This issue of JVIM has neurologic articles on myoclonus and myotonia (previously reviewed), paroxysmal dyskinesia, hereditary ataxia, cerebral microbleeds, and intranasal midazolam.
Paroxysmal dyskinesia in Border terriers
Stassen, et al, from Utrecht University investigated the clinical, epidemiological, and genetics of Border Terriers with paroxysmal dyskinesia, an episodic movement disorder characterized by dystonia, muscle fasciculations, and falling over. They found that the majority of owners believed that their dogs remained conscious during the episodes. A beneficial effect of anti-epileptic therapy was observed in 29 of 43 dogs. Fifteen owners changed their dogs’ diet to a hypoallergenic, gluten-free diet, and all reported reasonable to good improvement of signs. Clinical examinations, EEG, and MRI were unremarkable. The genome-wide genetic study did not identify significantly associated chromosome regions. Click here to read the full-text article.
Juvenile-onset hereditary ataxia in Scottish terriers
Scottish Terriers have a high incidence of juvenile onset hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex and causing slowly progressive cerebellar dysfunction. Researchers at the North Carolina State University and the Laboratory of Neurogenetics prospectively studied affected dogs. Linkage and genome-wide association studies in a cohort of Scottish Terriers both identified a region on CFA X strongly associated with the disease trait. Homozygosity mapping revealed a 4 Mb region of interest but pedigree evaluation failed to identify the possible mode of inheritance due to the lack of complete litter information. This finding suggests that further genetic investigation of the potential region of interest on CFA X should be considered to identify the causal mutation as well as develop a genetic test to eliminate the disease from this breed. Click here to read the full-text article.
Cerebral microbleeds are focal intraparenchymal signal voids on gradient-echo magnetic resonance imaging (MRI), corresponding to regions of chronic hemorrhage. In humans, they are associated with systemic disease and shorter survival times. Veterinarians at the Texas A&M University retrospectively evaluated 582 dogs to determine the epidemiology and clinical correlations of putative microbleeds (pMBs) in dogs. They found that dogs with putative microbleeds were older (P < 0.001) and smaller (P = 0.004) than unaffected dogs. Compared to matched controls, they presented more frequently for vestibular signs (P = 0.030) and cortical atrophy occurred concurrently with pMBs in 26% (14/54) of dogs. Diagnosed renal disease was not significantly associated with pMBs, but proteinuria was more common in dogs with pMBs than in matched controls (odds ratio = 3.01, P = 0.005). Dogs with pMBs had a shorter median survival time than did matched controls (P = 0.011). Click here to read the full-text article.
A randomized multi-center clinical trial was conducted to evaluate the clinical efficacy of intranasal midazolam (IN-MDZ), via a mucosal atomization device, as a first-line management option for canine status epilepticus and compare it to rectal administration of diazepam (R-DZP) for controlling status epilepticus before intravenous access is available. Client-owned dogs with idiopathic or structural epilepsy manifesting status epilepticus within a hospital environment were used. Dogs were randomly allocated to treatment with IN-MDZ (n = 20) or R-DZP (n = 15). IN-MDZ and R-DZP terminated status epilepticus in 70% (14/20) and 20% (3/15) of cases, respectively (P = 0.0059). All dogs showed sedation and ataxia. IN-MDZ is a quick, safe and effective first-line medication for controlling status epilepticus in dogs and appears superior to R-DZP. IN-MDZ might be a valuable treatment option when intravenous access is not available and for treatment of status epilepticus in dogs at home. Click here to read the full-text article.
Image courtesy of Mider