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Dewey CW, Rishniw M, Johnson PJ, Davies ES, Sackman JJ, O'Donnell M.2019. Presumptive spontaneous brain microhemorrhages in geriatric dogs: a comparative retrospective MRI study of dogs with and without evidence of canine cognitive dysfunction. PeerJ Preprints7:e27868v1https://doi.org/10.7287/peerj.preprints.27868v1
The objective of this study was to compare specific brain MRI anatomic measurements between three groups of geriatric ( > 8yrs) dogs: 1) neurologically impaired dogs with presumptive spontaneous brain microhemorrhages and no clinical evidence of canine cognitive dysfunction 2) dogs with canine cognitive dysfunction 3) dogs without clinical evidence of cognitive impairment or abnormalities on neurologic examination (control dogs). MR images from 46 geriatric dogs were reviewed and measurements were obtained of interthalamic adhesion height (thickness) and mid-sagittal interthalamic adhesion area for all dogs, in addition to total brain volume. Interthalamic adhesion measurements, either absolute or normalized to total brain volume were compared between groups. Signalment (age, breed, sex), body weight, presence and number of SBMs, as well as other abnormal MRI findings were recorded for all dogs. All interthalamic adhesion measurement parameters were significantly (p<0.05) different between control dogs and affected dogs. Both dogs with cognitive dysfunction (12/13; 92 %) and dogs with isolated brain microhemorrhages had more microhemorrhages than control dogs (3/19; 16%). Affected dogs without cognitive dysfunction had more microhemorrhages than dogs with cognitive dysfunction. In addition to signs of cognitive impairment for the CCD group, main clinical complaints for SBM and CCD dogs were referable to central vestibular dysfunction, recent-onset seizure activity, or both. Geriatric dogs with spontaneous brain microhemorrhages without cognitive dysfunction have similar MRI abnormalities as dogs with cognitive dysfunction but may represent a distinct diseasecategory.
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Raw volumetric data for all dogs identified via search criteria