Background: Diagnosing neuromuscular disorders can be challenging. Raman spectroscopy is an emerging technique that uses light of a single wavelength to produce a biochemical fingerprint of tissue. The talk will introduce Raman spectroscopy of muscle, the information it can provide and the fusion of Raman spectroscopy with EMG (‘optical EMG’).
Methods: Raman spectroscopy was performed using a fibre optic Raman needle probe. Spectra were collected in vivo from preclinical models of Duchenne muscular dystrophy (mdx) and motor neurone disease (SOD1G93A). Human muscle biopsies were studied from patients with a variety of myopathies. Optical EMG was then performed in vivo with a combined EMG/Raman spectroscopy needle in the preclinical motor neurone disease model. Data were analysed using multivariate statistics. Protein secondary structure profiling was performed to gain insight into biochemical features.
Results: Raman spectra were able to identify disease states in preclinical models and human muscle biopsies. Changes in fat and protein structure underpinned the differences across health and disease. EMG and Raman data could be collected during the same needle insertion with the novel optical EMG probe. We will demonstrate that optical EMG could lead to faster diagnoses in patients investigated for muscle disease.
Discussion: Raman spectroscopy of muscle offers a highly accurate and biochemically detailed assessment of muscle. The findings translate from in vivo preclinical models to ex vivo human biopsies. Raman spectra can be collected alongside EMG during a single needle insertion, and we are now developing technology for first-in-human studies.