Valtorta Filippo [Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy; and Vita-Salute San Raffaele University, Milan, Italy]
Basaia Silvia [Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy]
Albano Luigi [Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy; and Vita-Salute San Raffaele University, Milan, Italy; and Neurosurgery and Gamma Knife Radiosurgery Unit, IRCCS Ospedale San Raffaele, Milan, Italy]
Sarasso Elisabetta [Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy; and Vita-Salute San Raffaele University, Milan, Italy; and Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, University of Genoa, Genoa, Italy]
Pompeo Edoardo [Vita-Salute San Raffaele University, Milan, Italy; and Neurosurgery and Gamma Knife Radiosurgery Unit, IRCCS Ospedale San Raffaele, Milan, Italy]
Emedoli Daniele [Department of Rehabilitation and Functional Recovery, IRCCS Ospedale San Raffaele, Milan, Italy]
Sibilla Elisa [Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy; and Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy]
Mortini Pietro [Vita-Salute San Raffaele University, Milan, Italy; and Neurosurgery and Gamma Knife Radiosurgery Unit, IRCCS Ospedale San Raffaele, Milan, Italy]
Agosta Federica [Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy; and Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy; and Vita-Salute San Raffaele University, Milan, Italy]
Filippi Massimo [Neuroimaging Research Unit, Division of Neuroscience, and Neurology Unit, and Neurorehabilitation Unit, and Neurophysiology Service, IRCCS San Raffaele Scientific Institute, Milan, Italy; and Vita-Salute San Raffaele University, Milan, Italy]
Trigeminal Neuralgia (TN) is a chronic neuropathic pain disorder characterised by paroxysmal episodes of facial pain in the distribution of the fifth cranial nerve. First-line treatment is pharmacological, while Gamma Knife radiosurgery (GKRS) becomes an option if medications fail. This study aimed at investigating the neural correlates of pain during an observation functional MRI (fMRI) task in TN patients relative to controls.
Twelve TN patients were enrolled and underwent clinical assessment and brain MRI protocol including observation task functional MRI (fMRI) on a 3 Tesla scanner. Subjects repeated the same assessment at baseline (before GKRS) and 3-month after GKRS. All subjects underwent brain fMRI including an observational task, in which participants will be asked to observe facial gestures during activities of daily living or specific movements different for each subject depending on which action triggers the facial pain. The fMRI data were pre-processed using Statistical Parametric Mapping (SPM) tools to investigate brain area activation during the task. A one-sample analysis was performed to evaluate functional activation in TN patients during the task. Functional differences between baseline and three months after GKRS in TN patients were assessed using a paired two-sample t-test.
Considering one-sample analysis, TN patients showed the activation of inferior and middle occipital, inferior parietal, and inferior temporal areas, precentral, postcentral, and fusiform gyri, and inferior frontal pars opercularis during the observational task. Moreover, right-sided TN patients showed more activation in parahippocampal, hippocampal and middle temporal regions relative to left-sided TN patients, which activated more superior occipital, middle frontal, and superior temporal gyri and insula. Paired analysis between baseline and 3-month after GKRS shows that at baseline, the postcentral gyrus, supplementary motor area, and cerebellum area 6 are significantly more activated, while at the 3-month follow-up, the anterior cingulum and medial superior frontal area are significantly more activated.
Results suggested TN patient showed a significant activation in visual, somatosensory, and motor-related brain areas, which may reflect their heightened sensitivity to pain-related stimuli. Notably, different brain regions were activated based on the side of the facial pain, highlighting lateralization in neural responses. Post-GKRS, there was a shift in activation towards the anterior cingulum and medial superior frontal area, suggesting possible neural reorganization and adaptation following treatment. These findings enhance our understanding of the neural mechanisms underlying TN and the impact of GKRS on brain function.
Funding. Italian Ministry of Health (GR-2021-12374601).
Agosta F, Gatti R, Sarasso E, Volonté MA, Canu E, Meani A, Sarro L, Copetti M, Cattrysse E, Kerckhofs E, Comi G, Falini A, Filippi M. Brain plasticity in Parkinson’s disease with freezing of gait induced by action observation training. J Neurol. 2017 Jan;264(1):88-101. doi: 10.1007/s00415-016-8309-7. Epub 2016 Oct 24. PMID: 27778161.
