Whole-body fasciculation detection in amyotrophic lateral sclerosis using motor unit MRI

Objective: Compare fasciculation rates between amyotrophic lateral sclerosis (ALS) patients and healthy controls in body regions relevant for diagnosing ALS using motor unit MRI (MUMRI) at baseline and 6 months follow-up, and relate this to single-channel surface EMG (SEMG). Methods: Tongue, biceps brachii, paraspinals and lower legs were assessed with MUMRI and biceps brachii and soleus with SEMG in 10 healthy controls and 10 patients (9 typical ALS, 1 primary lateral sclerosis [PLS]). Results: MUMRI-detected fasciculation rates in typical ALS patients were higher compared to healthy controls for biceps brachii (2.40 +/- 1.90 cm(-3)min(-1) vs. 0.04 +/- 0.10 cm(-3)min(-1), p = 0.004), paraspinals (1.14 +/- 1.61 cm(-3)min(-1) vs. 0.02 +/- 0.02 cm(-3)min(-1), p = 0.016) and lower legs (1.42 +/- 1.27 cm(-3)min(-1) vs. 0.13 +/- 0.10 cm(-3)min(-1), p = 0.004), but not tongue (1.41 +/- 1.94 cm(-3)min(-1) vs. 0.18 +/- 0.18 cm(-3)min(-1), p = 0.556). The PLS patient showed no fasciculation. At baseline, 6/9 ALS patients had increased fasciculation rates compared to healthy controls in at least 2 body regions. At follow-up every patient had increased fasciculation rates in at least 2 body regions. The MUMRI-detected fasciculation rate correlated with SEMG-detected fasciculation rates (s = 0.475, p = 0.006). Conclusion: MUMRI can non-invasively image fasciculation in multiple body regions and appears sensitive to disease progression in individual patients. Significance: MUMRI has potential as diagnostic tool for ALS. (C) 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V.