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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.

The term Pontocerebellar Hypoplasia (PCH) was initially used to designate a heterogeneous group of fetal-onset genetic neurodegenerative disorders. As a descriptive term, PCH refers to pons and cerebellum of reduced volume. In addition to the classic PCH types described in OMIM, many other disorders can result in a similar imaging appearance. This study aims to review imaging, clinical and genetic features and underlying etiologies of a cohort of children with PCH on imaging. We systematically reviewed brain images and clinical charts of 38 patients with radiologic evidence of PCH. Our cohort included 21 males and 17 females, with ages ranging between 8 days to 15 years. All individuals had pons and cerebellar vermis hypoplasia, and 63% had cerebellar hemisphere hypoplasia. Supratentorial anomalies were found in 71%. An underlying etiology was identified in 68% and included chromosomal (21%), monogenic (34%) and acquired (13%) causes. Only one patient had pathogenic variants in an OMIM listed PCH gene. Outcomes were poor regardless of etiology, though no one had regression. Approximately one third of patients deceased at a median age of 8 months. All individuals had global developmental delay, 50% were non-verbal, 64% were non-ambulatory and 45% required gastrostomy feeding. This cohort demonstrates that radiologic PCH has heterogenous etiologies and the "classic" OMIM-listed PCH genes underlie only a minority of cases. Broad genetic testing, including chromosomal microarray and exome or multigene panels, is recommended in individuals with PCH-like imaging appearance. Our results strongly suggest that the term PCH should be used to designate radiologic findings, and not to imply neurogenerative disorders. [ABSTRACT FROM AUTHOR]

The cerebellar cognitive affective syndrome is a neuropsychiatric syndrome composed of affective (anxiety, depression, euphoria, and emotional lability) and cognitive symptoms (executive, attentional, and visuospatial deficits) that was described in the 1990s. We present the case of a 49-year-old woman with a history of an acute neurological episode at the age of 28, after which she reported a change in personality, brief and alternating periods of depression, hypomania, and mixed episodes, and cognitive impairment that had a major impact on her personal and occupational level of functioning. She was initially diagnosed with bipolar disorder, but a clinical, neuropsychological, and imaging re-evaluation prompted a diagnostic reconsideration in favor of a cerebellar cognitive affective syndrome. This enabled therapeutical and prognostic refinement. Here, we discuss the diagnostic challenges of this syndrome and the implications that an accurate diagnosis has for patients.

A common mechanism in inherited ataxia is a vulnerability of DNA damage. Spinocerebellar ataxia type 7 (SCA7) is a CAG-polyglutamine-repeat disorder characterized by cerebellar and retinal degeneration. Polyglutamine-expanded ataxin-7 protein incorporates into STAGA co-activator complex and interferes with transcription by altering histone acetylation. We performed chromatic immunoprecipitation sequencing ChIP-seq on cerebellum from SCA7 mice and observed increased H3K9-promoter acetylation in DNA repair genes, resulting in increased expression. After detecting increased DNA damage in SCA7 cells, mouse primary cerebellar neurons, and patient stem-cell-derived neurons, we documented reduced homology-directed repair (HDR) and single-strand annealing (SSA). To evaluate repair at endogenous DNA in native chromosome context, we modified linear amplification-mediated high-throughput genome-wide translocation sequencing and found that DNA translocations are less frequent in SCA7 models, consistent with decreased HDR and SSA. Altered DNA repair function in SCA7 may predispose the subject to excessive DNA damage, leading to neuron demise and highlights DNA repair as a therapy target.

Homozygous mutation of the RNA kinase CLP1 (cleavage factor polyribonucleotide kinase subunit 1) causes pontocerebellar hypoplasia type 10 (PCH10), a pediatric neurodegenerative disease. CLP1 is associated with the transfer RNA (tRNA) splicing endonuclease complex and the cleavage and polyadenylation machinery, but its function remains unclear. We generated two mouse models of PCH10: one homozygous for the disease-associated Clp1 mutation, R140H, and one heterozygous for this mutation and a null allele. Both models exhibit loss of lower motor neurons and neurons of the deep cerebellar nuclei. To explore whether Clp1 mutation impacts tRNA splicing, we profiled the products of intron-containing tRNA genes. While mature tRNAs were expressed at normal levels in mutant mice, numerous other products of intron-containing tRNA genes were dysregulated, with pre-tRNAs, introns, and certain tRNA fragments up-regulated, and other fragments down-regulated. However, the spatiotemporal patterns of dysregulation do not correlate with pathogenicity for most altered tRNA products. To elucidate the effect of Clp1 mutation on precursor messenger RNA (pre-mRNA) cleavage, we analyzed poly(A) site (PAS) usage and gene expression in Clp1R140H/- spinal cord. PAS usage was shifted from proximal to distal sites in the mutant mouse, particularly in short and closely spaced genes. Many such genes were also expressed at lower levels in the Clp1R140H/- mouse, possibly as a result of impaired transcript maturation. These findings are consistent with the hypothesis that select genes are particularly dependent upon CLP1 for proper pre-mRNA cleavage, suggesting that impaired mRNA 3' processing may contribute to pathogenesis in PCH10.

A woman, age 44, with a positive anti-YO paraneoplastic cerebellar syndrome and normal imaging developed an ocular motor disorder including periodic alternating nystagmus (PAN), gaze-evoked nystagmus (GEN) and rebound nystagmus (RN). During fixation there was typical PAN but changes in gaze position evoked complex, time-varying oscillations of GEN and RN. To unravel the pathophysiology of this unusual pattern of nystagmus, we developed a mathematical model of normal function of the circuits mediating the vestibular-ocular reflex and gaze-holding including their adaptive mechanisms. Simulations showed that all the findings of our patient could be explained by two, small, isolated changes in cerebellar circuits: reducing the time constant of the gaze-holding integrator, producing GEN and RN, and increasing the gain of the vestibular velocity-storage positive feedback loop, producing PAN. We conclude that the gaze- and time-varying pattern of nystagmus in our patient can be accounted for by superposition of one model that produces typical PAN and another model that produces typical GEN and RN, without requiring a new oscillator in the gaze-holding system or a more complex, nonlinear interaction between the two models. This analysis suggest a strategy for uncovering gaze-evoked and rebound nystagmus in the setting of a time-varying nystagmus such as PAN. Our results are also consistent with current ideas of compartmentalization of cerebellar functions for the control of the vestibular velocity-storage mechanism (nodulus and ventral uvula) and for holding horizontal gaze steady (the flocculus and tonsil).

Autosomal-recessive cerebellar hypoplasia and ataxia constitute a group of heterogeneous brain disorders caused by disruption of several fundamental cellular processes. Here, we identified 10 families showing a neurodegenerative condition involving pontocerebellar hypoplasia with microcephaly (PCHM). Patients harbored biallelic mutations in genes encoding the spliceosome components Peptidyl-Prolyl Isomerase Like-1 (PPIL1) or Pre-RNA Processing-17 (PRP17). Mouse knockouts of either gene were lethal in early embryogenesis, whereas PPIL1 patient mutation knockin mice showed neuron-specific apoptosis. Loss of either protein affected splicing integrity, predominantly affecting short and high GC-content introns and genes involved in brain disorders. PPIL1 and PRP17 form an active isomerase-substrate interaction, but we found that isomerase activity is not critical for function. Thus, we establish disrupted splicing integrity and "major spliceosome-opathies" as a new mechanism underlying PCHM and neurodegeneration and uncover a non-enzymatic function of a spliceosomal proline isomerase.

Cerebellar atrophy is a rare and challenging disease with few descriptions in the medical literature. Motor impairment is mild, but behavioral and linguistic alterations stand out, in what is known as the cerebellar cognitive affective syndrome secondary to cerebellar atrophy. We report the case of an older woman with early-onset (age 45) signs and symptoms of this syndrome, including impairment of executive functions and visuospatial cognition, personality changes, and language deficits, who was followed at a geriatric medical center for 14 years. Neuropsychological, imaging, and behavioral aspects during this period are discussed in light of scientific evidence. This case report contributes to the scientific literature by describing the progression of the signs and symptoms of cerebellar atrophy over the years, which can help guide medical management and support advice for patients and their families.

Cerebellar abiotrophy (CA) is a neurodegenerative disorder affecting the cerebellum and occurs in multiple species. Although CA is well researched in humans and mice, domestic species such as the dog, cat, sheep, cow, and horse receive little recognition. This may be due to few studies addressing the mechanism of CA in these species. However, valuable information can still be extracted from these cases. A review of the clinicohistologic phenotype of CA in these species and determining the various etiologies of CA may aid in determining conserved and required pathways necessary for proper cerebellar development and function. This review outlines research approaches of studies of CA in domestic species, compared to the approaches used in mice, with the objective of comparing CA in domestic species while identifying areas for further research efforts.

OBJECTIVE: To systematically review evidence regarding ataxia treatment. METHODS: A comprehensive systematic review was performed according to American Academy of Neurology methodology. CONCLUSIONS: For patients with episodic ataxia type 2, 4-aminopyridine 15 mg/d probably reduces ataxia attack frequency over 3 months (1 Class I study). For patients with ataxia of mixed etiology, riluzole probably improves ataxia signs at 8 weeks (1 Class I study). For patients with Friedreich ataxia or spinocerebellar ataxia (SCA), riluzole probably improves ataxia signs at 12 months (1 Class I study). For patients with SCA type 3, valproic acid 1,200 mg/d possibly improves ataxia at 12 weeks. For patients with spinocerebellar degeneration, thyrotropin-releasing hormone possibly improves some ataxia signs over 10 to 14 days (1 Class II study). For patients with SCA type 3 who are ambulatory, lithium probably does not improve signs of ataxia over 48 weeks (1 Class I study). For patients with Friedreich ataxia, deferiprone possibly worsens ataxia signs over 6 months (1 Class II study). Data are insufficient to support or refute the use of numerous agents. For nonpharmacologic options, in patients with degenerative ataxias, 4-week inpatient rehabilitation probably improves ataxia and function (1 Class I study); transcranial magnetic stimulation possibly improves cerebellar motor signs at 21 days (1 Class II study). For patients with multiple sclerosis-associated ataxia, the addition of pressure splints possibly has no additional benefit compared with neuromuscular rehabilitation alone (1 Class II study). Data are insufficient to support or refute use of stochastic whole-body vibration therapy (1 Class III study).

Cerebellar Abiotrophy (CA) is a neurodegenerative disease in Arabian horses affecting the cerebellum, more specifically the Purkinje neurons. Although CA occurs in several domestic species, CA in Arabian horses is unique in that a single nucleotide polymorphism (SNP) has been associated with the disease. Total RNA sequencing (RNA-seq) was performed on CA-affected horses to address the molecular mechanism underlying the disease. This research expands upon the RNA-seq work by measuring the impact of the CA-associated SNP on the candidate gene MutY homolog (MUTYH) and its regulation, isoform-specific expression and protein localization. We hypothesized that the CA-associated SNP compromises the promoter region of MUTYH, leading to differential expression of its isoforms. Our research demonstrates that the CA-associated SNP introduces a new binding site for a novel transcription factor (Myelin Transcription Factor-1 Like protein, MYT1L). In addition, CA-affected horses show differential expression of a specific isoform of MUTYH as well as different localization in the Purkinje and granular neurons of the cerebellum.

The cerebellar cognitive affective syndrome is a neuropsychiatric syndrome composed of affective (anxiety, depression, euphoria, and emotional lability) and cognitive symptoms (executive, attentional, and visuospatial deficits) that was described in the 1990s. We present the case of a 49-year-old woman with a history of an acute neurological episode at the age of 28, after which she reported a change in personality, brief and alternating periods of depression, hypomania, and mixed episodes, and cognitive impairment that had a major impact on her personal and occupational level of functioning. She was initially diagnosed with bipolar disorder, but a clinical, neuropsychological, and imaging re-evaluation prompted a diagnostic reconsideration in favor of a cerebellar cognitive affective syndrome. This enabled therapeutical and prognostic refinement. Here, we discuss the diagnostic challenges of this syndrome and the implications that an accurate diagnosis has for patients.

Background: Pontocerebellar hypoplasia type 10 (PCH10) due to CLP1 gene mutations is characterized by structural brain anomalies, progressive microcephaly, severe intellectual and physical disabilities, and spasticity. In this follow-up study, evolution of phenotypic and neurological characteristics of patients with PCH10 is discussed., Methods: Phenotype, growth parameters, motor functions, developmental tests, spasticity assessments, functional independence assessments, electroencephalography (EEG), and brain magnetic resonance imaging (MRI) of 10 patients with PCH10 were monitored on separate examinations. Alterations were recorded., Results: Patients were followed-up for an average of 2.83 years. The tone of the upper extremities was significantly higher than that of the lower extremities, according to Modified Ashworth Scale (MAS) values. Sixty percent of patients could sit unsupported; 20% achieved supported sitting initially but lost the ability during follow-up. Absence of grabbing or sitting was observed in 20% of patients. During follow-up, one person achieved supported sitting and one person achieved head holding. Only one patient was able to speak a few words. Cerebellar atrophy (two of 10), pons hypoplasia (four of 10), cortical atrophy (seven of 10), enlarged ventricles (10 of 10), thinning of the corpus callosum (10 of 10), hypomyelination (six of 10), and increased white matter signal intensity (six of 10) were the observed MRI findings., Conclusions: Progressive cerebral and cerebellar atrophy was demonstrated radiologically for the first time in a PCH10 cohort. It is of crucial importance to identify these patients promptly with the help of dysmorphic findings and spasticity being pronounced in the upper extremities. Furthermore, we note that phenotypic and neurological examination findings tend to change slightly over time., Competing Interests: Declaration of competing interest The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective Summarize the clinical characteristics and treatment plan of 2 cases of abnormal anastomosis at the origin of the posterior inferior cerebellar artery (PICA) complicated with aneurysm. Methods and Results Two cases of abnormal anastomosis of the PICA complicated with aneurysms all showed spontaneous subarachnoid hemorrhage (SAH). MRI showed abnormal anastomosis of the PICA, accompanied by multiple small aneurysms at the anastomotic vessel or anastomotic site. All patients underwent occipital artery (OA)⁃PICA bypass graft and electrocoagulation of the aneurysms at the same time. Use "PICA anastomosis" as the key words to search PubMed (January 1, 2000 to June 30, 2021) 8 articles in English, 8 patients, combined with 2 cases in this article cases, a total of 10 patients with abnormal anastomosis at the origin of the PICA complicated with aneurysm. All cases occurred as spontaneous SAH; 8 cases of aneurysms occurred at the anastomosis site, one case occurred at the distal end of the PICA, and one case occurred in a branch of the original artery. Five cases underwent craniotomy, 3 cases of OA⁃PICA bypass surgery and concurrent electrocoagulation (2 cases) or clipping (one case) of the aneurysms, one case of simple aneurysm clipping, and one case of aneurysm clipping combined with cutting off anastomotic artery, and there were no clear complications after surgery; 4 cases underwent endovascular interventional treatment, 2 cases of coil embolization of aneurysms, 2 cases of Glubran glue embolization of aneurysms, of which 3 cases had postoperative complications, manifested as mild brainstem infarction (2 cases) or disturbance of consciousness (one case). Conclusions Abnormal anastomosis at the origin of the PICA complicated with aneurysm is rare, and the risk of rupture and hemorrhage is high. OA⁃PICA bypass and electrocoagulation or clipping of the aneurysm can be used as a treatment option.

Purpose Acute cerebellar ataxia (ACA) is characterized by unsteady gait and instability of the trunk, and is caused by secondary autoimmune responses to infection or vaccination in healthy children. Although its prognosis is usually very good, full symptom recovery generally takes 2 to 3 months. This study aimed to investigate clinical symptoms, neuroimaging findings, and laboratory findings in children with ACA, and to evaluate the effects of steroid therapy on ACA according to the method of administration (intravenous methylprednisolone vs. oral prednisolone). Methods We retrospectively analyzed nine patients diagnosed with ACA or acute cerebellitis (AC) who received steroid therapy. Results Nine children were included in this study (mean age, 3.71±2.89 years). The mean duration between prodromal febrile illness and cerebellar symptoms was 9.63±4.66 days. Ataxia (limb and/or truncal) was the most common cerebellar sign. Steroids were administered in two ways: methylprednisolone (20 to 30 mg/kg/day) was changed to an oral steroid (prednisolone, 1 mg/kg/day) after 2 to 3 days of administration; an oral steroid was used from the beginning of treatment. The cerebellar symptoms began to improve within 2 to 4 days of steroid therapy. All patients fully recovered without sequelae. The mean interval until full recovery of the cerebellar symptoms was 28.0±19.3 days, and was not significantly different between patients who received an oral steroid after methylprednisolone pulse therapy and patients who only received an oral steroid (P>0.05). Conclusion Regardless of the method of drug administration, steroid therapy helps to improve cerebellar symptoms in children with ACA/AC.

Pontocerebellar hypoplasia (PCH) represents a group of recessive developmental disorders characterized by impaired growth of the pons and cerebellum, which frequently follows a degenerative course. Currently, there are 10 partially overlapping clinical subtypes and 13 genes known mutated in PCH. Here, we report biallelic TBC1D23 mutations in six individuals from four unrelated families manifesting a non-degenerative form of PCH. In addition to reduced volume of pons and cerebellum, affected individuals had microcephaly, psychomotor delay, and ataxia. In zebrafish, tbc1d23 morphants replicated the human phenotype showing hindbrain volume loss. TBC1D23 localized at the trans-Golgi and was regulated by the small GTPases Arl1 and Arl8, suggesting a role in trans-Golgi membrane trafficking. Altogether, this study provides a causative link between TBC1D23 mutations and PCH and suggests a less severe clinical course than other PCH subtypes.

Deadenylases are best known for degrading the poly(A) tail during mRNA decay. The deadenylase family has expanded throughout evolution and, in mammals, consists of 12 Mg2+-dependent 3'-end RNases with substrate specificity that is mostly unknown. Pontocerebellar hypoplasia type 7 (PCH7) is a unique recessive syndrome characterized by neurodegeneration and ambiguous genitalia. We studied 12 human families with PCH7, uncovering biallelic, loss-of-function mutations in TOE1, which encodes an unconventional deadenylase. toe1-morphant zebrafish displayed midbrain and hindbrain degeneration, modeling PCH-like structural defects in vivo. Surprisingly, we found that TOE1 associated with small nuclear RNAs (snRNAs) incompletely processed spliceosomal. These pre-snRNAs contained 3' genome-encoded tails often followed by post-transcriptionally added adenosines. Human cells with reduced levels of TOE1 accumulated 3'-end-extended pre-snRNAs, and the immunoisolated TOE1 complex was sufficient for 3'-end maturation of snRNAs. Our findings identify the cause of a neurodegenerative syndrome linked to snRNA maturation and uncover a key factor involved in the processing of snRNA 3' ends.

Background Joubert syndrome and mitochondrial disease are rare congenital diseases in which a wide range of symptoms affects multiple organs. Patients with these diseases present characteristic symptoms related to the musculoskeletal, respiratory, and neurological systems, which make it difficult for anesthesiologists to manage the patient’s airway and choose appropriate anesthetic drugs. Case A 13-year-old male patient with Joubert syndrome and mitochondrial disease underwent elective surgery to insert a continuous ambulatory peritoneal dialysis catheter. Anesthesia was induced and maintained with propofol, remifentanil, and rocuronium. An I-gel was inserted to secure the airway; however, the fitting did not work properly, so the patient was intubated. The operation was completed without any major problems, and the intubated patient was transferred to the intensive care unit. Conclusions Anesthesiologists should determine the method of anesthesia and prepare for unintended complications based on a full understanding of these congenital diseases.

Disturbed mitochondrial fusion and fission have been linked to various neurodegenerative disorders. In siblings from two unrelated families who died soon after birth with a profound neurodevelopmental disorder characterized by pontocerebellar hypoplasia and apnoea, we discovered a missense mutation and an exonic deletion in the SLC25A46 gene encoding a mitochondrial protein recently implicated in optic atrophy spectrum disorder. We performed functional studies that confirmed the mitochondrial localization and pro-fission properties of SLC25A46. Knockdown of slc24a46 expression in zebrafish embryos caused brain malformation, spinal motor neuron loss, and poor motility. At the cellular level, we observed abnormally elongated mitochondria, which was rescued by co-injection of the wild-type but not the mutant slc25a46 mRNA. Conversely, overexpression of the wild-type protein led to mitochondrial fragmentation and disruption of the mitochondrial network. In contrast to mutations causing non-lethal optic atrophy, missense mutations causing lethal congenital pontocerebellar hypoplasia markedly destabilize the protein. Indeed, the clinical severity appears inversely correlated with the relative stability of the mutant protein. This genotype-phenotype correlation underscores the importance of SLC25A46 and fine tuning of mitochondrial fission and fusion in pontocerebellar hypoplasia and central neurodevelopment in addition to optic and peripheral neuropathy across the life span.

The tRNA splicing endonuclease is a highly evolutionarily conserved protein complex, involved in the cleavage of intron-containing tRNAs. In human it consists of the catalytic subunits TSEN2 and TSEN34, as well as the non-catalytic TSEN54 and TSEN15. Recessive mutations in the corresponding genes of the first three are known to cause pontocerebellar hypoplasia (PCH) types 2A-C, 4, and 5. Here, we report three homozygous TSEN15 variants that cause a milder version of PCH2. The affected individuals showed progressive microcephaly, delayed developmental milestones, intellectual disability, and, in two out of four cases, epilepsy. None, however, displayed the central visual failure seen in PCH case subjects where other subunits of the TSEN are mutated, and only one was affected by the extensive motor defects that are typical in other forms of PCH2. The three amino acid substitutions impacted the protein level of TSEN15 and the stoichiometry of the interacting subunits in different ways, but all resulted in an almost complete loss of in vitro tRNA cleavage activity. Taken together, our results demonstrate that mutations in any known subunit of the TSEN complex can cause PCH and progressive microcephaly, emphasizing the importance of its function during brain development.

Background: The most deadly type of spontaneous intracerebral hemorrhage is spontaneous cerebellar hemorrhage (SCH). The purpose of this meta-analysis was to investigate risk factors for prognosis in SCH patients to provide a basis for taking preventive and therapeutic measures., Methods: Seven electronic databases were searched from inception to May 2023 for randomized controlled trial, cohort study, case control study and cross-sectional study on prognosis of spontaneous cerebellar hemorrhage. The quality of the selected studies were assessed by the American Agency for Healthcare Research and Quality (AHRQ). To assess the impact of the included risk factors on the prognosis of spontaneous cerebellar hemorrhage, combined odds ratios (ORs) with matching 95% confidence intervals (CIs) were combined., Results: Eight studies were included, including 539 participants. And a total of 31 potentially associated risk factors were identified. Ultimately, 6 risk factors were included in the meta-analysis after assessing. The factors supported by moderate evidence include the hydrocephalus (OR = 4.3, 95% CI: 2.33 to 7.91) and drug-induced coagulopathy (OR = 2.74, 95% CI: 1.23 to 6.09). The factors supported by limited evidence include the intraventricular bleeding(OR = 1.86, 95% CI: 1.13 to 3.07) and hematoma size>3 cm(OR = 3.18, 95% CI: 1.87 to 5.39). Meta-analysis revealed no association between hypertension, diabetes mellitus and SCH prognosis., Conclusion: The current meta-analysis revealed obvious risk factors for prognosis in spontaneous cerebellar hemorrhage patients, including hydrocephalus, drug-induced coagulopathy, intraventricular bleeding and hematoma size>3 cm., (© 2024. The Author(s).)

Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Pontocerebellar hypoplasia type 2a (PCH2a) is an ultra-rare, autosomal recessive pediatric disorder with limited treatment options. Its anatomical hallmark is hypoplasia of the cerebellum and pons accompanied by progressive microcephaly. A homozygous founder variant in TSEN54, which encodes a tRNA splicing endonuclease (TSEN) complex subunit, is causal. The pathological mechanism of PCH2a remains unknown due to the lack of a model system. Therefore, we developed human models of PCH2a using regionalized neural organoids. We generated induced pluripotent stem cell (iPSC) lines from three males with genetically confirmed PCH2a and subsequently differentiated cerebellar and neocortical organoids. Mirroring clinical neuroimaging findings, PCH2a cerebellar organoids were reduced in size compared to controls starting early in differentiation. Neocortical PCH2a organoids demonstrated milder growth deficits. Although PCH2a cerebellar organoids did not upregulate apoptosis, their stem cell zones showed altered proliferation kinetics, with increased proliferation at day 30 and reduced proliferation at day 50 compared to controls. In summary, we generated a human model of PCH2a, providing the foundation for deciphering brain region-specific disease mechanisms. Our first analyses suggest a neurodevelopmental aspect of PCH2a., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Polyuria in children may become a diagnostic challenge since it may be seen as presenting symptom of an underlying renal or systemic disease. An adolescent boy, who did not have any known illness, was presented with polyuria. The detailed history revealed the findings of learning difficulty, speech impairment, unsteady gait and an operation of polydactyly. He had consanguineous parents and a brother who had abruptly diagnosed with the end-stage renal disease at the age of 21. These clues pointed to genetic background. On physical examination, he had pectus excavatum, atypical facial appearance, dysarthria, hypotonia, rotatory nystagmus, impaired tandem walk, hyperpigmented retinal irregularities. Laboratory examinations showed Stage-4 chronic kidney disease accompanied by tubulopathy. Ultrasonography detected cystic lesions on the corticomedullary junction. Thus, the patient had diagnosed Juvenile-Nephronophthisis. During further examinations, Molar Tooth Sign was detected in cranial MRI imaging. All these clinical and radiological findings indicate the spectrum of Joubert-Syndrome-Related-Disorders (JSRD). Genetic analysis of the patient and his brother revealed homozygous NPHP1 deletion. Distinctly from literature, they both had hematological involvement in the form of persistent thrombocytopenia. Genetic heterogeneity and phenotypic variability of nephronophthisis are major challenges. Although NPHP1 deletions are mostly identified in isolated nephronophthisis, they have also been described in complex ciliopathy syndromes such as JSRD. This case is also specific due to haematological involvement additional to kidney, retina, skeleton, neurological. We think, this case may shed light on future genotype-phenotype studies. [ABSTRACT FROM AUTHOR]

Pediatric-onset ataxias often present clinically as developmental delay and intellectual disability, with prominent cerebellar atrophy as a key neuroradiographic finding. Here we describe a new clinically distinguishable recessive syndrome in 12 families with cerebellar atrophy together with ataxia, coarsened facial features and intellectual disability, due to truncating mutations in the sorting nexin gene SNX14, encoding a ubiquitously expressed modular PX domain-containing sorting factor. We found SNX14 localized to lysosomes and associated with phosphatidylinositol (3,5)-bisphosphate, a key component of late endosomes/lysosomes. Patient-derived cells showed engorged lysosomes and a slower autophagosome clearance rate upon autophagy induction by starvation. Zebrafish morphants for snx14 showed dramatic loss of cerebellar parenchyma, accumulation of autophagosomes and activation of apoptosis. Our results characterize a unique ataxia syndrome due to biallelic SNX14 mutations leading to lysosome-autophagosome dysfunction.

Purpose: Acute cerebellar ataxia (ACA) is characterized by unsteady gait and instability of the trunk, and is caused by secondary autoimmune responses to infection or vaccination in healthy children. Although its prognosis is usually very good, full symptom recovery generally takes 2 to 3 months. This study aimed to investigate clinical symptoms, neuroimaging findings, and laboratory findings in children with ACA, and to evaluate the effects of steroid therapy on ACA according to the method of administration (intravenous methylprednisolone vs. oral prednisolone). Methods: We retrospectively analyzed nine patients diagnosed with ACA or acute cerebellitis (AC) who received steroid therapy. Results: Nine children were included in this study (mean age, 3.71±2.89 years). The mean duration between prodromal febrile illness and cerebellar symptoms was 9.63±4.66 days. Ataxia (limb and/or truncal) was the most common cerebellar sign. Steroids were administered in two ways: methylprednisolone (20 to 30 mg/kg/day) was changed to an oral steroid (prednisolone, 1 mg/kg/day) after 2 to 3 days of administration; an oral steroid was used from the beginning of treatment. The cerebellar symptoms began to improve within 2 to 4 days of steroid therapy. All patients fully recovered without sequelae. The mean interval until full recovery of the cerebellar symptoms was 28.0±19.3 days, and was not significantly different between patients who received an oral steroid after methylprednisolone pulse therapy and patients who only received an oral steroid (P>0.05). Conclusion: Regardless of the method of drug administration, steroid therapy helps to improve cerebellar symptoms in children with ACA/AC. [ABSTRACT FROM AUTHOR]

Background and purpose: Bradykinesia is one of the cardinal motor symptoms of Parkinson's disease. However, clinical and experimental studies indicate that bradykinesia may also be observed in various neurological diseases not primarily characterized by parkinsonism. These conditions include hyperkinetic movement disorders, such as dystonia, chorea, and essential tremor. Bradykinesia may also be observed in patients with neurological conditions that are not seen as "movement disorders," including those characterized by the involvement of the cerebellum and corticospinal system, dementia, multiple sclerosis, and psychiatric disorders. Methods: We reviewed clinical reports and experimental studies on bradykinesia in non‐parkinsonian conditions and discussed the major findings. Results: Bradykinesia is a common motor abnormality in non‐parkinsonian conditions. From a pathophysiological standpoint, bradykinesia in neurological conditions not primarily characterized by parkinsonism may be explained by brain network dysfunction. Conclusion: In addition to the pathophysiological implications, the present paper highlights important terminological issues and the need for a new, more accurate, and more widely used definition of bradykinesia in the context of movement disorders and other neurological conditions. [ABSTRACT FROM AUTHOR]

Background: The spinocerebellar ataxias (SCAs) are a group of autosomal dominant degenerative diseases characterized by cerebellar ataxia. Classified according to gene discovery, specific features of the SCAs – clinical, laboratorial, and neuroradiological (NR) – can facilitate establishing the diagnosis. The purpose of this study was to review the particular NR abnormalities in the main SCAs. Methods: We conducted a literature search on this topic. Results: The main NR characteristics of brain imaging (magnetic resonance imaging or computerized tomography) in SCAs were: (1) pure cerebellar atrophy; (2) cerebellar atrophy with other findings (e.g., pontine, olivopontocerebellar, spinal, cortical, or subcortical atrophy; “hot cross bun sign”, and demyelinating lesions); (3) selective cerebellar atrophy; (4) no cerebellar atrophy. Discussion: The main NR abnormalities in the commonest SCAs, are not pathognomonic of any specific genotype, but can be helpful in limiting the diagnostic options. We are progressing to a better understanding of the SCAs, not only genetically, but also pathologically; NR is helpful in the challenge of diagnosing the specific genotype of SCA.

DOI: 10.3969/j.issn.1672-6731.2019.06.013

Background: Essential tremor (ET), one of the most common neurological diseases, is associated with cognitive impairment. Surprisingly, predictors of cognitive decline in ET remain largely unidentified, as longitudinal studies are rare. In the general population, however, lower physical activity has been linked to cognitive decline.Objectives: To determine whether baseline physical activity level is a predictor of cognitive decline in ET.Methods: One hundred and twenty-seven ET cases (78.1 ± 9.5 years, range = 55–95), enrolled in a prospective, longitudinal study of cognition. At baseline, each completed the Physical Activity Scale for the Elderly (PASE), a validated, self-rated assessment of physical activity. Cases underwent an extensive battery of motor-free neuropsychological testing at baseline, 1.5 years, and 3 years, which incorporated assessments of cognitive subdomains. Generalized estimating equations (GEEs) were used to assess the predictive utility of baseline physical activity for cognitive change.Results: Mean follow-up was 2.9 ± 0.4 years (range = 1.3–3.5). In cross-sectional analyses using baseline data, lower physical activity was associated with lower overall cognitive function as well as lower cognitive scores in numerous cognitive domains (memory, language, executive function, visuospatial function and attention, all p < 0.05). In adjusted GEE models, lower baseline physical activity level significantly predicted overall cognitive decline over time (p=0.047), and declines in the subdomains of memory (p = 0.001) and executive function (p = 0.03).Conclusions: We identified reduced physical activity as a predictor of greater cognitive decline in ET. The identification of risk factors often assists clinicians in determining which patients are at higher risk of cognitive decline over time. Interventional studies, to determine whether increasing physical activity could modify the risk of developing cognitive decline in ET, may be warranted.

Background: Essential tremor (ET), one of the most common neurological diseases, is associated with cognitive impairment. Surprisingly, predictors of cognitive decline in ET remain largely unidentified, as longitudinal studies are rare. In the general population, however, lower physical activity has been linked to cognitive decline. Objectives: To determine whether baseline physical activity level is a predictor of cognitive decline in ET. Methods: One hundred and twenty-seven ET cases (78.1 ± 9.5 years, range = 55–95), enrolled in a prospective, longitudinal study of cognition. At baseline, each completed the Physical Activity Scale for the Elderly (PASE), a validated, self-rated assessment of physical activity. Cases underwent an extensive battery of motor-free neuropsychological testing at baseline, 1.5 years, and 3 years, which incorporated assessments of cognitive subdomains. Generalized estimating equations (GEEs) were used to assess the predictive utility of baseline physical activity for cognitive change. Results: Mean follow-up was 2.9 ± 0.4 years (range = 1.3–3.5). In cross-sectional analyses using baseline data, lower physical activity was associated with lower overall cognitive function as well as lower cognitive scores in numerous cognitive domains (memory, language, executive function, visuospatial function and attention, all p < 0.05). In adjusted GEE models, lower baseline physical activity level significantly predicted overall cognitive decline over time (p =0.047), and declines in the subdomains of memory (p = 0.001) and executive function (p = 0.03). Conclusions: We identified reduced physical activity as a predictor of greater cognitive decline in ET. The identification of risk factors often assists clinicians in determining which patients are at higher risk of cognitive decline over time. Interventional studies, to determine whether increasing physical activity could modify the risk of developing cognitive decline in ET, may be warranted. [ABSTRACT FROM AUTHOR]

Cognitive and behavioral correlates of molecular variations related to the FMR1 gene have been studied rather extensively, but research about the long-term outcome in individuals with fragile X spectrum disorders remains sparse. In this review, we present an overview of aging research and recent findings in regard to cellular and clinical manifestations of aging in fragile X syndrome, and the FMR1 premutation.

Competing Interests: Disclosures Dr Savastano is the president of Endovascular Engineering, Inc, the chief medical officer of VerAvanti, and owns stock in Endovascular Horizons.

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The neuropsychological characteristics of the cerebellar cognitive affective syndrome (CCAS) in congenital, non-progressive malformations of the cerebellum have been scarcely investigated, and even less is known for Joubert syndrome (JS), an inherited, non-progressive cerebellar ataxia characterized by the so-called molar tooth sign. The few studies on this topic reported inconsistent results about intellectual functioning and specific neuropsychological impairments. The aim of this research is to examine the neuropsychological profile of JS compared to other congenital cerebellar malformations (CM), considering individual variability of intellectual quotient (IQ) in the two groups. Fourteen patients with JS and 15 patients with CM aged 6-25 years were tested through a comprehensive, standardized neuropsychological battery. Their scores in the neuropsychological domains were inspected through descriptive analysis and compared by mean of MANOVA and ANOVA models, then replicated inserting IQ as covariate. The two groups showed a largely overlapping neuropsychological profile, consistent with CCAS. However, the JS group showed worse performance in visual-spatial memory compared to CM patients, although this difference was mitigated when considering IQ. These findings highlight a divergence between JS and other CM in visual-spatial memory, which might suggest a critical role of the cerebellum in recalling task-relevant memories and might inform rehabilitative interventions., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

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., (© 2024. The Author(s) under exclusive licence to Belgian Neurological Society.)

Ataxia-telangiectasia (A-T) is a disease caused by mutations in the ATM gene (11q22.3-23.1) that induce neurodegeneration Sasihuseyinoglu AS et al.  Pediatr Allergy Immunol Pulmonol 31(1):9-14, 2018, Teive HAG et al. Parkinsonism Relat Disord 46:3-8, 2018. Clinically, A-T is characterized by ataxia, mucocutaneous telangiectasia, immunodeficiency, and malignancy. Movement disorders have been the most described and well-studied symptoms of A-T. Other studies have reported visuospatial processing disorders, executive function disorders and emotional regulation disorders, which are clinical manifestations that characterize cerebellar cognitive affective syndrome (CCAS) Choy KR et al. Dev Dyn 247(1):33-46, 2018. To describe the neurocognitive and emotional state of pediatric patients with ataxia-telangiectasia and to discuss whether they have cerebellar cognitive affective syndrome. This observational, cross-sectional, and descriptive study included 9 patients with A-T from May 2019 to May 2021. A complete medical history was retrieved, and tests were applied to assess executive functions, visual-motor integration and abilities, language, psychological disorders, and ataxia. Six girls and 3 boys agreed to participate. The age range was 6 to 14 years. The participants included five schoolchildren and four teenagers. Eight patients presented impaired executive functioning. All patients showed some type of error in copying and tracing (distortion) in the performance of visual perceptual abilities. Emotional disorders such as anxiety and depression were observed in six patients. Eight patients presented with dyslalia and impairments in word articulation, all patients presented with ataxia, and seven patients used a wheelchair. All patients presented symptoms consistent with CCAS and had variable cognitive performance., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)