Chiari I Malformation Patients Research Articles

Utilization of Vestibular Information for Balance Control in Children with Chiari I Malformation

(1) Background: Surgery for Chiari I malformation (CMI) is indicated when typical clinic-radiological features (syringomyelia, exertional headaches, sleep apnea syndrome, and tetraparesis) are present. Sometimes, patients have atypical complaints suggestive of otolaryngological (ENT) involvement, and it is sometimes difficult for the neurosurgeon to determine if these complaints are related to the CMI. Our aim was to describe postural control patterns in children with CMI using computerized dynamic posturography. To our knowledge, this is the first study addressing postural instability in pediatric CMI patients. (2) Methods: Twenty-eight children aged 6 to 17 years with both radiologically confirmed CMI and clinical ENT complaints were included. The children were separated into two groups, operated and non-operated patients, based on neurosurgical indication. Epidemiologic and posturographic results (CDP—Equitest®) were compared between both groups, as well as pre- and postoperatively in Group 2. (3) Results: In Group 2 patients, significant improvement of global SOT was found after intervention. When the three sensorial aspects of postural control calculated by the system were independently assessed, the greatest improvement was in the vestibular ratio. We also observed an altered CoG pattern (“lateral deviation”) in the Group 2 patients, which significantly differed from those in Group 1. Lateral deviation was significantly reduced postoperatively in the Group 2 patients. A correspondence between preoperative MRI and the side of lateralization on posturography was found in four children, but this cannot be regarded as significant due to the low number of patients. (4) Conclusions: Postural control seems to improve after surgery for CMI in children, mostly due to the improvement in vestibular function. There is a correspondence between the side of lateral deviation and the side of greatest tonsillar descent on MRI and perioperatively. Further studies are needed to support these results and to confirm the utility of CDP in CMI patients.

Transient Decrease in Cerebrospinal Fluid Motion Is Related to Cough-Associated Headache in Chiari I Malformation

Short-lasting cough-associated Headache (CAH) in patients with Chiari I Malformation (CMI) is believed to be due to transient worsening of CSF flow obstruction at the foramen magnum. We assessed changes in CSF flow in response to coughing in CMI patients with CAH and compared to those without CAH and healthy participants (HP) using real-time MRI. Seventeen CMI patients (12 with CAH, 5 without CAH) and 6 HP were prospectively assessed using real-time pencil-beam imaging (PBI) MR sequence. A 64-mm length PBI cylinder was placed at the cranio-cervical junction. CSF stroke volume (SVCSF) was assessed during resting, post-coughing and relaxation phases via a 90-second scan. SVCSF was measured at six levels at 5-mm intervals between 10 and 35 mm below the foramen magnum. During each phase, SVCSF was compared between CMI with and without CAH and HP and corrected for multiple comparisons. At multiple consecutive levels, post-coughing SVCSF was significantly lower in CMI with CAH compared to both CMI without CAH and HP (p <0.05). No differences in post-coughing SVCSF were seen between CMI without CAH and HP. At rest or relaxation phase, no differences in SVCSF were seen between patients with and without CAH but minimal differences were seen between CMI with CAH and HP. A decrease in CSF flow after coughing in CMI patients with CAH supports the notion that CAH is caused by transient worsening of CSF flow obstruction at the foramen magnum.

Cerebrospinal Fluid Flow and Brain Motion in Chiari I Malformation: Past, Present, and Future.

Cranio-spinal volume and pressure changes associated with the cardiac-cycle and respiration are altered in Chiari I malformation (CMI) due to obstruction of cerebrospinal fluid (CSF) flow at the foramen magnum. With the introduction of motion-sensitive MRI sequences, it was envisioned that these could provide noninvasive information about volume-pressure dynamics at the cranio-cervical junction in CMI hitherto available only through invasive pressure measurements. Since the early 1990s, multiple studies have assessed CSF flow and brain motion in CMI. However, differences in design and varied approaches in the presentation of results and conclusions makes it difficult to fully comprehend the role of MR imaging of CSF flow and brain motion in CMI. In this review, a cohesive summary of the current status of MRI assessment of CSF flow and brain motion in CMI is presented. Simplified versions of the results and conclusions of previous studies are presented by dividing the studies in distinct topics: 1) comparing CSF flow and brain motion between healthy subjects (HS) and CMI patients (before and after surgery), 2) comparing CSF flow and brain motion to CMI severity and symptoms, and 3) comparing CSF flow and brain motion in CMI with and without syringomyelia. Finally, we will discuss our vision of the future directions of MR imaging in CMI patients. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: 5.

Diagnostic utility of parasagittal measurements of tonsillar herniation in Chiari I malformation.

Although the cerebellar tonsils are parasagittal structures, the extent of tonsillar herniation (ETH) in Chiari I malformation (CMI) is currently measured in the midsagittal plane. We measured the ETH of each cerebellar tonsil in the parasagittal plane and assessed their diagnostic utility by comparing them to the midsagittal ETH measurements in predicting cough-associated headache (CAH), an indicator of clinically significant disease in CMI. Eighty-five CMI patients with 3D-MPRAGE images were included. Neurosurgeons determined the presence of CAH. Sagittal images were used to measure ETH in the midsagittal (MS_ETH) and parasagittal planes (by locating tonsillar tips on each side on reformatted coronal images). Given the parasagittal ETH (PS_ETH) asymmetry in the majority of cases, they were considered Smaller_PS_ETH or Larger_PS_ETH. The accuracy of ETH measurements was assessed by the receiver operating characteristic (ROC) curve. Of 85 patients, 46 reported CAH. ROC analysis showed an area under the curve (AUC) of 0.78 for Smaller_PS_ETH significantly better than 0.65 for MS-ETH in predicting CAH (p = 0.001). An AUC of 0.68 for Larger_PS_ETH was not significantly different from MS_ETH. The sensitivity and specificity of predicting CAH were 87% and 28% for MS_ETH >6 mm versus 90% and 46% for Smaller_PS_ETH >6 mm, and 52% and 67% for MS_ETH >9 mm versus 48% and 87% for Smaller_PS_ETH >9 mm. At ETH >15 mm, no differences were seen between the measurements. Diagnostic utility of ETH measurements in detecting clinically significant CMI can be improved by parasagittal measurements of the cerebellar tonsillar herniation.

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.

Obex position is associated with syringomyelia and use of posterior fossa decompression among patients with Chiari I malformation.

Chiari I malformation (CM-I) has traditionally been defined by measuring the position of the cerebellar tonsils relative to the foramen magnum. The relationships of tonsillar position to clinical presentation, syringomyelia, scoliosis, and the use of posterior fossa decompression (PFD) surgery have been studied extensively and yielded inconsistent results. Obex position has been proposed as a useful adjunctive descriptor for CM-I and may be associated with clinical disease severity. A retrospective chart review was performed of 442 CM-I patients with MRI who presented for clinical evaluation between 2003 and 2018. Clinical and radiological variables were measured for all patients, including presence/location of headaches, Chiari Severity Index (CSI) grade, tonsil position, obex position, clival canal angle, pB-C2 distance, occipitalization of the atlas, basilar invagination, syringomyelia, syrinx diameter, scoliosis, and use of PFD. Radiological measurements were then used to predict clinical characteristics using regression and survival analyses, with performing PFD, the presence of a syrinx, and scoliosis as outcome variables. Among the radiological measurements, tonsil position, obex position, and syringomyelia were each independently associated with use of PFD. Together, obex position, tonsil position, and syringomyelia (area under the curve [AUC] 89%) or obex position and tonsil position (AUC 85.4%) were more strongly associated with use of PFD than tonsil position alone (AUC 76%) (Pdiff = 3.4 × 10-6 and 6 × 10-4, respectively) but were only slightly more associated than obex position alone (AUC 82%) (Pdiff = 0.01 and 0.18, respectively). Additionally, obex position was significantly associated with occipital headaches, CSI grade, syringomyelia, and scoliosis, independent of tonsil position. Tonsil position was associated with each of these traits when analyzed alone but did not remain significantly associated with use of PFD when included in multivariate analyses with obex position. Compared with tonsil position alone, obex position is more strongly associated with symptomatic CM-I, as measured by presence of a syrinx, scoliosis, or use of PFD surgery. These results support the role of obex position as a useful radiological measurement to inform the evaluation and potentially the management of CM-I.

Cerebrospinal Fluid Dynamics Study: A Unique Tool for Management of Chiari 1 Malformation Patients

Background and Aim: Chiari I malformation(CIM) is defined as descent of cerebellar tonsils 5mm or more below the foramen magnum, with or without associated syrinx. Degree of tonsillar descent has a poor correlation with the progression of disease and symptomatology. Abnormal CSF dynamics at foramen magnum is the main pathophysiological factor responsible for the progression of tonsillar descent, syrinx formation and hence symptomatology. The aim of this study is to correlate CSF dynamic changes with the clinicoradiological profile of CIM patients. Methods and Materials/Patients: A prospective longitudinal study was done in 25 patients of CIM out of which 24 patients underwent standard midline suboccipital craniectomy with augmented duraplasty and 1 patient had ventriculoperitoneal shunt surgery for hydrocephalus. CSF flow study was done in sagittal as well as in axial sections at the level of foramen magnum using cine flow magnetic resonance imaging (MRI). Clinical and radiological assessment in reference to CSF flow parameters was done before and after decompression surgery. Results: After suboccipital decompression 23 out of 24 patients had relief in their symptoms and 1 patient had progressive syringomyelia. Postoperative MRI scan at 3months showed round shaped tonsils in all 24 patients. Ten out of 11 patients with syrinx had reduction in diameter of syrinx cavity. Peak CSF flow velocities reduced significantly (p value &lt; 0.05) in the postoperative period and correlated well with the clinicoradiological improvement. Conclusion: Abnormal CSF flow dynamics is responsible for the progression of disease and symptomatology in CIM patients. Cine flow MRI is a useful tool in the management of CIM patients both for proper selection of surgical candidates and in post-operative follow-up.

Treatment Options for Hydrocephalus Following Foramen Magnum Decompression for Chiari I Malformation: A Multicenter Study.

New-onset hydrocephalus following foramen magnum decompression (FMD) for Chiari I malformation (CM-I) is rare; its natural history and pathophysiology are poorly understood. To describe a series of patients who developed hydrocephalus following FMD for CM-I, provide possible explanations of this phenomenon, and outline treatment options. Out of patients undergoing FMD for CM-I from 6 different tertiary centers, we evaluated patients presenting with new-onset hydrocephalus following FMD. The retrospectively collected data included demographics, clinical, and radiological findings of the CM-I and hydrocephalus patients. Time from FMD and hydrocephalus onset, treatment, and surgical techniques were assessed. Of 549 patients who underwent FMD for CM-I, 28 (5.1%) subsequently developed hydrocephalus (18 females, 10 males), with a mean age of 11.7±11.9 yr (range 6 mo to 52 yr). Hydrocephalus occurred on average 2.2±2.6 mo after FMD (range 1 wk to 8 mo). Four patients did not have a violation of the arachnoid during the FMD surgery. Main presenting symptoms of hydrocephalus were headaches (17, 41%), vomiting (10, 24.4%), and cerebrospinal fluid (CSF) leak or pseudomeningocele (7, 17%).Overall, 23 patients (82.1%) underwent CSF shunting, 1 patient (3.5%) had an endoscopic third ventriculostomy, 3 patients (10.7%) temporary CSF diversion only, and 1 patient (3.5%) was treated with acetazolamide. Hydrocephalus following FMD for CM-I is uncommon, but important. Based on our series and literature review, its incidence is about 5% to 7% and most likely will require further surgery. Shunting appears to be the favored treatment option.

Clinical utility of 2-D anatomic measurements in predicting cough-associated headache in Chiari I malformation.

Cough-associated headache (CAH) is the most distinctive symptom of patients with Chiari I malformation (CMI) and indicates clinically significant disease. We determined the clinical utility of simple 2D anatomic measurements performed on a PACS workstation by assessing their diagnostic accuracy in predicting CAH in CMI patients. Seventy-two consecutive CMI patients (cerebellar tonsillar herniation >5mm) with headache seen by neurosurgeons over 6years were included. Sagittal T1 images were used by two readers to measure: extent of tonsillar herniation, lengths of the clivus and supra-occiput, McRae and pB-C2 lines, as well as clivus-canal, odontoid retroversion, and skull base angles. Neurosurgery notes were reviewed to determine presence of CAH. Mann-Whitney test was used to compare measurements between patients with and without CAH. Predictive accuracy was assessed by receiver operating characteristic (ROC) curve. 47/72 (65.3%) CMI patients reported CAH. Tonsillar herniation with CAH (10.2mm, 7-14mm; median, interquartile range) was significantly greater than those without CAH (7.9mm, 6.3-10.9mm; p = 0.02). Tonsillar herniation ≥ 10mm showed sensitivity and specificity of 51% and 68%, and tonsillar herniation > 14mm showed sensitivity and specificity of 30% and 100%, respectively, for predicting CAH. Other 2D measurements showed no statistically significant differences. Among the 2D measurements used, only the extent of tonsillar herniation is different between CMI patients with and without CAH. Although CMI is diagnosed with tonsillar herniation of only 5mm, we found that a much higher extent of herniation is needed to be predictive of CAH.

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

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

Chiari I malformation-neuropsychological functions and quality of life.

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

Headache in Chiari Malformation.

Headache is a common symptom in patients with Chiari I malformation (CMI), characterized by 5 mm or greater cerebellar tonsillar herniation below foramen magnum. Radiologists should be aware of the different types of headaches reported by CMI patients and which headache patterns are distinctive features of the diagnosis. A methodical imaging strategy is required to fully assess a CMI patient to exclude secondary causes of tonsillar herniation such as intracranial hypotension or associated conditions such as syrinx. Both anatomic and physiologic imaging can help determine if headaches are CMI associated, and assist clinicians in therapeutic decision making.

Swallowing Dysfunction in Adult Patients with Chiari I Malformation.

Background Swallowing difficulties have been reported in patients with Chiari I malformation (CMI) with a prevalence of 4 to 47%, but existing evidence is based only on case reports. We aimed to prospectively study swallowing function in adult patients with CMI before and 3 months after surgical decompression. Methods We included all adult patients diagnosed with CMI from September 2015 to October 2017 who underwent a planned surgery at Sahlgrenska University Hospital, Sweden. The patients were offered the opportunity to participate in and undergo an assessment consisting of the "Watson Dysphagia Scale (WDS)" and "EORTC QLQ-OG25" written questionnaires in addition to videofluoroscopic examination of swallowing (VFS) before and 3 months after surgery. Demographic data and comorbidities were recorded. Results Eleven patients were included, nine of which underwent both pre- and postoperative evaluations. Four patients (36%) reported varying degrees of swallowing complaints (mean WDS score, 16). In two of these, there was substantial penetration of contrast material into the laryngeal vestibule on VFS, and in the other two patients, minor swallowing disturbances were observed. Borderline deviations from normal VFS findings were also found in three asymptomatic patients. Although not all VFS deviations completely disappeared after surgery, the patients reported no remaining symptoms. Conclusion Symptoms of dysphagia and objective abnormalities on VFS are not uncommon in CMI patients. Surgery has the potential to remedy underlying causes of dysphagia, thereby relieving its symptoms.

Radiological evolution of peri-odontoid pannus in a patient with Chiari I malformation: a case-based review

The Chiari I malformation (CIM) is commonly encountered by neurosurgeons and can have different etiologies and clinical presentations. We report a CIM patient who presented with symptoms of ventral brain stem compression and was found to have a large peri-odontoid pannus. Posterior fossa decompression was performed with a planned second-stage odontoidectomy. However, at the 6-month follow-up, postoperative images demonstrated a mostly resolved pannus and improvement of the brain stem compression symptoms, and the patient progressed uneventfully without the need for odontoidectomy. This case illustrates the resolution of a significant and symptomatic peri-odontoid pannus in a patient with CIM without craniocervical fusion or odontoidectomy. Such a case indicates that not all peri-odontoid pannus formations in CIM patients are due to hypermobility at the craniocervical junction.

Diffusion tensor imaging findings of the brainstem in subjects with tonsillar ectopia.

We aimed to evaluate the differences between apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) values obtained from different cranial sites in subjects with Chiari I Malformation (CM-I) and borderline tonsillar ectopia (BTE), and to determine correlations between diffusion tensor imaging (DTI) metrics and the severity of tonsillar ectopia. A total of 73 subjects with CM-I and BTE and 35 control underwent MRI and DTI. In our study, ADC values measured from the level of medulla oblongata and the RD values measured in middle cerebellar peduncles, thalamus, and globus pallidus were higher in CM-I patients than in controls. FA values at the medulla oblongata level and AD values at the medulla oblongata and pons level higher in patients with CM-I. ADC and AD values measured at the pons level were higher in BTE subjects than in controls. Compared with BTE, the CM-I subjects' ADC values at the medulla oblongata and AD values at the pons level were higher. In addition, FAs at the pons and medulla oblongata level were higher. At the medulla oblongata level, a positive correlation was observed between ADC and the size of tonsillar ectopia. AD and FA values measured at the level of medulla oblongata and pons were positively correlated with the size of tonsillar ectopia. These findings may be related to the severity of microstructural changes involving neuronal tracts at the brainstem level due to tonsillar ectopia. DTI may be useful in determining the extent of microstructural changes at the tissue level in subjects with tonsillar ectopia.

Neurofibromatosis type 1 and Chiari type 1 malformation: A case report and literature review of a rare association.

Background:The association between neurofibromatosis type 1 (NF-I) and Chiari I malformation (CMI) is rare, and not many studies are reported in the literature. Performing magnetic resonance imaging (MRI) in patients with NF-1 is essential because several cases of Chiari type I are completely asymptomatic. We emphasize the need for inclusion of Chiari I as diagnosis in association with NF-1.Case Description:The patient was a 51-year-old black man who presented with complaints of pain and decreased motion and sensibility of his hands, wrists, and forearms, along with progressive dysarthria. Even though the computed tomography (CT) scan of the skull did not show changes, the MRI showed hydro/syringomyelia in the cervical spine area. Midline suboccipital craniectomy with total laminectomy of c1 and partial laminectomy of c2 was performed; tonsillectomy was also performed for cistern expansion because of intense thickening and obliteration of the obex by the cerebellar tonsils. Following treatment, the patient showed remission of symptoms.Conclusion:NF-1 in association with CMI is rare, and early diagnosis and surgical treatment are essential to slow down the myelopathy; although they prevent neurological damages, patients with NF-1 must remain under doctor's attention in case of association with CMI. Our literature review showed that symptoms can vary and include headache, gait disturbance, and sensory/motor diminution, until asymptomatic patients. Moreover, the incidence of NF-1 is considerably higher in CMI patients in comparison to the global incidence (8.6–11.8% and 0.775%, respectively). The surgical technique must be evaluated case by case according to the degree of cerebrospinal fluid obstruction.

Sports participation with Chiari I malformation.

OBJECT There is currently no consensus on the safety of sports participation for patients with Chiari I malformation (CM-I). The authors' goal was to define the risk of sports participation for children with the imaging finding of CM-I. METHODS A prospective survey was administered to 503 CM-I patients at 2 sites over a 46-month period. Data were gathered on imaging characteristics, treatment, sports participation, and any sport-related injuries. Additionally, 81 patients completed at least 1 subsequent survey following their initial entry into the registry and were included in a prospective group, with a mean prospective follow-up period of 11 months. RESULTS Of the 503 CM-I patients, 328 participated in sports for a cumulative duration of 4641 seasons; 205 of these patients participated in contact sports. There were no serious or catastrophic neurological injuries. One patient had temporary extremity paresthesias that resolved within hours, and this was not definitely considered to be related to the CM-I. In the prospective cohort, there were no permanent neurological injuries. CONCLUSIONS No permanent or catastrophic neurological injuries were observed in CM-I patients participating in athletic activities. The authors believe that the risk of such injuries is low and that, in most cases, sports participation by children with CM-I is safe.

Polisomnographyc results in chiari malformation type I

The most common symptom experienced by patients with Chiari I malformation (CM-I) is occipital headache many times started or worsened by Valsalva maneuvers a sneezing, coughing, or straining. They may also experience difficulties with balancing and dizziness, muscle weakness, coordination problems, as well as gait abnormalities. Some patients present with sleep disordered breathing a symptoms such as hypersomnia, insomnia or sleep disorder breathing. Although several authors have found distinct types of apneas and hypopneas in patients with CM-I, there are no studies that analyze sleep quality with this malformation. The main purpose of this study is to establish the impact of CM-I on sleep architecture, respiratory parameters and leg movements (PLMs). A prospective study was conducted in a correlative series of 105 CM-I patients (67 women and 38 men, mean age of 41.9 ± 12.5 years) admitted between 10/1997 and 04/2001. A whole-night video-polysomnography was performed in all patients. Sleepiness in pathological range (Epworth > 10) was present in only 12 patients (11.4%). Sleep architecture only showed a decrease in sleep efficiency due to wake after sleep onset with preservation in normal range of sleep stages proportions. Fifty-three patients showed a pathological respiratory disturbance index (RDI Y5) and in 29.5% moderate to severe range (RDIY15). The respiratory alterations were predominantly obstructive hypopneas during the supine position. Twenty-two patients showed PLMs > 15. Patients with CM-I had an increased prevalence of fragmented sleep and sleep disordered breathing respect to normal population. These alterations may not be reported by patients and can only be detected by performing a specific sleep study. Its detection may help to screen patients and to establish surgical indications.. This work has been supported in part by the Fondo de Investigación Sanitaria (Instituto de Salud Carlos III) with grant PI07/0681, co-financed by the European Regional Development Fund (ERDF) and awarded to Dr. M.A. Poca.

Morphometric comparison of foramen magnum in non-syndromic craniosynostosis patients with or without Chiari I malformation

In order to compare the morphometry of foramen magnum (FM) in a matched-pair study, in children with non-syndromic craniosynostosis with and without Chiari I malformation (CMI), both brain magnetic resonance (MRI) and multidetector computed tomography (MDCT) images were utilized. Brain MR images were retrieved from the Helsinki University Hospital Picture Archiving and Communications System to identify patients with CMI during 1.1.2004 to 31.3.2009. Age-, gender-, and craniosynostosis-matched controls were retrieved from the same cohort. Morphometric analysis of FM was carried out. Seven patients with non-syndromic craniosynostosis with CMI were recorded. In CMI patients, the absolute anteroposterior length was 33.4 mm as compared to 36.7 mm in controls (p = 0.023). The mean width was 28.1 and 29.9 mm (p = 0.29), and the cross-sectional area was 654.1 and 764.9 mm(2) (p = 0.11) in CMI and controls, respectively. In CMI patients, the relative anteroposterior length of the FM was, on average, 91 % of the control's measurements. On average, the width was 95 % and the cross-sectional area was 88 % of the control's results. In pediatric non-syndromic craniosynostosis patients, a statistically significant reduced anteroposterior diameter of the FM is found in patients with an adjacent CMI as compared to their age-, gender-, and type-matched controls of craniosynostosis.

Morphometric analysis of the craniocervical juncture in children with Chiari I malformation and concomitant syringobulbia

Although very uncommon, Chiari I malformation (CIM) with syringomyelia may be associated with concomitant syringobulbia. We hypothesized that the anatomy of the craniocervical region may be different in CIM patients with syringomyelia who develop syringobulbia in conjunction with their syringomyelia compared to other patients with CIM with and without syringomyelia. The present study was conducted in order to prove or disprove such a theory. A group of 189 children with operated CIM were reviewed for the presence of syringobulbia, and this cohort then underwent morphometric analyses of their craniocervical juncture. These measurements were then compared to both our prior patient findings and historic controls. The current study did not identify any morphometrical peculiarities for patients with CIM and syringobulbia compared to other CIM patients with and without isolated syringomyelia. Based on our study, the mechanism behind such cerebrospinal fluid distention into the brain stem remains elusive with no single morphometrical difference in patients with CIM and syringobulbia compared to other patients with CIM. Perhaps, future testing aimed at identifying pressure gradients across the foramen magnum in patients with and without syringobulbia and concomitant CIM may be useful.