Good outcome in adult-onset Rasmussen's encephalitis syndrome: is recovery possible?

Globally altered microstructural properties and network topology in Rasmussen's encephalitis

Rasmussen's encephalitis is an immune-mediated brain disorder characterised by progressive unilateral cerebral atrophy, neuroinflammation, drug-resistant seizures and cognitive decline. However, volumetric changes and epileptiform EEG activity were also observed in the contralateral hemisphere, raising questions about the aetiology of contralateral involvement. In this study, we aim to investigate alterations of white matter integrity, structural network topology and network efficiency in Rasmussen's encephalitis using diffusion-tensor imaging. Fourteen individuals with Rasmussen's encephalitis (11 female, median onset 6 years, range 4-22, median disease duration at MRI 5 years, range 0-42) and 20 healthy control subjects were included. All subjects underwent T1-weighted structural and diffusion-tensor imaging. Diffusion-tensor images were analysed using the fixel-based analysis framework included in the MRtrix3 toolbox. Fibre density and cross-section served as a quantitative measure for microstructural white matter integrity. T1-weighted structural images were processed using FreeSurfer, subcortical segmentations and cortical parcellations using the Desikan-Killiany atlas served as nodes in a structural network model, edge weights were determined based on streamline count between pairs of nodes and compared using network-based statistics. Global efficiency was used to quantify network integration on an intrahemispheric level. All metrics were compared cross-sectionally between individuals with Rasmussen's encephalitis and healthy control subjects using sex and age as regressors and within the Rasmussen's encephalitis group using linear regression including age at onset and disease duration as independent variables. Relative to healthy control subjects, individuals with Rasmussen's encephalitis showed significantly (family-wise-error-corrected P < 0.05) lower fibre density and cross-section as well as edge weights in intrahemispheric connections within the ipsilesional hemisphere and in interhemispheric connections. Lower edge weights were noted in the contralesional hemisphere and in interhemispheric connections, with the latter being mainly affected within the first 2 years after disease onset. With longer disease duration, fibre density and cross-section significantly (uncorrected P < 0.01) decreased in both hemispheres. In the contralesional corticospinal tract, fibre density and cross-section significantly (uncorrected P < 0.01) increased with disease duration. Intrahemispheric edge weights (uncorrected P < 0.01) and global efficiency significantly increased with disease duration in both hemispheres (ipsilesional r = 0.74, P = 0.001; contralesional r = 0.67, P = 0.012). Early disease onset was significantly (uncorrected P < 0.01) negatively correlated with lower fibre density and cross-section bilaterally. Our results show that the disease process of Rasmussen's encephalitis is not limited to the cortex of the lesioned hemisphere but should be regarded as a network disease affecting white matter across the entire brain and causing degenerative as well as compensatory changes on a network level.

Unilateral pallidal stimulation for disabling dystonia due to Rasmussen's disease

OBJECTIVE

To describe an adult patient with Rasmussen's disease with focal dystonia as the most disabling symptom and the good response to unilateral globus pallidus internus (GPi) deep brain stimulation (DBS).

METHODS

Retrospective review of clinical records and diagnostic tests.

RESULTS

The patient had displayedmild focal seizures with sensory and motor symptoms on the left arm and hemiface since the age of 22. Ten years later she experienced abrupt onset of focal left dystonia involving mainly the leg. Brain MRI showed progressive right hemisphere atrophy, and  ¹⁸ fluorodeoxyglucose-positron emission tomography (¹⁸FDG-PET) showed right hypometabolism mainly over the frontal and insular regions. Brain biopsy confirmed chronic encephalitis. The dystonia became very severe and made walking extremely difficult. Different treatments including dopaminergic, anticholinergic, immunomodulatory drugs and botulinum toxin were ineffective. Finally the patient was treated with unilateral GPi DBS. Shortly after the onset of the stimulation, the dystonia started to improve. Parameters have been adjusted, and 18 months after surgery the patient is able to walk and run unaided, although a mild left leg dystonia persists.

CONCLUSION

Rasmussen's disease may be difficult to diagnose in adult patients. Associated movement disorders may be more disabling than seizures. Focal dystonia may be treated successfully with DBS.

Ganciclovir and foscarnet dual-therapy for cytomegalovirus encephalitis: A case report and review of the literature

Cytomegalovirus (CMV) is a ubiquitous herpesvirus which establishes lifelong latency following primary infection. It is then capable of reactivating in the face of immunosuppression. Encephalitis is a less common, but particularly devastating syndrome associated with CMV. Here, we describe a case of CMV encephalitis in an allogeneic hematopoietic stem cell transplant recipient who received dual antiviral therapy with ganciclovir and foscarnet. The case presentation is followed by a summary of cases reported in the last ten years, with the goal of describing vulnerable patient populations, treatment courses, and outcomes. Finally, the discussion includes a review of the literature, with a focus on diagnostic criteria and the role for dual antiviral therapy in CMV encephalitis.

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.