Chiari Malformation Research Articles

Arnold Chiari Malformation

Chiari malformations (CM) refer to a series of anomalies characterized by the descent of cerebellar tonsils into the cervical spinal canal. These malformations can be associated with abnormalities such as syringomyelia, hydrocephalus, spina bifida, and scoliosis. Additionally, craniocervical junction anomalies, endocrinopathies, craniosynostosis, and syndromic disorders are also linked to CM. The treatment of CM is surgical, and there is no known medical therapy. Patients diagnosed with CM are typically advised to undergo surgical treatment or follow-up. Although surgical intervention is supported in the literature, debates exist regarding which procedure is most suitable and when surgery should be performed. In this article, we will examine the historical background of CM, its anatomical forms, pathophysiology, clinical presentation, relationship with other diseases, and diagnostic procedures in the light of the literature.

Volumetric assessment of Posterior cranial fossa in a West African population

Background and Objectives: Posterior fossa pathologies can have potentially devastating outcomes. The volumetric capacity of this fossa, known to have ethnoregional variations, can thus be critical in determining outcomes and intervention measures and approaches to pathologies involving this region. This study aimed to evaluate the normal posterior fossa volumes within the West-African subpopulation. Methods: This was a descriptive study of all patients presenting for a cranial imaging study at the study location within a two-year period using a 1.5T MRI of this cranial region. Obtained data included the transverse and anteroposterior diameters, and the height of this fossa and the obtained data was analyzed. P values < 0.05 was statistically significant. Results: A total of 315 patients were recruited (165 males and 150 females). The average posterior fossa transverse diameter, anteroposterior diameter and height were 108.19 mm, 71.58 mm and 35.53 mm respectively for males, and 105.7 mm, 66.48 mm, and 34.24 mm for females respectively. The average posterior fossa volume for males (292.36 cm3) was significantly higher than for females (252.90 cm3) (p= 0.0038). The highest average posterior fossa volume was between 16-30 years for males and above 75 years for females. Conclusion: Posterior cranial fossa volumes for the West African population is significantly higher than those obtained for other regions. In addition to being beneficial in some posterior fossa space occupying lesions, this larger volume can explain the relative rarity and sexual preferences of some posterior fossa congenital abnormalities like Chiari-1 malformation amongst the West African population

Type one chiari malformation as a cause of central sleep apnea and hypoventilation in children

ObjectivesChiari type 1 malformation (CM1) may occasionally lead to central sleep apnea (CSA). We studied, in a large clinical cohort of pediatric CM1 patients, the effect of CM1 on breathing during sleep. MethodsThis is a retrospective single pediatric pulmonology center study with a systematic evaluation of pediatric CM1 patients under age 18 with polysomnography (PSG) during 2008–2020. Children with syndromes were excluded. All patients had undergone head and spine magnetic resonance imaging. ResultsWe included 104 children with CM1 with a median age of 7 (interquartile range (IQR) 5–13) years. The median extent of tonsillar descent (TD) was 13 (IQR 10–18) mm. Syringomyelia was present in 19 children (18%). Of all children, 53 (51%) had normal PSG, 35 (34%) showed periodic breathing or central apnea and hypopnea index ≥5 h−1, and 16 (15%) displayed features of compensated central hypoventilation and end-tidal or transcutaneous carbon dioxide 99th percentile level above 50 mmHg. TD had the best predictive value for central breathing disorders. In a linear model, both age (61%) and TD (39%) predicted median breathing frequency (R = 0.33, p < 0.001). ConclusionsAlthough severe CSA is a rare complication of brainstem compression in pediatric patients with CM1, short arousal-triggered episodes of periodic breathing and mild compensated central hypoventilation are common. TD shows the best but still poor prediction of the presence of a central breathing disorder. This highlights the use of PSG in patient evaluation. Posterior fossa decompression surgery effectively treats central breathing disorders.

The Reality of the Management of Spinal Dysraphism in a Country in a Precarious Situation: A Retrospective Study

Background: To report the epidemiological, therapeutic and evolutionary aspects of spinal dysraphism, with emphasis on the difficulties encountered during management in Madagascar. Methods: This is a retrospective, descriptive, multicenter study in the 7 neurosurgical centers of Madagascar over 5 years on children operated on for spinal dysraphism. Results: We collected 50 cases over 5 years. The mean age was 16.95 ± 33.94 months. Girls predominated (sex ratio = 0.85). The absence of folic acid supplementation in the mother was found in 62%. In all cases, the diagnosis was made in the postnatal period. Myelomeningocele is the most frequent form. Hydrocephalus was found in 20% of cases, orthopaedic malformation in 20%, and Chiari type II malformation in 2%. The dysraphism was localized at the lumbar level in 50% of cases. A spinal CT scan was performed in 62% of cases and transfontanellar ultrasound in 22% of cases. No magnetic resonance imaging of the brain or spinal cord was performed. A ventriculoperitoneal shunt was performed in 8% of cases. Postoperative hydrocephalus was 4%and mortality was 1% due to meningitis. The average follow-up time was 3 months with an extreme of 3 months to 3 years. Conclusion: In spite of the difficulties in the management of these children and the technical platform available in the country, they are operated correctly and the hospital mortality is low.

Prenatal diagnosis of non-typical Chiari malformation type I associated with de novo Nuclear Factor I A gene mutation: a case report

BackgroundChiari malformation is one of the most common Central nervous system (CNS) abnormalities that can be detected in routine fetal scanning. Chiari malformation type I (CMI) is a congenital defect characterized by a displacement of the cerebellar tonsils through the foramen magnum. The etiology of CMI has not been well established and suggested having multifactorial contributions, especially genetic deletion. Clinical characteristics of this anomaly may express in different symptoms from neurological dysfunction and/or skeletal abnormalities in the later age, but it is rarely reported in pregnancy.Case presentationWe present a case in which the Chiari malformation type I was diagnosed with comorbidities of facial anomalies (flatting forehead and micrognathia) and muscular-skeletal dysmorphologies (clenched hands and clubfeet) at the 24+6 weeks of gestation in a 29-year-old Vietnamese pregnant woman. The couple refused an amniocentesis, and the pregnancy was followed up every 4 weeks until a spontaneous delivery occurred at 38 weeks. The newborn had a severe asphyxia and seizures at birth required to have an emergency resuscitation at delivery. He is currently being treated in the intensive neonatal care unit. He carries the novel heterozygous NFIA gene mutation confirmed after birth. No further postnatal malformation detected.ConclusionCMI may only represent with facial abnormalities and muscle-skeletal malformations at the early stage of pregnancy, which may also alert an adverse outcome. A novel heterozygous NFIA gene mutation identified after birth helps to confirm prenatal diagnosis of CMI and to provide an appropriate consultation.

Chiari I Malformation Presenting Vertical Gaze-Evoked Nystagmus : A Case Report

Abstract&#x0D; Introduction : Chiari malformation is characterized by herniation of posterior cerebellar vermis in which type 1 malformation has coexisting syringomyelia of cervicothoracic spinal cord. This malformation can be congenital or acquired, in which gaze-evoked nystagmus is the typical movement deficit. This case aimed to report a case of vertical gaze-evoked nystagmus as a primary symptom to detect Type I Chiari Malformation.&#x0D; Case Illustration : A 44-year-old woman presented with involuntary movements of both eyes in the last 5 months with vision problems in which objects appear to jump or vibrate. Visual acuity was 20/50 in both eyes with 12 prism diopters BI exotropia. We recognized vertical and torsional nystagmus in upgaze without any movement in primary gaze. While performing supraduction, the oscillation was detected and increased. Brain MRI revealed Type I Chiari Malformation.&#x0D; Discussion : Nystagmus was seen in many diseases of the central nervous system, in particular those affecting the brainstem and cerebellum. Vertical gaze evoked nystagmus was a disorder of the gaze holding function, purely vertical gaze-evoked nystagmus is observed in midbrain lesions involving the interstitial nucleus of Cajal (INC) as the neural integrator for vertical gaze-holding function. Based on this pathophysiology, the Brain MRI of this patient revealed some degrees of compression in midbrain, and cervico medullary junction due to her brain malformation.&#x0D; Conclusion : A sustained gaze-evoked nystagmus is an important ocular finding that may indicate serious neurologic pathology. It is important for an eye care provider to thoroughly examine additional tests to determine the underlying cause of the nystagmus.

Duraplasty using a combination of a pedicled dural flap and collagen matrix in posterior fossa decompression for pediatric Chiari malformation type 1 with syrinx.

In posterior fossa decompression for pediatric Chiari malformation type 1 (CM-1), duraplasty methods using various dural substitutes have been reported to improve surgical outcomes and minimize postoperative complications. To obtain sufficient posterior fossa decompression without cerebrospinal fluid-related complications, we developed a novel duraplasty technique using a combination of a pedicled dural flap and collagen matrix. The objective of this study was to describe the operative nuances of duraplasty using a combination of a pedicled dural flap and collagen matrix in posterior fossa decompression for pediatric CM-1. We reviewed the clinical and radiographic records of 11 consecutive pediatric patients who underwent posterior fossa decompression with duraplasty using a combination of a pedicled dural flap and collagen matrix followed by expansile cranioplasty for CM-1. The largest area of the syrinx and the size of the posterior fossa were calculated. The maximum syrinx area was reduced by a mean of 68.5% ± 27.3% from preoperatively to postoperatively. Four patients (36.4%) had near-complete syrinx resolution (> 90%, grade III reduction), five (45.5%) had 50% to 90% reduction (grade II), and two (18.2%) had < 50% reduction (grade I). The posterior fossa area in the midsagittal section increased by 8.9% from preoperatively to postoperatively. There were no postoperative complications, including cerebrospinal fluid leakage, pseudomeningocele formation, or infection. Duraplasty using a combination of a pedicled dural flap and collagen matrix in posterior fossa decompression is a promising safe and effective surgical technique for pediatric CM-1 with syrinx.

MRI of the Spine in Patients who Toe Walk: Is There a Role?

Little is known about the prevalence of intraspinal pathology in children who toe walk, but magnetic resonance imaging (MRI) may be part of the diagnostic workup. The purpose of this study was to examine the role of MRI for children who toe walk with a focus on the rate of positive findings and associated neurosurgical interventions performed for children with said MRI findings. A single-center tertiary hospital database was queried to identify a cohort of 118 subjects with a diagnosis of toe walking who underwent spinal MRI during a 5-year period. Patient and MRI characteristics were summarized and compared between subjects with a major abnormality, minor abnormality, or no abnormality on MRI using multivariable logistic regression. Major MRI abnormalities included those with a clear spinal etiology, such as fatty filum, tethered cord, syrinx, and Chiari malformation, while minor abnormalities had unclear associations with toe walking. The most common primary indications for MRI were failure to improve with conservative treatment, severe contracture, and abnormal reflexes. The prevalence of major MRI abnormalities was 25% (30/118), minor MRI abnormalities was 19% (22/118), and normal MRI was 56% (66/118). Patients with delayed onset of toe walking were significantly more likely to have a major abnormality on MRI ( P =0.009). The presence of abnormal reflexes, severe contracture, back pain, bladder incontinence, and failure to improve with conservative treatment were not significantly associated with an increased likelihood of major abnormality on MRI. Twenty-nine (25%) subjects underwent tendon lengthening, and 5 (4%) underwent neurosurgical intervention, the most frequent of which was detethering and sectioning of fatty filum. Spinal MRI in patients who toe walk has a high rate of major positive findings, some of which require neurosurgical intervention. The most significant predictor of intraspinal pathology was the late onset of toe walking after the child had initiated walking. MRI of the spine should be considered by pediatric orthopedic surgeons in patients with toe walking who present late with an abnormal clinical course. Level III Retrospective Comparative Study.

Multicenter comparison of Chiari malformation type I presentation in children versus adults.

Treatment for Chiari malformation type I (CM-I) often includes surgical intervention in both pediatric and adult patients. The authors sought to investigate fundamental differences between these populations by analyzing data from pediatric and adult patients who required CM-I decompression. To better understand the presentation and surgical outcomes of both groups of patients, retrospective data from 170 adults and 153 pediatric patients (2000-2019) at six institutions were analyzed. The adult CM-I patient population requiring surgical intervention had a greater proportion of female patients than the pediatric population (p < 0.0001). Radiographic findings at initial clinical presentation showed a significantly greater incidence of syringomyelia (p < 0.0001) and scoliosis (p < 0.0001) in pediatric patients compared with adult patients with CM-I. However, presenting signs and symptoms such as headaches (p < 0.0001), ocular findings (p = 0.0147), and bulbar symptoms (p = 0.0057) were more common in the adult group. After suboccipital decompression procedures, 94.4% of pediatric patients reported symptomatic relief compared with 75% of adults with CM-I (p < 0.0001). Here, the authors present the first retrospective evaluation comparing adult and pediatric patients who underwent CM-I decompression. Their analysis reveals that pediatric and adult patients significantly differ in terms of demographics, radiographic findings, presentation of symptoms, surgical indications, and outcomes. These findings may indicate different clinical conditions or a distinct progression of the natural history of this complex disease process within each population, which will require prospective studies to better elucidate.

Pediatric neurosurgery through the lens of time-driven activity-based costing: a pilot study.

Time-driven activity-based costing (TDABC) is a method used in cost accounting that has gained traction in health economics to identify value optimization initiatives. It measures time, assigns value to time increments spent on a patient, and integrates the cost of material and human resources utilized in each episode of care. In this study, the authors report the first use of TDABC to evaluate costs in a pediatric neurosurgical practice. A clinical pathway was developed with a multifunction team. A time survey among each care team member, including surgeons, medical assistants (MAs), and patient service representatives (PSRs), was carried out prospectively over a 10-week period at a pediatric neurosurgery clinic. Consecutive patient encounters for Chiari malformation (CM), hydrocephalus, or tethered cord syndrome (TCS) were included. Encounters were categorized as new or established. Relative annual personnel costs, using the salary of a PSR as a reference (i.e., 1.0-unit cost), were calculated for all members using departmental financial data after adjustments. The relative capacity cost rates (minute-1) for each personnel, a representation of per capita cost per minute, were then derived, and the relative costs per visit were calculated. A total of 110 visits (24 new, 86 established) were captured, including 40% CM, 41% hydrocephalus, and 19% TCS encounters. Surgeons had the highest relative capacity cost rate (118.4 × 10-6), more than 10-fold higher than that of an MA or PSR (10.65 × 10-6 and 9.259 × 10-6, respectively). Surgeons also logged more time with patients compared with the rest of the care team in nearly all visits (p ≤ 0.002); consequently, the total visit costs were primarily driven by the surgeon cost (p < 0.0001). Overall, surgeon cost constituted the vast majority of the total visit cost (92%-93%), regardless of whether the visits were new or established. Visit costs did not differ by diagnosis. On average, new visits took longer than established visits (p < 0.001). This difference was largely driven by new CM visits (44.3 ± 13.7 minutes), which were significantly longer than established CM visits (29.8 ± 9.2 minutes; p = 0.001). TDABC may reveal opportunities to maximize value by highlighting instances of variability and high cost in each module of care delivery. Physician leaders in pediatric neurosurgery may be able to use this information to allocate costs and streamline value care pathways.

A novel classification and management scheme for craniocervical junction disorders with ventral neural element compression.

Craniocervical junction (CCJ) pathologies with ventral neural element compression are poorly understood, and appropriate management requires accurate understanding, description, and a more uniform nomenclature. The aim of this study was to evaluate patients to identify anatomical clusters and better classify CCJ disorders with ventral compression and guide treatment. A retrospective review of adult and pediatric patients with ventral CCJ compression from 2008 to 2022 at a single center was performed. The incidence of anatomical abnormalities and compressive etiologies was assessed. Surgical approach, radiographic data, and outcomes were recorded. Association rules analysis (ARA) was used to assess variable clustering. Among 51 patients, the main causes of compression were either purely bony (retroflexed dens [n = 18]; basilar invagination [BI; n = 13]) or soft tissue (degenerative pannus [n = 16]; inflammatory pannus [n = 2]). The primary cluster in ARA was a retroflexed dens, platybasia, and Chiari malformation (CM), and the secondary cluster was BI, C1-2 subluxation, and reducibility. These, along with degenerative pannus, formed the three major classes. In assessing the optimal treatment strategy, reducibility was evaluated. Of the BI cases, 12 of the 13 patients had anterolisthesis of C1 that was potentially reducible, compared with 2 of the 18 patients with a retroflexed dens (both with concomitant BI), and no pannus cases. The mean C1-2 facet angle was significantly higher in BI at 32.4°, compared with -2.3° in retroflexed dens and 8.1° in degenerative pannus (p < 0.05). Endonasal decompression with posterior fixation was performed in 48 (94.0%) of the 51 patients, whereas posterior reduction/fixation alone was performed in 3 patients (6.0%). Of 16 reducible cases, open posterior reduction alone was successful in 3 (60.0%) of 5 cases, with all successes containing isolated BI. Reduction was not attempted if vertebral anatomy was unfavorable (n = 9) or the C1 lateral mass was absent (n = 5). The mean follow-up was 28 months. Symptoms improved in 88.9% of patients and were stable in the remaining 11.1%. Tracheostomy and percutaneous G-tube placement occurred in 7.8% and 11.8% of patients, respectively. Reoperation for an endonasal CSF leak repair or posterior cervical wound revision both occurred in 3.9% of patients. In classifying, one cluster caused decreased posterior fossa volume due to an anatomical triad of retroflexed dens, platybasia, and CM. The second cluster caused pannus formation due to degenerative hypertrophy. For both, endonasal decompression with posterior fixation was ideal. The third group contained C1 anterolisthesis characterized by a steep C1-2 facet angle causing reducible BI. Posterior reduction/fixation is the first-line treatment when anatomically feasible or endonasal decompression with in situ posterior fixation when anatomical constraints exist.

Patient and caregiver perceptions of Chiari malformation: a qualitative analysis of online discussion boards.

Patients and their caregivers utilize online discussion board forums as a means to seek and exchange information about their or a loved one's condition. It is important for providers to be aware of such concerns and experiences. The goal of this study was to identify the primary concerns expressed on these discussion boards regarding Chiari malformation type I (CM) and to help guide clinicians in understanding patient challenges in the treatment of CM. The authors performed thematic analysis of anonymous online discussion board posts as identified through internet search engines. They then adopted a previously developed grounded theory method that utilizes a three-tiered coding and grouping process of posts based on commonly discovered content themes. Analysis of 400 discussion board posts identified four distinct themes raised by CM patients and their caregivers: the path to diagnosis, symptoms experienced, surgical intervention, and high emotional burden. Although each individual experience was unique, the path toward a CM diagnosis was expressed as a journey involving multiple physicians, alternative diagnoses, and feelings of dismissal from providers. The most common reported symptoms included dizziness, headaches, neck and back pain, sensory issues, weakness and paresthesias of the extremities, speech issues, and general fatigue. Additionally, there was an overall sense of uncertainty from patients seeking advice regarding surgical intervention, with users expressing diverse sentiments that included both positive and negative outcomes regarding surgical treatment. Lastly, a wide range of emotions was expressed related to a CM diagnosis, including concern, worry, anxiety, depression, stress, fear, and frustration. CM is a frequent imaging diagnosis identified in patients presenting with a wide range of symptoms, and as a result this leads to a diverse set of patient experiences. Analysis of CM patient and caregiver discussion boards revealed key themes that clinicians may address when counseling for CM.

Clinical details of individuals with Rauch-Steindl syndrome due to NSD2 truncating variants.

Rauch-Steindl syndrome (RAUST) is a very rare genetic syndrome caused by a pathogenic variant in NSD2 on chromosome 4p16.3. Although NSD2 was previously thought to be the major gene in Wolf-Hirschhorn syndrome (WHS), a contiguous gene syndrome of chromosome 4p16.3 deletion, RAUST has been found to present different facial and clinical features from WHS. In this study, we report the details of two newly diagnosed individuals with RAUST in order to better understand the molecular and clinical features of RAUST. Whole-genome sequencing was performed on two individuals with psychomotor delay and growth failure. Detailed clinical evaluation of growth parameters, craniofacial features, electroencephalogram (EEG), magnetic resonance imaging of the brain, and developmental assessment were performed. Both individuals had de novo truncating variants in NSD2. One had a novel variant (c.2470C>T, p.Arg824*), and the other had a recurrent variant (c.4028del, p.Pro1343Glnfs*49). Both exhibited characteristic RAUST facial features, growth failure, and mild psychomotor delay. A novel finding of RAUST was seen in individual 2, a Chiari malformation type 1, and both showed delayed bone age. They lacked common WHS features such as congenital heart defects, cleft lip/palate, and seizures (EEG with abnormal findings). We present a novel variant and clinical presentations of RAUST, expand the molecular and clinical diversity of RAUST, and improve our understanding of this rare syndrome, which is distinct from WHS. Further researches are needed on more RAUST cases and on functional analysis of NSD2.

Evaluation of in patients with sleep related breathing disorders Arnold-Chiari Malformation type 1, before and after surgical treatment

Evaluation of in patients with sleep related breathing disorders Arnold-Chiari Malformation type 1, before and after surgical treatment

A Rare Case of Cornelia De Lange Syndrome

An 8-year-old female child was referred to our Cleft and Craniofacial centre, Department of Plastic &amp; Reconstructive Surgery, Saveetha Medical College &amp; Hospital, after being diagnosed with cleft palate and hyper nasal speech. She is the first child born from a non- consanguineous marriage with a birth weight of 2.6 kg. Following her, a girl and a boy were born and exhibited no apparent abnormalities. Both parents maintain a normal status, and there is no history of deformities in their family lineage. The patient underwent a typical vaginal delivery and was born at full term. At the time of birth, the child was differentially diagnosed with a neurogenic tumour in the occipital region of the skull. The child was not treated for the growth in the occiput. Patient had growth retardation, global developmental delays and features of facial dysmorphism like microcephaly, bushy and uni eyebrow, long eyelashes, low set ears, small nose, concave nasal bridge, and hirsutism. The child was subjected to an MRI brain scan in our unit and it suggested a hyperechoic lesion in the midline at C3, C4 level with an impression of Arnold Chiari malformation. Clinically, on palpation of the lesion, it approximately measured 4x3 cm, soft in consistency and the lesion hardened while coughing or sneezing and regressed back to normalcy within a few minutes. USG abdomen was done and a well-defined hypoechoic dumbbell shaped bilobed solid lesion with smooth margins with no significant vascularity was noted in the gastrohepatic region. Echocardiogram was done and it ruled out cardiac anomalies like patent ductus arteriosus or coarctation of aorta. Inspection of the oral cavity was done to diagnose the cleft of the secondary palate. (Fig. 1) Based on all features in examination and investigation, a diagnosis of Cornelia de Lange syndrome was made. The surgery was planned after a routine blood workup. The child was advised for CECT of abdomen to confirm the USG findings of abdominal anomalies, however, the report suggested cystic lymphangioma. (Fig. 2) Fitness for palatoplasty surgery was obtained from paediatrician, paediatric surgeon, neurosurgeon, cardiologist and anaesthesiologist. Under antibiotic cover, the child was operated under general anaesthesia for palatoplasty by Sommerlad’s technique. (Fig. 3 &amp; 4) The post-operative period was uneventful.

Clinical Relevance of Painful Congenital Early-onset Scoliosis: A Magnetic Resonance Image-based Study.

Back pain, as a clinical marker in scoliosis, has been associated with underlying pathology for many years, warranting further magnetic resonance imaging (MRI). Failures of segmentation, mixed defects, female gender, rib anomalies, congenital thoracic anomalies, and neurocutaneous markers are known risk factors for abnormal MRI pathology findings in patients with congenital early-onset scoliosis (Congenital-EOS). Yet, back pain has not been evaluated as a risk factor for underlying MRI pathology in patients with Congenital-EOS. This study aimed to assess back pain as a risk factor for underlying pathology in Congenital-EOS using MRI as a diagnostic tool. A retrospective database review from the Pediatric Spine Study Group (PSSG) of all patients with Congenital-EOS who reported a back pain complaint, and underwent a spinal MRI study before surgical intervention was performed. Patients were divided into those with an underlying MRI pathology and those without. Demographics were compared between groups. From a total of 2355 patients with Congenital-EOS registered in PSSG, 107 patients reported a back pain complaint, with only 42 patients fulfilling the inclusion criteria (being evaluated with an MRI study). Overall group mean age was 8.1±4.5 years, with 25 of the 42 patients (60%) being females. Twenty-four of 42 patients (57%) had a comorbidity reported such as cardiac problems, musculoskeletal complaints, neurological deficits/myelopathy, gastrointestinal symptoms, developmental delay, respiratory problems, craniofacial abnormalities, and chromosomal conditions. An underlying MRI pathology was found in 21 of 42 patients with Congenital-EOS (50%) with back pain. The underlying MRI pathologies found were tethered spinal cord, spinal canal stenosis, syringomyelia, Arnold-Chiari malformation, and arachnoid cyst. Abnormal MRI findings are common in patients with Congenital-EOS who report back pain. Gender, age, major coronal curve angle, thoracic or lumbar predominance deformity, and comorbidities type or amount were not associated with abnormal MRI findings. Level II-Prognostic study.

Pulsatile microvascular cerebral blood flow waveforms change with intracranial compliance and age.

Diffuse correlation spectroscopy (DCS) is an optical method to measure relative changes in cerebral blood flow (rCBF) in the microvasculature. Each heartbeat generates a pulsatile signal with distinct morphological features that we hypothesized to be related to intracranial compliance (ICC). We aim to study how three features of the pulsatile rCBF waveforms: the augmentation index (AIx), the pulsatility index, and the area under the curve, change with respect to ICC. We describe ICC as a combination of vascular compliance and extravascular compliance. Since patients with Chiari malformations (CM) () have been shown to have altered extravascular compliance, we compare the morphology of rCBF waveforms in CM patients with age-matched healthy control (). AIx measured in the supine position was significantly less in patients with CM compared to healthy controls (). Since physiologic aging also leads to changes in vessel stiffness and intravascular compliance, we evaluate how the rCBF waveform changes with respect to age and find that the AIx feature was strongly correlated with age (, , and , ). These results suggest that the AIx measured in the cerebral microvasculature using DCS may be correlated to changes in ICC.

Morphological and ultrastructural investigation of the posterior atlanto-occipital membrane: Comparing children with Chiari malformation type I and controls.

The fibrous posterior atlanto-occipital membrane (PAOM) at the craniocervical junction is typically removed during decompression surgery for Chiari malformation type I (CM-I); however, its importance and ultrastructural architecture have not been investigated in children. We hypothesized that there are structural differences in the PAOM of patients with CM-I and those without. In this prospective study, blinded pathological analysis was performed on PAOM specimens from children who had surgery for CM-I and children who had surgery for posterior fossa tumors (controls). Clinical and radiographic data were collected. Statistical analysis included comparisons between the CM-I and control cohorts and correlations with imaging measures. A total of 35 children (mean age at surgery 10.7 years; 94.3% white) with viable specimens for evaluation were enrolled: 24 with CM-I and 11 controls. There were no statistical demographic differences between the two cohorts. Four children had a family history of CM-I and five had a syndromic condition. The cohorts had similar measurements of tonsillar descent, syringomyelia, basion to C2, and condylar-to-C2 vertical axis (all p>0.05). The clival-axial angle was lower in patients with CM-I (138.1 vs. 149.3 degrees, p = 0.016). Morphologically, the PAOM demonstrated statistically higher proportions of disorganized architecture in patients with CM-I (75.0% vs. 36.4%, p = 0.012). There were no differences in PAOM fat, elastin, or collagen percentages overall and no differences in imaging or ultrastructural findings between male and female patients. Posterior fossa volume was lower in children with CM-I (163,234 mm3 vs. 218,305 mm3, p<0.001), a difference that persisted after normalizing for patient height (129.9 vs. 160.9, p = 0.028). In patients with CM-I, the PAOM demonstrates disorganized architecture compared with that of control patients. This likely represents an anatomic adaptation in the presence of CM-I rather than a pathologic contribution.

Retroflexed dens in paediatric Chiari 1 patients and implications: Single centre retrospective study.

Chiari 1 malformation and hind brain hernia can be associated with skull base and craniocervical anomalies. One of the more recently associated anomalies is a retroverted or retroflexed odontoid process or dens. We conducted a retrospective study of our operated symptomatic and conservatively managed asymptomatic Chiari cohort to assess the impact of dens retroflexion on rate of revision or cerebrospinal fluid diversion following primary foramen magnum decompression (FMD). We undertook a retrospective study of all foramen magnum decompression (FMD) cases for Chiari type 1 malformation performed over a 15-year period in a single tertiary paediatric neurosurgical unit. For comparison, non-operated asymptomatic Chiari cases were considered as reference cohort.Information gathered included: demographics, age, sex, length of cerebellar tonsils below McRae's line, pB-C2 distance (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C2 body), angle of retroflexion (angle formed between a line drawn through the odontoid synchondrosis and its intersection with a line drawn from the tip of the odontoid process) and angle of retroversion (angle formed between the line drawn from the base of C2 and its intersection with a line drawn from the tip of the odontoid process). Grade of retroflexion was measured using pre-operative mid-sagittal MR images and classified as grade 0 (> 90°), grade 1 (85°-89°); grade 2 (80°-84°) and grade 3 (< 80°). The rates for redo surgery or need for cerebrospinal fluid (CSF) diversion were obtained from clinical records and compared in the operated and non-operated groups. One hundred twenty-six Chiari 1 patients were included in this study with adequate imaging. Sixty-five patients were in the non-operated asymptomatic cohort with 61 patients in the operated symptomatic cohort.Mean age of non-operated cohort was 10.2years with M:F ratio (30:35). Mean cerebellar tonsillar length below McRae's line was 10.3mm. 7.7% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 76 and 78°, respectively. Retroflexion grades included (9.2% grade 1, 35% grade 2 and 52.3% grade 3). pB-C2 distance was 6.8mm. Mean age of operated cohort was 11.3years, with M:F ratio (21:40). Mean cerebellar tonsillar length below McRae's line was 15mm. 45.9% of this cohort had associated syrinx. Mean angles of retroversion and retroflexion were 73 and 74.5°, respectively. Retroflexion grades included (4.9% grade 1, 16.5% grade 2 and 78.6% grade 3). pB-C2 distance was 6.9mm. No association was identified between retroflexion grade and rate of revision or CSF diversion following primary foramen magnum decompression. The operated Chiari 1 cohort had more retroflexed dens, longer tonsils and associated syrinx compared to the non-operated asymptomatic cohort.

Optic neuropathy in craniosynostosis.

Craniosynostosis (CS) or the premature fusion of one or more cranial sutures in utero, or during the first years of life, can present in isolation or as a multisystem clinical disorder with a particular impact on visual function. Among ophthalmic complications, optic neuropathy is a significant cause of irreversible vision loss in these patients. Children with CS are at higher risk of developing elevated intracranial pressure which can lead to papilledema and, ultimately, optic atrophy. In addition, sometimes associated obstructive sleep apnea, abnormalities in central nervous system venous development, and Chiari malformation may contribute to optic neuropathy. Ophthalmologists have an important role in managing a number of coexistent ophthalmologic complications such as strabismus, anisometropia, amblyopia, ptosis, and exposure keratopathy in addition to maintaining surveillance for early signs of optic neuropathy; they play a critical consultative role contributing to the decision for primary or repeat decompressive surgery. In this article, we aim to review the etiology, diagnostic approach, and management of optic neuropathies in patients with craniosynostosis.