Effect of a Gluten-Free Diet on Cortical Excitability in Adults with Celiac Disease.

Abstract

Listen

Translate article

IntroductionAn imbalance between excitatory and inhibitory synaptic excitability was observed in de novo patients with celiac disease (CD) in a previous study with Transcranial Magnetic Stimulation (TMS), suggesting a subclinical involvement of GABAergic and glutamatergic neurotransmission in asymptomatic patients. The aim of this investigation was to monitor the eventual changes in the same cohort of patients, evaluated after a period of gluten-free diet.MethodsPatients were re-evaluated after a median period of 16 months during which an adequate gluten-free diet was maintained. Clinical, cognitive and neuropsychiatric assessment was repeated, as well as cortical excitability by means of single- and paired-pulse TMS from the first dorsal interosseous muscle of the dominant hand.ResultsCompared to baseline, patients showed a significant decrease of the median resting motor threshold (from 35% to 33%, p<0.01). The other single-pulse (cortical silent period, motor evoked potentials latency and amplitude, central motor conduction time) and paired-pulse TMS measures (intracortical inhibition and intracortical facilitation) did not change significantly after the follow-up period. Antibodies were still present in 7 subjects.DiscussionIn patients under a gluten-free diet, a global increase of cortical excitability was observed, suggesting a glutamate-mediated functional reorganization compensating for disease progression. We hypothesize that glutamate receptor activation, probably triggered by CD-related immune system dysregulation, might result in a long-lasting motor cortex hyperexcitability with increased excitatory post-synaptic potentials, probably related to phenomena of long-term plasticity. The impact of the gluten-free diet on subclinical neurological abnormalities needs to be further explored.