Selective attention impairment in amyotrophic lateral sclerosis

Abstract

Objective of this study was to evaluate attentional control mechanisms in amyotrophic lateral sclerosis (ALS) using an auditory event-related potentials (ERPs) paradigm. Fifteen mild to moderate ALS patients and 15 healthy controls were administered a brief neuropsychological test battery and an ERPs paradigm assessing selective attention. Four types of auditory stimuli were presented in random order: short standard (200 Hz, 200 ms), long standard (200 Hz, 500 ms), short deviant (1000 Hz, 200 ms) and long deviant (1000 Hz, 500 ms). Participants had to respond to the long deviant stimuli only. During the task the electroencephalogram (EEG) was recorded. The N200, P300 and re-orienting negativity (RON) ERP components were analysed. Compared to controls ALS patients showed reduced amplitudes and delayed latencies of N200, P300 and RON. These results could be attributable to both an alteration in change detection resulting in a reduction of the allocation and re-orientation of attentional resources or a general slowing or reduction of neural processing efficiency in the same system. The ERPs results support the hypothesis that ALS involves extramotor cognitive functions including auditory attentional processing at all processing stages, early (200 ms) and late (300–600 ms). These data prove the usefulness and sensitivity of the auditory ERPs in detection of cognitive functions in ALS patients.

Key words:

• Amyotrophic lateral sclerosis
• auditory event-related potentials
• selective attention

Acknowledgements

The authors thank all the patients for their cooperation. This study was supported by the Italian Ministry of Health, Current Research Funding [grant number 2609198], the Deutsche Forschungsgemeinschaft (DFG, Koselleck Project to Niels Birbaumer [grant number BI 195/69-1]), Eva Luise und Horst Köhler Stiftung, Stiftung Volkswagen, Brain Products Munich. The funding agencies had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Declaration of interest

The authors have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.

Figure 1. The figure shows the grand average ERPs recorded in response to short deviant, long deviant, short standard and long standard tones of ALS patients and controls at Fz, Cz and Pz.