Altered brain structure and function associated with sensory and affective components of classic trigeminal neuralgia

Abstract

Classic trigeminal neuralgia (CTN) is a chronic neuropathic pain state characterized by intense, piercing spasms of the orofacial region, and may be attributable to abnormal pain processing in the central nervous system. Our study investigated neuronal alterations using voxel-based morphometry (VBM), diffuse tensor imaging (DTI), and resting-state functional connectivity in 38 patients with CTN and 38 matched healthy controls. For voxel-based morphometry analyses, patients with CTN displayed gray matter volume (GMV) reductions in the anterior-cingulate cortex (ACC) and mid-cingulate cortex, insula, secondary somatosensory cortex (S2), primary motor cortex (M1), premotor area, and several regions in the temporal lobe. For DTI analysis, patients compared with controls had increased mean diffusivity (MD) and decreased fractional anisotropy (FA) in the corpus callosum and the bilateral corona radiata, and increased mean diffusivity with no fractional anisotropy changes across the bilateral superior longitudinal fasciculus, the internal and external capsule, the thalamus and brainstem. Additionally, patients with CTN had enhanced functional connectivity between the right insula/S2 and ACC, medial prefrontal cortex, posterior cingulate cortex, and bilateral dorsolateral prefrontal cortex. Furthermore, gray matter volume of left inferior temporal gyrus negatively correlated with current pain intensity and disease duration in patients, and connectivity of the right insula/S2-ACC was negatively correlated with pain intensity, depression, and anxiety ratings. This study provides multiple lines of evidence supporting aberrant structural and functional patterns that are observed in patients with CTN, which may help us better understand the pathophysiology of CTN and facilitate the development of new therapies for this disease.

Effects of observing normal and abnormal goal‐directed hand movements on somatosensory cortical activation

“…Our previous work together with other evidences (Hari et al ., ; Jarvelainen et al ., ; Ichikawa et al ., ; Tominaga et al ., ) further supported the role of the MI in the MNS. Moreover, several lines of research by investigating anatomical or functional connectivity have shown direct neural connections of somatosensory system to MI (Pavlides et al ., ; Shinoura et al ., ), inferior parietal cortex (Caspers et al ., ), and prefrontal cortex (Wang et al ., ). Thus, it was reasonable to postulate that the somatosensory cortex was also modulated by action modulation.…”

Subcortical Brain Abnormalities and Clinical Relevance in Patients With Hemifacial Spasm

“…All subjects underwent a structured clinical interview and completed a brief psychological assessment. The Hamilton Anxiety Rating Scale (HAM-A) was used to evaluate anxiety symptoms (18,19), and the Hamilton Depression Rating Scale (HAM-D) measured feelings of depression (20). The obtained data were reviewed by a psychiatrist who was blinded to the experimental groups.…”

Diffusion tensor imaging of white matter microstructure in chronic pain: a tract-based spatial statistics study and a systematic review

“…DTI allows investigating the macrostructure (e.g., the thickness and fiber density of major white matter fiber bundles) and microstructure of white matter (27). Using DTI, changes in white matter microstrucure were found in patients with various pain disorders, including musculoskeletal pain (28,29), fibromyalgia (30), trigeminal neuralgia (31)(32)(33), primary dysmenorrhea (34)(35)(36), and chronic neuropathic pain following spinal cord injury (37,38). Impaired white matter structure in chronic pain may be of con-siderable clinical importance because white matter disorder may be associated with cognitive deficits and may predict transition to chronic pain (39).…”