Peripheral nerve ultrasound in ALS patients

Abstract

Introduction. Peripheral nerve ultrasound helps in the differential diagnosis of amyotrophic lateral sclerosis (ALS) and treatable diseases with a similar clinic. The cross–sectional area (CSA) values of the nerves of the hands and spinal nerves in ALS is normal or even reduced in comparison with control. The CSA of the nerves in a clinically similar condition – multifocal motor neuropathy (MMN) increases and has a characteristic ultrasound pattern of changes in the form of an increase in CSA in the proximal parts of the nerves of the hands and spinal nerves of the brachial plexuses.Materials and methods. Cervical root and peripheral nerve CSA on both sides was performed in 31 patients with ALS and 25 patients with MMN, using a 8–15 MHz linear array probe (ultrasound scanner «Sonoscape S20» (China). The control group included 92 healthy people without diseases of the nervous system, as well as conditions potentially causing damage to the peripheral nervous system.Results. The average values of the CSA of cervical roots and peripheral nerves in the upper limb in ALS patients were normal. However, there was an increase in the CSA of the median nerve at the shoulder level on the left by 23 %, the radial nerve on the right by 24 %, and the ulnar nerve on the left at the wrist level by 33 % in the ALS group compared with the control group. The CSA of nerves in MMN patients was significantly higher than in ALS and compared with the control group. In MMN nerve trunks increase was observed in the proximal parts of the nerves in the upper limb and cervical roots on both sides.Conclusions. Peripheral nerve ultrasound is a reliable tool for differential diagnosis ALS and ALS mimics. It can be widely used in routine clinical practice.