Chiari Malformation and Hyper-Vigilance: An EEG Study

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Psychonomics Society Annual Meeting 2016


We tested 15 Chiari patients and 12 controls on an attentional dual-task (Task 1: tone discrimination, Task 2: emotional face discrimination task using angry, happy, and neutral faces) that varied stimulus onset asynchrony (SOA: 100, 300, and 900 ms).  Chiari malformation Type I is a neurological syndrome in which the cerebellar tonsils descend into the cervical spine area resulting in cervicomedullary compression (i.e., the brainstem is compressed).  Common symptoms are chronic headaches and balance problems.  We collected P100 and P300 ERP components (measured from 100-200 ms, and 400-600 ms, respectively, after Stimulus 2 presentation) at electrode sites O1 and O2, and Pz, respectively.  We observed no group differences in either SOA (a measure of attentional capacity) or emotional valence.  However, Chiari patients showed significantly higher-amplitude P100 components (but not P300 components) than controls.  These results are consistent with a hyper-vigilance effect in the ventral attentional stream for the Chiari group.        


James R. Houston, Philip A. Allen, Mark Luciano, Sarel Vorster, Francis Loth