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Muscle Disease
MS Module
71
Medical
Graduate
05/16/2009

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Cards

Term
What does a myopathy present with?
Definition
proximal/generalized weakness
Term
How does a neurogenic muscle disease present?
Definition
distal weakness
Term
How are the muscle fibers shaped in a myopathy?
Definition
rounded
Term
How are the muscle fibers shaped in a neurogenic muscle disease?
Definition
angular
Term
Where are the nuclei of the muscle cells in lLmb Girdle and myotonic dystrophy?
Definition
internal
Term
What stain do you not want to use when trying to determine fiber type for muscle atrophy and why?
Definition
do not use SDH b/c there will be an increase in mitochondria in both fibers and they both will be dark
Term
What is the best stain for typing fiber?
Definition
ATPase
Term
When do muscular dystrophies usually present in a patient?
Definition
in childhood, not at birth
Term
What is true of the fibers at birth and later on in a muscular dystrophy disease?
Definition
they are fine at birth and get worse
Term
What is true of the muscle fibers in a congenital myopathy?
Definition
they are worse at birth and get better
Term
Is muscle dystrophy progressive or not?
Definition
is progressive
Term
What is the most common muscular dystrophy?
Definition
Duchenne
Term

What chromosome are most of the Duchenne Muscular Dystrophy mutation located on?

 

What percentage of time will it be there?

Definition

xp21.2

 

60-70% of the time

Term
What protein is deficient as a result of the Duchenne mutation?
Definition
dystrophin
Term
What is the inheritance of Duchenne?
Definition
X linked
Term
What does dystrophin do for a muscle cell?
Definition
it stabalizes the membrane
Term
What manuver is often seen in both Duchenne and Limb Girdle?
Definition
Gower's
Term
What happens to the calfs of a Duchenne patient?
Definition
psuedohypertrophy
Term
What happens to the muscle in Duchenne muscular dystrophy?
Definition
necrosis followed by macrophage invasion
Term
What is the typical lesion seen in Duchenne muscular dystrophy as a result of the holes made by the missing dystrophin followed by calcium influx?
Definition
Delta Lesion
Term
How often is pseudohypertrophy seen in Limb Girdle patients?
Definition
1/3 of the time
Term
What is the inheritance of Limb Girdle?
Definition
AR
Term
What is the shape and location of the nuclei in the muscle cells of Limb Girdle ?
Definition
round and internal nuclei
Term

What occurs to the muscle fibers as they enlarge in limb girdle?

 

What name do they give to them based on how they appear?

Definition

the split (splitting hypertrophy)

 

moth eaten

Term
Which disease has moth eaten muscle fibers due to splitting hypertrophy?
Definition
Limb Girdle Muscular Dystrophy
Term
When is the onset of congenital myopathies?
Definition
at birth
Term
What is the inheritance of both of the congenital myopathies?
Definition
AD
Term
What are the two congenital myopathies studied?
Definition

central core

nermline

Term
What is the defected protein in central core disease?
Definition
ryanodine receptor
Term
What disease can present with malignant hyperthermia?
Definition
Central Core Disease
Term
In the central core of the muscle fibers in central core disease what is not occuring?
Definition
muscle contraction
Term
Why do patients with central core disease have progression to get better?
Definition
b/c the central core doesn't get larger as the muscle gets larger with age; therefore, there is less proportion of central core
Term
What is often true of the infant in central core disease when you hold them by the stomach?
Definition
floppy infant syndrome
Term
What is present in the muscle cells in nermline myopathy?
Definition
rods
Term
What do the rods look like in the muscle cells of nermline myopathy?
Definition
Z bands
Term
What is the characteritic finding in Nermline Myopathy in relation to the palate, face, eyes?
Definition

high arched palate

facial dysmorphism (long face, prognathism)

ptosis

Term
What two proteins are defected in Nermline Myopathy?
Definition

alpha tropomysoin (NEM1)

nebulin (NEM2)

 

Term
What is true of the amplitude and duration in a myopathic EMG?
Definition
small amplitude and duration due to death of muscle fibers so decreased density and number
Term

What is the amplitude and duration of a neurogenic EMG?

 

Hint: 2 possibilities

Definition

before reinnervation: amplitude high, duration the same because muscle cells only become smaller

 

 

after reinnervation: amplitude high, duration longer because you have type grouped therefore increased the number of fibers

Term
What is the inheritence pattern of myotonic dystrophy?
Definition
AD
Term
What is the pentrance of myotonic dystrophy?
Definition
variable
Term
What are the three characteristic findings of myotonic dystrophy on a biopsy?
Definition

internal nuclei

type one atrophy

ring fibers

Term
What two diseases present with internal nuclei?
Definition
limb girdle and myotonic dystrophy
Term
What are the three most common systemic manifestations of myotonic dystrophy?
Definition

cardiac problems

male sterility

dysphagia

Term
What do most patients die of from myotonic dystrophy? (similar to DMD)
Definition
cardiac complication
Term
What are fiber rings and what disease presents with them?
Definition

they are perpindicular myofibrils in a transverse section of a fiber

 

seen in myotonic dystrophy

Term

What is gene mutation in myotonic dystrophy?

 

 

What is the mechanism of the mutation in the gene?

Definition

mutation in DMPK gene for myotonic protein kinase

 

the mechanisim is a trinucleotide repeat

Term

Where is the atrophy in myotonic dystrophy (proximal or distal)?

 

Why is this unique?

Definition

it is distal

 

one would think this was a neurogenic disorder, but this is not the case despite the location of the atrophy

Term
What are the two inflammatory myopathies studied in the course?
Definition

Inclusion body myositis

Polymyositis

 

Term
Which myositis myopathy presents with unilateral weakness?
Definition
inclusion body myositis
Term
What type of muscle weakness is present in polymyositis?
Definition
generalized weakness
Term
What cell mediates polymyositis?
Definition
T-cell mediated
Term
What inflammatory markers are positive in polymyositis?
Definition
CD8 and MHC-I
Term

WHich inflammatory myopathy can be treated with steriods?

 

Which is resistant to them?

Definition

polymyostitis

 

 

inclusion body myostitis is resitant to steriods

Term
Which two muscle diseases present with hypertrophy and splitting of the fibers?
Definition

limb girdle

 

inclusion body myostitis

Term

What is the characteristic vacule in inclusion body myositis?

 

And what is true about this vacule?

 

How does it stain?

Definition

rimmed vacule

 

it is autophagocytic

 

congo red b/c of amyloid

Term
Which muscle disease will stain with congo red due to amyloid deposits?
Definition
Inclusion body myositis
Term
Which of the inflammatory myopathies typically presents earlier than the other?
Definition
polymyositis
Term
What is the inheritence of acid maltase deficiency?
Definition
AR
Term

What is the inheritience of the following dystrophies?

 

DMD

Myotonic

BMD

Limb Girdle

Definition

DMD: x-linked

BMD: x-linked

Myotonic: AD

Limb Girdle: AR

Term
What enzyme is deficient in acid maltase deficieny?
Definition
lysosomal alpha glycosidic
Term
What is the name of the infantile type of Acid Maltase Deficiency?
Definition
Pompi
Term

What disease presents with a large tongue and hepatomegaly?

 

What causes the large liver?

Definition

Acid Maltase Deficincy (Pompi)

 

hepatomegaly caused by increased liver glycogen

Term

What does CPT deficiency present with?

 

What preceeds its episodes?

Definition

myoglobinuria

myalgia

 

exercise induced episodes

Term
What is Kearns Sayre Syndrome?
Definition
A disease in which the mitochondria is abnormal
Term
What are the three findings of the mitochondria in Kearns-Sayre syndrome?
Definition

abnormal mitochondria

too many mitochondria

inclusions

Term
What disease presents with ragged red fibers in the mitochondria and ptosis?
Definition
Kearns-Sayre Syndrome
Term
What enzyme is deficient in CPT deficiency?
Definition
CPT II
Term
What four diseases studied present with ptosis?
Definition

nermline

myotonic dystrophy

Myesthenia Gravis

Kearns-Sayre

Term
What are four reasons for type two atrophy?
Definition

aging

misuse

Myesthenia Gravis

steriods

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