Muscle and nerve biopsy may be vital diagnostic tools in various neuromuscular disorders. Since these procedures are invasive, it matters to decide when to perform a biopsy, which muscle or nerve to be selected, and how to interpret the pathologies. This review addresses the indications, methods of biopsies, and also significant pathological findings frequently encountered in muscle and nerve pathology.

Muscle pathology findings may guide the diagnosis of neuromuscular disorders since they are helpful for understanding the pathological processes causing muscle weakness and also provide significant clues for the diagnosis of muscle diseases. Recent advances in molecular genetics mean that a muscle biopsy can be omitted when diagnosing inherited muscle diseases. However, the muscle pathology can still play a role in those cases and its findings are also required when diagnosing inflammatory myopathies.

Citations

• Sarcolemmal Excitability Properties of the Trapezius
  Mitchell J. Lycett, James Lee, Robert Boland‐Freitas, Karl Ng
  Muscle & Nerve.2025; 71(4): 600.     CrossRef
• Redox-active metals and oxidative stress–mediated myopathies in Callinectes amnicola, blue crab populations from impacted sites of the Lagos Lagoon: inferences for adverse ecological outcomes
  Azubuike Victor Chukwuka, Fisayo C. Jerome, Adesola Hassan, Benjamin Ebonwu, Aina O. Adeogun
  Environmental Science and Pollution Research.2023; 30(50): 108565.     CrossRef

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degenerative disease that clinically manifests both upper and lower motor neuron signs. However, it is unknown where and how the motor neuron degeneration begins, and conflicting hypotheses have been suggested. Recent advanced radiological techniques enable us to look into ALS neuropathology in vivo. Herein, we report a case with upper motor neuron-predominant ALS in whom the results of brain magnetic resonance imaging (MRI) and myelin water fraction MRI suggest axonal degeneration.