Split hand syndrome and the split hand index in ALS patients

Florian Antonescu,Marin Adam,Sorin Tuta,Constantin Popa

doi:10.37897/rjn.2018.2.1

Abstract

Split hand syndrome and the split hand index in ALS patients

Highlights

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which, despite extensive ongoing research, the diagnosis remains a clinical one, with significant assistance from electrophysiological studies, especially EMG [1,2].More than twenty years have passed since Wilbourn first described asymmetric atrophy of the hand muscles in ALS patients, with preferential wasting of the lateral group, consisting of the abductor pollicis brevis (APB) and first dorsal interosseous muscle (FDI), and relative sparing of the medial group, especially abductor digiti minimi (ADM), a phenomenon he later dubbed Split Hand Syndrome [3,4].Repeated reports show the split hand to be a specific and early clinical marker for ALS [5,6]
The split hand sign is an important clinical element in patients suspected of ALS [4], especially if the flexor pollicis longus seems to be spared [7]
The differences in patterns of small hand muscle involvement can be of clinical significance in differentiating ALS from spondylotic atrophies

Summary

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which, despite extensive ongoing research, the diagnosis remains a clinical one, with significant assistance from electrophysiological studies, especially EMG [1,2]. More than twenty years have passed since Wilbourn first described asymmetric atrophy of the hand muscles in ALS patients, with preferential wasting of the lateral group, consisting of the abductor pollicis brevis (APB) and first dorsal interosseous muscle (FDI), and relative sparing of the medial group, especially abductor digiti minimi (ADM), a phenomenon he later dubbed Split Hand Syndrome [3,4]. Repeated reports show the split hand to be a specific and early clinical marker for ALS [5,6]. In addition to its diagnostic utility, the split hand sign has provided insights into ALS physiopathology. In EMG studies a new index has been developed, to more precisely diagnose and quantify the split hand

CLINICAL PRESENTATION

THE SPLIT HAND INDEX

Findings

CONCLUSIONS