk and proximal limbs, diaphragmatic weakness with risk of nocturnal hypoventilation

Answer 20

Minicore disease

Question 21

Which congenital myopathy?
- autosomal recessive and AD
AD gene has been localized to ch 1q21-q23
mild nonprogressive myopathy with hypotonia and proximal weakness

Answer 21

nemaline myopathy (rod-body myopathy)

Question 22

Which congenital myopathy?

• Can be AD/AR or X-linked (Xq28)
• xentronuclear myopathy (muscle fiber nuclei found at the center of the cell as opposed to the periphery where they are usually found)
• AR present with hypotonia, delay in motor milestones, generalized weakness of proximal and distal musculature, and ptosis with weakness of external ocular muscles and axial muscles
• X-linked inherited type presents iwth neonatal onset of severe generalized hypotonia, severe muscle weakness, dysphagia, and respiratory insufficiency, often requiring ventilator support at birth

Answer 22

myotubular myopathy

Question 23

____ are muscular dystrophies that are characterized by delayed relaxation (sustained contraction) of muscles after contraction (myotonia).

Answer 23

Myotonic myopathies - including Myotonic muscular dystrophy, myotonia congenita, schwartz-jampel syndrome, congenital myotonic dystrophy

Question 24

_____ is an AD muscular dystrophy with myotonia, muscle weakness/wasting, cataracts, premature balding, cardiomyopathy, conduction deficits, gonadal atrophy and variable intellectual deficits and dementia.

Answer 24

myotonic muscular dystrophy

Question 25

inheretence of myotonic muscular dystrophy: steinerts disease or dystrophia myotonica

Answer 25

AD with marked clinical heterogeneity, gene 19q13

Question 26

inheretence of friedreichs ataxia

Answer 26

AR - linked to chromosome 9q21

Question 27

What is the protein abnormality in friedreichs ataxia?

Answer 27

mitochondrial protein called frataxin

Question 28

wheelchair reliance becomes imminent when _____ strength becomes < than antigravity and time ________ is > 12 seconds

Answer 28

knee extension strength

ambulate 30 feet

Question 29

surgical intervention for management of scoliosis in NMD is prior to curvature of ______ and vital capacity falling to below _____

Answer 29

35 degrees

35%

Question 30

_____ is the most effective treatment of progressive scoliosis

Answer 30

spinal arthrodesis

Question 31

______ is an AD disorder inhereted as dominant or recessive trait in which myotonia is the onlyor predominant feature. Symptoms usually present after birth and exacerbated by prolonged rest or inactivity and cold. muscle hypertrophy is commonly seen. Can also see sustained eye closure in a crying infant

Answer 31

myotonia congenity Thomsens disease (little hercules)

normal muscle tone and function - myotonia following hand closure, eye-closure, ocular deviation, or other sustained movements.

Question 32

myotonia congenita (thomsens disease aka little hercules) can overlap with ______ in some families

Answer 32

hyperkalemic periodic paralysis

Question 33

gene of concern in myotonia congenita?

Answer 33

gene 7q35

Question 34

myotonia congenity may benefit from these medications whensymptoms become disabling (5)

Answer 34

quinine
procainamide
phenytoin
corticosteroids
tocainide

Question 35

_____ is an autosomal recessive disease with symptoms of hypotonia, dwarfism, diffuse bone disease, narrow palpebral fissures and blepharospasm, micrognathia, and flattened facies. Symptoms are non-progressive

Answer 35

Schwartz-Jampel syndrome

Question 36

______ is a type of mytonic dystrophy occuring in infants who are almost always born to mothers affected with myotonic dystrophy. It is characterized by severe hypotonia at birth, facial weakness, arthrogryposis,a nd variable breathing and swallowing difficulties

Answer 36

congenital myotonic dystrophy

Question 37

Name the different types of myasthenia gravis

Answer 37

1. transient - born to MG + moms and self-limiting in 2-3 weeks.
2. Congenital/infantile - AR inheritance, AChR Ab are usually absent.
3. Juvenile myasthenia - similar to adult AI type, high titer of AChR ab. Particularly affects adolescent girls and is often severe and labile.
4. autoimmune

Question 38

juvenile myasthenia shows fatigability of muscle (surface electrodes) after stimluation of peripheral nerve (surface electrodes) at _____ Hz

Answer 38

4 or 10 hz

Question 39

In AI MG, repetitive nerve stimlulation studies show a characteristic decrement in compound motor action potential at slow stimulation rates(______hz) over a train of ____ stimuli. Decrements of > _____% are noted

Answer 39

2-5Hz
4-5 stimuli
10%

Question 40

_____ presents with a prodromal respiratory or GI infection occuring within 1-month of onset. This often occurs with mycoplasma, CMV, EBV, campylobacter jejuni, and various vaccinations.

Answer 40

acute inflammatory demyelinating polyradiculoneuropathy (AIDP) also known as GBS

Question 41

Name the four different types of hereditary motor sensory neuropathies (HMSN)

Answer 41

Type I (CMT I) 70-80% of cases presents with hypertrophic demyelinating neuropathy (onion bulbs) on nerve biopsy- 17p11.2-12

Type II (CMT II) axonal neuropathy with low amplitudes; inverted champagne leg or stork leg (calf and anterior compartment wasting)

Type III (Dejerine-Sottas disease) severe hypertrophic demyelinating polyneuropathy with onset in infancy or early childhood

Type IV (Refsum disease) autosomal recessive disorder; presents as weakness in distal extremities

Question 42

Pathology?

anorexia, N/V, GI distubance, clumsiness, seizures, mental status changes, and papilledema. Weakness predominantly occurs inthe lower extremities

Answer 42

lead poisoning with toxic neuropathy

Question 43

Spinal muscular atrophy Types I-IV are linked to _________gene on chromosome ____

Answer 43

autosomal recessive SMN1

5

Question 44

Name the 4 types of SMA

Answer 44

I: at birth to 6 months (Werdnig-HOffman Disease - severe SMA)
II: 7-18 months
III: after 18 months
IV: adulthood

Question 45

inheritence of SMA I - Werdnig-HOffman Disease

Answer 45

AR, gene 5q11-q13

Question 46

seen as a characteristic picture of increased echo in muscle atrophy and increased subcutaneous space

Answer 46

SMA II - intermediate SMA