Muscle and Nerve Biopsies
Muscle Biopsies
Either needle or surgical biopsies are submitted to the EMU for investigations. All biopsies are processed for conventional EM but only a select number are ultimately examined by EM. The bulk of the samples are observed by LM from 0.5 µm transverse and longitudinal sections stained with methylene blue.
Muscular Dystrophy (muscle degeneration) and myopathies can be identified from these LM sections. Hereditary, progressive, degenerative, metabolic and non-inflammatory conditions (e.g. Duchenne disease, glycogen storage disease, mitochondrial aberrations, honeycomb structures and triads) can be observed by EM. In addition, structural changes take place in the muscle fiber involving myofibrils, nuclei, mitochondria and membranes. These structural alterations cannot be usually linked to a specific condition but the changes in some instances follow a pattern that implies a particular disorder which can be critical in the treatment of the patient.
 Normal muscle |
 Myelin Bodies |
 Glycogen deposits |
 Mitochondrial deposits |
 Honeycomb |
Nerve Biopsies
All nerve biopsies are processed for electron microscopy. Part of the fixed nerve after osmification is transferred to glycerol and later teased out into individual fibers under a dissecting microscope to identify demylonation of the fiber sheath.
During an ultrastructural examination, overlapping micrographs are taken in an area of interest, digitally stitched into a montage and analysed for the range of fiber size and distribution in the fascicle.
Montage
Teased Nerve
