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Comparison of the Relationship between Cerebral White Matter and Grey Matter in Normal Dogs and Dogs with Lateral Ventricular Enlargement.

Schmidt MJ, Laubner S, Kolecka M, Failing K, Moritz A, Kramer M, Ondreka N - PLoS ONE (2015)

Bottom Line: There is a distinct relationship between white matter and grey matter in the cerebrum of all eutherian mammals.Whereas no significant different adjusted means of the grey matter could be determined, the group of brachycephalic dogs had significantly larger adjusted means of lateral cerebral ventricles and significantly less adjusted means of relative white matter volume.Based on the changes in the relative proportion of WM and CSF volume, and the unchanged GM proportions in dogs with ventriculomegaly, we rather suggest that distension of the lateral ventricles might be the underlying cause of pressure related periventricular loss of white matter tissue, as occurs in internal hydrocephalus.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany.

ABSTRACT
Large cerebral ventricles are a frequent finding in brains of dogs with brachycephalic skull conformation, in comparison with mesaticephalic dogs. It remains unclear whether oversized ventricles represent a normal variant or a pathological condition in brachycephalic dogs. There is a distinct relationship between white matter and grey matter in the cerebrum of all eutherian mammals. The aim of this study was to determine if this physiological proportion between white matter and grey matter of the forebrain still exists in brachycephalic dogs with oversized ventricles. The relative cerebral grey matter, white matter and cerebrospinal fluid volume in dogs were determined based on magnetic-resonance-imaging datasets using graphical software. In an analysis of covariance (ANCOVA) using body mass as the covariate, the adjusted means of the brain tissue volumes of two groups of dogs were compared. Group 1 included 37 mesaticephalic dogs of different sizes with no apparent changes in brain morphology, and subjectively normal ventricle size. Group 2 included 35 brachycephalic dogs in which subjectively enlarged cerebral ventricles were noted as an incidental finding in their magnetic-resonance-imaging examination. Whereas no significant different adjusted means of the grey matter could be determined, the group of brachycephalic dogs had significantly larger adjusted means of lateral cerebral ventricles and significantly less adjusted means of relative white matter volume. This indicates that brachycephalic dogs with subjective ventriculomegaly have less white matter, as expected based on their body weight and cerebral volume. Our study suggests that ventriculomegaly in brachycephalic dogs is not a normal variant of ventricular volume. Based on the changes in the relative proportion of WM and CSF volume, and the unchanged GM proportions in dogs with ventriculomegaly, we rather suggest that distension of the lateral ventricles might be the underlying cause of pressure related periventricular loss of white matter tissue, as occurs in internal hydrocephalus.

No MeSH data available.


Related in: MedlinePlus

Comparison of a canine brain with normal lateral cerebral ventricles (A) and enlarged ventricles (B).
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pone.0124174.g001: Comparison of a canine brain with normal lateral cerebral ventricles (A) and enlarged ventricles (B).

Mentions: The archive of MRI scans of the Justus Liebig University (JLU), Giessen, Germany, was searched retrospectively for MR-imaging reports including the diagnoses “primary or idiopathic epilepsy”, “within normal limits” and “ventriculomegaly” or “enlarged ventricles”. The presence of ventriculomegaly was based on the following criteria: The majority of dogs have very narrow and slit-like horns of the lateral ventricles. In the finding of large ventricles/ventriculomegaly, the interpreter subjectively noted a greater proportion of the intracranial volume occupied by the lateral ventricles. The closely spaced walls of the temporal horns and/or the olfactory recesses were separated by CSF in these brains and the lacking septum pellucidum created a large connection between the first and second ventricle (Fig 1) [26]. MRI reports for each series were obtained by board certified radiologists at the JLU. These dog brain series were assessed for suitability of inclusion in this study using the following criteria. None of the patients was allowed to show evidence of space occupying lesions or other morphological alterations of the brain parenchyma. Transverse scans had to include the whole brain from the cribriform plate rostrally to the first cervical spinal cord segment caudally. Series with inadequate image contrast and spatial resolution or incomplete transverse series were excluded from the study. The finding of “ventriculomegaly” or “enlarged ventricles” had to be judged as an incidental finding. “The breed, gender, age, and body weight of the dog at the time of scanning were recorded, and dogs that were between 1 and 6 years of age and up to 17 kg in bodyweight were included.” Subjects were divided into the following groups: Group one included dogs whose brain and lateral ventricles were assessed as normal by the diagnosis of “within normal limits”. Group two included dogs in which a dilatation of the lateral ventricles was noted on interpretation of the images and ventriculomegaly or enlarged ventricles were recorded as an incidental finding.


Comparison of the Relationship between Cerebral White Matter and Grey Matter in Normal Dogs and Dogs with Lateral Ventricular Enlargement.

Schmidt MJ, Laubner S, Kolecka M, Failing K, Moritz A, Kramer M, Ondreka N - PLoS ONE (2015)

Comparison of a canine brain with normal lateral cerebral ventricles (A) and enlarged ventricles (B).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4418575&req=5

pone.0124174.g001: Comparison of a canine brain with normal lateral cerebral ventricles (A) and enlarged ventricles (B).
Mentions: The archive of MRI scans of the Justus Liebig University (JLU), Giessen, Germany, was searched retrospectively for MR-imaging reports including the diagnoses “primary or idiopathic epilepsy”, “within normal limits” and “ventriculomegaly” or “enlarged ventricles”. The presence of ventriculomegaly was based on the following criteria: The majority of dogs have very narrow and slit-like horns of the lateral ventricles. In the finding of large ventricles/ventriculomegaly, the interpreter subjectively noted a greater proportion of the intracranial volume occupied by the lateral ventricles. The closely spaced walls of the temporal horns and/or the olfactory recesses were separated by CSF in these brains and the lacking septum pellucidum created a large connection between the first and second ventricle (Fig 1) [26]. MRI reports for each series were obtained by board certified radiologists at the JLU. These dog brain series were assessed for suitability of inclusion in this study using the following criteria. None of the patients was allowed to show evidence of space occupying lesions or other morphological alterations of the brain parenchyma. Transverse scans had to include the whole brain from the cribriform plate rostrally to the first cervical spinal cord segment caudally. Series with inadequate image contrast and spatial resolution or incomplete transverse series were excluded from the study. The finding of “ventriculomegaly” or “enlarged ventricles” had to be judged as an incidental finding. “The breed, gender, age, and body weight of the dog at the time of scanning were recorded, and dogs that were between 1 and 6 years of age and up to 17 kg in bodyweight were included.” Subjects were divided into the following groups: Group one included dogs whose brain and lateral ventricles were assessed as normal by the diagnosis of “within normal limits”. Group two included dogs in which a dilatation of the lateral ventricles was noted on interpretation of the images and ventriculomegaly or enlarged ventricles were recorded as an incidental finding.

Bottom Line: There is a distinct relationship between white matter and grey matter in the cerebrum of all eutherian mammals.Whereas no significant different adjusted means of the grey matter could be determined, the group of brachycephalic dogs had significantly larger adjusted means of lateral cerebral ventricles and significantly less adjusted means of relative white matter volume.Based on the changes in the relative proportion of WM and CSF volume, and the unchanged GM proportions in dogs with ventriculomegaly, we rather suggest that distension of the lateral ventricles might be the underlying cause of pressure related periventricular loss of white matter tissue, as occurs in internal hydrocephalus.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany.

ABSTRACT
Large cerebral ventricles are a frequent finding in brains of dogs with brachycephalic skull conformation, in comparison with mesaticephalic dogs. It remains unclear whether oversized ventricles represent a normal variant or a pathological condition in brachycephalic dogs. There is a distinct relationship between white matter and grey matter in the cerebrum of all eutherian mammals. The aim of this study was to determine if this physiological proportion between white matter and grey matter of the forebrain still exists in brachycephalic dogs with oversized ventricles. The relative cerebral grey matter, white matter and cerebrospinal fluid volume in dogs were determined based on magnetic-resonance-imaging datasets using graphical software. In an analysis of covariance (ANCOVA) using body mass as the covariate, the adjusted means of the brain tissue volumes of two groups of dogs were compared. Group 1 included 37 mesaticephalic dogs of different sizes with no apparent changes in brain morphology, and subjectively normal ventricle size. Group 2 included 35 brachycephalic dogs in which subjectively enlarged cerebral ventricles were noted as an incidental finding in their magnetic-resonance-imaging examination. Whereas no significant different adjusted means of the grey matter could be determined, the group of brachycephalic dogs had significantly larger adjusted means of lateral cerebral ventricles and significantly less adjusted means of relative white matter volume. This indicates that brachycephalic dogs with subjective ventriculomegaly have less white matter, as expected based on their body weight and cerebral volume. Our study suggests that ventriculomegaly in brachycephalic dogs is not a normal variant of ventricular volume. Based on the changes in the relative proportion of WM and CSF volume, and the unchanged GM proportions in dogs with ventriculomegaly, we rather suggest that distension of the lateral ventricles might be the underlying cause of pressure related periventricular loss of white matter tissue, as occurs in internal hydrocephalus.

No MeSH data available.


Related in: MedlinePlus