Detection of pre-clinical motor unit loss in familial amyotrophic lateral sclerosis

Motor unit number estimation (MUNE) is an electrophysiological method designed to quantify motor unit loss in target muscles of interest. Most of the techniques are noninvasive and are therefore well suited for longitudinal monitoring. In this brief review, we describe the more commonly used techniques and their applications in amyotrophic lateral sclerosis, poliomyelitis, spinal muscular atrophy and hereditary sensorimotor neuropathies. Findings in some of these studies offer important pathophysiological insights. Since conventional electrophysiologic methods are not sensible measures of motor neuronal loss, MUNE could play a potentially important role in the diagnosis, monitoring of disease progression and response to treatment in neuromuscular diseases in which motor unit loss is a major feature.

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Serum microRNAs in patients with genetic amyotrophic lateral sclerosis and pre-manifest mutation carriers

Brain ◽

10.1093/brain/awu249 ◽

2014 ◽

Vol 137 (11) ◽

pp. 2938-2950 ◽

Cited By ~ 49

Author(s):

Axel Freischmidt ◽

Kathrin Müller ◽

Lisa Zondler ◽

Patrick Weydt ◽

Alexander E. Volk ◽

...

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Expression Profiles ◽

Consensus Sequence ◽

Disease Onset ◽

Therapeutic Targets ◽

Familial Amyotrophic Lateral Sclerosis ◽

Sequence Motif ◽

Mutation Carriers ◽

Disease Modifying ◽

Lateral Sclerosis

Abstract Knowledge about the nature of pathomolecular alterations preceding onset of symptoms in amyotrophic lateral sclerosis is largely lacking. It could not only pave the way for the discovery of valuable therapeutic targets but might also govern future concepts of pre-manifest disease modifying treatments. MicroRNAs are central regulators of transcriptome plasticity and participate in pathogenic cascades and/or mirror cellular adaptation to insults. We obtained comprehensive expression profiles of microRNAs in the serum of patients with familial amyotrophic lateral sclerosis, asymptomatic mutation carriers and healthy control subjects. We observed a strikingly homogenous microRNA profile in patients with familial amyotrophic lateral sclerosis that was largely independent from the underlying disease gene. Moreover, we identified 24 significantly downregulated microRNAs in pre-manifest amyotrophic lateral sclerosis mutation carriers up to two decades or more before the estimated time window of disease onset; 91.7% of the downregulated microRNAs in mutation carriers overlapped with the patients with familial amyotrophic lateral sclerosis. Bioinformatic analysis revealed a consensus sequence motif present in the vast majority of downregulated microRNAs identified in this study. Our data thus suggest specific common denominators regarding molecular pathogenesis of different amyotrophic lateral sclerosis genes. We describe the earliest pathomolecular alterations in amyotrophic lateral sclerosis mutation carriers known to date, which provide a basis for the discovery of novel therapeutic targets and strongly argue for studies evaluating presymptomatic disease-modifying treatment in amyotrophic lateral sclerosis.

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