Role of neuromuscular ultrasound in ALS
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| Date Issued | Start Page | End Page |
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2023-09-15 | 1 | 1 |
I Session: Motor neuron diseases across the age spectrum
Amyotrophic lateral scerosis (ALS) is neurodegenerative disorder leading to progressive muscle weakness, respiratory dysfunction and death. Frequently patients visit several specialists untill they get diagnosed. Despite better diagnostic tools, diagnostic process is still complicated and time consuming. New biomarkers are necessary to decrease the uncertainty of diagnosis of fast progressing disease. Nerve conduction studies (ENG) and electromyography (EMG) are considered to be the gold-standard for the nerve damage and muscle activity assessments. However NCS and EMG require special equipment and experienced specialists because the diagnosis can be challenging especially in the early stages of ALS. Ultrasound is non invasive and usually well tolerated diagnostic tool. Many studies showed that some changes of peripheral nerves and muscles might be found in patient with ALS but these findings are still contraversal.
The aim of our study was to identify changes in clinical and sonographic findings and to determine their correlations in patients with amyotrophic lateral sclerosis. Primary results of the study: 56 participants were included in the study: 23 patients with ALS (65.2 % female) and 33 healthy controls (HC) (60.6 % female). Mean age of patients with ALS was 58.3 (11.42) and control group 53.5 (11.77) years, p=0.13. Groups did not differ according to age and sex. ALS group was divided into two clinical subgroups: bulbar and limb onset. The subgroups did not differ according to disease duration. The most common initial ALS symptoms were limb weakness, muscle atrophy, and dysarthria. No statistically significant difference was found when comparing the frequency of detection of fasciculations in the muscles of patients with bulbar-onset and limb-onset ALS by sonography (p=0.08-1). Increased muscle echogenicity (using Heckmatt scale) most often was found in these mucles: the anterior tibial (85%), quadriceps (93%), I dorsal interosseous (63%) and submental (56%) muscles. A statistically significant difference was found comparing ALS vs HC groups evaluating the echogenicity of the upper trunk of the right brachial plexus (34.62 (20.33-55.08) and 17.82 (10.31-29.15), p=0.01)and cross-sectional area (3.6 (2.6-4.9) and 5 (3.9-5.8), p=0.01), echogenicity of the left ulnar nerve in the midline of the forearm (63.02 (44.23 -80.97) and 68.44 (57.84-82.22), p=0.03) respectively. There was no statistically significant correlation found between the frequency of sonographically detected fasciculations and muscle strength (p=0.15-0.53). No significant difference was found in the frequency of fasciculation detection between needle electromyography and sonography comparing ALS vs HC (p=0.36-0.91). Statistically significant correlation was found between increased echogenicity of the biceps brachii (p<0.001) and anterior tibial (p<0.001) muscles and decreased muscle strength. Significant correlations were observed between ALS-FRS-R score and echogenicity of the left ulnar nerve in the midline of the forearm (r=0.44, p=0.047).
Conclusions: We have found ultrasound echogenicity changes of brachial plexus and ulnar nerves in patients with ALS. Ulnar nerve echogenicity changes might be associated with worse clinical status. Observed muscle ultrasound echogenicity changes are associated with decrease of muscle strength. We could not find statistically significant difference in fasciculation detection comparing ultrasound and EMG. Our results showed that specific pattern of nerves ultrasound changes exists, but bigger sample size should be analyzed to provide more reliable and accurate results.