FreeSurfer is useful for early detection of Rasmussen's encephalitis prior to obvious atrophy

Cortical Alterations Are Associated with Depression in Subcortical Vascular Mild Cognitive Impairment Revealed by Surface-Based Morphometry

BACKGROUND

Late-life depression often coexists with vascular cognitive impairment and affects the quality of life for elders. However, little is known about cortical morphometric interactions between subcortical vascular mild cognitive impairment (svMCI) and concomitant mild depressive symptoms at the early stage.

OBJECTIVE

We aimed to investigate cortical alterations of svMCI with and without depressive symptoms and determine whether these parameters are associated with depression symptoms and/or cognitive impairments.

METHODS

Surface based morphometry was performed on 18 svMCI patients with depressive symptoms (svMCI + D), 16 svMCI patients without depressive symptoms (svMCI-D), and 23 normal controls (NC).

RESULTS

Compared to NC, both svMCI + D and svMCI-D patients exhibited significantly decreased surface area (SA) in many cortical areas. Interestingly, svMCI + D patients showed significantly increased rather than decreased SA in right lateral occipital gyrus (LOG.R), and a consistent trend of increased SA in these areas compared to svMCI-D. In addition, the svMCI + D showed increased gray matter volume of left pericalcarine (periCAL.L) than svMCI-D, whereas svMCI-D showed decreased gray matter volume of periCAL.L than NC. Further correlation analyses revealed that the SA of left superior temporal gyrus (STG.L) and right lateral orbital part of frontal gyrus (lorbFG.R) were significantly correlated with Hamilton depression rating scale of svMCI + D.

CONCLUSION

In conclusion, these results extend our insight into svMCI and add weight to reevaluation of concomitant early stage depressive symptoms. Moreover, we suggest that LOG.R∖periCAL.L∖STG.L∖lorbFG.R might serve as sensitive and trait-dependent biomarkers to detect concomitant depressive symptoms in svMCI patients.

Alterations of Sub-cortical Gray Matter Volume and Their Associations With Disease Duration in Patients With Restless Legs Syndrome

Object: The purpose of this study was to uncover the pathology of restless legs syndrome (RLS) by exploring brain structural alterations and their corresponding functional abnormality.

Method: Surface-based morphometry (SBM) and voxel-based morphometry (VBM) were performed to explore the alterations in cortical and sub-cortical gray matter volume (GMV) in a cohort of 20 RLS and 18 normal controls (NC). Furthermore, resting-state functional connectivity (RSFC) was also performed to identify the functional alterations in patients with RLS.

Results: We found significant alterations of sub-cortical GMV, especially the bilateral putamen (PUT), rather than alterations of cortical GMV in patients with RLS compared to NC using both SBM and VBM. Further sub-regional analysis revealed that GMV alterations of PUT was mostly located in the left dorsal caudal PUT in patients with RLS. In addition, altered RSFC patterns of PUT were identified in patients with RLS compared to NC. Moreover, correlation analyses showed that the GMV of the left caudate and the left ventral rostral PUT were positively correlated with disease duration in patients with RLS.

Conclusions: The alterations of subcortical GMV might imply that the primarily affected areas are located in sub-cortical areas especially in the sub-region of PUT by the pathologic process of RLS, which might be used as potential biomarkers for the early diagnosis of RLS.

A Case Series of Adult-Onset Rasmussen's Encephalitis: Diagnostic and Therapeutic Challenges

Rasmussen’s encephalitis (RE) is a rare neurologic disorder characterized by progressive cerebral hemiatrophy and medically refractory epilepsy. The majority of current literature on this topic is focused on the pediatric population. In this case series, we will review three cases of adult-onset RE, as defined by fulfillment of the 2005 Bien criteria. The diagnostic challenge of characterizing this rare disease will be highlighted by the extensive serum, CSF, and pathologic sampling in all three patients. MR imaging and EEG data will be examined over time to characterize hallmark findings as well as progression. In addition, we will review the various forms of therapy attempted in these three patients, namely anti-epileptic drug therapy and immunomodulatory therapy. We will also utilize this case series to critically evaluate the broader context of atypical presentations of this disease and the value of current diagnostic criteria.

Cortical and Subcortical Structural Plasticity Associated with the Glioma Volumes in Patients with Cerebral Gliomas Revealed by Surface-Based Morphometry

Postlesional plasticity has been identified in patients with cerebral gliomas by inducing a large functional reshaping of brain networks. Although numerous non-invasive functional neuroimaging methods have extensively investigated the mechanisms of this functional redistribution in patients with cerebral gliomas, little effort has been made to investigate the structural plasticity of cortical and subcortical structures associated with the glioma volume. In this study, we aimed to investigate whether the contralateral cortical and subcortical structures are able to actively reorganize by themselves in these patients. The compensation mechanism following contralateral cortical and subcortical structural plasticity is considered. We adopted the surface-based morphometry to investigate the difference of cortical and subcortical gray matter (GM) volumes in a cohort of 14 healthy controls and 13 patients with left-hemisphere cerebral gliomas [including 1 patients with World Health Organization (WHO I), 8 WHO II, and 4 WHO III]. The glioma volume ranges from 5.1633 to 208.165 cm². Compared to healthy controls, we found significantly increased GM volume of the right cuneus and the left thalamus, as well as a trend toward enlargement in the right globus pallidus in patients with cerebral gliomas. Moreover, the GM volumes of these regions were positively correlated with the glioma volumes of the patients. These results provide evidence of cortical and subcortical enlargement, suggesting the usefulness of surface-based morphometry to investigate the structural plasticity. Moreover, the structural plasticity might be acted as the compensation mechanism to better fulfill its functions in patients with cerebral gliomas as the gliomas get larger.

Rethinking the Magnetic Resonance Imaging Findings in Early Rasmussen Encephalitis: A Case Report and Review of the Literature

OBJECTIVE

We present a child with Rasmussen encephalitis and highlight the pitfalls of diagnosis when magnetic resonance imaging (MRI) is negative for atrophy. We review the literature regarding this issue, introduce the FreeSurfer software as a potential means of noninvasive diagnosis, and discuss methods for prompt and definitive treatment.

METHODS

In addition to the patient description, we review the English language literature regarding pathologic diagnosis of Rasmussen encephalitis using the key words Rasmussen encephalitis, focal lesions, MRI, atrophy, epilepsia partialis continua and hemiparesis in PubMed. We conducted a retrospective, volumetric analysis of our patient's MRIs using FreeSurfer.

RESULTS

Unlike the majority of patients in the literature with Rasmussen encephalitis, our patient's initial MRI was normal and later showed only a small area of T2 and fluid-attenuated inversion recovery high signal despite the presence of epilepsia partialis continua and a rapidly deteriorating clinical course. She did not meet the Rasmussen encephalitis diagnostic criteria until biopsy was obtained but is now seizure-free after functional hemispherotomy performed six months after her initial seizure. FreeSurfer analysis did not show cortical atrophy.

CONCLUSION

The Bien criteria have poor sensitivity for the diagnosis of Rasmussen encephalitis when the MRI is negative for atrophy. Tissue diagnosis is essential in such instances. We suggest a high clinical index of suspicion and multidisciplinary collaboration between radiology, pathology, and neurosurgery to facilitate a greater emphasis on biopsy followed by hemispherotomy as definitive therapy for individuals with early Rasmussen encephalitis.