Nerve conduction studies in the early diagnosis of amyotrophic lateral sclerosis and the importance of split-hand phenomenon

Year 2022, , 451 - 454, 31.08.2022

Orhan Sümbül , Dürdane Aksoy , Semiha Gülsüm Kurt , Betül Çevik

https://doi.org/10.54005/geneltip.1130954

Abstract

Aim: The heterogeneity of the Amyotrophic Lateral Sclerosis (ALS) clinical phenotypes leads to difficulties in early diagnosis. The ‘split hand’ sign is defined as the thenar muscles that are more prominently affected by hypothenar. In this study, the results of the initial nerve conduction study of the patients were compared with those of the controls in order to increase the findings supporting early diagnosis.
Material and Method: Seventy-five patients who were diagnosed with ALS in our clinic were included in the study. The initial ENMG findings of the patients were compared with those of 70 healthy controls: Distal motor latency (DML), the compound muscle action potential (CMAP) amplitude, velocity in the motor conduction of median, ulnar, peroneal and tibial nerves; distal latency, amplitude, velocity in sensorial conduction were evaluated. Ulnar/median DML and ulnar/median CMAP amplitude ratios were examined.
Results: In ALS group, DMLs of the median, ulnar, peroneal, and tibial nerves were significantly longer, and CMAP amplitudes were significantly smaller than those of the controls. The sensory conductions of the median, ulnar, and sural nerves were not statistically different between the groups. The ulnar/median DML ratio of the patients was lower than the ratio of controls (0.73/0.80;p=0.003); while the ulnar/median CMAP amplitude ratio was greater (1.40/1.11; p=0.002).
Conclusion: Prolonged DML and reduced amplitudes were observed in the motor nerve conduction of ALS patients in the early period. The results of the present study also support the presence of split-hand phenomenon even in early period of limb-onset ALS (both upper and lower). These findings suggest that nerve conduction studies and electrophysiologically detected split-hand sign are important clues for the early diagnosis of ALS in case of heterogeneous clinical phenotype.

Keywords

Amyotrophic lateral sclerosis, split-hand, nerve conduction study

Amyotrofik lateral skleroz erken tanısında sinir iletim çalışmaları ve ayrık el bulgusunun önemi

Abstract

Amaç: Amyotrofik Lateral Skleroz' da (ALS) özellikle başlangıç döneminde klinik ve muayene bulgularının heterojenliği erken tanıda zorluklara yol açmaktadır. 'Ayrık el' işareti, ALS' de tenar kasların hipotenar kaslardan daha belirgin olarak etkilenmesini tanımlamak için kullanılır. Bu çalışmada erken tanıyı destekleyen bulguları artırmak için hastaların kliniğimizdeki ilk sinir iletim çalışmalarının sonuçları araştırıldı ve kontrol grubuyla karşılaştırıldı.
Gereç ve Yöntem: Kliniğimizde ALS tanısı ile takip edilen 75 hasta çalışmaya dahil edildi. Hastaların ilk elektronöromyografi bulguları 70 sağlıklı kontrol ile karşılaştırıldı: Distal motor latans (DML), bileşik kas aksiyon potansiyeli (CMAP) amplitüdü, median, ulnar, peroneal ve tibial sinirlerin motor iletim hızları; distal latanslar, amplitüdler ve duyusal iletim hızları değerlendirildi. Ayrıca ulnar/median DML ve ulnar/median CMAP amplitüd oranları karşılaştırıldı.
Bulgular: ALS grubunda kontrol grubuna göre median, ulnar, peroneal ve tibial sinirlerin DML' leri anlamlı olarak daha uzundu ve CMAP amplitüdleri anlamlı olarak daha küçüktü p˂0.05). Median, ulnar ve sural sinirlerin duyusal iletimleri gruplar arasında istatistiksel olarak farklı değildi. Hastaların ulnar/median DML oranı kontrollere göre daha düşüktü (0.73/0.80;p=0.003); ulnar/median CMAP amplitüd oranı ise daha yüksekti (1.40/1.11; p=0.002).
Sonuç: ALS hastalarının erken dönemde motor sinir iletimlerinde uzamış DML ve düşük amplitüdler gözlendi. Bu çalışmada sonuçlarımız, ekstremite başlangıçlı ALS' nin (hem üst hem de alt) erken döneminde bile Ayrık el fenomeninin varlığını ve önemini desteklemektedir. Bulgularımız, ALS' nin spesifik muayene ve elektrofizyoloji bulgularının oldukça heterojen olduğu başlangıç döneminde dahi sinir iletim çalışmaları ve Ayrık el işaretinin erken tanıda önemli ipuçları olduğunu düşündürmektedir.

Keywords

Amyotrofik lateral skleroz, sinir iletim çalışması, ayrık el

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