Comparison of the inter-laminar approach and laminotomy open approach for filum terminale lipoma: A retrospective analysis.

PURPOSE: Filum terminale lipoma (FTL) causes spinal-cord tethering and is associated with tethered-cord syndrome, which is treated by dissection of the entrapment. The conventional treatment for FTL involves dissection of the spinal cord through a laminotomy open approach (LOA). However, in recent years, the interlaminar approach (ILA) has gained popularity as a minimally invasive surgery. This study compares the effectiveness of the minimally invasive ILA with the conventional LOA in treating FTL. METHODS: We retrospectively evaluated data on the ILA and LOA for FTL at our center. In total, 103 participants were enrolled, including 55 in the ILA group and 48 in the LOA group. RESULTS: The ILA required significantly less surgical time and resulted in less blood loss. The improvement rate of symptoms in symptomatic patients was 84%, and for urinary symptoms and abnormal urodynamic study findings, it was 77%. The postoperative maintenance rate for asymptomatic patients was 100%. Postoperative complications of ILA included delayed wound healing in two patients (3.6%). CONCLUSION: Compared with LOA, ILA offers advantages in terms of shorter operative time and less blood loss, with no significant difference in long-term symptom-improvement rates between the groups.

Extrasynaptic acetylcholine signaling through a muscarinic receptor regulates cell migration.

Acetylcholine (ACh) promotes various cell migrations in vitro, but there are few investigations into this nonsynaptic role of ACh signaling in vivo. Here we investigate the function of a muscarinic receptor on an epithelial cell migration in Caenorhabditis elegans We show that the migratory gonad leader cell, the linker cell (LC), uses an M1/M3/M5-like muscarinic ACh receptor GAR-3 to receive extrasynaptic ACh signaling from cholinergic neurons for its migration. Either the loss of the GAR-3 receptor in the LC or the inhibition of ACh release from cholinergic neurons resulted in migratory path defects. The overactivation of the GAR-3 muscarinic receptor caused the LC to reverse its orientation through its downstream effectors Gαq/egl-30, PLCß/egl-8, and TRIO/unc-73 This reversal response only occurred in the fourth larval stage, which corresponds to the developmental time when the GAR-3::yellow fluorescent protein receptor in the membrane relocalizes from a uniform to an asymmetric distribution. These findings suggest a role for the GAR-3 muscarinic receptor in determining the direction of LC migration.

Does Preoperative Manual Reduction (Omoto Technique) Affect Surgical Outcomes for Calcaneal Fractures? A Multicenter (TRON Group) Retrospective Study.

The Omoto technique is a well-known method that is commonly used for noninvasive manual repair of calcaneal fractures. However, there have been no detailed studies on its clinical outcomes in preoperative closed reduction for surgical cases. This multicenter retrospective study aimed to compare the clinical and radiographic outcomes of calcaneal fractures treated with and without the preoperative Omoto technique, assessing its effectiveness. We extracted 335 patients with calcaneal fracture who underwent surgery between 2015 and 2020 from our multicenter database, named TRON. We evaluated the clinical outcomes using the American Orthopedic Foot and Ankle Society (AOFAS) score, the Böhler angle (BA) for radiographic analysis, and noted any complications. We divided the patients into those managed with the Omoto technique (group O) and those managed without the Omoto technique (group N). Patients were matched by age, sex, and fracture type, resulting in 43 patients per group. The use of the Omoto technique at the time of injury significantly improved the Böhler angle (BA). Furthermore, there were no significant differences in AOFAS, postoperative complications, or BA values at the final follow-up. In conclusion, our study demonstrates that the Omoto technique, when used preoperatively for calcaneal fractures, does not negatively impact the outcomes of subsequent surgical treatments. For patients who prefer to avoid surgery, the Omoto technique can be an effective initial intervention. Additionally, our findings suggest that the Omoto technique may facilitate less invasive surgical options in certain cases.

Comparison of the Outcomes of Plating, Screw Fixation, and Pinning in Sanders Type II Fractures: A Multicenter (TRON) Retrospective Study.

Calcaneus fractures Sanders type II have been historically treated with various modalities. However, few studies compared these procedures directly. The multicenter (TRON group) retrospective study compared the radiographic and clinical outcomes of operative procedures using Kirschner wires (K-wires), cannulated cancellous screws (CCSs) and plates. Between 2014 and 2020, 121 patients with Sanders type II calcaneus fractures were surgically treated in our group using K-wire (Group K: n = 31), CCS (Group C: n = 60) or plate (Group p: n = 30) fixation. We assessed the American Orthopedic Foot and Ankle Society (AOFAS) score and infection after operation as clinical outcomes and Böhler's and Preiss' angles as radiographic outcomes. The AOFAS scores of the 3 groups showed a significant difference, with Group P showing significantly inferior scores to Group C at 6 months postoperatively and at the final follow-up examination (p = .015 and p < .001, respectively). The rate of infection did not differ to a statistically significant extent, but the incidence in Group P tended to be higher in comparison to the other groups. Among the three groups, Böhler's angle did not differ to a statistically significant extent immediately after the operation (p = .113) or at the final follow-up examination (p = .383). Postoperatively, Preiss' angle did not differ to a statistically significant extent (p = .251) but was significantly smaller in the Group C at the final follow-up examination (p = .0331). In Sanders type II calcaneus fracture, CCS fixation may obtain the best functional outcomes.

Minor Suture Fusion is Associated With Chiari Malformation in Nonsyndromic Craniosynostosis.

Here, we focused on the association between minor suture fusion and Chiari malformation (CM) occurrence in nonsyndromic craniosynostosis (NSC), and evaluated how the minor suture affects the posterior cranial fossa by measuring the posterior fossa deflection angle (PFA). In this retrospective study, the clinical records of 137 patients who underwent surgery for NSC at Aichi Children's Health and Medical Center between April 2010 and May 2022 were analyzed. Clinical data from Aichi Developmental Disability Center Central Hospital was collected for 23 patients as the external validation set. Among the 137 patients, 123 were diagnosed with NSC and the remaining 14 with syndromic craniosynostosis. Of the 123 NSC patients, 23 patients presented with CM. Multivariate analysis showed that occipito-mastoid fusion was the only significant risk factor for CM ( P =0.0218). Within the NSC group, CM patients had a significantly increased PFA (6.33±8.10 deg) compared with those without CM (2.76±3.29 deg, P =0.0487). Nonsyndromic craniosynostosis patients with occipito-mastoid suture fusion had a significantly increased PFA (6.50±7.60 deg) compared with those without occipito-mastoid fusion (2.60±3.23 deg, P =0.0164). In the validation cohort, occipito-mastoid suture fusion was validated as an independent risk factor for CM in univariate analysis. Minor suture fusion may cause CM associated with NSC. Chiari malformation could develop due to an increased PFA due to minor suture fusion, which causes growth disturbance in the affected side and compensatory dilation in the contralateral side within the posterior cranial fossa.

Impact of a Demyelination-Inducing Central Nervous System Virus on Expression of Demyelination Genes in Type 2 Lymphoid Cells.

We recently reported the role of type 2 innate lymphoid cells (ILC2s) in central nervous system (CNS) demyelination using a model of CNS demyelination involving recombinant herpes simplex virus 1 (HSV-1) that constitutively expresses mouse interleukin 2 (HSV-IL-2). In this investigation, we studied how ILC2s respond to HSV-IL-2 at the cellular level using cytokine and gene expression profiling. ILC2s infected with HSV-IL-2 expressed higher levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-5, IL-6, IL-13, IP-10, MIP-2, and RANTES, which include proinflammatory cytokines, than did those infected with parental control virus. In contrast, TH2 cytokines IL-4 and IL-9, which are typically expressed by ILC2s, were not induced upon HSV-IL-2 infection. Transcriptome sequencing (RNA-seq) analysis of HSV-IL-2 infected ILC2s showed significant upregulation of over 350 genes and downregulation of 157 genes compared with parental virus-infected ILC2s. Gene Ontology (GO) term analysis indicated that genes related to "mitosis" and "inflammatory response" were among the upregulated genes, suggesting that HSV-IL-2 infection drives the excessive proliferation and atypical inflammatory response of ILC2s. This change in ILC2 activation state could underlie the pathology of demyelinating diseases.IMPORTANCE Innate lymphocytes have plasticity and can change functionality; type 2 innate lymphoid cells (ILC2s) can convert to ILC1 or ILC3 cells or change their activation state to produce IL-17 or IL-10 depending on environmental cues. In this study, we investigated the gene and cytokine profiles of ILC2s, which play a major role in HSV-IL-2-induced CNS demyelination. ILC2s infected with HSV-IL-2 displayed a massive remodeling of cellular state. Additionally, ILC2s infected with HSV-IL-2 differed from those infected with parental HSV in cellular and viral gene expression profiles and in cytokine/chemokine induction, and they displayed enhanced activation and proinflammatory responses. These changes in ILC2 activation state could underlie the pathology of demyelinating diseases. These results also highlight the possible importance of pathogens as environmental cues to modify innate lymphocyte functionalities.

[VP Shunts:Do's and Don'ts in Case of Shunt Failure].

Hydrocephalus is a relatively common pediatric neurosurgical disease. Although congenital hydrocephalous is the most common cause, cerebral bleeding, infection of the central nervous system or brain tumors can also cause hydrocephalous in children. As timing of initial treatment varies depending on the cause of hydrocephalous, customized therapeutic strategy should be considered on a case-by-case basis to cope with growth and development. After the initiation of treatment such as shunt, most patients should be placed under clinical observation for life, as permanent devices which can adapt children's growth are not available, and shunt troubles such as occlusion, infection, disconnection, and inappropriate drainage are common during long term observation. Overall, ventriculoperitoneal shunt is a standard treatment. Other options such as ventriculoatrial or ventriculopleural shunt are selected to treat various shunt complications. In this article, we describe the characteristics of shunt complications in pediatric patients, as well as the symptoms, diagnosis, and treatments for various possible shunt complications. In addition, what kinds of attention should be paid for treating shunt trouble due to infection is discussed using a complicated case report.

Autism-associated missense genetic variants impact locomotion and neurodevelopment in Caenorhabditis elegans.

Autism spectrum disorder (ASD) involves thousands of alleles in over 850 genes, but the current functional inference tools are not sufficient to predict phenotypic changes. As a result, the causal relationship of most of these genetic variants in the pathogenesis of ASD has not yet been demonstrated and an experimental method prioritizing missense alleles for further intensive analysis is crucial. For this purpose, we have designed a pipeline that uses Caenorhabditis elegans as a genetic model to screen for phenotype-changing missense alleles inferred from human ASD studies. We identified highly conserved human ASD-associated missense variants in their C. elegans orthologs, used a CRISPR/Cas9-mediated homology-directed knock-in strategy to generate missense mutants and analyzed their impact on behaviors and development via several broad-spectrum assays. All tested missense alleles were predicted to perturb protein function, but we found only 70% of them showed detectable phenotypic changes in morphology, locomotion or fecundity. Our findings indicate that certain missense variants in the C. elegans orthologs of human CACNA1D, CHD7, CHD8, CUL3, DLG4, GLRA2, NAA15, PTEN, SYNGAP1 and TPH2 impact neurodevelopment and movement functions, elevating these genes as candidates for future study into ASD. Our approach will help prioritize functionally important missense variants for detailed studies in vertebrate models and human cells.

Mapping a multiplexed zoo of mRNA expression.

In situ hybridization methods are used across the biological sciences to map mRNA expression within intact specimens. Multiplexed experiments, in which multiple target mRNAs are mapped in a single sample, are essential for studying regulatory interactions, but remain cumbersome in most model organisms. Programmable in situ amplifiers based on the mechanism of hybridization chain reaction (HCR) overcome this longstanding challenge by operating independently within a sample, enabling multiplexed experiments to be performed with an experimental timeline independent of the number of target mRNAs. To assist biologists working across a broad spectrum of organisms, we demonstrate multiplexed in situ HCR in diverse imaging settings: bacteria, whole-mount nematode larvae, whole-mount fruit fly embryos, whole-mount sea urchin embryos, whole-mount zebrafish larvae, whole-mount chicken embryos, whole-mount mouse embryos and formalin-fixed paraffin-embedded human tissue sections. In addition to straightforward multiplexing, in situ HCR enables deep sample penetration, high contrast and subcellular resolution, providing an incisive tool for the study of interlaced and overlapping expression patterns, with implications for research communities across the biological sciences.

Lateral temporal encephaloceles: case-based review.

PURPOSE: Lateral temporal encephalocele is an extremely rare clinical condition, with only 18 cases presented in the literature to date. No review articles have examined lateral temporal encephalocele in depth. We therefore reviewed past cases of lateral encephalocele to clarify the clinical characteristics of this extremely rare deformity. We also present a case of lateral encephalocele with arachnoid cyst which has never been reported in past reports. METHODS: We identified 8 reports describing 18 cases of lateral temporal encephalocele. We therefore reviewed 19 cases of lateral temporal encephalocele, including our own experience, and discussed the clinical characteristics of this pathology. RESULTS: All the cases with lateral temporal encephalocele were detected at birth except for an occult case. The majority occurred at the pterion, and occurrence at the asterion appears much rarer. Due to the preference for the pterion, the ipsilateral orbital wall was also distorted in some cases. Lateral temporal encephalocele seems to have fewer associated malformations: only 3 cases of lateral temporal encephalocele had associated malformations, including our case which was associated with intracranial arachnoid cyst. The only case of lateral temporal encephalocele to have shown hydrocephalus was our own case. Patients with this deformity have relatively good prognoses: only 3 of the 19 cases showed delayed psychomotor development during follow-up. CONCLUSIONS: Provision of adequate treatment is likely to achieve a good prognosis in patients with lateral temporal encephalocele, so we should keep in mind this deformity when encountering pediatric patients with mass lesions on the temporal cranium.

The "steppingstone" phenomenon: a new endoscopic finding in slit-ventricle syndrome.

Slit-ventricle syndrome (SVS) seems to encompass various pathophysiological abnormalities, including overdrainage of cerebrospinal fluid (CSF) and craniocerebral disproportion after extracranial CSF shunt placement. These pathologies result in small ventricle morphologically, and the ventricular catheter is obstructed by the collapsed ventricular walls. Patients with intermittent headaches, small ventricles on neuroimaging, and slow refill of the shunt reservoir are diagnosed with SVS. In this report, we present a case of SVS treated endoscopically. We detected bulges in a zigzag line on the ventricular walls according to side holes of the ventricular tube, and named them "steppingstone" phenomenon. It is a curious finding which directly shows that the intermittent obstruction of the ventricular tube occurs in patients with SVS. No previous articles have reported this phenomenon, and it indicates adequate treatment for SVS should be provided.

Identification of a wide range of motifs inhibitory to shiga toxin by affinity-driven screening of customized divalent peptides synthesized on a membrane.

Shiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli, binds to target cells through a multivalent interaction between its B-subunit pentamer and the cell surface receptor globotriaosylceramide, resulting in a remarkable increase in its binding affinity. This phenomenon is referred to as the "clustering effect." Previously, we developed a multivalent peptide library that can exert the clustering effect and identified Stx neutralizers with tetravalent peptides by screening this library for high-affinity binding to the specific receptor-binding site of the B subunit. However, this technique yielded only a limited number of binding motifs, with some redundancy in amino acid selectivity. In this study, we established a novel technique to synthesize up to 384 divalent peptides whose structures were customized to exert the clustering effect on the B subunit on a single cellulose membrane. By targeting Stx1a, a major Stx subtype, the customized divalent peptides were screened to identify high-affinity binding motifs. The sequences of the peptides were designed based on information obtained from the multivalent peptide library technique. A total of 64 candidate motifs were successfully identified, and 11 of these were selected to synthesize tetravalent forms of the peptides. All of the synthesized tetravalent peptides bound to the B subunit with high affinities and effectively inhibited the cytotoxicity of Stx1a in Vero cells. Thus, the combination of the two techniques results in greatly improved efficiency in identifying biologically active neutralizers of Stx.

Niche-associated activation of rac promotes the asymmetric division of Drosophila female germline stem cells.

BACKGROUND: Drosophila female germline stem cells (GSCs) reside adjacent to a cellular niche that secretes Bone Morphogenetic Protein (BMP) ligands and anchors the GSCs through adherens junctions. The GSCs divide asymmetrically such that one daughter remains in the niche as a GSC, while the other is born away from the niche and differentiates. However, given that the BMP signal can be diffusible, it remains unclear how a local extracellular asymmetry is sufficient to result in a robust pattern of asymmetric division. METHODS AND FINDINGS: Here we show that GSCs are polarized with respect to the cellular niche. We first use a modified biosensor to demonstrate that the small GTPase Rac is asymmetrically activated within the GSC at the niche-GSC interface. Experiments using loss-of-function and gain-of-function mutations in Rac indicate that asymmetric Rac activity both localizes the microtubule binding protein Apc2 to orient one GSC centrosome at the niche-GSC interface during interphase and activates the Jun N-terminal kinase pathway to increase the ability of the GSC to respond to BMP ligands. Other processes act in concert with each function of Rac. Specifically, we demonstrate that the GSC cell cycle arrests at prometaphase if centrosomes are misoriented. CONCLUSIONS: Thus, the GSCs, an adult stem cell present in a cellular niche, have a niche-associated polarity that couples control of the division plane with increased response to an extracellular maintenance signal. Other processes work in parallel with the Rac-mediated polarity to ensure a robust pattern of asymmetric division. We suggest that all adult stem cells likely employ multiple, independently acting mechanisms to ensure asymmetric division to maintain tissue homeostasis.

The usage of the three-dimension distractor in the NAVID system for plagiocephaly-three case reports.

BACKGROUND: Distraction osteogenesis is a standard method for craniosynostosis. However, the technique using conventional devices still has some disadvantages, especially for anterior or posterior plagiocephaly with complex deformities. In the Nakajima's angle-variable internal distraction (NAVID) system originally for maxillary surgeries, the cranial three-dimension (D) distractor with three dimensionally movable joint at the anterior arm has been developed recently in order to prevent the interference in the distraction process and excessive force. CASE REPORTS: In this paper, we first reported two cases of anterior plagiocephaly, and one case of posterior plagiocephaly received distraction osteogenesis using new 3-D distractor in the NAVID system. In two cases of anterior plagiocephaly, the reshaping of supra-orbital bar in reference of simulating by the 3-D skull model was performed. In all cases, we fixed two paralleled 2-D distractors and a 3-D distractor in the upper frontal or parietal region. CONCLUSION: Within the limitations of this study, we believe that the NAVID system is suitable for infant plagiocephaly due to the simple and small joint arm. Furthermore, the usage of the 3-D distractor would reduce the interference with 2-D distractors and easily lead to attainment of targeted distracting distance.

Functional transcriptomics of a migrating cell in Caenorhabditis elegans.

In both metazoan development and metastatic cancer, migrating cells must carry out a detailed, complex program of sensing cues, binding substrates, and moving their cytoskeletons. The linker cell in Caenorhabditis elegans males undergoes a stereotyped migration that guides gonad organogenesis, occurs with precise timing, and requires the nuclear hormone receptor NHR-67. To better understand how this occurs, we performed RNA-seq of individually staged and dissected linker cells, comparing transcriptomes from linker cells of third-stage (L3) larvae, fourth-stage (L4) larvae, and nhr-67-RNAi-treated L4 larvae. We observed expression of 8,000-10,000 genes in the linker cell, 22-25% of which were up- or down-regulated 20-fold during development by NHR-67. Of genes that we tested by RNAi, 22% (45 of 204) were required for normal shape and migration, suggesting that many NHR-67-dependent, linker cell-enriched genes play roles in this migration. One unexpected class of genes up-regulated by NHR-67 was tandem pore potassium channels, which are required for normal linker-cell migration. We also found phenotypes for genes with human orthologs but no previously described migratory function. Our results provide an extensive catalog of genes that act in a migrating cell, identify unique molecular functions involved in nematode cell migration, and suggest similar functions in humans.

Analysis of Calcaneal Avulsion Fractures Treated Surgically and Nonsurgically: A Retrospective Multicenter Study.

Background: Calcaneal avulsion fractures (CAvFs) at the Achilles tendon insertion are among the more challenging fractures to treat. Although rare, they often require reoperation. The optimal treatment, including nonsurgical procedures and better implants for surgical procedures in the treatment of CAvFs, remains to be established. Therefore, our study aimed to (1) perform a descriptive evaluation of CAvFs, including cases managed nonsurgically, and (2) assess surgical procedures, including the incidence of complications and reoperation for surgically treated CAvFs. Methods: In this multicenter retrospective study, we collected data of patients with CAvFs treated at 9 hospitals from 2012 to 2022. We performed a descriptive study of CAvFs and compared postoperative complications and reoperation rates for multiple surgical techniques and implants. The size of the bone fragments was quantified. Results: The data of 70 patients with CAvFs were analyzed; 20 patients were treated nonsurgically, and 50 were treated surgically. The mean age of patients was 68.5 years; 67% of the patients were female. Nineteen percent of the patients had diabetes, and 19% had osteoporosis. The incidence of postoperative complications was 30%, with infection in 14%, necrosis in 26%, and loss of reduction in 18%. The reoperation rate was 22%. Surgical techniques with use of cannulated cancellous screws were performed in 80% of the surgical cases. Cannulated cancellous screw (CCS) fixation alone resulted in a reoperation rate of 35%, whereas additional augmentation, including washers with CCS fixation, resulted in a reoperation rate of 10%. CCS fixation was successfully performed, although suture anchors were used in some cases with smaller fragments. Conclusions: CAvFs occurred more frequently in older women and had a high rate of postoperative complications. A combination of CCS with augmentation was more effective at reducing postoperative complications than CCS fixation alone, even when the bone fragment size was small. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Correlations of intracranial pathology and cause of head injury with retinal hemorrhage in infants and toddlers: A multicenter, retrospective study by the J-HITs (Japanese Head injury of Infants and Toddlers study) group.

INTRODUCTION: In infants who have suffered head trauma there are two possible explanations for retinal hemorrhage (RH): direct vitreous shaking and occurrence in association with intracranial lesions. Which possibility is more plausible was examined. MATERIAL AND METHODS: This multicenter, retrospective study reviewed the clinical records of children younger than four years with head trauma who had been diagnosed with any findings on head computed tomography (CT) and/or magnetic resonance imaging (MRI). Of 452 cases, 239 underwent an ophthalmological examination and were included in this study. The relationships of RH with intracranial findings and the cause of injury were examined. RESULT: Odds ratios for RH were significant for subdural hematoma (OR 23.41, p = 0.0004), brain edema (OR 5.46, p = 0.0095), nonaccidental (OR 11.26, p<0.0001), and self-inflicted falls (OR 6.22, p = 0.0041). CONCLUSION: Although nonaccidental, brain edema and self-inflicted falls were associated with RH, subdural hematoma was most strongly associated with RH.

IL-17A expression by both T cells and non-T cells contribute to HSV-IL-2-induced CNS demyelination.

Previously we reported that a recombinant HSV-1 expressing murine IL-2 (HSV-IL-2) causes CNS demyelination in different strains of mice and in a T cell-dependent manner. Since TH17 cells have been implicated in CNS pathology, in the present study, we looked into the effects of IL-17A-/- and three of its receptors on HSV-IL-2-induced CNS demyelination. IL-17A-/- mice did not develop CNS demyelination, while IL-17RA-/-, IL-17RC-/-, IL-17RD-/- and IL-17RA-/-RC-/- mice developed CNS demyelination. Adoptive transfer of T cells from wild-type (WT) mice to IL-17A-/- mice or T cells from IL-17A-/- mice to Rag-/- mice induced CNS demyelination in infected mice. Adoptive T cell experiments suggest that both T cells and non-T cells expressing IL-17A contribute to HSV-IL-2-induced CNS demyelination with no difference in the severity of demyelination between the two groups of IL-17A producing cells. IL-6, IL-10, or TGFß did not contribute to CNS demyelination in infected mice. Transcriptome analysis between IL-17A-/- brain and spinal cord of infected mice with and without T cell transfer from WT mice revealed that "neuron projection extension involved in neuron projection guidance" and "ensheathment of neurons" pathways were associated with CNS demyelination. Collectively, the results indicate the importance of IL-17A in CNS demyelination and the possible involvement of more than three of IL-17 receptors in CNS demyelination.

Ruptured Middle Cerebral Artery Aneurysm in an Infant: Case Report and Literature Review.

Intracranial aneurysms (IA) in infants are reportedly rare at 0.5% to 4.5% of all aneurysms. Furthermore, subarachnoid hemorrhage in infants younger than three months are even rarer as it has been reported in approximately 20 cases only till date. A 3-month-old infant with seizures and impaired consciousness was admitted to our hospital. Three-dimensional computed tomography angiography (3D-CTA) revealed a dissecting aneurysm with a maximum diameter of 13 mm in the right M2. Internal trapping using detachable coil were successfully performed, following which he was discharged without significant neurological deficit after one month of onset. Thus, we have reported a rare case of a large ruptured dissecting IA in a 3-month-old infant, in the right middle cerebral artery (MCA), successfully treated with an endovascular therapy, along with a literature review.