ERP P300 and brain magnetic resonance imaging in patients with vibroacoustic disease

Introduction: Subjects occupationally exposed to large pressure amplitude ( greater than or equal to 90 dB SPL) and low frequency (less than or equal t o 500 Hz) (LPALF) noise for long term periods (>10 yr) can develop vibroaco ustic disease (VAD). One of the earliest complaints of VAD patients deals w ith memory and attention disturbances. On the other hand, in over 50% of th ese patients, magnetic resonance imaging (MRI) of the CNS revealed cortical atrophy and dilation of the perivascular spaces, and small hyperintense le sions in T2 of the cerebral white matter, basal ganglia, and brainstem. The purpose of this study is to investigate whether there is any relationship between these morphological changes and the event-related potentials (ERP) P300 parameters. Methods: Sixty aeronautical workers with more than 10 yr o f LPALF noise exposure were studied using brain MRI and ERP P300. A careful neurological examination had been previously performed on ail of them. Res ults: The neurological examination revealed abnormalities in 80%, the most common finding being the archaic palmo-mental reflex. Some 37 subjects had hyperintense loci in T2 of the subcortical and periventricular white matter , the basal ganglia and the brainstem. Comparing the ERP P300 amplitude and latency values, morphology and topography, obtained in these 37 subjects w ith the data from the 23 who did not have any morphological changes in CNS, we found a strong correlation between the brain MRI lesions and the neurop hysiological changes (p < 0.01). Conclusions: These results are important f or understanding the pathophysiology of the cognitive impairment found in V AD patients.