The Chiari Malformations: A Bibliometric Analysis of the 100 Most Cited Articles.

OBJECTIVE: The Chiari malformations present heterogeneous entities, raising many questions regarding their natural history, pathophysiology, treatment options, and prognosis. Bibliometric analyses have emerged as a method to assess the impact of articles in current clinical practice. METHODS: The most cited articles were identified via Scopus Library by using the keywords "Chiari," "Arnold-Chiari," and "Chiari malformation." The 100 most cited articles were then assembled and analyzed in detail. RESULTS: The top 100 articles yielded a mean of 155,28 citations per article, ranging from 87 to 896 citations, and from 1.63 to 38.96 per year. Years of publications ranged from 1950 to 2015. Oakes was the most cited author (n = 7), followed by Tubbs and Milhorat. The country with the highest cited articles was the United States (n = 63), followed by the United Kingdom (n = 6), Italy (n = 5), Spain (n = 5), Japan (n = 4), and Germany (n = 3). Neurosurgery is the journal with the most highly cited articles (n = 21), followed by Journal of Neurosurgery (n = 19). Most articles focused on Chiari malformation type I (n = 83). The topic discussed most often was imaging (n = 63), followed by the evaluation of treatment outcome (n = 58), clinical signs and symptoms (n = 57), and the role of surgery (n = 56). CONCLUSIONS: The present bibliometric analysis provides a succinct appraisal of the most cited articles concerning Chiari malformation, allowing a deeper insight in this area and its main influential articles with their impact on current clinical practice and future research.

A Comprehensive Approach to the Diagnosis and Management of Klippel Feil Syndrome.

Klippel-Feil Syndrome (KFS) is a rare genetic disorder characterized by the abnormal development of the cervical spine, leading to the fusion of two or more cervical vertebrae. The syndrome presents diverse symptoms, including limited neck movement, chronic pain, and neurological manifestations such as limb numbness or weakness. The severity of KFS can vary significantly, and treatment primarily focuses on symptom management and preventing complications such as scoliosis or spinal cord compression. Surgical interventions are often necessary for patients with complex forms of the syndrome. Interestingly, Chiari 1 malformation, a cranial anomaly affecting the brainstem, can coincide anatomically with KFS. In this case report, we present the case of a 9-year-old patient who sought medical attention due to persistent, unchanging neck pain. The patient's medical history was notable for developmental delays and cervical restraint observed during physical examination. Magnetic resonance imaging (MRI) findings revealed hydrocephalus and brainstem descent, indicating the presence of Chiari 1 malformation. Comprehensive MRI and CT scans were performed, and a management plan was formulated, primarily involving cranial surgery and physiotherapy. Implementation of the treatment approach resulted in significant improvement in the patient's symptoms. This case highlights the significance of considering Chiari 1 malformation as a potential comorbidity in patients diagnosed with KFS who present with persistent neck pain. Early detection and appropriate management of both conditions are crucial for achieving favorable outcomes and enhancing the quality of life for affected individuals. Understanding the complex interplay between KFS and Chiari 1 malformation is essential for providing comprehensive care and tailored treatment strategies. Further research is warranted to elucidate the underlying mechanisms linking these two conditions and to explore optimal management approaches for patients with dual pathology. By reporting this case, we contribute to the existing literature and increase awareness among healthcare professionals regarding the potential coexistence of KFS and Chiari 1 malformation. Continued efforts in identifying associated anomalies and optimizing therapeutic interventions will aid in improving patient outcomes and ensuring optimal care for individuals affected by these conditions.

Neck pain and Headache Complicated by Persistent Syringomyelia After Foramen Magnum Decompression for Chiari I Malformation: Improvement with Multimodal Chiropractic Therapies.

BACKGROUND Patients with Arnold-Chiari Malformation I (CM-I) treated with foramen magnum decompression (FMD) can have ongoing neck pain, headaches, and other symptoms complicated by persistent syringomyelia, yet there is little research regarding treatment of these symptoms. CASE REPORT A 62-year-old woman with a history of residual syringomyelia following FMD and ventriculoperitoneal shunt for CM-I presented to a chiropractor with progressively worsening neck pain, occipital headache, upper extremity numbness and weakness, and gait abnormality, with a World Health Organization Quality of Life score (WHO-QOL) of 52%. Symptoms were improved by FMD 16 years prior, then progressively worsened, and had resisted other forms of treatment, including exercises, acupuncture, and medications. Examination by the chiropractor revealed upper extremity neurologic deficits, including grip strength. The chiropractor ordered whole spine magnetic resonance imaging, which demonstrated a persistent cervico-thoracic syrinx and findings of cervical spondylosis, and treated the patient using a multimodal approach, with gentle cervical spine mobilization, soft tissue manipulation, and core and finger muscle rehabilitative exercises. The patient responded positively, and at the 6-month follow-up her WHO-QOL score was 80%, her grip strength and forward head position had improved, and she was now able to eat using chopsticks. CONCLUSIONS This case highlights a patient with neck pain, headaches, and persistent syringomyelia after FMD for CM-I who improved following multimodal chiropractic and rehabilitative therapies. Given the limited, low-level evidence for these interventions in patients with persistent symptoms and syringomyelia after FMD, these therapies cannot be broadly recommended, yet could be considered on a case-by-case basis.

Conservative Treatment of Chiari Malformation Type I Based on the Phase-Contrast Magnetic Resonance Imaging: A Retrospective Study.

BACKGROUND: The use of phase-contrast magnetic resonance imaging is interestingly increased in the diagnosis and follow up of patients with Chiari type I malformation (CM1). The current study aimed to elaborate the benefits of conservative treatment by evaluating consecutively treated adult patients with CM1 who were selected on basis of phase-contrast magnetic resonance imaging. METHODS: Medical records of patients diagnosed with CM1 were retrospectively reviewed at 2 neurosurgical centers spanning 8 years (2010-2017). Adult patients with CM1, who were treated conservatively and met study criteria, were selected to be the core sample for this study. Between-group (benefited vs. nonbenefited) comparisons were performed to understand the factors that may affect the outcomes. RESULTS: Ninety adult patients (68 female and 22 male) received conservative treatment for CM1. The mean age was 40.6 years. Headaches and pinprick loss were the most commonly recorded symptoms and clinical findings, which were recorded in 58 (64.4%) and 31 (34.4%) patients, respectively. Eleven patients were presented with a syrinx. The mean aqueductal stroke volume (ASV) was 16.5 µL. Conservative treatment was ineffective in treating 5 (5.6%) patients, who underwent surgical intervention. The means of ASV in the benefited and nonbenefited groups were 16.7 and 13.2 µL, respectively (P = 0.004). CONCLUSIONS: Conservative approaches (prescriptive medications, physical therapy, Pilates, and swimming) can improve the life quality of nonsurgical candidate adult patients with CM1. Conservative treatment can be useful in selected patients with variably CM1 (ASV = 16.7 µL). Heavy sleep apnea or/and functional symptoms were prognostic factors that affected the conservative treatment negatively.

The factors affecting the outcomes of conservative and surgical treatment of chiari i adult patients: a comparative retrospective study.

BACKGROUND: The prognosis of the Chiari malformation type 1 (CM1) demonstrates a variant spectrum that varies from full recovery to complicated worse neurological disability. OBJECTIVE: To investigate the factors affecting the outcomes of conservative and surgical treatment for CM1 by evaluating adult patients consecutively managed at our institutions. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients diagnosed with CM1 at two reference neurosurgical centers for eight years (2010-2017). We selected all CM1 adult patients who managed conservatively or surgically as the core sample for this study. For clinical evaluation, we used a Chicago Chiari Outcome Scale (CCOS). For radiological assessment, we adopted both craniocervical and contrast-phase MRIs. We investigate factors such as age, sex, pretreatment symptoms, symptoms duration, and radiological findings in both groups. RESULTS: Ninety patients were treated conservatively. After a progression, five of them were treated surgically later and included in a total of 72 patients who underwent decompressive surgery. We successfully managed 85 patients (94.4%) of the conservative group and 64 patients (88.9%) of the surgical group. We found that patients with aqueductal stroke volume (ASV) of 12 µl are surgical candidates. We observed a strong positive correlation between clinical improvement and the increase in ASV values. CONCLUSIONS: ASV≤12 µl is a significant predictor for surgical intervention. The presence of heavy sleep apnea or/and functional symptoms, tonsillar herniation >13.4 mm on coronal images, low ASV, long symptom durations, and a syrinx are the independent prognostic factors that affected outcomes negatively.

Diagnosis and treatment of Chiari malformation type 1 in children: the International Consensus Document.

BACKGROUND: Chiari malformation type 1 (CM1) is a rare condition where agreed classification and treatment are still missing. The goal of this study is to achieve a consensus on the diagnosis and treatment of CM1 in children. METHODS: A multidisciplinary panel formulated 57 provisional statements based on a review of the literature. Thirty-four international experts (IE) participated in a Delphi study by independently rating each statement on a 4-point Likert scale ("strongly disagree," "disagree," "agree," "strongly agree"). Statements that were endorsed ("agree" or "strongly agree") by < 75% of raters were re-formulated, or new statements were added, and another Delphi round followed (up to a maximum of three). RESULTS: Thirty-five IE were contacted and 34 agreed to participate. A consensus was reached on 30/57 statements (52.6%) after round 1. Three statements were added, and one removed. After round 2, agreement was reached on 56/59 statements (94.9%). Finally, after round 3, which took place during the 2019 Chiari Consensus Conference (Milan, Italy), agreement was reached on 58/59 statements (98.3%) about four main sections (Definition and Classification, Planning, Surgery, Isolated Syringomyelia). Only one statement did not gain a consensus, which is the "definition of radiological failure 24 month post-surgery." CONCLUSIONS: The consensus document consists of 58 statements (24 on diagnosis, 34 on treatment), serving clinicians and researchers following children with CM1. There is a clear need for establishing an international network and registry and to promote collaborative studies to increase the evidence base and optimize the long-term care of this patient population.

Diagnosis, Management, and Return to Sport of a 16-Year-Old Patient With a Chiari I Malformation: A Case Report and Literature Review.

This case report discusses a 16-year-old female volleyball, basketball, and track and field athlete who was diagnosed with a Chiari I malformation after a concussion. Surgical decompression was recommended and performed 3 months after her initial diagnosis. This patient presented unique challenges due to her age, desire to return to sport, and lack of access to medical care due to living in a rural area. Few evidence-based best-practice recommendations are available for the management and return to sport of patients with Chiari I malformation, particularly for those who have undergone surgical decompression. In this case study, we address the treatment and return-to-sport process for the patient and provide a comprehensive review of the published literature on patients attempting to return to sport after a diagnosis of Chiari I malformation. In addition, we explore the value of an athletic trainer in reconciling various barriers in management and return to sport evident in this case and the reviewed literature.

The management of Chiari malformation type 1 and syringomyelia in children: a review of the literature.

In anticipation of the "Chiari and Syringomyelia Consensus Conference" held in Milan in 2019, we performed a systematic literature review on the management of Chiari malformation type 1 (CM1) and syringomyelia (Syr) in children.We aimed to summarize the available evidence and identify areas where consensus has not been reached and further research is needed.In accordance with PRISMA guidelines, we formulated seven questions in Patients-Interventions-Comparators-Outcomes (PICO) format. Six PICOs concerned CM1 children with/without additional structural anomalies (Syr, craniosynostosis, hydrocephalus, tethered cord, and cranio-vertebral junction anomalies), and one PICO Syr without CM1. We searched Medline, Embase, Cochrane, and NICE databases from January 1, 1999, to May 29, 2019. Cohort studies, controlled and randomized clinical trials (CCTs, RCTs), and systematic reviews were included, all pertinent only to patients ≤ 18 years of age.For CM1, 3787 records were found, 460 full texts were assessed and 49 studies (46 cohort studies, one RCT, and two systematic reviews) were finally included. For Syr, 376 records were found, 59 full texts were assessed, and five studies (one RCT and four cohort studies) were included. Data on each PICO were synthetized narratively due to heterogeneity in the inclusion criteria, outcome measures, and length of follow-up of the included studies.Despite decades of experience on CM1 and Syr management in children, the available evidence remains limited. Specifically, there is an urgent need for collaborative initiatives focusing on the adoption of shared inclusion criteria and outcome measures, as well as rigorous prospective designs, particularly RCTs.

Management of Chiari malformation type I and syringomyelia during pregnancy and delivery.

OBJECTIVE: Although a recurrent question in clinical practice, the management of Chiari malformation type I (CMI) and/or syringomyelia during pregnancy and delivery is still debated. The aim of this study was to investigate the modalities of delivery and anesthesia in women presenting with CMI and/or syringomyelia at a national reference center, and to question their potential role in the natural history of these conditions. STUDY DESIGN: We conducted a retrospective cohort study using a standardized questionnaire, a customized clinical severity score and data from medical records. RESULTS: 83 patients were included in the final analysis: 32 had CMI without syringomyelia, 27 had CMI with syringomyelia and 24 had non-foraminal syringomyelia. Most patients (55/83) were not diagnosed at the time of their pregnancy, 12 had surgery before being pregnant and 16 were diagnosed but not operated. Most women underwent vaginal delivery (62 %) and neuraxial (i.e. epidural or spinal) anesthesia (69 %). However, the proportion of cesarean procedures increased to 53.6 % and even 83.3 % when considering only patients already diagnosed or operated on, respectively. Nonetheless, neither vaginal compared to cesarean delivery (change in clinically severity score: -1.5 ± 0.4 versus -0.9 ± 0.4, p = 0.4) nor neuraxial compared to general anesthesia (-1.2 ± 0.3 versus -1.5 ± 0.6, p = 0.7) were associated with increased clinical deterioration. CONCLUSION: Although individual evaluation is mandatory, this study supports that neither delivery nor anesthesia modalities affect the natural history for the vast majority of patients with CMI and/or syringomyelia.

Syrinx Secondary to Chiari-like Tonsillar Herniation in Spontaneous Intracranial Hypotension.

OBJECTIVE: Syrinx development in patients with spontaneous intracranial hypotension (SIH) has rarely been described. To better understand this entity, we compared the clinical and radiographic findings in a series of patients with SIH and acquired Chiari-like tonsillar herniation with and without syrinx formation. METHODS: Six patients with syrinx in the setting of SIH and Chiari-like tonsillar herniation were retrospectively identified. The clinical and radiographic findings and outcomes were compared with those from a control group of patients with SIH and Chiari-like tonsillar herniation without syrinx. RESULTS: The patients with SIH and syrinx had had a higher opening pressure than had the control group (mean, 14.0 cm H2O vs. 7.4 cm H2O; P = 0.02) and a higher body mass index (mean, 33 kg/m2 vs. 26 kg/m2; P = 0.01). The patients with syrinx had had an average obex displacement of 3.7 ± 2.2 mm below the plane of the foramen magnum compared with a position of 1.9 ± 3.1 mm above the plane of the foramen magnum in the control group (P = 0.004). The mean tonsillar descent was 12.7 ± 4.7 mm below the foramen magnum in those with syrinx compared with 5.9 ± 2.5 in the control group (P = 0.009). The clinical symptoms had improved in 83.3% of the patients with syrinx and 75% of the control patients after spinal cerebrospinal fluid leak closure. Three patients (50%) also had radiographic syrinx reduction. CONCLUSION: Our results have shown that SIH can be an underrecognized cause of syrinx with key differences in body habitus and obex displacement compared with SIH without syrinx. In patients with tonsillar herniation into the foramen magnum associated with syrinx, the presence of SIH should be considered to avoid unnecessary foramen magnum decompression, even in those with a normal opening pressure.

Determinants of Chiari I progression in pregnancy.

Chiari Malformation type 1 (CM-I) is congenital or an acquired anomaly of the hind brain; develops when the cerebellar tonsils recede downwards below the foramen magnum. Recurrent post tussive suboccipital headache is the common presentation in a pregnant woman and the diagnosis is usually missed or delayed due to lack of formal understanding of this neurological pathology. Much has been written regarding presentation, morphology and the treatment of CM-I; however, little is known when the etiology is acquired or an iatrogenic in its evolution. Similarly, unknown is the progression of CM-I (diagnosed or undiagnosed) in pregnancy. The objective of this study is to elucidate the causes of progression of CM-I in pregnancy, and how this can be avoided. A detailed literature review has been conducted to find the case reports or case studies on association of CM-I in pregnancy; therefore, the risk factors regarding the progression have been sought. There is a lack of literature on timing, mode of anesthesia, and the management of CM-I. Moreover, authors have sought a questionnaire to screen these patients at pre-conception, intrapartum visits if, the initial diagnosis is delayed. Crucial points of concern including but not limited to the diagnosis, pre-conception counseling, timing of intervention during pregnancy, and mode of anesthesia, have been discussed in detail. In summary, a formal management algorithm has been proposed to avoid the rapid progression of this complex neurological pathology especially, in women of child bearing age and/or during pregnancy.

Chiari I malformation and pregnancy: a comprehensive review of the literature to address common questions and to guide management.

BACKGROUND: The optimal management of Chiari I malformation during pregnancy remains uncertain. Labor contractions, which increase intracranial pressure, and neuraxial anesthesia both carry the theoretical risk of brainstem herniation given the altered CSF dynamics inherent to the condition. Mode of delivery and planned anesthesia, therefore, require forethought to avoid potentially life-threatening complications. Since the assumed potential risks are significant, we seek to systematically review published literature regarding Chiari I malformation in pregnancy and, therefore, to establish a best practice recommendation based on available evidence. METHODS: The English-language literature was systematically reviewed from 1991 to 2018 according to PRISMA guidelines to assess all pregnancies reported in patients with Chiari I malformation. After analysis, a total of 34 patients and 35 deliveries were included in this investigation. Additionally, a single case from our institutional experience is presented for illustrative purposes but not included in the statistical analysis. RESULTS: No instances of brain herniation during pregnancy in patients with Chiari I malformation were reported. Cesarean deliveries (51%) and vaginal deliveries (49%) under neuraxial blockade and general anesthesia were both reported as safe and suitable modes of delivery. Across all publications, only one patient experienced a worsening of neurologic symptoms, which was only later discovered to be the result of a previously undiagnosed Chiari I malformation. Several patients underwent decompressive suboccipital craniectomy to treat the Chiari I malformation during the preconception period (31%), during pregnancy (3%), and after birth (6%). Specific data regarding maternal management were not reported for a large number (21) of these patients (60%). Aside from one abortion in our own institutional experience, there was no report of any therapeutic abortion or of adverse fetal outcome. CONCLUSIONS: Although devastating maternal complications are frequently feared, very few adverse outcomes have ever been reported in pregnant patients with a Chiari I malformation. The available evidence is, however, rather limited. Based on our survey of available data, we recommend vaginal delivery under neuraxial blockade for truly asymptomatic patients. Furthermore, based on our own experience and physiological conceptual considerations, we recommend limiting maternal Valsalva efforts either via Cesarean delivery under regional or general anesthesia or by choosing assisted vaginal delivery under neuraxial blockade. There is no compelling reason to offer suboccipital decompression for Chiari I malformation during pregnancy. For patients with significant neurologic symptoms prior to conception, decompression prior to pregnancy should be considered.

Conservative management for pediatric patients with chiari 1 anomaly: A retrospective study.

OBJECTIVE: To better understand the natural history of non-surgical management of chiari 1 anomaly. PATIENTS AND METHODS: After obtaining approval of the institutional review board, medical records and radiological exams of patients treated for CM1 at our institution between the years 2010 and 2016 were reviewed. Twenty-nine patients total were included in our study. RESULTS: The average age of our patient population was 8.5 years old at the time of diagnosis. The average tonsillar herniation on first MRI was 9.4 mm (+/- 4.6) and the average tonsillar herniation on second MRI was 10.4 mm (+/- 4.8). The average follow up time of our sample of patients was 26 months. Of the 29 patients in our study 9 (31 %) had symptomatic presentation. Interestingly, four of our patients (13.8 %) presented with epilepsy. CONCLUSIONS: Our findings support the previous work that nonoperative management is best in asymptomatic or mildly symptomatic chiari patients.

Chiari 1 malformation management: the Red Cross War Memorial Hospital approach.

PURPOSE: In this paper, we aimed to review our institutional opinions and experience with Chiari 1 malformation management to determine physician practice and outcomes. METHODS: Discussion between 3 clinicians about practice preferences and the management of Chiari 1 worldwide. Retrospective review of clinical cases over a 10-year period (2009-2018). RESULTS: Although there are some minor differences between clinicians in our practice, our approach is broadly similar. We treat incidental Chiari 1 malformations conservatively, with clinical and radiological surveillance, reserving intervention for patients who develop clinical signs or radiological deterioration. We prefer surgical intervention for patients with typical symptoms or a Chiari 1 malformation with radiological progression. If symptoms are atypical, we prefer surveillance. Our preferred operation is a conservative suboccipital craniectomy with expansion duraplasty and adhesiolysis. Our operative complication rate was low and there was no mortality or major morbidity in our series. Surveillance for incidentally discovered Chiari 1 malformations has been a safe practice in our experience. CONCLUSION: Clinical practice among three clinicians in our institution is broadly consistent. We have a conservative approach to Chiari 1 malformation management and our approach appears to have a low morbidity.

Scoliosis in patients with Chiari malformation type I.

The literature about the association between Chiari malformations (CMs) and scoliosis has been growing over the last three decades; yet, no consensus on the optimal management approach in this patient population has been reached. Spinal anomalies such as isolated syrinxes, isolated CM, and CM with a syrinx are relatively common among patients with presumed idiopathic scoliosis (IS), a rule that also applies to scoliosis among CM patients as well. In CM patients, scoliosis presents with atypical features such as early onset, left apical or kyphotic curvature, and neurological deficits. While spinal X-rays are essential to confirm the diagnosis of scoliosis among CM patients, a magnetic resonance imaging (MRI) is also recommended in IS patients with atypical presentations. Hypotheses attempting to explain the occurrence of scoliosis in CM patients include cerebellar tonsillar compression of the cervicomedullary junction and uneven expansion of a syrinx in the horizontal plane of the spinal cord. Early detection of scoliosis on routine spinal examination and close follow-up on curve stability and progression are essential initial steps in the management of scoliosis, especially in patients with CM, who may require full spine MRI to screen for associated neuro-axial anomalies; bracing and spinal fusion may be subsequently pursued in high-risk patients.

Arthrogryposis in a Case of Chiari Malformation II: First Case Report in a Mediterranean Population.

BACKGROUND Arthrogryposis multiplex congenita is a multifactorial syndromic or non-syndromic group of conditions consisting of multiple congenital contractures of the body, of unknown etiology. It is associated with a heterogenous group of disorders that include but are not limited to processes such as myopathic and neuropathic. Neural tube defect is a neuropathic disorder that incorporates myelomeningocele that might be either isolated or within a spectrum of multiple diseases. CASE REPORT This is a case report of a 28-day-old male born with lower limb arthrogryposis with myelomeningocele and Chiari II malformation in a Mediterranean population. CONCLUSIONS Lower extremity arthrogryposis with myelomeningocele and Chiari II malformation is a prenatal diagnosis that requires high clinical suspicion, early multidisciplinary intervention, and genetic counselling. As long as new approaches are being explored in the management of such cases, babies born now with neural tube defects can expect better quality of life.

Syringobulbia in Patients with Chiari Malformation Type I: A Systematic Review.

This study aimed to summarize the clinical features, diagnosis, and treatment of Chiari malformation type I- (CM-1-) associated syringobulbia. We performed a literature review of CM-1-associated syringobulbia in PubMed, Ovid MEDLINE, and Web of Science databases. Our concerns were the clinical features, radiologic presentations, treatment therapies, and prognoses of CM-1-associated syringobulbia. This review identified 23 articles with 53 cases. Symptoms included headache, neck pain, cranial nerve palsy, limb weakness/dysesthesia, Horner syndrome, ataxia, and respiratory disorders. The most frequently involved area was the medulla. Most of the patients also had syringomyelia. Surgical procedures performed included posterior fossa decompression, foramen magnum decompression, cervical laminectomy, duraplasty, and syringobulbic cavity shunt. Most patients experienced symptom alleviation or resolution postoperatively. A syringobulbic cavity shunt provided good results in refractory cases. Physicians should be aware of the possibility of syringobulbia in CM-1 patients, especially those with symptoms of sudden-onset brain-stem involvement. The diagnosis relies on the disorder's specific symptomatology and magnetic resonance imaging. Our review suggests that the initial therapy should be posterior fossa decomposition with or without duraplasty. In refractory cases, additional syringobulbic cavity shunt is the preferred option.