Sonographic Evaluation of Peripheral Nerves and Cervical Nerve Roots in Amyotrophic Lateral Sclerosis: A Systematic Review and Meta-Analysis.

Background: Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that leads to nerve atrophy. Ultrasonography has a significant role in the diagnosis of ALS.

Aim: We aimed to sonographically assess the size of all peripheral nerves and cervical nerve roots in ALS compared to controls.

Methods: We searched MEDLINE (PubMed), Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and Scopus using comprehensive MeSH terms for the keywords nerve, ultrasound, and ALS. We extracted data regarding cross-sectional area (CSA) or diameter for the following nerves: vagus, phrenic, tibial, fibular, sural, radial, ulnar, and median nerves, and the roots of C5, C6, C7, and C8 in both ALS patients and controls.

Results: Our study included 2683 participants, of which 1631 were ALS patients (mean age = 60.36), 792 were healthy controls (mean age = 57.79), and 260 were patients with other neurological disorders. ALS patients had significantly smaller nerve size compared to controls. Nerve size differences were observed in the vagus nerve [MD = -0.23], phrenic nerve [MD = -0.25], C5 nerve root [SMD = -0.94], C6 nerve root [SMD = -1.56], C7 nerve root [SMD = -1.18], C8 nerve root [MD = -1.9], accessory nerve [MD = -0.32], sciatic nerve [MD = -11], tibial nerve [MD = -0.68], sural nerve [MD = -0.32,], ulnar nerve [MD = -0.80], and median nerve [MD = -1.21].

Conclusions: Our findings showed that ALS patients have a sonographically smaller nerve size than healthy controls. Therefore, this is a potential marker for neuronal diseases.