Cerebellum最新文献

Silica nanoparticles (SiNPs) have been touted for their role in the management of non-communicable diseases. Their neuroprotective benefits against heavy metal-induced neurotoxicity remain largely unexplored. This is a comparative evaluation of the oxido-inflammatory and neurotrophic effects of Ni, Al, and Ni/Al mixture on the cerebellum of male albino rats with or without treatment with SiNPs generated from melon seed husk. The study complied with the ARRIVE guidelines for reporting in vivo experiments. A total of 91, 7-9 week-old weight-matched male Sprague rats (to avoid sex bias) were randomly divided into 13 different dosing groups where Group 1 served as the control. Other groups received 0.2 mg/kg Ni, 1 mg/kg Al, and 0.2 mg/kg Ni + 1 mg/kg Al mixture with or without different doses of SiNP for 90 days. Rotarod performance was carried out. Oxidative stress markers, Ni, Al, Ca, Fe, Mg, neurotrophic factors, amyloid beta (Aβ-42), cyclooxygenase-2 (COX-2), and acetylcholinesterase (AChE) were determined in the cerebellum. SiNPs from melon seed husk caused a significant decrease in Aβ-42 level and activities of AChE and COX-2 and a significant increase in brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) mediated by Ni, Al, and Ni/Al mixture exposure in rats. Neurotoxicity of the Ni/Al mixture is via heightened neuronal lipoperoxidative damage, decreased Mg, and increased Fe, and co-administration of SiNPs from melon seed husk with the Ni/Al mixture attenuated some of these biochemical changes in the cerebellum.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) and disease spectrum is an autosomal recessive disorder associated with biallelic repeat expansion (RE) in the RFC1 gene. A high carrier frequency in the healthy population determines the possibility of having affected members in two consecutive generations. We describe pseudodominance in two families affected with RFC1 disorder (10 affected, 5 oligo/asymptomatic individuals). In Family A, after the 75-year-old index case was diagnosed with CANVAS, the 73-year-old wife decided to undergo screening for carrier testing. Although she did not report any symptoms, she resulted positive for the biallelic AAGGG RE thus leading to a diagnosis in the asymptomatic offspring as well and revealing a pseudodominant pattern of inheritance. In Family B pseudodominance was suspected after the identification of the RFC1 RE in the proband affected by sensitive neuropathy because of a positive family history for undetermined polyneuropathy in the mother. The post-mortem identification of the RFC1 RE in a sample specimen from the deceased mother, who had been under our care, allowed the solution of a "cold case". Our report suggests that pseudodominance is a confounding phenomenon to consider in RFC1-spectrum disorder and genetic counselling is instrumental in families with affected individuals.

Background: In patients presenting with acute prolonged vertigo and/or gait imbalance, the HINTS [Head-Impulse, Nystagmus, Test-of-Skew] are very valuable. However, their application may be limited by lack of training and absence of vertigo/nystagmus. Alternatively, a graded gait/truncal-instability (GTI, grade 0-3) rating may be applied.

Methods: We performed a systematic search (MEDLINE/Embase) to identify studies reporting on the diagnostic accuracy of bedside examinations in adults with acute vestibular syndrome. Diagnostic test properties were calculated for findings using a random-effects model. Results were stratified by GTI-rating used.

Results: We identified 6515 articles and included 18 studies (n = 1025 patients). Ischemic strokes (n = 665) and acute unilateral vestibulopathy (n = 306) were most frequent. Grade 2/3 GTI had moderate sensitivity (70.8% [95% confidence-interval (CI) = 59.3-82.3%]) and specificity (82.7 [71.6-93.8%]) for predicting a central cause, whereas grade 3 GTI had a lower sensitivity (44.0% [34.3-53.7%] and higher specificity (99.1% [98.0-100.0%]). In comparison, diagnostic accuracy of HINTS (sensitivity = 96.8% [94.8-98.8%]; specificity = 97.6% [95.3-99.9%]) was higher. When combining central nystagmus-patterns and grade 2/3 GTI, sensitivity was increased to 76.4% [71.3-81.6%] and specificity to 90.3% [84.3-96.3%], however, no random effects model could be used. Sensitivity was higher in studies using the GTI rating (grade 2/3) by Lee (2006) compared to the approach by Moon (2009) (73.8% [69.0-78.0%] vs. 57.4% [49.5-64.9%], p = 0.001).

Conclusions: In comparison to HINTS, the diagnostic accuracy of GTI is inferior. When combined with central nystagmus-patterns, diagnostic accuracy could be improved based on preliminary findings. GTI can be readily applied in the ED-setting and also in patients with acute imbalance syndrome.

Biallelic WARS2 pathogenic variants responsible for partial defect in aminoacylation, have recently been reported in subjects presenting with late-onset phenotypes combining dopa-responsive early-onset dystonia parkinsonism with altered DaTSCAN and progressive myoclonus ataxia. Here, we present the case of a 39-year-old male with childhood-onset progressive dopa-responsive dystonia parkinsonism, prominent psychiatric features and ataxia whose genome sequencing identified a p.(Arg36Ter) nonsense variant and a hypomorphic p.(Trp13Gly) missense variant, allowing the diagnosis of WARS2-related disease. The p.(Trp13Gly) missense variant has previously been reported in individuals with less severe phenotypes than those carrying biallelic WARS2 loss-of-function variants. Among these individuals, two subjects had similar genetic backgrounds and almost identical clinical history to our patient. Our report brings additional proof that the p.(Trp13Gly) variant acts as a hypomorphic allele, offering insight on a genotype-phenotype correlation in WARS2-related disorders.

Spinocerebellar ataxias (SCA) are most frequently due to (CAG)_n (coding for polyglutamine, polyQ) expansions and, less so, to expansion of other oligonucleotide repeats (non-polyQ) or other type of variants (non-repeat expansion SCA). In this study we compared polyQ and non-repeat expansion SCA, in a cohort of patients with hereditary ataxia followed at a tertiary hospital. From a prospective study, 88 patients (51 families) with SCA were selected, 74 (40 families) of whom genetically diagnosed. Thirty-eight patients (51.4%, 19 families) were confirmed as having a polyQ (no other repeat-expansions were identified) and 36 (48.6%, 21 families) a non-repeat expansion SCA. Median age-at-onset was 39.5 [30.0-45.5] for polyQ and 7.0 years [1.00-21.50] for non-repeat expansion SCA. PolyQ SCA were associated with cerebellar onset, and non-repeat expansion forms with non-cerebellar onset. Time to diagnosis was longer for non-repeat expansion SCA. The most common polyQ SCA were Machado-Joseph disease (MJD/SCA3) (73.7%) and SCA2 (15.8%); whereas in non-repeat expansion SCA ATX-CACNA1A (14.3%), ATP1A3-related ataxia, ATX-ITPR1, ATX/HSP-KCNA2, and ATX-PRKCG (9.5% each) predominated. Disease duration (up to inclusion) was significantly higher in non-repeat expansion SCA, but the difference in SARA score was not statistically significant. Cerebellar peduncles and pons atrophy were more common in polyQ ataxias, as was axonal neuropathy. SCA had a wide range of genetic etiology, age-at-onset and presentation. Proportion of polyQ and non-repeat expansion SCA was similar; the latter had a higher genetic heterogeneity. While polyQ ataxias were typically linked to cerebellar onset in adulthood, non-repeat expansion forms associated with early onset and non-cerebellar presentations.

Introduction: The COVID-19 pandemic has brought attention to neurological complications, including cerebellitis, characterized by inflammation of the cerebellum. Despite its rare occurrence, cerebellitis has been associated with COVID-19 infection, albeit the pathogenic mechanisms remain unclear.

Case report: We present the case of a 22-year-old male with acute onset ataxia and dysarthria during a SARS-CoV-2 infection. Diagnostic evaluations ruled out other causes, confirming cerebellitis. Treatment included steroid therapy, vitamin supplementation, physiotherapy, and intravenous immunoglobulins. Rehabilitation focused on enhancing balance, coordination, and daily activities. The patient showed significant improvement in functional abilities, with increased autonomy in daily activities and improved ambulation. Despite persistent mild symptoms, the multidisciplinary rehabilitation approach led to remarkable progress.

Conclusions: This case underscores the importance of recognizing and managing neurological complications, such as cerebellitis, in COVID-19 patients. A comprehensive approach combining medical treatment and rehabilitation is essential for optimizing outcomes. Further research is needed to elucidate the pathogenesis and optimal management strategies for such complications.

Working memory refers to the process of temporarily storing and manipulating information. The role of the cerebellum in working memory is thought to be achieved through its connections with the prefrontal cortex. Previous studies showed that theta burst stimulation (TBS), a form of repetitive transcranial magnetic stimulation, of the cerebellum changes its functional connectivity with the prefrontal cortex. Specifically, excitatory intermittent TBS (iTBS) increases, whereas inhibitory continuous TBS (cTBS) decreases this functional connectivity. We hypothesized that iTBS on the cerebellum will improve working memory, whereas cTBS will disrupt it. Sixteen healthy participants (10 women) participated in this study. Bilateral cerebellar stimulation was applied with a figure-of-eight coil at 3 cm lateral and 1 cm below the inion. The participants received iTBS, cTBS, and sham iTBS in three separate sessions in random order. Within 30 min after TBS, the participants performed four working memory tasks: letter 1-Back and 2-Back, digit span forward, and digit span backward. Repeated measures analysis of variance revealed a significant effect of the type of stimulation (iTBS/cTBS/Sham) on performance in the digit span backward task (p = 0.02). The planned comparison showed that the cTBS condition had significantly lower scores than the sham condition (p = 0.01). iTBS and cTBS did not affect performance in the 1- and 2-Back and the digit span forward tasks compared to sham stimulation. The findings support the hypothesis that the cerebellum is involved in working memory, and this contribution may be disrupted by cTBS.

Spinocerebellar ataxias (SCAs) are a diverse group of hereditary neurodegenerative disorders characterized by progressive degeneration of the cerebellum and other parts of the nervous system. In this study, we examined the genotype‒phenotype correlations in SCAs within the Brazilian population by leveraging a comprehensive dataset of 763 individuals from SARAH Network of Rehabilitation Hospitals. Using a retrospective, cross-sectional, observational, multicentric approach, we analysed medical records and conducted standardized molecular testing to explore epidemiological characteristics, clinical manifestations, and genetic profiles of SCAs in Brazil. Our findings revealed the predominance of SCA3, followed by SCA7 and SCA2, which aligns with global trends and reflects the specific genetic landscape of Brazil. A significant inverse relationship between the age of symptom onset and CAG repeat length in the mutated allele was observed across SCAs 2, 3, and 7. This study also highlights a trend towards paternal inheritance in SCA2 and details the distribution of CAG repeat expansions, which correlates larger expansions with earlier onset and specific symptomatology. This extensive analysis underscores the critical importance of genetic testing in the diagnosis and management of SCAs and enlightens the intricate genotype‒phenotype interplay within a genetically diverse population. Despite certain limitations, such as potential selection bias and the retrospective nature of the study, our research provides invaluable insights into the prevalence, genetic underpinnings, and clinical variability of SCAs in Brazil. We suggest a broader demographic scope and investigations into nonmotor symptoms in future studies to obtain a more comprehensive understanding of SCAs.

Ataxia telangiectasia (AT), Louis-Bar syndrome, is a rare neurodegenerative disorder caused by autosomal recessive biallelic mutations within the ataxia telangiectasia mutated (ATM) gene. Currently, there are no curative therapies available for this disorder. This review provides an overview of the latest advances in treatment methods including 1- Acetyl-DL-leucine, 2- Bone Marrow Transplantation, 3- Gene Therapy, 4- Dexamethasone, and finally 5- Red Blood Cells (RBCs) as a carrier for dexamethasone (encapsulation of dexamethasone sodium phosphate into autologous erythrocytes, known as EryDex). Most of the treatments under investigation are in the early stages, except for the EryDex System. It appears that the EryDex system and N-Acetyl-DL-Leucine may hold promise as potential treatment options.

Cerebellar transcranial direct current stimulation (ctDCS) has emerged as a promising, non-invasive, and safe neuromodulatory intervention capable of reducing ataxia symptoms and restoring cerebellum-motor connectivity. However, previous studies have only applied ctDCS in isolation, without association with specific training. This study aimed to assess the effect of ctDCS combined with gait training on functional mobility, balance, and symptoms and severity of ataxia. A randomized, triple-blind, sham-controlled, bi-center clinical trial was conducted with forty-four adults with cerebellar ataxia. Volunteers were randomized to receive five daily sessions of either real ctDCS (n = 11; 2 mA for 25 min) or sham ctDCS (n = 11) during gait training. Functional mobility, balance, and symptoms and severity of ataxia were assessed using the Time Up and Go test, the MiniBESTest, and the Scale for the Assessment and Rating of Ataxia (SARA), respectively, before and after the interventions. Both groups showed improvement in functional mobility, but there was no significant difference between the ctDCS and sham groups. However, the ctDCS group demonstrated significant improvements in cerebellar ataxia severity as reflected by SARA scores, particularly in tests of stance, sitting, speech disturbance, nose-finger test, and heel-shin slide test. Notably, no improvements were observed in balance. This study indicates that while ctDCS combined with gait training may improve specific symptoms of cerebellar ataxia, it does not significantly enhance overall functional mobility compared to sham treatment.