Muscles

Question 1

5 types of inflammatory myopathies

Answer 1

• dermatomyositis
• polymyositis
• inclusion body myositis
• antisynthetase syndrome
• immune mediated necrotizing myopathy.

Question 2

Types of primary muscular disorders

Answer 2

• Myositis and immune mediated myopathies (inflammatory myopathies)
• mitochondrial myopathies
• Congenital myopathoes
  Glycogen storage diseases

Question 3

best sites for muscle biopsy

Answer 3

deltoid, biceps and quadriceps. avoid muscles that were the site for the EMG, injections or trauma

Question 4

when are fresh muscle samples fixed with glutaraldehyde?

Answer 4

for electron microscopy

Question 5

how is the muscle biopsy received? (snap freezing?)

Answer 5

in a saline soaked swab - not soaked in saline as that would cause freeze artifacts later on.
Muscle biopsies received at the IHC lab are then snap frozen immediately.
Muscle biopsies for mitochondrial myopathies are snap frozen at the bed side/surgical theatre. sent abroad for enzyme tests, and genetic analysis of mDNA.
Cut using cryotomy

Question 6

Orientation of muscld biopsy - slices required

Answer 6

trasverse cuts are carried out, no longitudinal architecture should be seen. Thawing can be used to reorient the sample