The role of spinal cord tractography in detecting lesions following selective bladder afferent and efferent fibers injury: A novel method for induction of neurogenic lower urinary tract dysfunction in rabbit

Abstract

Objective: Neurogenic lower urinary tract dysfunction (NLUTD), a challenging disorder, is defined by lack of bladder control due to the abnormalities in neural pathways and can be classified based on the location of lesions within the nervous system, thus investigating the neural pathways can help us to know the site of the lesion and specify the class of the NLUTD. Diffusion Tensor Imaging (DTI) tractography, a noninvasive advanced imaging method, is capable of detecting central nervous system pathologies, even if routine magnetic resonance imaging shows no abnormality. Accordingly, tractography is an ideal technique to evaluate patients with NLUTD and visualize the pathology site within the spine. This study aimed to introduce a novel method of spinal cord injury (SCI) to establish NLUTD in the rabbit and to investigate the potential of tractography in tracing neural tracts of the spinal cord in an induced NLUTD animal model. Materials and Methods: An animal model of NLUTD was induced through cauterization of the spinal cord at the level T12-L1 in 12 rabbits. Then rabbits were assessed via DTI, urodynamic studies (UDS), voiding cystourethrogram (VCUG), and pathology assessments using antineurofilament 200 (NF200) antibody, anti-S100, anti-Smooth Muscle Actin, anti-Myogenin, and anti-MyoD1. Results: The tractography visualized lesions within spinal cord fibers. DTI parameters including fractional anisotropy (FA) value and tract density were significantly decreased (FA: p-value = 0.01, Tract density: p-value = 0.05) after

Molecular Mechanism Operating in Animal Models of Neurogenic Detrusor Overactivity: A Systematic Review Focusing on Bladder Dysfunction of Neurogenic Origin

“…From these publications, 59% report complete transection of thoracic segments to induce SCI [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 38 , 39 , 43 , 44 , 46 , 48 , 49 , 50 , 55 , 57 , 62 , 63 ], followed by spinal contusion (13%). The use of spinal hemisections was less frequent (10%) [ 42 , 47 , 52 ], as were spinal compressions (8%) [ 32 , 36 , 54 , 56 ] and other SCI methods (10%) [ 41 , 51 , 53 , 58 ] ( Figure 3 ). Regarding the SCI model of NDO, we found that, irrespective of the type of injury, the thoracic level was the preferred level to inflict spinal lesion, with the T8–T9 levels being particularly favored.…”

“…Most of the studies reporting urodynamic recordings used awake cystometry as the recording method (37%) [ 31 , 32 , 33 , 34 , 35 , 38 , 39 , 42 , 46 , 47 , 48 , 52 , 56 , 59 , 63 , 68 , 70 , 71 ]. Cystometry under anesthesia represented 26% of studies, with 16% using urethane delivered via subcutaneous [ 26 , 27 , 28 , 37 , 41 , 43 , 51 ] or intraperitoneal injection [ 57 ], 8% using zolotyl [ 53 , 58 , 61 , 74 ], and 2% referring the use of chloral hydrate as anesthetic [ 54 ].…”

“…Other SCI protocols include incomplete sectioning of the cord with a scalpel of iridectomy scissors, the most frequent of which are spinal hemisections [ 42 , 47 , 52 ]. This model is particularly useful in studies in which the goal is to compromise a particular area of the cord.…”