Chiari-like malformation (CM) and syringomyelia (SM) is a frequent diagnosis in predisposed brachycephalic toy breeds since increased availability of MRI. However, the relevance of that MRI diagnosis has been questioned as CM, defined as identification of a cerebellar herniation, is ubiquitous in some breeds and SM can be asymptomatic. This article reviews the current knowledge of neuroanatomical changes in symptomatic CM and SM and diagnostic imaging modalities used for the clinical diagnosis of CM-pain or myelopathy related to SM. Although often compared to Chiari type I malformation in humans, canine CM-pain and SM is more comparable to complex craniosynostosis syndromes (i.e., premature fusion of multiple skull sutures) characterized by a short skull (cranial) base, rostrotentorial crowding with rostral forebrain flattening, small, and ventrally orientated olfactory bulbs, displacement of the neural tissue to give increased height of the cranium and further reduction of the functional caudotentorial space with hindbrain herniation. MRI may further reveal changes suggesting raised intracranial pressure such as loss of sulci definition in conjunction with ventriculomegaly. In addition to these brachycephalic changes, dogs with SM are more likely to have craniocervical junction abnormalities including rostral displacement of the axis and atlas with increased odontoid angulation causing craniospinal junction deformation and medulla oblongata elevation. Symptomatic SM is diagnosed on the basis of signs of myelopathy and presence of a large syrinx that is consistent with the neuro-localization. The imaging protocol should establish the longitudinal and transverse extent of the spinal cord involvement by the syrinx. Phantom scratching and cervicotorticollis are associated with large mid-cervical syringes that extend to the superficial dorsal horn. If the cause of CSF channel disruption and syringomyelia is not revealed by anatomical MRI then other imaging modalities may be appropriate with radiography or CT for any associated vertebral abnormalities.

Background: Recent studies including an innovative machine learning technique indicated Chiari-like malformation (CM) is influenced by brachycephalic features. Objectives: Morphometric analysis of facial anatomy and dysmorphia in CMassociated pain (CM-P) and syringomyelia (SM) in the Cavalier King Charles Spaniel (CKCS). Animals: Sixty-six client-owned CKCS. Methods: Retrospective study of anonymized T2W sagittal magnetic resonance imaging of 3 clinical groups: (1) 11 without central canal dilation (ccd) or SM (CM-N), (2) 15 with CM-P with no SM or <2 mm ccd (CM-P), and (3) 40 with syrinx width ≥4 mm (SM-S). Morphometric analysis assessed rostral skull flattening and position of the hard and soft palate relative to the cranial base in each clinical group and compared CKCS with and without SM-S.Results: Sixteen of 28 measured variables were associated to SM-S compared to CM-N and CM-P. Of these 6 were common to both groups. Predictive variables determined by discriminant analysis were (1) the ratio of cranial height with cranial length (P < .001 between SM-S and CM-N) and (2) the distance between the cerebrum and the frontal bone (P < .001 between SM-S and CM-P). CM-P had the lowest mean height of the maxillary area. Conclusions and ClinicalImportance: CKCS with CM-P and SM-S have cranial brachycephaly with osseous insufficiency in the skull with rostral flattening and increased proximity of the hard and soft palate to the cranial base. Changes are greatest with CM-P. These findings have relevance for understanding disease pathogenesis and for selection of head conformation for breeding purposes. dogs without central canal dilation or syringomyelia with no clinical or behavioural signs of pain; CM-P, dogs with clinical and behavioral signs of pain with no syringomyelia or with a central canal dilation less than 2 mm wide; CSF, cerebrospinal fluid; DA, discriminant function analysis; DICOM, Digital Imaging and Communications in Medicine; FS, feature selection; ICC, intraclass correlation coefficient; ML, machine learning; MRI, magnetic resonance imaging; SM, syringomyelia; SM-S, dogs with syrinx width ≥4 mm and with SM specific signs of phantom scratching, scoliosis, paresis or proprioceptive deficits.

Recent studies have demonstrated the risk of contrast‐associated acute kidney injury (CA‐AKI) is low post‐multimodal computed tomography (MMCT) in the evaluation of acute stroke. We provide a complementary study with long‐term renal follow up. A retrospective analysis was performed on all suspected strokes from January 2019 to June 2020 for those who had undergone computed tomography angiography, computed tomography perfusion or both. We identified 776 cases, of which 538 were excluded. The incidence of CA‐AKI was 7.6% (n/N = 18/238; 95% confidence interval = 4.2–11.0). All CA‐AKI cases had renal confounders. No AKI at >30 days was found in 60.5% (n = 144) of all cases studied. The long‐term renal outcome post‐MMCT in stroke evaluation is favourable at >30 days.

2 animals. Histopathological examination demonstrated a mucosal fluid containing cyst lined by ciliated, pseudostratified epithelium consistent with previous reports of pharyngeal hypophysis. STATEMENT (CONCLUSIONS) Cystic pharyngeal hypophysis is a common finding on canine MRI which contrary to previous reports has no apparent consistent clinical significance

This study provides vital information for veterinarians, breeders and owners of CKCS about common presentations of syringomyelia and other neurological diseases to allow for earlier recognition of these potentially painful disorders. It concludes that syringomyelia is the most prevalent neurological disease in referral practices and emphasizes the frequency of pain associated with neurological disorders, but when compared to previous studies, it may be underdiagnosed in first opinion practices.