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Cerebellar mutism syndrome is a disorder of speech, movement and affect that can occur after tumour removal from the posterior fossa. Projections from the fastigial nuclei to the periaqueductal grey area were recently implicated in its pathogenesis, but the functional consequences of damaging these projections remain poorly understood. Here, we examine functional MRI data from patients treated for medulloblastoma to identify functional changes in key brain areas that comprise the motor system for speech, which occur along the timeline of acute speech impairment in cerebellar mutism syndrome. One hundred and twenty-four participants, all with medulloblastoma, contributed to the study: 45 with cerebellar mutism syndrome, 11 patients with severe postoperative deficits other than mutism, and 68 without either (asymptomatic). We first performed a data-driven parcellation to spatially define functional nodes relevant to the cohort that align with brain regions critical for the motor control of speech. We then estimated functional connectivity between these nodes during the initial postoperative imaging sessions to identify functional deficits associated with the acute phase of the disorder. We further analysed how functional connectivity changed over time within a subset of participants that had suitable imaging acquired over the course of recovery. Signal dispersion was also measured in the periaqueductal grey area and red nuclei to estimate activity in midbrain regions considered key targets of the cerebellum with suspected involvement in cerebellar mutism pathogenesis. We found evidence of periaqueductal grey dysfunction in the acute phase of the disorder, with abnormal volatility and desynchronization with neocortical language nodes. Functional connectivity with periaqueductal grey was restored in imaging sessions that occurred after speech recovery and was further shown to be increased with left dorsolateral prefrontal cortex. The amygdalae were also broadly hyperconnected with neocortical nodes in the acute phase. Stable connectivity differences between groups were broadly present throughout the cerebrum, and one of the most substantial differences—between Broca's area and the supplementary motor area—was found to be inversely related to cerebellar outflow pathway damage in the mutism group. These results reveal systemic changes in the speech motor system of patients with mutism, centred on limbic areas tasked with the control of phonation. These findings provide further support for the hypothesis that periaqueductal grey dysfunction (following cerebellar surgical injury) contributes to the transient postoperative non-verbal episode commonly observed in cerebellar mutism syndrome but highlights a potential role of intact cerebellocortical projections in chronic features of the disorder. [ABSTRACT FROM AUTHOR]

Novel human astroviruses (HAstVs) have recently been implicated as rare causes of fatal encephalitis in immunocompromised patients, for which there is no proven treatment. We report 2 cases from our institution in which HAstV-VA1 was detected in the cerebrospinal fluid by metagenomic next-generation sequencing after the initial evaluation revealed no etiology. [ABSTRACT FROM AUTHOR]

Objective To investigate the methylphenidate (MPH) response rate among childhood survivors of acute lymphoblastic leukemia (ALL) and brain tumors (BTs) and to identify predictors of positive MPH response. Methods Cancer survivors (N = 106; BT = 51 and ALL = 55) identified as having attention deficits and learning problems participated in a 3-week, double-blind, crossover trial consisting of placebo, low-dose MPH (0.3 mg/kg), and moderate-dose MPH (0.6 mg/kg). Weekly teacher and parent reports on the Conners’ Rating Scales were gathered. Results Following moderate MPH dose, 45.28% of the sample was classified as responders. Findings revealed that more problems endorsed prior to the medication trial on parent and teacher ratings were predictive of positive medication response (p < .05). Conclusions MPH significantly reduces attention problems in a subset of childhood cancer survivors. Parent and teacher ratings may assist in identifying children most likely to respond to MPH so prescribing may be optimally targeted. [ABSTRACT FROM PUBLISHER]

Objective To investigate the acute efficacy and adverse side effects of methylphenidate (MPH) among survivors of childhood cancer [acute lymphoblastic leukemia (ALL) or brain tumor (BT)] with learning impairments. Methods Participants (N = 122) completed a two-day, in-clinic, double-blind, cross-over trial during which they received MPH (0.60 mg/kg of body weight) and placebo that were randomized in administration order across participants. Performance was evaluated using measures of attention, memory, and academic achievement. Results A significant MPH versus placebo effect was revealed on a measure of attention, cognitive flexibility, and processing speed (Stroop Word-Color Association Test). Male gender, older age at treatment, and higher intelligence were predictive of better medication response. No significant differences were found for number or severity of adverse side effects as a function of active medication. Conclusions MPH shows some neurocognitive benefit and is well tolerated by the majority of children surviving ALL and BT. [ABSTRACT FROM AUTHOR]