Artikel
Amyotrophic Lateral Sclerosis.
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Veröffentlicht: | 11. September 2012 |
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Introduction: ALS is the most common form of motor neuron disease and is characterized by progressive and relentless loss of both upper and lower motor neurons in the brain and spinal cord. Decease, usually from respiratory failure, within 3 to 5 years from symptom onset.In about 10% of cases, ALS is autosomal dominant with age-dependent penetrance. Examination reveals mixed upper and lower motor neuron signs. The diagnosis of ALS is usually straightforward clinically. Electromyography evidence in support of the diagnosis is mandatory.
Objective: Observe the changes at the muscle biopsy in patients with ALS .
Methods: Muscle biopsy was performed in the deltoid muscle, which is processed in isopentane precooled in liquid nitrogen. Cuts are made of eight microns thick. Staining techniques and histochemistry are H&E, Gomori trichrome and NADH.
Results: Typically, there is loss of pyramidal neurons of the corticospinal tract with loss and degeneration of large anterior horn cells and brainstem cranial nerve nuclei. Skeletal muscles show denervation atrophy.
Muscle biopsy: A small group of angulated atrophic fibers and more rounded hypertrophied fibers. Denervated fibres may also lose their glycogen content. Grouping of fibers of the same type is pathognomonic of denervated muscle. In NADH we observe target fibers that are characteristics of ALS.
Conclusions: Even though, ALS diagnosis must be clinically performed, histopathology may be useful in order to exclude other entities, specially when different types of motor neuro diseases are a differential diagnosis because of the greater damage and the target fibers seen in ALS.