Exploring the split hand phenomenon with the neurophysiological index

• Author(s): Santos Silva, Cláudia ; Swash, Michael ; Carvalho, Mamede
• Date: 2023
• Persistent ID: http://hdl.handle.net/10451/58048
• Origin: Repositório da Universidade de Lisboa
• Subject(s): Age; Amyotrophic lateral sclerosis; Compound muscle action potential; Neurophysiological index; Split hand
• Document Type: Journal article
• Language: English
• Contributor(s): Repositório Científico de Acesso Aberto da ULisboa

Description

In 164 subjects of different age groups, we studied the neurophysiological index (NI) ([CMAP amplitude/Distal motor latency] *[F-wave frequency]; CMAP=compound muscle action potential) for three hand muscles (APB= abductor pollicis brevis; FDI= first dorsal interosseous; ADM= abductor digiti minimi). A split hand index based on CMAP amplitude (SHI_CMAP) and NI (SHI_NI) were calculated ([APB CMAP amplitude or NI * FDI CMAP amplitude or NI]/[ADM CMAP amplitude or NI]). All these neurophysiological measurements differed between age groups (p<0.001). Hand muscle NIs, as well as SHI_NI and SHI_CMAP were age dependent. This may be relevant for diagnostic purposes in motor neuron diseases.