Somatosensory temporal discrimination analysis reveals impaired processing in amyotrophic lateral sclerosis

BORAN H. E., Kilinc H., KURTKAYA KOÇAK Ö., YANIK E., KURUOĞLU H. R., CENGİZ B.

MUSCLE & NERVE, cilt.70, sa.6, ss.1257-1262, 2024 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 70 Sayı: 6
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1002/mus.28278
  • Dergi Adı: MUSCLE & NERVE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, CINAHL
  • Sayfa Sayıları: ss.1257-1262
  • Anahtar Kelimeler: amyotrophic lateral sclerosis, cortical excitability, primary somatosensory cortex, somatosensory temporal discrimination
  • Gazi Üniversitesi Adresli: Evet

Özet

Introduction/AimsWhile amyotrophic lateral sclerosis (ALS) is primarily characterized as a motor system disorder, there is a growing body of evidence indicating sensory involvement. This study aimed to examine the hypothesis that somatosensory processing is impaired in ALS.MethodsStudy participants were ALS patients followed at the Neuromuscular Outpatient Unit, as well as healthy volunteers, from March 2021 to July 2023. The Medical Research Council (MRC) sum score was calculated for nine muscle groups bilaterally. The clinical status of patients was evaluated with the ALS Functional Rating Scale-Revised (ALSFRS-R) and the Penn Upper Motor Neuron core. Somatosensory temporal discrimination thresholds (STDTs) were recorded on the medial and lateral parts of both hands. Somatosensory cortex excitability was investigated with the paired somatosensory evoked potentials (SEP) paradigm in a subgroup.ResultsIncreased STD values were detected in ALS patients compared to controls in both medial (107.66 +/- 35 ms vs. 82.7 +/- 32.5 ms, p = .001) and lateral (106.5 +/- 34.5 ms vs. 82.9 +/- 31.3 ms, p = .002) hands. There were no significant differences in STDTs among ALS patients across four regions (medial and lateral parts of the right and left hands). Amplitude ratios obtained from the paired-pulse SEP paradigm were approximately 1 for all interstimulus intervals (ISIs). STDTs did not show any correlations with motor findings or scales.DiscussionSomatosensory processing appears to be compromised among ALS patients. The lack of correlation between impaired STDT and motor findings implies that it is a purely sensory deficit in ALS.