2021-Lanza TMS de-novo celiac disease
Celiac disease (CD) may present or be complicated by cognitive and neuropsychiatric manifestations. Transcranial magnetic stimulation (TMS) probes brain excitability changes non-invasively, even preclinically. We previously demonstrated an intracortical motor disinhibition and hyperfacilitation in newly diagnosed CD patients, which reverts back after a long-term gluten-free diet (GFD). In this new cross-sectional study, we assessed the central cholinergic functioning through the short-latency afferent inhibition (SAI) to TMS, which does not seems to have been investigated before in CD. A total of 15 right-handed de novo, neurologically asymptomatic, CD patients and 15 age-matched healthy controls in whom cognitive and depressive symptoms were assessed with the Montreal Cognitive Assessment (MoCA) and the 17-item Hamilton Depression Rating Scale (HDRS), respectively. Brain computed tomography (CT) was performed in all patients to rule out intracranial calcifications or other clear radiological abnormalities. SAI at two interstimulus intervals (2 and 8 ms) was assessed as the percentage amplitude ratio between the conditioned and the unconditioned motor evoked potential (MEP) response. Resting motor threshold, MEP amplitude and latency, and central motor conduction time were also measured. MoCA was significantly worse in patients, although the mean score was still within the normal limits. HDRS score was higher in patients than in controls but was compatible with a very mild depression in this sample. Brain CT was normal in all patients. No statistically significant difference was observed for all TMS measures, including SAI, between patients and controls. Central cholinergic pathways to TMS do not seem to be functionally involved in de novo neurologically asymptomatic CD patients, who do not show an overt cognitive impairment or depressive disorder. Longitudinal studies correlating clinical, TMS, and neuroimaging data, both before and after GFD, are needed.