Structural Abnormalities and Treatment-related Plasticity in Classical Trigeminal Neuralgia
Year: 2015
Type: dissertation
Study design: Observational Study
Abstract: Classical trigeminal neuralgia (TN) is a unique neuropathic pain disorder characterized by highly intense electric shock-like attacks of unilateral facial pain. While TN is commonly associated with neurovascular compression of the trigeminal nerve at the root entry zone (REZ) its pathophysiology is not well understood. In conjunction with trigeminal nerve abnormalities, central gray matter and white matter (GM, WM) structure may be affected and/or contribute to the maintenance of TN. Surgical treatment for TN may produce analgesia by effectively normalizing these structural abnormalities. The main aim of this thesis is to determine if there are structural neural abnormalities in patients with TN and whether effective neurosurgical treatment can reverse these abnormalities. The specific aims were to determine: 1) if patients with TN have brain GM abnormalities; 2) if patients with TN have trigeminal nerve and/or brain WM abnormalities based on multiple DTI-derived metrics; 3) if effective neurosurgical treatment for TN is associated with a reversal of the trigeminal REZ and cortical and subcortical GM abnormalities that we report in studies 1 and 2 of this thesis. In groups of TN patients with right-sided pain and healthy age- and sex-matched controls, magnetic resonance imaging revealed that patients had: 1) increased GM in the sensory thalamus, amygdala, periaqueductal gray, basal ganglia, contralateral primary somatosensory cortex, and frontal pole and less GM in the pregenual anterior cingulate cortex, insula, and orbitofrontal cortex; 2) abnormalities in the trigeminal REZ and cerebral WM tracts including the corpus callosum, cingulum, corona radiata, and superior longitudinal fasciculus; and 3) a reversal ventral anterior insula and trigeminal REZ abnormalities following effective treatment, with the degree of REZ normalization correlating with pain relief. Taken together, this thesis demonstrates for the first time both trigeminal nerve and brain abnormalities in patients with TN, and the impact of effective treatment on these abnormalities.
Source: TSpace (University of Toronto)
Author: Danielle D. DeSouza
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2561919549