Relative Cerebellar Volume Research Articles

Relative Cerebellum Size Is Not Sexually Dimorphic across Primates

Background/Aims: Substantive sex differences in behavior and cognition are found in humans and other primates. However, potential sex differences in primate neuroanatomy remain largely unexplored. Here, we investigate sex differences in the relative size of the cerebellum, a region that has played a major role in primate brain evolution and that has been associated with cognitive abilities that may be subject to sexual selection in primates. Methods: We compiled individual volumetric and sex data from published data sources and used MCMC generalized linear mixed models to test for sex effects in relative cerebellar volume while controlling for phylogenetic relationships between species. Given that the cerebellum is a functionally heterogeneous structure involved in multiple complex cognitive processes that may be under selection in males or females within certain species, and that sexual selection pressures vary so greatly across primate species, we predicted there would be no sex difference in the relative size of the cerebellum across primates. Results: Our results support our prediction, suggesting there is no consistent sex difference in relative cerebellum size. Conclusion: This work suggests that the potential for sex differences in relative cerebellum size has been subject to either developmental constraint or lack of consistent selection pressures, and highlights the need for more individual-level primate neuroanatomical data to facilitate intra- and inter-specific study of brain sexual dimorphism.

Dose dependent cerebellar atrophy in glioma patients after radio(chemo)therapy

Background and purposeRadiotherapy is a standard treatment option for high-grade gliomas. Brain atrophy has previously been associated with radiotherapy. The goal of this study was to investigate dose dependent cerebellar atrophy using prospective, longitudinal MR data from adult glioma patients who received radiotherapy. Materials and methodsCerebellar volumes were measured using T1-weighted MR images from 91 glioma patients before radiotherapy (N = 91) and from longitudinal follow-ups acquired in three monthly intervals (N = 349). Relative cerebellar volumes were calculated as ratios to the corresponding baseline values. Univariate mixed effects models were used to determine factors that were significantly associated with relative cerebellar volumes. These factors were subsequently included as fixed effects in a final multivariate linear mixed effects model. ResultsIn multivariate analysis, cerebellar volume decreased significantly as a function of time (p < 0.001), time × dose (p < 0.001) and patient age (p = 0.007). Considering a 55 year patient receiving a mean cerebellar dose of 0 Gy (10 Gy), the linear mixed effects model predicts a relative cerebellar volume loss of 0.4% (2.0%) after 1 year and 0.7% (3.6%) after 2 years. Compared to patients treated with photons, the cerebellar dose was significantly lower in patients treated with proton therapy (p < 0.001, r = 0.62). ConclusionCerebellar volume decreased significantly and irreversibly after radiotherapy as function of time and mean cerebellar dose. Further work is now needed to correlate these results with cognitive function and motor performance.

Cerebral and cerebellar MRI volumes in Williams syndrome

Individuals with Williams syndrome (WS) present a set of cognitive, affective and motor symptoms that resemble those of patients with lesions to the cerebellum. Although there is some evidence for overall structural alterations in this brain region in WS, explorations on cerebellar white matter and cerebellar cortex volumes remain rather neglected. We aimed to compare absolute and relative cerebellar volumes, as well as patterns of white matter to cortex volumes in this brain region, between a group of individuals with WS and a group of healthy controls. T1-weighted magnetic resonance images were acquired in 17 individuals with WS and in 15 typically developing individuals. Our results showed that even though individuals from the clinical group had significantly smaller cerebrums (and cerebellums), cerebellar volumes relative to intracranial volumes were significantly enlarged. In addition, while gray matter was relatively spared and white matter disproportionately reduced in the cerebrum in WS, relative cerebellar cortex and white matter volumes were preserved. These findings support the hypothesis that volume alterations in the cerebellum are associated with the cognitive, affective and motor profiles in WS.

Is There Relationship between Brain Atrophy and Higher Incidence of Hip Fracture in Old Age? -A Preliminary Study-

PurposeThe studies on the correlation between incidence of fall and brain atrophy have been going on to find out the cause of fall and its prevention. The purpose of this study was to explore the relationship between incidence of hip fracture and brain volume, measured by magnetic resonance image.Materials and MethodsA total of 14 subjects with similar conditions (age, height, weight, and past history) were selected for this study. Fracture group (FG) was consisted of 5 subjects with intertrochanteric fracture. Control group (CG) had 9 subjects without intertrochanteric fracture. MRI-based brain volumetry was done in FG and CG with imaging software (V-works, CyberMed Co., Korea). Total brain (tBV), absolute cerebellar volumes (aCV) and relative cerebellar volumes (rCV) were compared between two groups. Student t-test was used to statistically analyze the results.ResultsIn FG, average tBV, aCV and rCV were 1034.676±38.80, 108.648±76.80 and 10.50±0.72 cm3, respectively. In CG, average tBV, aCV and rCV were found to be 1106.459±89.15, 114.899±98.06 and 10.39±0.53 cm3, respectively, having no statistically significant difference (p>0.05).ConclusionThere was no significant difference between the fracture and control groups. Patients with neurologic disease such as cerebellar ataxia definitely have high incidence of fall that causes fractures and have brain changes as well. However, FG without neurologic disease did not have brain volume change. We consider that high risk of fall with hip fracture might decrease brain function which is not obvious to pickup on MRI.

Increase in Cerebellar Volume in Cavalier King Charles Spaniels with Chiari-like Malformation and Its Role in the Development of Syringomyelia

Previous research in Cavalier King Charles Spaniels (CKCS) has found that Chiari-like malformation and syringomyelia (CM/SM) are associated with a volume mismatch between the caudal cranial fossa (CCF) and the brain parenchyma contained within. The objectives of this study were to i) compare cerebellar volume in CKCS (a “high risk’ group which frequently develops CM/SM), small breed dogs (medium risk – occasionally develop CM/SM), and Labradors (low risk – CM/SM not reported); ii) evaluate a possible association between increased cerebellar volume and CM/SM in CKCS; iii) investigate the relationship between increased cerebellar volume and crowding of the cerebellum in the caudal part of the CCF (i.e. the region of the foramen magnum). Volumes of three-dimensional, magnetic resonance imaging derived models of the CCF and cerebellum were obtained from 75 CKCS, 44 small breed dogs, and 31 Labradors. As SM is thought to be a late onset disease process, two subgroups were formed for comparison: 18 CKCS younger than 2 years with SM (CM/SM group) and 13 CKCS older than 5 years without SM (CM group). Relative cerebellar volume was defined as the volume of the cerebellum divided by the total volume of brain parenchyma. Our results show that the CKCS has a relatively larger cerebellum than small breed dogs and Labradors and provide evidence that increased cerebellar volume in CKCS is associated with crowding of cerebellum in the caudal part of the CCF. In CKCS there is an association between increased cerebellar volume and SM. These findings have implications for the understanding of the pathological mechanisms of CM/SM, and support the hypothesis that it is a multifactorial disease process governed by increased cerebellar volume and failure of the CCF to reach a commensurate size.

Early rearing environment impacts cerebellar growth in juvenile salmon

The size and structure of an animal's brain is typically assumed to result from either natural or artificial selection pressures over generations. However, because a fish's brain grows continuously throughout life, it may be particularly responsive to the environmental conditions the fish experiences during development. Salmon are an ideal model system for studying these effects because natural habitats differ significantly from the hatchery environments in which these fish are frequently reared. For example, in the wild, salmon alevins (i.e. yolk-sac fry) are buried in the gravel, while hatchery environments lack this structural component. We show that the simple manipulation of adding stones to a standard rearing tank can dramatically alter the growth of specific brain structures in steelhead salmon alevins (Oncorhynchus mykiss). We found that alevins reared with stones grew brains with significantly larger cerebella than genetically similar fish reared in conventional tanks. This shift to a larger cerebellar size was, in turn, accompanied by changes in locomotory behaviors--behaviors that correlate strongly to the function of this brain region. We next show that hatchery fish reared in a more naturalistic setting in the wild had significantly larger brains than their lab-reared counterparts. However, relative cerebellar volumes were similar between wild-reared alevins and those reared in the complex treatment in the laboratory. Together our results indicate that, within the first three weeks of life, variation in rearing environment can result in brain differences that are commonly attributed to generations of selection. These results highlight the need to consider enrichment strategies when designing captive rearing facilities for both conservation and laboratory use.

Evaluation of Morphological Plasticity in the Cerebella of Basketball Players with MRI

Cerebellum is a key structure involved in motor learning and coordination. In animal models, motor skill learning increased the volume of molecular layer and the number of synapses on Purkinje cells in the cerebellar cortex. The aim of this study is to investigate whether the analogous change of cerebellar volume occurs in human population who learn specialized motor skills and practice them intensively for a long time. Magnetic resonance image (MRI)-based cerebellar volumetry was performed in basketball players and matched controls with V-works image software. Total brain volume, absolute and relative cerebellar volumes were compared between two groups. There was no significant group difference in the total brain volume, the absolute and the relative cerebellar volume. Thus we could not detect structural change in the cerebellum of this athlete group in the macroscopic level.

Cerebellar changes in partial seizures: clinical correlations of quantitative SPECT and MRI analysis.

To determine the frequency and patterns of periictal cerebellar hyperperfusion, whether it is associated with increased cerebellar atrophy, and whether cerebellar hyperperfusion and cerebellar atrophy are associated with predisposing clinical factors or with the outcome of epilepsy surgery. Periictal and interictal SPECT scans and volumetric brain magnetic resonance imaging (MRI) were quantitatively analyzed in 54 consecutive patients with medically refractory partial epilepsy. Their histories were reviewed and their postsurgical outcomes assessed. Significant periictal cerebellar hyperperfusion was found in 26 (48.1%) patients, of whom 18 had CCH, two had homolateral cerebellar hyperperfusion (HCH), and six had symmetrical bilateral hyperperfusion (BCH). No relation found between the site of the SPECT seizure localization and the presence or type of cerebellar hyperperfusion. CCH was more common when the injected seizure involved unilateral clonic motor activity (p < 0.05). A smaller MRI relative cerebellar volume (cerebellar volume/cerebral volume) was correlated with a greater seizure frequency (Rs = -0.30; p < 0.05) but not with the duration of epilepsy. There was no difference in the cerebellar volumes between the different patterns of cerebellar perfusion (p > 0.05). However, patients without a focal structural MRI lesion had significantly smaller cerebellar volumes (p < 0.05). In patients who underwent epilepsy surgery (n = 31), there was a trend for those without excellent outcomes to have smaller relative cerebellar volumes than did those with excellent outcome (10.6 vs. 11.8%; p = 0.08). Periictal changes in cerebellar perfusion, particularly CCH, are common in patients with intractable partial epilepsy. However, periictal hyperperfusion does not appear to be a major contributor to the development of cerebellar atrophy.