Symptomatic Chiari Research Articles

Neurosurgical Management of Rubinstein-Taybi Syndrome: An Institutional Experience

Introduction: Rubinstein-Taybi syndrome (RTS) is a rare genetic condition with a distinctive set of physical features. This case series reports a single institutional experience of RTS cases, highlighting the role of neurosurgery in the comprehensive management of RTS patients. Methods: A retrospective review of patients with genetically confirmed RTS presenting between 2010 and 2023 at Children’s Hospital of Pittsburgh was performed. Patient demographics, genetic profile, clinical symptoms, radiographic characteristics, and neurosurgical management were recorded for all patients. Results: Twenty-one patients (13 females, 8 males) aged 0 to 22 years presented for formal genetic counseling and diagnosis. Twenty patients (95%) had CREBBP pathogenic variants (RTS type 1), and 1 patient (5%) had EP300 pathogenic variants (RTS type 2). Ten patients (48%) had a low-lying conus medullaris, and 3 patients (30%) underwent subsequent spinal cord detethering. Four patients (19%) had a Chiari malformation, and three (75%) underwent Chiari decompression surgeries. One patient (5%) had Chiari-associated syringomyelia. Conclusions: RTS patients have an increased rate of tethered cord syndrome requiring detethering. The incidence of symptomatic Chiari I malformation requiring decompression has not been previously reported. The RTS series presented here demonstrates a high incidence of symptomatic Chiari I malformation in addition to tethered cord syndrome.

Safety and Preliminary Efficacy of Cervical Paraspinal Interfascial Plane Block for Postoperative Pain after Pediatric Chiari Decompression.

Surgery for lesions of the posterior fossa is associated with significant postoperative pain in pediatric patients related to extensive manipulation of the suboccipital musculature and bone. In this study, we assess the preliminary safety, effect on neuromonitoring, and analgesic efficacy of applying a cervical paraspinal interfascial plane block in pediatric patients undergoing posterior fossa surgery. In this prospective case series, we enrolled five patients aged 2-18 years undergoing surgery for symptomatic Chiari type I malformation. An ultrasound-guided cervical cervicis plane (CCeP) block was performed prior to the incision. A local anesthetic agent (bupivacaine) and a steroid adjuvant (dexamethasone) were injected into the fascial planes between the cervical semispinalis capitis and cervical semispinalis cervicis muscles at the level of the planned suboccipital decompression and C1 laminectomy. Motor-evoked and somatosensory-evoked potentials were monitored before and after the block. Patients were assessed for complications from the local injection in the intraoperative period and for pain in the postoperative period. No adverse events were noted intraoperatively, and there were no changes in neuromonitoring signals. Pain scores were low in the immediate postoperative period, and rescue medications were minimal. No complaints of incisional pain or need for narcotics were noted at the time of the 3-month postsurgical follow-up. In this study, we demonstrate the preliminary safety and analgesic efficacy of a novel application of a CCeP block to pediatric patients undergoing suboccipital surgery. Larger studies are needed to further validate the use of this block in children.

Evaluating the Need for Durotomy and Duraplasty in Adults Undergoing Suboccipital Craniectomy for Chiari Decompression: A Case Series Analysis of Radiographic and Clinical Outcomes.

Background Suboccipital craniectomy (SOC)in conjunction withdura opening and duraplasty for posterior fossa decompression is an effective treatment for symptomatic Chiari 1 malformations (CM1), primarily carried out in the pediatric population. However, dural opening and reconstruction are associated with an increased risk of complications, and their necessity in the adult population has not yet been robustly demonstrated. Givendifferences in clinical presentation and disease severity between the pediatric and adult patients, we aimed to identify if SOC alone with intraoperative ultrasound confirmation of adequate restoration of pulsatile motion of cerebellar tonsil is sufficient to treat symptomatic CM1 while mitigating surgical risks. Methods We identified a retrospective, institutional cohort of adult patients who underwent SOC for Chiari decompression between 2014 and 2023. Demographic, clinical, and radiographic features were extracted for each patient. Clinical outcomes were assessed using the Chicago Chiari Outcome Scale (CCOS) and Motor-Sensory-Sphincter signs score (Clinical Sign Score (CSS)). Radiographic outcomes assessed cerebellar ectopia and associated syrinx characteristics. Results A total of 15 patients were identified, with an average follow-up period of three years. Eight patients underwent SOC with duraplasty, whereas seven patients underwent SOC only without duraplasty. Both groups of patients were of similar age at surgery and had similar nature and duration of symptoms prior to surgery. On pre-operative radiographic evaluation, both groups of patients had similar lengths of cerebellar ectopia (9.9±11.0 mm to 11.1±5.7 mm, p=0.591), and associated syrinxes (75% vs. 42.9%, p=0.205). Intraoperatively, both groups had similar estimated blood losses, though the length of surgery was significantly shorter when durotomy was spared (202±58.3 minutes to 116.3±47.8 minutes, p=0.011). The length of ICU stay was also significantly longer in the durotomy group (1.1±0.6 days to 0.0 days, p<0.001). Neither group reported any post-operative complications. On follow-up, both groups demonstrated similar reductions in cerebellar ectopia and syrinx characteristics. Clinically, the CCOS and CSS scores were similar between the two cohorts at follow-up, with no repeat surgery required in either group. Conclusion Our cohort suggests that for adult CM1 patients, SOC decompression alone without dural reconstruction might lead to comparable clinical and radiographic outcomes to SOC decompression with durotomy/duraplasty, especially if intraoperative ultrasound confirms good cerebrospinal fluid (CSF) flow after SOC. Notably, sparing durotomy and duraplasty is also associated with decreased operative time and decreased ICU stay.

Evaluation and Treatment of Patients with Small Posterior Cranial Fossa and Chiari Malformation, Types 0 and 1.

The diagnosis of Chiari I malformation is straightforward in patients with typical signs and symptoms of Chiari I malformation and magnetic resonance imaging (MRI) confirming ≥5 mm of cerebellar tonsillar ectopia, with or without a syrinx. However, in many cases, Chiari I malformation is discovered incidentally on MRI to evaluate global headache, cervical radiculopathy, or other conditions. In those cases, the clinician must consider if cerebellar tonsillar ectopia is related to the presenting symptoms. Surgical decompression of the cerebellar tonsils and foramen magnum in patients with symptomatic Chiari I malformation effectively relieves suboccipital headache, reduces syrinx distension, and arrests syringomyelia progression. Neurosurgeons must avoid operative treatments decompressing incidental tonsillar ectopia, not causing symptoms. Such procedures unnecessarily place patients at risk of operative complications and tissue injuries related to surgical exploration. This chapter reviews the typical signs and symptoms of Chiari I malformation and its variant, Chiari 0 malformation, which has <5 mm of cerebellar tonsillar ectopia and is often associated with syringomyelia. Chiari I and Chiari 0 malformations are associated with incomplete occipital bone development, reduced volume and height of the posterior fossa, tonsillar ectopia, and compression of the neural elements and cerebrospinal fluid (CSF) pathways at the foramen magnum. Linear, angular, cross-sectional area, and volume measurements of the posterior fossa, craniocervical junction, and upper cervical spine identify morphometric abnormalities in Chiari I and Chiari 0 malformation patients. Chiari 0 patients respond like Chiari I patients to foramen magnum decompression and should not be excluded from surgical treatment because their tonsillar ectopia is <5 mm. The authors recommend the adoption of diagnostic criteria for Chiari 0 malformation without syringomyelia. This chapter provides updated information and guidance to the physicians managing Chiari I and Chiari 0 malformation patients and neuroscientists interested in Chiari malformations.

Complication Avoidance in Chiari Malformation Surgery.

Posterior fossa decompression for symptomatic Chiari malformation is an effective and frequently performed procedure, but it does carry risks of significant complications including cerebrospinal fluid leak and craniocervical instability. Patients sometimes do not improve or worsen after decompression, which may discourage neurosurgeons from performing Chiari decompression surgery. In this chapter, management strategies and surgical approaches are discussed that minimize the risks of complications and maximize favorable outcomes in Chiari malformation surgery.

Prospective, Longitudinal Study of Clinical Outcome and Morphometric Posterior Fossa Changes after Craniocervical Decompression for Symptomatic Chiari I Malformation.

The time course of changes in posterior fossa morphology, quality of life, and neurologic function of patients with Chiari I malformation after craniocervical decompression requires further elaboration. To better understand the pace of these changes, we longitudinally studied patients with Chiari I malformation, with or without syringomyelia, before and after the operation for up to 5 years. Thirty-eight symptomatic adult patients (35 women, 3 men) diagnosed with Chiari I malformation only (n = 15) or Chiari I malformation and syringomyelia (n = 23) and without previous Chiari I malformation surgery were enrolled in a clinical study. Patients underwent outpatient study visits and MR imaging at 7 time points (ie, initial [before the operation], 3 months, 1 year, 2 years, 3 years, 4 years, and 5 years) during 5 years. The surgical procedure for all patients was suboccipital craniectomy, C1 laminectomy, and autologous duraplasty. Morphometric measurements demonstrated an enlargement of the CSF areas posterior to the cerebellar tonsils after the operation, which remained largely stable through the following years. There was a decrease in pain and improved quality of life after the operation, which remained steady during the following years. Reduction in pain and improved quality of life correlated with CSF area morphometrics. Most changes in MR imaging morphometrics and quality of life measures occurred within the first year after the operation. A 1-year follow-up period after Chiari I malformation surgery is usually sufficient for evaluating surgical efficacy and postoperative MR imaging changes.

The role of traditional social determinants of health in referral patterns, timing of surgery, and Chiari Health Index for Pediatrics-determined quality of life in children with symptomatic Chiari type I malformation.

Understanding the impact of the social determinants of health on the utilization of healthcare resources is an important step in eliminating inequalities. The goal of this study was to determine the role of social determinants of health in referral patterns, timing of consultation/intervention, and quality of life in children with Chiari malformation type I (CM-I). A retrospective study was conducted of children aged 0 to 18 years who underwent surgical treatment for CM-I at a single pediatric facility from 2015 to 2019. The variables included demographic and socioeconomic characteristics, referral patterns, timing, and quality of life data based on the Chiari Health Index for Pediatrics (CHIP). The cohort consisted of 103 surgically treated CM-I patients. No differences were seen in race, sex, insurance, or household income when evaluating referral source (community, specialist, or emergency department) or when comparing patients with incidental versus symptomatic findings. In the evaluation of timing from initial evaluation to surgery, no statistical differences were seen between racial, sex, insurance status, or income groups. Children from households of lower median family income were significantly more likely to report pain at the time of consultation (pain group median [interquartile range] $46,660 [$41,004-$50,367] vs nonpain group $53,604 [$41,427-$59,828], p = 0.004). Those in the lower-income group also reported lower CHIP scores corresponding to increased symptomatology in the nonpain physical symptoms (p = 0.004) and psychosocial domains (p = 0.018). There was no evidence of a difference in referral patterns or a delay in time from clinic presentation to surgery based on the traditional social determinants of health categories. Children from households in the lower-income group were associated with increased severity of pain and nonpain symptoms.

Pre and postnatal care characteristics and management features of children born with myelomeningocele in the post-folate fortification era of staple foods in Costa Rica (2004-2022).

To describe the clinical characteristics of pre- and postnatal care of children born with myelomeningocele in Costa Rica from 2004 to 2022 after the introduction of mandatory fortification of four major staple foods, describing the clinical features of this cohort including the size of the meningomyelocele, neurological level, presence of symptomatic Chiari II at birth, kyphosis, and the severity of hydrocephalus requiring cerebrospinal fluid (CSF) shunting. These results were compared against the pre-fortification historical data to determine favorable outcomes from this health policy. We performed a retrospective review of the clinical records of patients with myelomeningocele at the spina bifida clinic from the National Children's Hospital of Costa Rica who were born between 2004 and 2022, a period when staple food fortification was implemented in the country for four food staples (wheat and corn flour, rice, and dairy products). Pre and postnatal care data pertaining to the number of obstetric ultrasound studies, the trimester in which they were performed, the detection of myelomeningocele and associated hydrocephalus, gestational age and route of delivery, neurological level, myelomeningocele defect size, associated kyphosis and symptomatic Chiari II malformation at birth, time periods of myelomeningocele repair, and CSF shunting were examined. A descriptive comparative frequency analysis between myelomeningocele (MMC) defect size, CSF shunt insertion, symptomatic Chiari II, and kyphosis between the different functional levels was performed with the estimation of the Fisher's exact chi-square test by contingency tables, and 0.05 was set as significance level. Additionally, the postnatal features of this cohort were compared against pre-fortification historical data obtained from 100 live-born patients between 1995 and 1996. A total of 215 patients that were live born between 2004 and 2022 were eligible for analysis with a follow up ranging from 1 to 19years (median follow up: 7.9years). Among 99.1% of the mothers of patients who had prenatal consultations, 95.8% had an average of 3.8 obstetric ultrasound studies which led to a 59% prenatal detection rate of myelomeningocele. The pre and post fortification features showed a male/female ratio that changed from 0.92 to 1.25 respectively. Among these newborns, there was an increase from 54 to 64% cesarean sections as method for delivery. Only 26% of the pre fortification patients had the MMC defect repaired in the first 24h, 32% from 24 to 72h, 20% from 72h to 1week, and 22% later than 10days respectively which deeply contrasted with the post fortification cohort where 7.5% had the MMC defect repaired in less than 8h, 12.2% from 8 to 12h, 66.5% 12-24h, and 12.7% from 24 to 48h and 1% later than 48h, respectively (P < 0.01). Regarding the post fortification myelomeningocele anatomic and functional characteristics, defect size was measured as less than 3cm in 7% of cases, 3 to 5cm in 50% of cases, 5 to 7cm in 42% of cases, and greater than 7cm in 1% of cases. Thirteen percent of the cases had paraplegia due to a thoracic level, 10% had a high lumbar level, 58% had a middle lumbar level, 13% a lower lumbar level, and 6% only sacral compromise. When the data from the pre and post fortification cohorts were adjusted and compared, there was a reduction from thoracic/high lumbar cases from 26 to 23% (P < 0.56), with an increase of middle lumbar cases from 43 to 58% and a reduction from 25 to 13% of low lumbar cases (P < 0.01) while there was no change in the 6% percentage of sacral cases respectively. Lesions that were considered too extensive or larger than 7cm decreased from 7 to 1% while associated kyphotic deformities decreased from 6 to 1.4% (P < 0.01); symptomatic Chiari II malformation at birth also decreased from 7 to 2% in the pre- and post-fortification cohorts respectively with all these changes being statistically significant (P < 0.01). Seventy-nine percent and 80% of the pre and post FAF cohorts required CSF VP shunting with a mean time for insertion of 10days after spinal defect closure with no significant statistical change between the two groups. This study describes a four-staple folate fortified population of live-born patients with myelomeningocele lesions whose neurological level, defect size, and associated deformities such as spinal kyphosis and symptomatic Chiari II at birth suggest that folate fortification could have diminished the severity of this congenital disease.

Symptomatic Cerebellar Ptosis After Wide Foramen Magnum Decompression for Chiari I Malformation

We present the case of a 22-year-old who developed severe neck pain within two weeks after undergoing posterior fossa decompression for a symptomatic Chiari I malformation. A diagnosis of cerebellar ptosis was made after magnetic resonance imaging (MRI) and he underwent a partial cranioplasty, following which his symptoms resolved. The pathology, diagnostic criteria, and management options are discussed.

Intraoperative neuromonitoring for pediatric Chiari decompression: when is it useful?

Surgical treatment for symptomatic Chiari I malformation involves surgical decompression of the craniovertebral junction. Given the proximity of critical brainstem structures, intraoperative neuromonitoring (IONM) is employed for safe decompression in some institutions. However, IONM adds time and cost to the operation, and the benefit to the patient has not been defined. Given the diversity in surgical practices, there is no evidence-based standard of care regarding when to use IONM and which modalities are most helpful. The purpose of this study was to review a single-surgeon experience with IONM in order to determine the sensitivity, specificity, and predictive values of various IONM modalities routinely used in pediatric Chiari I decompression; to examine the associations between patient, clinical, and radiographic characteristics and IONM alerts; and to obtain data regarding the usefulness of these modalities during the surgical process to improve patient outcomes. A retrospective review was performed for 300 consecutive pediatric patients who underwent suboccipital craniectomy and C1 laminectomy for Chiari decompression performed by a single surgeon over a 15-year period. Clinical, radiographic, and IONM data were collected. Radiographic measurements of the skull base morphological abnormalities, including clival angle, Chamberlain's line, and Grabb-Oakes line, were compared between patients with and without true IONM signal changes. A total of 291 cases were included, with an age range of 6 months to 19 years. Among 291 cases, somatosensory evoked potentials (SSEPs) were monitored in 291, motor evoked potentials (MEPs) in 209, cranial nerve spontaneous electromyography (sEMG) in 290, and brainstem auditory evoked potentials (BAEPs) in 110. Sensitivity, specificity, positive predictive value, and negative predictive value, respectively, were as follows: 1.00, 1.00, 1.00, and 1.00 for SSEPs; 1.00, 0.99, 0.67, and 1.00 for MEPs; 0.00, 0.88, 0.00, and 1.00 for sEMG; and not appliable, 1.00, not applicable, and 1.00 for BAEPs. Six patients had true IONM signal changes. These patients had radiographic evidence of more severe concomitant craniocervical instability and basilar invagination, with steeper clival angles (124° vs 146°, p = 0.02) and larger Grabb-Oakes lines (10.1 mm vs 6.7 mm, p = 0.02), when compared with the patients without any true IONM changes. Intraoperative neuromonitoring may be best utilized for patients who show radiographic features of abnormal skull base morphology, defined as a clival angle < 135° or Grabb-Oakes line > 9 mm. When IONM is employed, SSEP and MEP monitoring are the most useful modalities.

Epidemiology of Chiari I Malformation and Syringomyelia.

Chiari I malformation is a common condition seen by adult and pediatric neurosurgeons. With increased utilization of MRI over time, incidental findings of Chiari I malformation are occurring more frequently. The prevalence of symptomatic Chiari I malformation is much smaller than that of asymptomatic Chiari I malformation. The prevalence of Chiari I malformation-associated syringomyelia is likely overestimated in the literature. The epidemiology of Chiari I malformation and associated syringomyelia differs based on age, sex, ethnicity, race, and socioeconomic status. The natural history of Chiari I malformation and associated syringomyelia appears to be quite benign as few patients who are managed nonsurgically later require surgical intervention.

Acquired Chiari type I malformation: a late and misunderstood supratentorial over-drainage complication.

Acquired Chiari I malformation is an uncommon but possible late complication of supratentorial shunting in children. This condition can be caused by an abnormal thickening of the cranial vault and consequent reduction of the posterior cranial fossa (PCF) volume especially in children with already a small PCF volume. The management of Acquired Chiari I malformation is very challenging, and several options have been proposed for this condition. These are aimed to expand the PCF volume both through decompression and PCF remodeling in order to relieve symptoms of acquired Chiari I malformation. A cranial vault remodeling or a standard Chiari decompression is two proposed techniques aimed to expand the PCF volume thus relieving symptoms . We describe the case of a 16-year-old girl undergone surgical removal of sellar-suprasellar glioneuronal tumor and ventriculo-peritoneal shunting, who developed an acquired symptomatic Chiari type I malformation some years after ventricular-peritoneal shunting. For this condition, she underwent successful standard Chiari decompression with C0-C1 craniectomy and duroplasty. We retrospectively analyzed MRI and CT scan performed during follow-up, in order to evaluate the volume of the posterior cranial fossa and to measure the variation of skull thickness at different periods. MRI and CT scan analysis showed a progressive thickening of the calvaria, in particular of the occipital bone, leading to a progressive reduction of PCF volume with the establishment of acquired Chiari type I malformation. In this case, standard C0-C1 Chiari decompression was effective in restoring PCF volume and relieving symptoms. Acquired Chiari I malformation due to chronic overhunting could be a severe and late complication in patient undergone supratentorial shunting. These patients require careful clinical and radiological follow-up to avoid over-drainage. According to our analysis, a careful selection of pediatric patients for supratentorial shunting should be made according to pre-operative PCF volume in order to foresee higher odds of possible late complications from over-drainage.

Dura Management Strategies in the Surgical Treatment of Adult Chiari Type I Malformation: A Retrospective, Multicenter, Population-Based Parallel Cohort Case Series.

Symptomatic Chiari I malformation is treated with suboccipital decompression and C1 laminectomy. However, whether the dura should be opened (durotomy) or enlarged with a graft (duraplasty) remains unclear. To compare outcomes in adult Chiari I malformation patients treated with duraplasty, durotomy, or without dural opening ("mini-decompression"). A retrospective, multicenter, population-based cohort study was performed of all adult patients surgically treated for a Chiari I malformation at 3 regional neurosurgical centers between 2005 and 2017. Three different dura management strategies were favored by the participating hospitals, with data stratified accordingly. The primary outcome was measured using the Chicago Chiari Outcome Scale (CCOS), dichotomized into favorable (CCOS ≥13) or unfavorable (CCOS ≤12). Propensity score matching was used to adjust for potential confounders in outcome comparisons. In total, 318 patients were included, of whom 52% were treated with duraplasty, 37% with durotomy, and 11% with mini-decompression. In total, 285 (90%) showed a favorable surgical outcome (CCOS ≥13). Duraplasty was associated with more favorable CCOS and shorter hospital stay compared with durotomy, both in unadjusted (93% vs 84%. P = .018 and 6.0 vs 8.0 days, P < .001) and adjusted analyses (92% vs 84%, P = .044 and 6.0 vs 8.0 days, P < .001). Mini-decompression was excluded from the adjusted analyses because of its small sample size. In this study of adult Chiari I malformation, posterior fossa decompression with duraplasty was associated with more favorable postoperative outcome, as determined by the CCOS, compared with posterior fossa decompression with durotomy alone.

Foramen magnum decompression for Chiari malformation type I – UK surgical practice

Background: Symptomatic Chiari 1 malformation (CM1) is a common condition in Neurosurgery. Surgery involves hindbrain decompression and restoration of CSF flow through different surgical approaches. No Class 1 evidence exists to suggest the superiority of any of the surgical techniques. Aims: To investigate current surgical practice for symptomatic CM1 patients in the United Kingdom (UK) and determine the willingness to participate in a randomised controlled trial (RCT) comparing different surgical techniques. Methods: An electronic survey was sent to consultant members of the Society of British Neurological Surgeons and the British Chiari-Syringomyelia Group. The questions covered pre-operative and intra-operative management, presence of equipoise/uncertainty in optimal technique and willingness to participate in an RCT. Results: 98 responses were received. 67% operate on adults. 30% on adult and paediatric patients. There is variation in routine pre-operative use of: ICP monitoring (18%), flexion/extension x-rays (16%), venography (20%) and ophthalmology assessment (26%). 18% of neurosurgeons would not offer foramen magnum decompression when the presenting symptom is only refractory cough/sneeze headache. 15% routinely perform bony decompression alone in adults vs 8% in children. In 68% of adult cases, durotomy is performed routinely (46% of them leave the dura open, 54% perform a type of duroplasty) and 16% routinely resect the cerebellar tonsils. Only 17% leave the dura open in children. The most common indicators for durotomy are syringomyelia and intra-operative ultrasound findings. 61% believe there is equipoise/uncertainty in the optimal strategy for decompression and would be willing to participate in an RCT. Comments also mention the heterogeneity of CM1 and that treatment should be tailored to each patient. Conclusion: There is wide variation in pre- and intra-operative management of CM1 patients in the UK and the majority of neurosurgeons would be willing to participate in an RCT comparing bony decompression alone vs dural opening with/without duroplasty.

A different perspective on the dilemma of durotomy or duraplasty in Chiari type 1 malformation surgery

Purpose Symptomatic Chiari type 1 malformation (CIM) patients may elect to be treated; however, choosing the optimum surgical method remains problematic: posterior fossa decompression with duraplasty (PFDD) or without duraplasty (PFD). Many studies have compared these surgical methods from several perspectives. We looked at soft tissue density (STD) at the foramen magnum to add another perspective to the comparison of PFD with PFDD. Materials and methods Eighty-six patients who underwent surgery in our clinic were included in the study. We examined preoperative and postoperative MR images taken in the 1st year. We obtained the foramen magnum area (FMA) and soft tissue at the level of the foramen magnum. The STD within the foramen magnum was calculated as the percentage ratio of soft tissue area (STA) to FMA. Anteroposterior diameters of the syrinx cavities in sagittal T2 sections were measured preoperatively and at 1-year postoperatively. Measurements were double-blind and were performed by the neurosurgeon and by the neuroradiologist. Results There was no statistically significant difference between the postoperative FMA increases, STA changes, STD changes in patients who underwent PFD and PFDD. In this study, there was no statistically significant difference between PFD and PFDD in terms of syrinx changes. Conclusions The medium-term anatomical outcome following craniovertebral decompression for CIM, is no different whether performed PFD or PFDD.

Posterior cranial fossa and cervical spine morphometric abnormalities in symptomatic Chiari type 0 and Chiari type 1 malformation patients with and without syringomyelia

To better understand how anatomical features of Chiari malformation type 0 (CM0) result in the manifestation of Chiari malformation type 1 (CM1) signs and symptoms, we conducted a morphometric study of the posterior cranial fossa (PCF) and cervical canal in patients with CM1 and CM0. This retrospective study had a STROBE design and included 120 adult patients with MRI evidence of a small PCF (SPCF), typical clinical symptoms of CM1, and a diagnosis of CM1, CM0, or SPCF-TH0-only (SPCF with cerebellar ectopia less than 2mm and without syringomyelia). Patients were divided by MRI findings into 4 groups: SPCF-TH0-only, SPCF-TH0-syr (CM0 with SPCF and syringomyelia), SPCF-CM1-only (SPCF with cerebellar ectopia 5mm or more without syringomyelia), and SPCF-CM1-syr (CM1 with syringomyelia). Neurological examination data and MRI parameters were analyzed. All patient cohorts had morphometric evidence of a small, flattened, and overcrowded PCF. The PCF phenotype of the SPCF-TH0-only group differed from that of other CM cohorts in that the length of clivus and supraocciput and the height of the PF were longer, the upper CSF spaces of PCF were taller, and the area of the foramen magnum was smaller. The SPCF-TH0 groups had a more significant narrowing of the superior cervical canal and a smaller decrease in PCF height than the SPCF-CM1 groups. Patients with SPCF-TH0 with and without syringomyelia developed Chiari 1 symptoms and signs. Patients with SPCF-TH0-syr (Chiari 0) had more constriction of their CSF pathways in and around the foramen magnum than patients with SPCF-TH0-only.

Treatment of symptomatic Chiari I malformation by "all-factors-surgery": a report of 194 cases.

Inadequate decompressions can lead to poor improvement of symptoms in patients with Chiari I malformation (CMI). In this study, the "all-factors-surgery" that including all levels decompressions was performed on symptomatic CMI patients for the snake of eliminating all possible pathogenic factors and reducing the chance of reoperation. The "all-factors-surgery" combined operations of posterior fossa decompression, enlarged cranioplasty, duraplasty, cerebellar tonsil partial resection and adhesion release. Total 194 patients from January 2010 to December 2015. The outcome measures included improvement rate of symptoms, patients self-evaluation (improved, unchanged, worsened), Visual Analogue Scale (VAS) score, Japanese Orthopaedic Association (JOA) score, Chicago Chiari Outcome Scale (CCOS) score, the diameter of the syrinx and complications. Postoperative data were collected from the three stages: at discharge, the short-term follow-up (average, 9.39months), and the long-term follow-up (average, 54.44months). Patients self-evaluation improvement rate in the three follow-up stages was 92.27%, 90.07% and 85.93%. The VAS scores (mean, 1.49, 1.21, 1.47 vs 3.76) and JOA scores (mean, 15.66, 15.99, 16.10 vs 14.84) were significant difference between the follow-up and pre-operation (P < .05). The CCOS scores of short-term and long-term follow-up were significantly better than that at discharge (mean, 14.75, 14.87 vs 13.68) (P < .05). The diameter of syrinx in each follow-up stage was significantly less than that in pre-operation (mean, 3.39, 1.95, 1.87 vs 5.09) (P < .05). There were no serious complications, and no one asked for reoperation during the follow up. Symptomatic CMI patients undergoing "all-factors-surgery" had persistently high rates of symptom relief and rarely needed reoperation.

The impact of neurosurgical technique on the short- and long-term outcomes of adult patients with Chiari I malformation

ObjectiveThis study is aimed to compare and evaluate any differences in clinical and radiological outcomes of different operative techniques of cranio-cervical decompression (CCD) performed in adults with symptomatic Chiari malformation type I (CM-1) within a single tertiary neurosurgical center. MethodsA retrospective review using the Hospital theatre management system (ORSOS) and records of patients who underwent CCD for CM-1 between January 2011 and October 2019 was performed.Patients were divided in three cohorts according to the operative technique used: an extradural osteo-ligamentous decompression (BD), BD followed by dural opening either without duraplasty (DOWD) or plus duroplasty (DOPD). The primary clinical outcome was measured by utilizing the Chicago Chiari Outcome Scale (CCOS). Syrinx outcome was measured on post-op MRI. Statistical analysis was performed using IBM SPSS 24 with α = 0.05. Results67 adults underwent 69 CCD: 10 BD, 29 DOWD and 30 DOPD. Median follow-up was 47.3 months (Interquartile Range (IQR) 26.3–73.7). Patients who underwent DOPD had a shorter median hospital stay (p-value 0.001), fewer unplanned readmissions (p-value 0.015), a higher median CCOS (p-value 0.001) and a lower post-operative complications rate (p-value 0.001) compared to patients who underwent DOWD. BD revealed a 40 % failure rate and was ineffective in cases with syringomyelia. ConclusionBetter clinical outcomes, lower complication risk, and short duration of hospital stay were associated with patients who underwent dural opening with augmentative watertight duraplasty. Bony decompression alone despite being a very safe technique, does not appear to be reliable and effective in controlling and relieving the clinical symptoms and the syringomyelia of adult patients with CM-1.

Reply to the Letter to the Editor Regarding “Shunt Valve Rupture in Ventriculoperitoneal Shunt Failure”

The nucleus tractus solitarius and paratrigeminal nucleus, which are implicated in the processing of airway-derived sensory information, are found in the dorsal medulla. The mechanism and localization of higher-order processing of urge to cough is poorly understood, and much of the existing anatomical localization is limited to animal studies.A 44-year-old Caucasian lady underwent elective foramen magnum decompression for symptomatic Chiari I malformation; postoperatively she had resolution of Chiari symptoms but developed an intractable neurogenic cough. She has no significant medical history or premorbid respiratory issues. Postoperative magnetic resonance imaging of her head demonstrated signal change in the left dorsal medulla, corresponding with the nucleus tractus solitarius and paratrigeminal nucleus.We suggest that this lesion explains her isolated new cough and localizes the pathway for “urge to cough” to this region of the medulla.

"Growing cerebellum" requiring operative decompression following perinatal ventriculoperitoneal shunting.

While cases of acquired Chiari I malformation following ventriculoperitoneal shunting for posthemorrhagic hydrocephalus have been reported, true disproportionate cerebellar growth is rare, with no previous cases requiring posterior fossa decompression reported. We present a premature neonate who underwent ventriculoperitoneal shunt placement for suspected posthemorrhagic hydrocephalus. He subsequently developed a symptomatic Chiari I malformation with volumetric measurements demonstrating disproportionate growth of the cerebellum. He did not demonstrate thickening of the supratentorial or posterior fossa cranium. The patient underwent an extradural posterior fossa decompression, with resolution of symptoms. We review the extant literature regarding the development of Chiari malformation type I as a manifestation of craniocerebral disproportion (CCD) following shunt placement for posthemorrhagic hydrocephalus of prematurity. Most previous reports reflect a mechanism that includes underdevelopment of the intracranial posterior fossa (or supratentorial) volume. The case presented in this report, as well as one additional case, indicates that there may exist a variant mechanism, characterized by rapid growth of the cerebellum itself, in the absence of one of the rare syndromes associated with primary macrocerebellum. While this case was effectively managed with extradural posterior fossa decompression, previous reports indicate that supratentorial cranial expansion procedures are preferable in some cases. As such, pediatric neurosurgeons should be able to distinguish the patterns of craniocerebral disproportion when considering treatment options for these patients. Further investigation regarding these uncommon patients may better describe the underlying mechanisms.