Thoracolumbar meningeal fibrosis in pugs

Abstract

Background Thoracolumbar myelopathies associated with spinal cord and vertebral column lesions, with a similar clinical phenotype, but different underlying etiologies, occur in pugs. Objectives To further characterize the clinical and neuropathological characteristics of pugs with longstanding thoracolumbar myelopathy. Animals Thirty client‐owned pure‐bred pugs with a history of more than a month of ataxia and paresis of the pelvic limbs, suggesting a myelopathy localized to the thoracolumbar spinal cord, were included in the study. Methods Prospective clinicopathological study. Included pugs underwent a complete neurological examination and gross and histopathologic postmortem studies with focus on the spinal cord. Computed tomography (n = 18), magnetic resonance imaging (n = 17), and cerebrospinal fluid analysis (n = 27) were performed before or immediately after death. Results Twenty male and 10 female pugs had a median age at clinical onset of 84 months (interquartile range, 66‐96). Affected pugs presented with a progressive clinical course and 80% were incontinent. There was circumferential meningeal fibrosis with concomitant focal, malacic, destruction of the neuroparenchyma in the thoracolumbar spinal cord in 24/30 pugs. Vertebral lesions accompanied the focal spinal cord lesion, and there was lympho‐histiocytic inflammation associated or not to the parenchymal lesion in 43% of the pugs. Conclusions and Clinical Importance Meningeal fibrosis with associated focal spinal cord destruction and neighboring vertebral column lesions were common findings in pugs with long‐standing thoracolumbar myelopathy.

Surgical techniques used in the management of intra‐arachnoid diverticula in dogs across four referral centres and their immediate outcome

“…Diagnosis of the IAD was based on a board-certified radiologist and neurologist's interpretation with surgical confirmation of a fluid-filled cyst-like structure and intra-arachnoid adhesions. We only included dogs with an MRI describing a single welldefined expansion or "tear drop" dilation of the subarachnoid space and excluded dogs with an unclear dilation or circumferential adhesions because there is evidence that a multitude of intraarachnoid adhesion phenotypes exists, some of which appear to be characterised by constriction or circumferential fibrosis (Meren et al 2017, Driver et al 2019, Lourinho et al 2020, Rohdin et al 2020. Whether this distinction is accurate and/or has any prognostic importance remains to be elucidated, but if varying proportions of congenital versus acquired disease existed in each surgical technique, this might influence outcome.…”

Tail end of the brachycephalic problem: diagnostic and treatment options for spinal malformations

“…This causes spinal cord compression and leads to focal gliosis, although the exact pathophysiological mechanism is not completely understood. It seems to be a common finding in pugs with chronic thoracolumbar myelopathies (Fig 4), and recently a breed predisposition to meningeal proliferation has been suggested (Driver and others 2019, Lourinho and others 2020, Rohdin and others 2020).…”

“…Caudal articular process hypoplasia and aplasia, affecting the thoracic vertebrae, are a common incidental finding in English bulldogs, French bulldogs and pugs (Bertram and others 2018) (Fig 6). In pugs, it is more common to see bilateral aplasia of the articular processes in multiple vertebrae of the thoracolumbar region, and in some cases it has been hypothesised that this could potentially contribute to the development of chronic intervertebral disc protrusion, meningeal fibrosis and acquired subarachnoid diverticula (Driver and others 2019, Nishida and others 2019, Lourinho and others 2020, Rohdin and others 2020).…”

“…They usually show gradual and slowly progressive paraparesis and pelvic limb ataxia without spinal pain. Faecal incontinence with a normal perianal reflex is commonly present (Driver and others 2019, Lourinho and others 2020, Rohdin and others 2020).…”

Retrospective evaluation of surgical outcomes after closure of durotomy in eight dogs affected by spinal subarachnoid diverticulum

“…A causal relationship between these theories and the development of the SAD has not yet been confirmed. (Dyce et al, 1991;McKee and Renwick, 1994;Frykman, 1999;Webb, 1999;Skeen et al, 2003;Lowrie et al, 2014;Driver et al, 2019;Rohdin et al, 2020). SAD is often localized at the cervical region in large dog breeds and in the thoracolumbar spinal cord in small breeds (Jurina and Grevel, 2004;Mauler et al, 2014Mauler et al, , 2017.…”