Selective hippocampal subfield volume reductions in classic trigeminal neuralgia

Abstract

Trigeminal Neuralgia (TN) is a chronic neuropathic pain syndrome characterized by paroxysmal unilateral shock-like pains in the trigeminal territory most frequently attributed to neurovascular compression of the trigeminal nerve at its root entry zone. Recent advances in the study of TN suggest a possible central nervous system (CNS) role in modulation and maintenance of pain. TN and other chronic pain patients commonly experience alterations in cognition and affect, as well as abnormalities in CNS volume and microstructure in regions associated with pain perception, emotional modulation, and memory consolidation. However, the microstructural changes in the hippocampus, an important structure within the limbic system, have not been previously studied in TN patients. Here, we use grey matter analysis to assess whether TN pain is associated with altered hippocampal subfield volume in patients with classic TN. Anatomical magnetic resonance (MR) images of twenty-two right-sided TN patients and matched healthy controls underwent automated segmentation of hippocampal subfields using FreeSurfer v6.0. Right-sided TN patients had significant volumetric reductions in ipsilateral cornu ammois 1 (CA1), CA4, dentate gyrus, molecular layer, and hippocampus-amygdala transition area – resulting in decreased whole ipsilateral hippocampal volume, compared to healthy controls. Overall, we demonstrate selective hippocampal subfield volume reduction in patients with classic TN. These changes occur in subfields implicated as neural circuits for chronic pain processing. Selective subfield volume reduction suggests aberrant processes and circuitry reorganization, which may contribute to development and/or maintenance of TN symptoms.

A Regions of Interest Voxel‐Based Morphometry Study of the Human Brain During High‐Frequency Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome

“…This study revealed a bilateral decrease of the GM volume in the hippocampus after 3 months of HF‐10 SCS. Reductions in hippocampal GM have previously been demonstrated in different chronic pain populations 44–46 . Moreover, these results are in line with the study of Luchtmann et al, 47 who demonstrated a decreased hippocampal volume in patients suffering from chronic low back pain after microsurgical lumbar discectomy.…”

“…Reductions in hippocampal GM have previously been demonstrated in different chronic pain populations. [44][45][46] Moreover, these results are in line with the study of Luchtmann et al, 47 who demonstrated a decreased hippocampal volume in patients suffering from chronic low back pain after microsurgical lumbar discectomy. It might be suggested that treatment could reverse the previously occurring neuroplastic changes due to the presence of chronic pain.…”

“…However, direct effects on the hippocampus have not been previously explored, wherefore future studies are necessary to evaluate the exact role of medication on this type of study. 46 Concerning pain intensity scores, a pain diary was used in this study to obtain more accurate pain intensity scores and limit recall bias. However, this choice makes it rather difficult to compare the obtained pain relief with other studies.…”

Acupuncture affects different ways for migraineurs of long- and short- courses on the efficiency of structural brain network

“…Within them, LC had four regions decreased in nodal efficiency after acupuncture. The cingulum hippocampus, which was the essential structure with the limbic system, was related to cognitive impairment and emotional change on trigeminal neuralgia and chronic pain patients [47].…”

FreeSurfer based segmentation of hippocampal subfields: a review of methods and applications, with a novel quality control procedure for ENIGMA studies and other collaborative efforts

“…PTSD (Bøen et al, 2014;Chen et al, 2016;Averill et al, 2017;Hayes et al, 2017), childhood maltreatment (Teicher et al, 2012;Chalavi et al, 2015), verbal abuse , childhood trauma in schizophrenia and healthy controls (du Plessis et al, 2019), in bipolar disorders and healthy controls (Janiri et al, 2019a) and in adolescence (Malhi et al, 2019) Other neuropsychiatric conditions Pain symptoms (Ezzati et al, 2014), ADHD (Al-Amin et al, 2018), anorexia nervosa (Myrvang et al, 2018), obsessive compulsive disorder (Zhang et al, 2019), and transient global amnesia (Wang et al, 2018b), essential tremor (Prasad et al, 2019), rapid eye movement sleep behavior disorder (Campabadal et al, 2019), trigeminal neuralgia (Vaculik et al, 2019) Thalamic infarction (Chen et al, 2016), sequelae of microsurgical aneurysm clipping (Hedderich et al, 2019)…”