Whole-body fasciculation detection in amyotrophic lateral sclerosis using motor unit MRI
Linda Heskamp, Matthew Birkbeck, Julie Hall, Ian Schofield, James A. Bashford, Timothy L. Williams, Hugo M. De Oliveira, Roger G. Whittaker, Andrew M. Blamire
Abstract
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). 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]). MUMRI-detected fasciculation rates in typical ALS patients were higher compared to healthy controls for biceps brachii (2.40±1.90 cm-3min-1 vs. 0.04±0.10 cm-3min-1, p=0.004), paraspinals (1.14±1.61 cm-3min-1 vs. 0.02±0.02 cm-3min-1, p=0.016) and lower legs (1.42±1.27 cm-3min-1 vs. 0.13±0.10 cm-3min-1, p=0.004), but not tongue (1.41±1.94 cm-3min-1 vs. 0.18±0.18 cm-3min-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 (τ=0.475, p=0.006). MUMRI can non-invasively image fasciculation in multiple body regions and appears sensitive to disease progression in individual patients. MUMRI has potential as diagnostic tool for ALS.