Chiari type III malformation associated with Klippel-Feil syndrome, a case report with a narrative review of the literature.

BACKGROUND: Chiari malformation type III (CM III), a rare hindbrain anomaly, often presents with various concurrent anomalies. This paper reports a unique case of CM III associated with Klippel-Feil syndrome (KFS), a condition previously unreported in Saudi Arabia and documented in only one other case globally in Turkey. This study aims to share insights into the unusual association between CM III and KFS, considering their close embryological development and involvement in the craniocervical junction. METHODOLOGY: The study presents a case of a 2.5-year-old female diagnosed with CM III and KFS. Diagnostic tools such as ultrasound, CT scans, MRI, and physical examinations were used to confirm the patient's condition. Surgical interventions, including decompression and encephalocele repair, were performed. RESULTS: Successful surgical interventions, including encephalocele repair and duraplasty, were carried out. Follow-up visits indicated a stable condition, marked improvement in lower limb strength, and the patient's ability to walk with assistance. CT follow-up affirmed a satisfactory surgical outcome. CONCLUSION: This case study illustrates the potential for an optimistic prognosis in CM III, even when accompanied by complex conditions such as KFS, through early diagnosis and intervention. It underscores the significance of antenatal screening for effective care planning and calls for further research and publications due to the rarity of this association. These findings contribute to our understanding of CM III and its related conditions, emphasizing the need for open-minded consideration of potential embryological associations.

Regression of Chiari malformation type 2 following early postnatal meningomyelocele repair-a retrospective observation from an institutional series of patients.

PURPOSE: Spontaneous regression of Chiari malformation type 2 (CM2) is observed rarely, as CM2 is associated with meningomyelocele (MMC) that is surgically repaired either pre- or early postnatally. While the radiological regression of CM2 occurs frequently following prenatal repair of MMC, it has been reported in only a few studies after postnatal repair. METHODS: From the consecutive series of children with postnatally repaired MMC, we reviewed the clinical and radiological data regarding CM2, particularly its regression either spontaneously or following CSF diversion. RESULTS: Eighteen children underwent postnatal repair of MMC between February 2011 and April 2023. CM2 was present in 16 (89%), and hydrocephalus in 15 children (83%), requiring shunting in 14 of them. During the mean clinical observation time (from birth to April 2023) of 59 ± 51 months, three children with CM2 (19%) underwent 1-2 foramen magnum decompressions (FMD), five children (28%) 1-4 surgical untethering procedures and 13 children with shunted hydrocephalus (93%) 1-5 shunt revisions. Out of sixteen children with CM2, we observed regression of CM2 on MRI in only one case (6%) during the mean radiological follow-up (from birth to the last MRI taken) of 49 ± 51 months. CONCLUSION: In our experience, spontaneous regression of CM2 in children with postnatally repaired MMC occurs quite rarely. Pathophysiological mechanisms behind the development of CM2 in children with MMC remain unclear, but our observation supports the hypothesis of an association between the downward displacement of the hindbrain and the low intraspinal pressure secondary to CSF leakage in children born with MMC.

Clinical presentation and outcomes of neonates born with neural tube defects- an experience from a level III B NICU in Western India.

PURPOSE: Neural tube defects (NTDs) are one of the most common congenital anomalies and a cause of chronic disability. The study was done to study outcomes of neural tube defects admitted at a tertiary level neonatal intensive care unit (NICU) from 2018 to 2022, a period of 4 years that also coincided with the COVID pandemic. The secondary outcome was to study the clinical presentation, associated anomalies and epidemiological features. METHODS: It was a retrospective observational study; data of infants was obtained from medical records and analysis was done. RESULTS: Thirty-four neonates were enrolled, of which there were 16 (47%) males and 18 (53%) females. History of pre-pregnancy maternal folate intake was present in 4 (11.7%) cases. 33 (97%) babies were diagnosed with meningomyelocele (MMC) and one each had anencephaly, iniencephaly and encephalocele, of which one had frontal and two had occipital encephalocele. The median age of surgery was 16 days of life with primary repair being the most common procedure followed by MMC repair with VP shunt. Twenty babies (58.8%) were discharged successfully, while 9 (26.5%) expired and 5 (14.7%) were discharged against medical advice; which can be attributed to the financial problems of the patients in a developing country. The overall deaths in our series were four (26.5%) which is slightly higher than other studies which may be due to the fact that this study was conducted during the COVID era with lesser rates of folate supplementation, reduced access to prenatal diagnosis coupled with poor follow-up and compliance of patients post-surgical repair. CONCLUSION: This study emphasizes the importance of periconceptional folic acid supplementation, prenatal diagnosis, early surgery and meticulous follow-up as being pivotal to improving outcomes in children with NTDs.

Intraoperative neuromonitoring in Chiari I malformation surgery: a systematic review and meta-analysis.

Chiari Malformation Type I (CMI) is a prevalent neurosurgical condition characterized by the descent of cerebellar tonsils below the foramen magnum. Surgery, aimed at reducing symptomatology and syrinx size, presents risks, making intraoperative neuromonitoring (IONM) a potentially vital tool. Despite its widespread use in cervical spine surgery, the utility of IONM in CMI surgery remains controversial, with concerns over increased operative time, cost, restricted anesthetic techniques and tongue lacerations. This systematic review and meta-analysis followed the Cochrane Group standards and PRISMA framework. It encompassed an extensive search through PubMed, Embase, and Web of Science up to December 2023, focusing on clinical and surgical outcomes of IONM in CMI surgery. Primary outcomes included the use of various IONM techniques, complication rates, clinical improvement, reoperation, and mortality. The review, registered at PROSPERO (CRD42024498996), included both prospective and retrospective studies, with rigorous selection and data extraction processes. Statistical analysis was conducted using R software. The review included 16 studies, comprising 1358 patients. It revealed that IONM techniques predominantly involved somatosensory evoked potentials (SSEPs), followed by motor evoked potentials (MEPs) and Brainstem auditory evoked potentials (BAEPs). The estimated risk of complications with IONM was 6% (95% CI: 2-11%; I2 = 89%), lower than previously reported rates without IONM. Notably, the clinical improvement rate post-surgery was high at 99% (95% CI: 98-100%; I2 = 56%). The analysis also showed lower reoperation rates in surgeries with IONM compared to those without. Interestingly, no mortality was observed in the included studies. This systematic review and meta-analysis indicate that intraoperative neuromonitoring in Chiari I malformation surgery is associated with favorable clinical outcomes, including lower complication and reoperation rates, and high rates of clinical improvement.

Mosaic variegated aneuploidy syndrome 2 with biallelic novel CEP57 splice site variation in Indian siblings: Expanding the clinical and molecular spectrum.

Mosaic variegated aneuploidy syndrome 2 (MVA2) (MIM# 614114) is a rare autosomal recessive condition caused by biallelic loss of function variants in the CEP57 gene. MVA2 is characterized by a variable phenotype ranging from poor growth to facial dysmorphism, short stature and congenital heart defects. Only 11 families and 5 pathogenic variants of MVA2 have been described so far. Intragenic duplication of 11 nucleotides (c.915_925dup11) in homozygous or compound heterozygous state is the commonest genetic aberration (10/13). We describe the first Indian family with two siblings with a novel homozygous splice site variant (c.382+2T>C) in CEP57. Molecular characterization demonstrated skipping of exon 3 due to the variant with protein modeling predicting subsequent complete loss of function. This is the first report of a splice site variation in CEP57 leading to MVA2.

Neurological pathologies in acute acquired comitant esotropia.

BACKGROUND: Acute acquired comitant esotropia (AACE) is an uncommon subtype of esotropia characterized by sudden and usually late onset of a relatively large angle of comitant esotropia with diplopia in older children and adults. METHODS: A literature survey regarding neurological pathologies in AACE was conducted using databases (PubMed, MEDLINE, EMBASE, BioMed Central, the Cochrane Library, and Web of Science) in order to collect data for a narrative review of published reports and available literature. RESULTS: The results of the literature survey were analyzed to provide an overview of the current knowledge of neurological pathologies in AACE. The results revealed that AACE with unclear etiologies can occur in many cases in both children and adults. Functional etiological factors for AACE were found to be due to many reasons, such as functional accommodative spasm, the excessive near work use of mobile phones/smartphones, and other digital screens. In addition, AACE was found to be associated with neurological disorders, such as astrocytoma of the corpus callosum, medulloblastoma, tumors of the brain stem or cerebellum, Arnold-Chiari malformation, cerebellar astrocytoma, Chiari 1 malformation, idiopathic intracranial hypertension, pontine glioma, cerebellar ataxia, thalamic lesions, myasthenia gravis, certain types of seizures, and hydrocephalus. CONCLUSIONS: Previously reported cases of AACE with unknown etiologies have been reported in both children and adults. However, AACE can be associated with neurological disorders that require neuroimaging probes. The author recommends that clinicians should perform comprehensive neurological assessments to rule out neurological pathologies in AACE, especially in the presence of nystagmus or abnormal ocular and neurological indications (e.g., headache, cerebellar imbalance, weakness, nystagmus, papilloedema, clumsiness, and poor motor coordination).

Practical Algorithm for the Management of Multisutural Craniosynostosis with Associated Chiari Malformation and/or Hydrocephalus.

INTRODUCTION: The association between multisutural craniosynostosis with Chiari malformation (CM), venous hypertension, and hydrocephalus is widely described in the literature, especially in children with paediatric craniofacial syndromes. Some efforts have been done in the last years to understand the complex pathogenetic mechanisms underlying this association, and several theories have been proposed. In particular, it is now accepted that the hypothesis of the overcrowding of the posterior fossa due to precocious suture fusion is the cause of the cerebellar herniation in syndromic and non-syndromic patients, against the theory of intrinsic cerebellar anomalies, ventriculomegaly, and venous hypertension. However, whatever the pathophysiological mechanism, it is still unclear what the best management and treatment of CM and hydrocephalus are in multisutural craniosynostosis patients. The aim of this study was to report our 25 years' experience in treating paediatric patients affected by these rare pathologies in order to propose a simple and effective therapeutic flow chart for their management. MATERIALS AND METHODS: We retrospectively collected data of each patient who underwent a cranial vault remodelling (CVR) for complex multisutural craniosynostosis in our institution in the last 25 years, while monosutural craniosynostosis was excluded. We recorded data concerning type of craniosynostosis and craniofacial syndromes, presence of ventriculomegaly, and CM at presentation and clinical and radiological follow-up. Therefore, we evaluated the final outcomes (improved, stable, deteriorated) of these patients and created a practical flow chart that could help physicians choose the best surgical treatment when different pathological conditions, as Chiari malformation I (CMI) or hydrocephalus, affect complex craniosynostosis children. RESULTS: Thirty-nine patients (39 out of 55; 70.9%), with an isolated multisutural craniosynostosis at presentation, underwent a two-step CVR as first surgery; 36 patients (92.3%) had an improved outcome, 2 patients (5.1%) had a stable outcome, and 1 patient (2.56%) had a deteriorated outcome. Other eight children (8 out of 55; 14.5%) had a radiological evidence of asymptomatic CMI at presentation. In this group, we performed CVR as first surgery. As for the final outcome, 7 patients had an improved outcome (87.5%) with good aesthetic result and stability or resolution of CMI. Finally, 7 patients (7 out of 55; 12.7%) presented a various combination of CMI and ventriculomegaly or hydrocephalus at presentation. Among them, 3 patients had an improved outcome (42.8%), and 4 patients had a deteriorated outcome (57.1%). DISCUSSION: The prevalence of one pathological condition with associated symptoms over the others was the key factor leading our therapeutic strategy. When craniosynostosis is associated with a radiological CM, the assessment of clinical symptoms is of capital importance. When asymptomatic or pauci-symptomatic, we suggest a CVR as first step, for its efficacy in reducing tonsillar herniation and solving CM symptoms. When craniosynostosis is associated with ventricular enlargement, the presence of intracranial hypertension signs and symptoms forces physicians to first treat hydrocephalus with a ventriculo-peritoneal shunt or endoscopic third ventriculostomy. For patients with various degrees and severity of ventriculomegaly and associated CM, the outcomes were very heterogeneous, even when the same therapeutic strategy was applied to patients with similar starting conditions and symptoms. This is maybe the most unexpected and least clear part of our results. Despite the proposed algorithm comes from a clinical experience on 85% successfully treated patients with multiple craniosynostosis, more extensive and deep studies are needed to better understand CM and hydrocephalus development in such conditions.

Neurological pathologies associated with acute acquired comitant esotropia.

Previously reported cases of acute acquired comitant esotropia (AACE) with unknown etiologies have been reported in both children and adults. However, AACE can be associated with neurological disorders that require neuroimaging probes. The author recommends that clinicians should perform comprehensive neurological assessments to rule out neurological pathologies in AACE, especially in the presence of A or V pattern esotropia, nystagmus, or abnormal ocular and neurological indications (e.g. headache, cerebellar imbalance, weakness, nystagmus, papilloedema, clumsiness, and poor motor coordination).

Anesthetic management for cesarean delivery in a woman with congenital atlantoaxial dislocation and Chiari type I anomaly: a case report and literature review.

BACKGROUND: The preferable choice of anesthesia for the patients with congenital atlantoaxial dislocation (CAAD) and type I Arnold Chiari malformations (ACM-I) has been a very confusing issue in clinical practice. We describe the successful administration of combined spinal-epidural anesthesia for a woman with CAAD and ACM-1 accompanied by syringomyelia. CASE PRESENTATION: Our case report presents the successful management of a challenging obstetric patient with CAAD and ACM-1 accompanied by syringomyelia. She had high risks of difficult airway and aspiration. The injection of bolus drugs through the spinal or epidural needle may worsen the previous neurological complications. The patient was well evaluated with a multidisciplinary technique before surgery and the anesthesia was provided by a skilled anesthesiologist with slow spinal injection. CONCLUSIONS: An interdisciplinary team approach is needed to weigh risks and benefits for patients with CAAD and ACM-1 undergoing cesarean delivery. Therefore, an individual anesthetic plan should be made basing on the available anesthetic equipments and physicians' clinical experience on anesthetic techniques.

Arnold-Chiari Malformation: Core Concepts.

Arnold-Chiari malformation (ACM), a defect that involves downward displacement of the hindbrain and herniation of the cerebellar vermis, tonsils, pons, medulla, and fourth ventricle through the foramen magnum, is the most complex of the 4 types of Chiari malformations. Unique to the other types of Chiari malformations, approximately 95 percent of infants with ACM also present with an associated myelomeningocele (MMC), the most severe form of spina bifida. Among affected infants, those with symptomatic comorbidities incur a significantly higher morbidity and mortality risk. Prompt identification and diagnosis of ACM, as well as evidence-based postnatal and postsurgical nursing and medical care, is critical. Early surgical intervention can repair an existing MMC and restore proper cerebrospinal fluid circulation, which can dramatically improve patient outcomes and quality of life, and reduce disease and health care burden.

Arnold-Chiari malformation type I and the posterior dislocation of the odontoid process aggravate prolonged weaning in a patient with severe viral pneumonia: a case report.

BACKGROUND: Prolonged and difficult weaning is associated with higher rates of complications and mortality. Therefore, it is important to identify the associated factors. CASE PRESENTATION: We describe our experience with a 37-year-old man diagnosed with severe viral pneumonia (influenza A). He presented with acute respiratory failure type I on admission. During intubation, his blood pressure and heart rate decreased, and epinephrine and norepinephrine were administered. Although his clinical condition improved 8 days after intensive care unit (ICU) admission, he experienced difficulty weaning. He remained conscious but had a poor spontaneous cough with sputum production and weak limb muscle strength. His cough reflex was absent during bronchoscopic sputum suction, and he used abdominal breathing during the T-tube test. Magnetic resonance imaging revealed an Arnold-Chiari malformation type I, posterior dislocation of the odontoid process, and syringomyelia, with compression and deformation of the medulla and high cervical cord. The patient was successfully weaned from the ventilator at 20 days after ICU admission. CONCLUSIONS: Arnold-Chiari malformation type I and posterior dislocation of the odontoid process, which aggravate medullary compression and increase the risk of cervical nerve injury, might be a rare factor affecting prolonged weaning in critical illness.

Chiari I malformation-neuropsychological functions and quality of life.

OBJECTIVE: To assess the neuropsychological (NP) functioning and quality of life (QOL) before and 3 months after surgery on adults with Chiari I malformation (CMI). PATIENTS AND METHODS: All adult patients who had been diagnosed with CMI were invited to participate. Those who participated were assessed using a Hospital Anxiety and Depression scale (HAD) and NP examinations. Their QOL was assessed using the self-reported life satisfaction checklist, LiSat-11 and the five-dimensional EuroQol measurement of health outcome, EQ-5D-5L. All assessments were carried out both before and 3 months after surgery was performed. Demographic data and comorbidities were also registered. RESULTS: Of the 11 patients who underwent NP assessment, the majority demonstrated cognitive functioning within the normal range. However, postoperatively, their performance in verbal learning, psychomotor speed, colour naming speed and the ability to manage interference through response selection and inhibition (aspects of executive functioning) was significantly improved. Thirteen patients completed QOL assessments. When LiSat-11 item domains were compared with those of healthy subjects, patients reported a lower level of satisfaction with their life quality both before and after surgery. However, the EQ-5D-5L measurements, i.e., the descriptive system and the visual analogue, indicated that their QOL of life was significantly improved after surgery. CONCLUSION: There is scarcely any literature documenting effects of surgery on the QOL of CMI patients. The study we present here breaks new ground by comparing pre- and postoperative NP functions in CMI. We also examine the value of surgery for improving both NP functions and QOL in CMI.

Acute deterioration of adults with Chiari I malformation associated with extensive syrinx.

Background: Chiari I malformation (CMI) is usually a chronic disorder, although it may also present as a life-threatening condition with need for urgent decompression. Studies of acute deterioration of CMI are scarce. The identification of preoperative radiological factors that predict acute deterioration in adult patients with CMI facilitates planning of early decompression and decreases CMI-related morbidity.Patients and methods: This is a retrospective study of all adult patients with CMI who were referred to Sahlgrenska University Hospital, Sweden and underwent occipitocervical decompression in the period 2006-2016. In total, 65 consecutive patients were included and data regarding the preoperative degree of tonsillar herniation and syrinx (size, length and degree of rostral extension) were registered. Acute deterioration and the need for urgent surgical decompression within 24 h of hospitalisation were noted.Results: Three patients presented with acute deterioration of symptoms (4.6%) and showed an increased length and size of syrinx and more rostral extension of syrinx as compared to non-acute patients with CMI.Conclusion: Our study highlights the incidence of acute deterioration of CMI and shows the importance of assessing preoperative size, length and rostral extension of CMI-associated syrinx as indicators of acute deterioration so that CMI patients can be assigned to early surgical decompression.

«A case of a pharmacoresistant tachyarrhythmia associated with Arnold-Chiari malformation¼.

Introduction: Arnold-Chiari malformation is a group of congenital malformations of the hindbrain. Common symptoms include cephalgia, vestibular, cerebral and cochlear disorders We present a case of pharmacoresistant tachyarrhythmia associated with Arnold-Chiari malformation.Case Description: A 49-year-old female patient had an Arnold-Chiari malformation (ACM), syringomyelia, a retrocerebellar cyst and a 6 year history of tachyarrhythmia. Heart rhythm normalized after Chiari decompression.Conclusion: ACM can lead to heart rhythm disorders.

A Systematic Review of Cognition in Chiari I Malformation.

Displacement of the cerebellar tonsils in Chiari type I malformation (CMI) can affect functions controlled by the cerebellum and brainstem. While playing an integral role in the control of movement, the cerebellum also has widespread cortical connections, influencing a range of cognitive process. A systematic literature review was conducted to examine the relationship between cognition and CMI, assessing evidence for general or domain-specific cognitive change. The search protocol examined the AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus databases. Articles meeting the following criteria were included in this review (i) examined children or adults with a clinically defined diagnosis of CMI, (ii) assessed cognitive function with a prospective examination, (iii) included at least one standardized instrument designed to measure general or specific domains of cognitive function, and (iv) were published in English in a peer-reviewed journal. Twelve articles were identified, including 783 cases aged 3 months to 64 years. General cognition, processing speed, and learning and memory appeared less affected, while language deficits appeared to diminish with age. Executive dysfunction was the most commonly reported cognitive impairment, while attention and working memory, and visuospatial and perceptual skills also appeared vulnerable. Numerous methodological limitations were identified that should be considered in interpreting the impact of CMI and planning future investigations. Overall, there is currently insufficient evidence to describe a valid and reliable profile of cognitive impairment in CMI. Further research is required to confirm these preliminary psychometric results and integrate them with pathophysiological models.

Embryology and pathophysiology of the Chiari I and II malformations: A comprehensive review.

Although the Chiari malformations are well-studied and described developmental anomalies, there remains some incongruity in regards to their underlying etiologies. A number of theories have been proposed with the purpose of accounting for the embryology and pathogenesis of the Chiari I and II malformations and their associated complications and clinical syndromes. The present review aims to review the pertinent literature for all of the main theories that have been proposed, and outline their validity and relevance to our contemporary understanding of these anomalies. Clin. Anat. 31:202-215, 2018. © 2017 Wiley Periodicals, Inc.

Neural tube defects in Waardenburg syndrome: A case report and review of the literature.

Waardenburg syndrome type 1 (WS1) is an autosomal dominant genetic condition characterized by sensorineural deafness and pigment abnormalities, and is caused by variants in the PAX3 homeodomain. PAX3 variants have been associated with severe neural tube defects in mice and humans, but the frequency and clinical manifestations of this symptom remain largely unexplored in humans. Consequently, the role of PAX3 in human neural tube formation remains a study of interest, for clinical as well as research purposes. Though the association between spina bifida and WS1 is now well-documented, no study has attempted to characterize the range of spina bifida phenotypes seen in WS. Spina bifida encompasses several diagnoses with a wide scope of clinical severity, ranging from spina bifida occulta to myelomeningocele. We present a patient with Waardenburg syndrome type 1 caused by a novel missense variant in PAX3, presenting with myelomeningocele, Arnold-Chiari malformation, and hydrocephalus at birth. Additionally, we review 32 total cases of neural tube defects associated with WS. Including this report, there have been 15 published cases of myelomeningocele, 10 cases of unspecified spina bifida, 3 cases of sacral dimples, 0 cases of meningocele, and 4 cases of miscellaneous other neural tube defects. Though the true frequency of each phenotype cannot be determined from this collection of cases, these results demonstrate that Waardenburg syndrome type 1 carries a notable risk of severe neural tube defects, which has implications in prenatal and genetic counseling.

Loss-of-function variants in NFIA provide further support that NFIA is a critical gene in 1p32-p31 deletion syndrome: A four patient series.

The association between 1p32-p31 contiguous gene deletions and a distinct phenotype that includes anomalies of the corpus callosum, ventriculomegaly, developmental delay, seizures, and dysmorphic features has been long recognized and described. Recently, the observation of overlapping phenotypes in patients with chromosome translocations that disrupt NFIA (Nuclear factor I/A), a gene within this deleted region, and NFIA intragenic deletions has led to the hypothesis that NFIA is a critical gene within this region. The wide application and increasing accessibility of whole exome sequencing (WES) has helped identify new cases to support this hypothesis. Here, we describe four patients with loss-of-function variants in the NFIA gene identified through WES. The clinical presentation of these patients significantly overlaps with the phenotype described in previously reported cases of 1p32-p31 deletion syndrome, NFIA gene disruptions and intragenic NFIA deletions. Our cohort includes a mother and daughter as well as an unrelated individual who share the same nonsense variant (c.205C>T, p.Arg69Ter; NM_001145512.1). We also report a patient with a frameshift NFIA variant (c.159_160dupCC, p.Gln54ProfsTer49). We have compared published cases of 1p32-p31 microdeletion syndrome, translocations resulting in NFIA gene disruption, intragenic deletions, and loss-of-function mutations (including our four patients) to reveal that abnormalities of the corpus callosum, ventriculomegaly/hydrocephalus, macrocephaly, Chiari I malformation, dysmorphic features, developmental delay, hypotonia, and urinary tract defects are common findings. The consistent overlap in clinical presentation provides further evidence of the critical role of NFIA haploinsufficiency in the development of the 1p32-p31 microdeletion syndrome phenotype.

[Comparison of posterior fossa decompression with and without duraplasty for surgical management for adult Chiari malformation type â ].

Objective: To evaluate and compare the efficacy between posterior fossa decompression without duraplasty (PFD) and posterior fossa decompression with duraplasty (PFDD) in the surgical management for adult Chiari Ⅰ malformation. Methods: Fifty-seven patients suffered from Chiari malformation type Ⅰ were treated in Department of Neurosurgery, Henan Provincial People's Hospital from August 2008 to October 2013. Twenty-three patients received posterior fossa decompression without duraplasty and the other 34 patients received posterior fossa decompression with duraplasty. The clinical results were retrospectively analyzed to compare the efficacy of two different surgical approaches. Results: There was no death or severe neurological dysfunction case in 57 patients of the two groups. Patients undergoing PFD had shorter length of hospital stay[(13.7±3.5) d vs (16.2±4.1) d, P<0.05]and surgical time[(98.7±22.1) min vs (132.3±39.6)min, P<0.05]. Cerebrospinal fluid-related complications and intracranial infection were more common in patients undergoing PFDD[(0/23, 0) vs (8/34, 23.5%), P<0.05]. Clinical improvement was comparable in two groups[(15/23, 65.2%) vs (26/34, 76.5%), P>0.05]at the one-year follow-up. The rate of syrinx regression in patients with Syringomyelia was higher in patients undergoing PFDD[(3/12, 25%) vs (17/22, 77.3%), P<0.05]. Conclusion: For adult patients with Chiari malformation type Ⅰ, PFD has the advantages of simple manipulation, short length of hospital stay and low incidence of cerebrospinal fluid-related complications and intracranial infection, compared with PFDD. It is comparable to PFDD in clinical improvement, but the effect of PFD is not as good as that of PFDD in the aspect of syrinx regression.

[Treatment of single one-stage posterior atlantoaxial fixation in Chiari malformation].

Objective: To explore the effects of surgical technique of single one-stage posterior C(1-2) screw rod fixation of Chiari malformation (CM) associated with occipitalization and without atlantoaxial dislocation. Methods: A total of 23 patients with CM treated between January 2014 and October 2015 in Department of Neurosurgery of Chinese People's Liberation Army General Hospital were retrospective reviewed. All of them were diagnosis with CM associated with occipitalization and without atlantoaxial dislocation, including 8 males and 15 females, aging from 11 to 57 years (mean (35.5±10.52) years). Single one-stage posterior C(1-2) screw rod fixation with bone grafting fusion was performed. Operation time and intraoperative blood loss were recorded. Japanese Orthopaedic Association (JOA) scores and Odom rating were used to evaluate the clinical effects at pre- and post-operative. Regression of the cerebellar tonsillar was measured by MRI. The results were analyzed by paired samples t test. Results: Twenty-three patients were implanted screws successfully, the vertebral artery injury and cerebrospinal fluid leakage were not found. The mean operation time was (172.7±19.9) minutes, the intraoperative blood loss was (153.9±49.3) ml. Compared to preoperative, the JOA score increased (13.7±1.6 vs. 11.5±1.4) and the tonsillar herniation decreased ((0.8±0.6)cm vs. (1.9±0.6) cm) in the last follow-up, there were statistical difference (t=13.386, P<0.01; t=17.995, P<0.01). The results of the postoperative Odom grading were as follows: 6 cases were perfect (26.1%), 13 cases were good (56.5%), 4 cases were moderate (17.4%) and no case was poor.No signs of instrument loosen or screw broken was noticed. 100% bony fusion rate was achieved. The follow-up time was 6 to 23 months (mean (10.5±3.2) months). One case developed internal fixator related discomfort, the symptom was relieved by internal fixator removal surgery performed 4 months after the operation when osseous fusion had already been achieved. No new neurologic symptoms were observed in other 22 patients. Conclusions: The results of the study substantiates the effectiveness of single one-stage posterior fixation strategy for CM, which is associated with occipitalization and without atlantoaxial dislocation. This technique could be an alternative choice for this type of CM.