Cerebellar syndrome as the presenting feature of Hashimoto encephalopathy.

Hashimoto encephalopathy presents with a myriad of neuropsychiatric features in the background of elevated antithyroid antibodies and it may or may not be associated with Hashimoto thyroiditis. It is a diagnosis of exclusion. Here, we present the case of a hypothyroid woman in her 30s, with a 5-year history of chronic progressive gait ataxia along with hand and head tremor, inattention and electroencephalogram (EEG) suggestive of interictal epileptiform discharges without any clinical seizures. The patient had very high titres of anti-thyroid peroxidase antibodies >2000 IU/mL and was on very high-dose levothyroxine replacement therapy. She responded to intravenous pulse corticosteroids. Improvement was noted both clinically and on subsequent EEGs. Pure cerebellar syndrome without frank encephalopathy can also be a rare presentation of Hashimoto encephalopathy. This highlights the importance of antithyroid antibodies testing even in cases of pure cerebellar syndrome to rule out Hashimoto encephalopathy associated ataxia.

I saw the "shrimp sign": Cerebellar progressive multifocal leukoencephalopathy.

The shrimp sign is characterized by a well-defined lesion in the deep cerebellar white matter, with hyperintense signal on T2- and hypointense signal on T1-weighted imaging, abutting and outlining the dentate nucleus, unilaterally or bilaterally. This sign has high sensitivity and specificity for cerebellar progressive multifocal leukoencephalopathy (PML) within the correct clinical scenario. In this article, we present a case of cerebellar PML in a woman living with human immunodeficiency virus, who was not using antiretroviral therapy, and presented the shrimp sign on brain MRI.

Bimanual coordinated motor skill learning in patients with a chronic cerebellar stroke.

Cerebellar strokes induce coordination disorders that can affect activities of daily living. Evidence-based neurorehabilitation programs are founded on motor learning principles. The cerebellum is a key neural structure in motor learning. It is unknown whether and how well chronic cerebellar stroke individuals (CCSIs) can learn to coordinate their upper limbs through bimanual motor skill learning. The aim was to determine whether CCSIs could achieve bimanual skill learning through a serious game with the REAplan® robot and to compare CCSIs with healthy individuals (HIs). Over three consecutive days, sixteen CCSIs and eighteen HIs were trained on an asymmetric bimanual coordination task ("CIRCUIT" game) with the REAplan® robot, allowing quantification of speed, accuracy and coordination. The primary outcomes were the bimanual speed/accuracy trade-off (BiSAT) and bimanual coordination factor (BiCo). They were also evaluated on a bimanual REACHING task on Days 1 and 3. Correlation analyses between the robotic outcomes and clinical scale scores were computed. Throughout the sessions, BiSAT and BiCo improved during the CIRCUIT task in both HIs and CCSIs. On Day 3, HIs and CCSIs showed generalization of BiSAT, BiCo and transferred to the REACHING task. There was no significant between-group difference in progression. Four CCSIs and two HIs were categorized as "poor learners" according to BiSAT and/or BiCo. Increasing age correlated with reduced BiSAT but not BiCo progression. Over three days of training, HIs and CCSIs improved, retained, generalized and transferred a coordinated bimanual skill. There was no between-group difference, suggesting plastic compensation in CCSIs. Clinical trial NCT04642599 approved the 24th of November 2020.

Unraveling the molecular landscape of Ataxia Telangiectasia: Insights into Neuroinflammation, immune dysfunction, and potential therapeutic target.

BACKGROUND: Ataxia Telangiectasia (AT) is a genetic disorder characterized by compromised DNA repair, cerebellar degeneration, and immune dysfunction. Understanding the molecular mechanisms driving AT pathology is crucial for developing targeted therapies. METHODS: In this study, we conducted a comprehensive analysis to elucidate the molecular mechanisms underlying AT pathology. Using publicly available RNA-seq datasets comparing control and AT samples, we employed in silico transcriptomics to identify potential genes and pathways. We performed differential gene expression analysis with DESeq2 to reveal dysregulated genes associated with AT. Additionally, we constructed a Protein-Protein Interaction (PPI) network to explore the interactions between proteins implicated in AT. RESULTS: The network analysis identified hub genes, including TYROBP and PCP2, crucial in immune regulation and cerebellar function, respectively. Furthermore, pathway enrichment analysis unveiled dysregulated pathways linked to AT pathology, providing insights into disease progression. CONCLUSION: Our integrated approach offers a holistic understanding of the complex molecular landscape of AT and identifies potential targets for therapeutic intervention. By combining transcriptomic analysis with network-based methods, we provide valuable insights into the underlying mechanisms of AT pathogenesis.

Prevalence, recovery and phenotype of dysphagia in patients with ischaemic cerebellar stroke.

BACKGROUND AND PURPOSE: Swallowing is a complex task, moderated by a sophisticated bilateral network including multiple supratentorial regions, the brainstem and the cerebellum. To date, conflicting data exist about whether focal lesions to the cerebellum are associated with dysphagia. Therefore, the aim of the study was to evaluate dysphagia prevalence, recovery and dysphagia pattern in patients with ischaemic cerebellar stroke. METHODS: A retrospective analysis of patients consecutively admitted to an academic stroke centre with ischaemic stroke found only in the cerebellum was performed. The presence of dysphagia was the primary end-point and was assessed by a speech-language pathologist, according to defined criteria. Dysphagia pattern was evaluated by analysing the videos of the flexible endoscopic evaluation of swallowing. Brain imaging was used to identify lesion size and location associated with dysphagia. RESULTS: Between January 2016 and December 2021, 102 patients (35.3% female) with a mean age of 52.8 ± 17.3 years were included. Thirteen (12.7%) patients presented with dysphagia. The most frequently observed flexible endoscopic evaluation of swallowing phenotype was premature spillage (n = 7; 58.3%), whilst significant residues or aspiration did not occur. One patient died (7.7%); the other patients showed improvement of dysphagia and one patient (7.7%) was discharged with dietary restrictions. CONCLUSIONS: Although the involvement of the cerebellum in deglutition has become increasingly evident, isolated lesions to the cerebellum are less likely to cause clinically relevant and persisting dysphagia compared to other brain regions. The observed dysphagia pattern shows a lack of coordination and control, resulting in premature spillage or fragmented bolus transfer in some patients.

Vestibular Testing and Impairments in Postoperative Pediatric Cerebellar Mutism Syndrome: A Case Series.

BACKGROUND: Postoperative pediatric cerebellar mutism syndrome (CMS) may occur following a process affecting the posterior cranial fossa. Recent evidence demonstrates disabling and potentially lasting motor components of this syndrome, including ataxia, hemiparesis, and oculomotor dysfunction. These impairments may contribute to vestibular deficits. METHODS: This case series contributes data to quantify vestibular dysfunction in postoperative CMS. The pair consisted of one female and one male. RESULTS: Vestibular testing demonstrated both peripheral and central dysfunction. CONCLUSIONS: Given these findings, a thorough vestibular assessment may be indicated as part of a comprehensive evaluation following a postoperative CMS diagnosis. Further research is needed to understand the pathophysiology, treatment, and long-term outcomes of postoperative pediatric CMS.

Paraneoplastic cerebellar and brainstem disorders.

Paraneoplastic cerebellar and brainstem disorders are a heterogeneous group that requires prompt recognition and treatment to help prevent irreversible neurologic injury. Paraneoplastic cerebellar degeneration is best characterized by Yo antibodies in patients with breast or ovarian cancer. Tr (DNER) antibodies in patients with Hodgkin lymphoma can also present with a pure cerebellar syndrome and is one of the few paraneoplastic syndromes found with hematological malignancy. Opsoclonus-myoclonus-ataxia syndrome presents in both pediatric and adult patients with characteristic clinical findings. Other paraneoplastic brainstem syndromes are associated with Ma2 and Hu antibodies, which can cause widespread neurologic dysfunction. The differential for these disorders is broad and also includes pharmacological side effects, infection or postinfectious processes, and neurodegenerative diseases. Although these immune-mediated disorders have been known for many years, mechanisms of pathogenesis are still unclear, and optimal treatment has not been established.

Reduced cerebral blood flow and cognitive dysfunction following isolated cerebellar infarction: two case reports.

Cognitive impairment in focal cerebellar disorders has been widely recognized and is described as cerebellar cognitive affective syndrome (CCAS). However, the relationship between CCAS and crossed cerebello-cerebral diaschisis (CCD) has rarely been discussed. The present report describes the uncommon phenomenon of CCD in two cases with isolated cerebellar infarction, and discuss its contribution to cognitive impairment. Cognitive performance was examined using the CCAS scale and a battery of neuropsychological assessments. Moreover, the relative distribution of cerebral and cerebellar blood flow was measured using three-dimensional arterial spin labeling imaging. Case 1 showed deficits in general cognition and had impaired language, episodic memory, and executive function. Case 2 showed deficits in general cognition at baseline, and cognitive deterioration of visuospatial abilities, language, episodic memory, and executive function was observed at the 3-month follow-up. Both cases met the diagnosis criteria of CCAS. Reduced cerebral blood flow was observed in the cerebral hemisphere contralateral to the cerebellar infarction at baseline in Case 1, and at the 3-month follow-up in Case 2. The present report describes cognitive decline after isolated cerebellar infarction in combination with contralateral cerebral hypoperfusion, as measured using quantitative arterial spin labeling. One possible mechanism involves the functional depression of cerebello-cerebral pathways.

Evaluation of safety of fluoxetine for cerebellar mutism syndrome in children after posterior fossa surgery.

BACKGROUND: Cerebellar mutism syndrome (CMS) occurs in 8-29 % of children undergoing posterior fossa tumor surgery. Its main symptoms are mutism and emotional lability. Although it is always transient, recovery time can be lengthy with long-term cognitive sequelae. There is no approved drug treatment for CMS, but some drugs are used in everyday medical practice. One of these is fluoxetine, which has been used for many years in our institution. The main objective of this study was to establish the safety profile of fluoxetine in this condition. MATERIALS AND METHODS: The records of patients admitted to the pediatric intensive care unit after brain surgery at Angers University Hospital from 2010 to 2020 were reviewed. Children aged 2 years and older who underwent a posterior fossa tumor surgery and were diagnosed with CMS were included. Data on patient characteristics, prescription of fluoxetine treatment, side effects if any, and complete mutism duration were collected. RESULTS: Among 246 patients admitted to the pediatric intensive care unit for brain surgery during the study period, 23 had CMS and eight were prescribed fluoxetine. No serious adverse event related to fluoxetine was reported. Complete mutism duration did not differ significantly between the fluoxetine group and the non-fluoxetine group(p = 0.22). However, the treatment was initiated after recovery from complete mutism in half of the treated patients. CONCLUSION: This study suggests a positive safety profile of fluoxetine used in postoperative CMS. It does not answer the question of whether the treatment is effective for this indication. A randomized controlled trial based on a syndrome severity scale should be conducted to provide a more reliable assessment of the efficacy and safety of fluoxetine.

Association Between First-time Neurologic Events and Metronidazole Treatment: A Case-time Control Study.

PURPOSE: Metronidazole, a widely used antimicrobial medication, has been linked to neurologic adverse drug reactions. This study investigates the association between metronidazole use and first-time neurologic events. METHODS: We conducted a case-time-control study using data from the Danish National Patient Register and the National Prescription Register in years 2013 to 2021. Patients with a first-time diagnosis of encephalopathy, cerebellar dysfunction, or peripheral neuropathy were included. Conditional logistic regression analyses were performed to estimate the risk of neurologic events associated with metronidazole use. FINDINGS: Out of 476,066 first-time metronidazole prescriptions, the 100-day cumulative incidence of peripheral neuropathy was 0.016%, and 0.002% for cerebellar dysfunction or encephalopathy. In the case-time control study, we identified 17,667 persons with a first-time neurologic event and were included for the analysis. The estimated odds ratio for the combined neurologic events was 0.98 (95% CI, 0.59-1.64, P = 0.95) with no statistically significant association across different subgroups and time windows. IMPLICATIONS: Our findings suggest that metronidazole-induced neurologic events may be rarer than previously described, and we did not find any consistent or statistically significant association between metronidazole exposure. Nonetheless, clinicians should remain vigilant to potential neurologic risks in patients receiving metronidazole, to ensure its safe and effective use.

Surgical evacuation of spontaneous cerebellar hemorrhage: Comparison of safety and efficacy of suboccipital craniotomy and robotic-assisted stereotactic hematoma drainage.

OBJECTIVE: This study compared the efficacies of robotic-assisted stereotactic hematoma drainage and suboccipital craniotomy (SC) in patients with spontaneous cerebellar hemorrhage (SCH). METHODS: This retrospective study included 138 non-comatose patients with SCH (Glasgow Coma Scale score [GCS] >8), divided into the SC and Robotic Stereotactic Assistance (ROSA) groups. The study recorded and analyzed complications and prognoses 90 days after ictus. RESULTS: The inclusion criteria were met by 138 patients: 61 in the SC and 77 in the ROSA group, with no significant differences in sex, age, GCS score, hematoma volume, and the time from ictus to operation. The time of operation was greater in the SC group (287.53±87.57) than in the ROSA group (60.54±20.03). The evacuation rate (ER) was greater in the SC group (93.20±1.58) than in the ROSA group (89.13±2.75). The incidence of pneumonia and stress ulcers, as well as the length or costs of medical services, were lower in the ROSA group than in the SC group. Ninety days after ictus, the modified Rankin Scale (mRS), Glasgow Prognostic Scale (GOS), and Karnofsky Performance Scale (KPS) scores significantly differed between the groups. The rate of good prognosis in the ROSA group was significantly higher compared with that in the SC group. The incidence of balance disorders was lower in the ROSA group than in the SC group; no statistically significant difference was found in the incidence of dysarthria and swallowing disorders. CONCLUSION: Robotic-assisted stereotactic hematoma drainage may be suitable for non-comatose and stable condition patients with SCH. This procedure improves prognosis 90 days after ictus, lowers the incidence of pneumonia and stress ulcers, and reduces the length and costs of medical services.

Neurorestorative effects of cerebellar transcranial direct current stimulation on social prediction of adolescents and young adults with congenital cerebellar malformations.

BACKGROUND: Converging evidence points to impairments of the predictive function exerted by the cerebellum as one of the causes of the social cognition deficits observed in patients with cerebellar disorders. OBJECTIVE: We tested the neurorestorative effects of cerebellar transcranial direct current stimulation (ctDCS) on the use of contextual expectations to interpret actions occurring in ambiguous sensory sceneries in a sample of adolescents and young adults with congenital, non-progressive cerebellar malformation (CM). METHODS: We administered an action prediction task in which, in an implicit-learning phase, the probability of co-occurrence between actions and contextual elements was manipulated to form either strongly or moderately informative expectations. Subsequently, in a testing phase, we probed the use of these contextual expectations for predicting ambiguous (i.e., temporally occluded) actions. In a sham-controlled, within-subject design, participants received anodic or sham ctDCS during the task. RESULTS: Anodic ctDCS, compared to sham, improved patients' ability to use contextual expectations to predict the unfolding of actions embedded in moderately, but not strongly, informative contexts. CONCLUSIONS: These findings corroborate the role of the cerebellum in using previously learned contextual associations to predict social events and document the efficacy of ctDCS to boost social prediction in patients with congenital cerebellar malformation. The study encourages the further exploration of ctDCS as a neurorestorative tool for the neurorehabilitation of social cognition abilities in neurological, neuropsychiatric, and neurodevelopmental disorders featured by macro- or micro-structural alterations of the cerebellum.

Pseudotumoral neuro-behcet's disease: case series and review of literature.

BACKGROUND: Behcet's disease (BD) is a multisystem autoimmune relapsing vasculitis with an almost unknown etiology involving both large and small vessels. The neurological involvement called neuro-Behcet's disease (NBD) is rare. NBD can be responsible for tumor-like masses mimicking low-grade gliomas in only a few cases. METHODS: We report here the main characteristics, treatment, and outcome of 43 patients (4 personal cases and 39 patients from the literature) with a pseudotumoral presentation of NBD (PT NBD). We compared our findings with those of the classical form of NBD. RESULTS: The median age was 35.86 (12-59 years) years, with a male predominance (67.4%). PT NBD was the inaugural of the disease in 51.2% of cases. The neurological manifestations included headache (n = 31), pyramidal syndrome (n = 28), cerebellar syndrome (n = 5), behavioral changes (n = 5), and pseudobulbar signs (n = 2). Ophthalmologic examination revealed papilledema in 3 cases. On cerebral imaging, the most affected regions of the brain were the capsulothalamic region (n = 15, 37.5%) and the brainstem (n = 14, 35). Histological analysis revealed necrotic lesions with perivascular inflammatory infiltrate without signs of tumoral or infectious lesions. Treatment consisted of corticosteroids (n = 40, 93%) and immunosuppressive agents (n = 28, 65.11%), leading to complete clinical and imaging remission in 41.5% of patients. CONCLUSION: PT NBD is a rare but life-threatening condition.

Language outcomes in children who underwent surgery for the removal of a posterior fossa tumor: A systematic review.

BACKGROUND: Children who underwent posterior fossa tumor removal may have spoken or written language impairments. The present systematic review synthesized the literature regarding the language outcomes in this population. Benefits of this work were the identification of shortcomings in the literature and a starting point toward formulating guidelines for postoperative language assessment. METHODS: A systematic literature search was conducted, identifying studies with patients who had posterior fossa surgery before 18 years of age. Included studies were narratively synthesized to understand language outcomes by language function (e.g., phonology, morphosyntax) at a group and individual level. Furthermore, the influence of several mediators (e.g., postoperative cerebellar mutism syndrome (pCMS), tumor type) was investigated. A critical evaluation of the language assessment tools was conducted. RESULTS: The narrative synthesis of 66 studies showed that a broad spectrum of language impairments has been described, characterized by a large interindividual heterogeneity. Patients younger at diagnosis, receiving treatment for a high-grade tumor and/or radiotherapy and diagnosed with pCMS seemed more prone to impairment. Several gaps in language assessment remain, such as a baseline preoperative assessment and the assessment of pragmatics and morphosyntax. Further, there were important methodological differences in existing studies which complicated our ability to accurately guide clinical practice. CONCLUSION: Children who had posterior fossa surgery seem to be at risk for postoperative language impairment. These results stress the need for language follow-up in posterior fossa tumor survivors.

Neuropeptides and Their Roles in the Cerebellum.

Although more than 30 different types of neuropeptides have been identified in various cell types and circuits of the cerebellum, their unique functions in the cerebellum remain poorly understood. Given the nature of their diffuse distribution, peptidergic systems are generally assumed to exert a modulatory effect on the cerebellum via adaptively tuning neuronal excitability, synaptic transmission, and synaptic plasticity within cerebellar circuits. Moreover, cerebellar neuropeptides have also been revealed to be involved in the neurogenetic and developmental regulation of the developing cerebellum, including survival, migration, differentiation, and maturation of the Purkinje cells and granule cells in the cerebellar cortex. On the other hand, cerebellar neuropeptides hold a critical position in the pathophysiology and pathogenesis of many cerebellar-related motor and psychiatric disorders, such as cerebellar ataxias and autism. Over the past two decades, a growing body of evidence has indicated neuropeptides as potential therapeutic targets to ameliorate these diseases effectively. Therefore, this review focuses on eight cerebellar neuropeptides that have attracted more attention in recent years and have significant potential for clinical application associated with neurodegenerative and/or neuropsychiatric disorders, including brain-derived neurotrophic factor, corticotropin-releasing factor, angiotensin II, neuropeptide Y, orexin, thyrotropin-releasing hormone, oxytocin, and secretin, which may provide novel insights and a framework for our understanding of cerebellar-related disorders and have implications for novel treatments targeting neuropeptide systems.

TBC1D23 mediates Golgi-specific LKB1 signaling.

Liver kinase B1 (LKB1), an evolutionarily conserved serine/threonine kinase, is a master regulator of the AMPK subfamily and controls cellular events such as polarity, proliferation, and energy homeostasis. Functions and mechanisms of the LKB1-AMPK axis at specific subcellular compartments, such as lysosome and mitochondria, have been established. AMPK is known to be activated at the Golgi; however, functions and regulatory mechanisms of the LKB1-AMPK axis at the Golgi apparatus remain elusive. Here, we show that TBC1D23, a Golgi-localized protein that is frequently mutated in the neurodevelopment disorder pontocerebellar hypoplasia (PCH), is specifically required for the LKB1 signaling at the Golgi. TBC1D23 directly interacts with LKB1 and recruits LKB1 to Golgi, promoting Golgi-specific activation of AMPK upon energy stress. Notably, Golgi-targeted expression of LKB1 rescues TBC1D23 deficiency in zebrafish models. Furthermore, the loss of LKB1 causes neurodevelopmental abnormalities in zebrafish, which partially recapitulates defects in TBC1D23-deficient zebrafish, and LKB1 sustains normal neuronal development via TBC1D23 interaction. Our study uncovers a regulatory mechanism of the LKB1 signaling, and reveals that a disrupted Golgi-LKB1 signaling underlies the pathogenesis of PCH.