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]
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]
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]
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 Scied Neurology Unit, IRCCS San Raffantific 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 condition characterized by sudden episodes of facial pain in the distribution of the fifth cranial nerve. Primary treatment involves medications, while Gamma Knife radiosurgery (GKRS) become an option if drugs fail. The goal of this study was to investigate microstructural gray matter (GM) and white matter (WM) alterations in TN patients.
Twelve TN patients and 18 controls age- and sex-matched were enrolled and underwent clinical assessment and brain MRI protocol including performed multi-shell diffusion brain MRI on a 3 Tesla scanner. Fractional anisotropy (FA) maps were computed on diffusion-tensor imaging (DTI). Additionally, Intra-Cellular Volume Fraction (ICVF) and Orientation Dispersion Index (ODI) maps have been estimated using the NODDI model. Then, tract-based spatial statistics (TBSS) and GM-based spatial statistics (GBSS) were performed to estimate WM and GM damage respectively between TN subjects and controls. Correlation analysis has been tested between WM/GM damage and clinical data.
TBSS and GBSS showed significant differences in TN group relative to controls. Particularly, FA maps showed no significant differences in WM and GM maps in TN group relative to controls. Moreover, ODI showed specific damage along bilateral corticospinal tract (CST) and right superior longitudinal fasciculus (p<0.05), while ICVF tends toward significance in left CST and internal capsule (p<0.06) and in right and left CST and anterior thalamic radiation at brainstem level (p<0.06). Moreover, ICVF reduction in CST showed a positive correlation pain scale: Penn Facial Pain Scale, Pain Disability Index, Numeric Rating Scale (NRS) and Barrow Neurological Institute Pain Intensity Score (BNI-P), while ODI reduction showed a negative correlation with NRS and BNI-P. Moreover, only ODI maps demonstrated a GM reduction in left temporal pole and parahippocampal (p<0.05) in GBSS analysis when comparing TN subjects and controls.
These findings suggest that both ODI and ICVF might be potential biomarkers for neural damage associated with TN. CST is involved in motor control, and alterations might indicate neural disruptions beyond the sensory pathways directly affected by TN. Moreover, alterations in superior longitudinal fasciculus might reflect changes in connectivity and integration of brain functions. Notably, GM reductions were observed in the left temporal pole and parahippocampal regions, emphasizing the impact of TN beyond the trigeminal pathways. These findings highlighted the importance of advanced imaging techniques in understanding the neuropathological underpinnings of TN and potentially guiding more targeted therapeutic interventions.
Funding. Italian Ministry of Health (GR-2021-12374601).
Albano L, Agosta F, Basaia S, Castellano A, Messina R, Parisi V, Barzaghi LR, Falini A, Mortini P, Filippi M. Alterations of brain structural MRI are associated with outcome of surgical treatment in trigeminal neuralgia. Eur J Neurol. 2022 Jan;29(1):305-317. doi: 10.1111/ene.15105. Epub 2021 Sep 24. PMID: 34519132.
