Craniocervical Decompression Research Articles

Novel Assessment of Cerebrospinal Fluid Dynamics by Time-Spatial Labeling Inversion Pulse Magnetic Resonance Imaging in Patients with Chiari Malformation Type I.

We investigated cerebrospinal fluid (CSF) dynamics at the craniocervical junction (CCJ) using Time-SLIP magnetic resonance imaging to demonstrate the significance of ventral and dorsal combined CSF dynamics in assessing CSF flow disturbance in patients with Chiari malformation type I. Fifteen examinations were performed in 9 cases of CM-I (3 female patients; mean age, 24.7 years; age range, 11-46 years) before or after craniocervical decompression. The longitudinal maximum movement of the caudal edge of tagged midsagittal CSF at the CCJ was measured as length of motion (LOM), and total on the ventral and dorsal sides was defined as total LOM. In 8 conditions, where it was concluded that no craniocervical decompression was necessary or where symptoms improved following craniocervical decompression based on the clinical symptoms, total LOM was 49.8 ± 13.1 mm. In contrast, in the 7 cases where craniocervical decompression was mandatory, total LOM was 23.2 ± 9.2 mm. Significant differences were identified between the 2 groups. Total LOM <35.0 mm resulted to indicate the insufficiency of CSF dynamics, because it corresponded to the necessity of craniocervical decompression based on patients' symptoms. Time-SLIP MRI enabled clinicians to use novel dynamic indices, such as CSF motions, in addition to the conventional findings acquired by MRI. In particular, it was essential to examine combined ventral and dorsal CSF dynamics in assessing CSF patency at the CCJ in patients with CM-I.

Bilambdoid and sagittal synostosis: Report of 39 cases.

Background:Bilambdoid and sagittal synostosis (BLSS), also called “Mercedes Benz synostosis,” is a multisutural craniosynostosis that has been described as a specific entity. However, this synostotic pattern can also be found in syndromic craniostenosis. To better define this entity we reviewed our experience with bilambdoid and sagittal synostosis.Methods:We searched our prospective database for cases of bilambdoid and sagittal synostosis among all types of craniosynostosis. Two groups were distinguished – patients with isolated BLSS and the group of syndromic craniostenosis for whom BLSS was observed at initial presentation. We reviewed the clinical findings, associated diseases, and their management specifically for isolated BLSS patients.Results:Thirty-nine patients were diagnosed with bilambdoid and sagittal synostosis among 4250 cases of craniosynostosis treated in our department over a period of 42 years. Among them, 8 were finally diagnosed as Crouzon syndrome. Of the 31 patients identified with isolated bilambdoid and sagittal synostosis, 25 (81%) were males and 6 (19%) were females. The average age at diagnosis was 17 months. At diagnosis, 16% of the population presented with papillary edema and 58% posterior digitate impressions. Two types of craniofacial dysmorphy were observed – a pattern with narrow occiput (71% of cases) and a pattern with dolichocephaly (29% of cases). Cerebellar tonsillar herniation was the most frequently associated malformation (61% of the isolated BLSS). Surgical management evolved during the years, and several surgical techniques were used to treat patients with BLSS, including isolated biparietal vault remodeling, posterior vault remodelling, and posterior vault expansion with internal or external distraction. In some cases, a craniocervical junction decompression was also performed. The mean follow-up was 82 months (7 years). The overall mental development was within normal limits in most children, but a mental delay was found in 25%.Conclusion:Bilambdoid and sagittal synostosis constitute an isolated entity in almost 80% of the cases, whereas in the remaining 20% it is part of a faciocraniosynostosis syndrome. Two phenotypes may be found. Early surgical management is indicated, and several techniques can be used in this heterogeneous population. A cerebellar tonsillar prolapse is present in a majority of cases.

Comparison of Three Different Cranio-Cervical Decompression Procedures in Children with Chiari Malformation Type I: Does the Surgical Technique Matter?

Background/Aims: A broad spectrum of cranio-cervical decompression techniques (CCD) is employed for the treatment of Chiari malformation type I (CM1). The aim of this study was to compare the clinical and radiological outcome of 3 different CCD performed in a single paediatric centre. Methods: A retrospective analysis of children treated between 2008 and 2014 was performed. Three different surgical techniques were offered to the patients: an extradural osseo-ligamentous bony decompression (BD), or a BD plus opening of the dura either without duroplasty (DOWD) or with watertight expansile duroplasty (DOPD). The primary clinical outcome was measured by utilizing the Chicago Chiari Outcome Scale (CCOS). Results: Forty-six children underwent 51 CCD: 17 BD, 17 DOWD, and 17 DOPD. The median follow-up period was 46 months (16-98 months). Patients who underwent BD had a shorter length of hospital stay than those who underwent DPTC and DOWD. Clinical improvement, defined by the mean CCOS score, was comparable in patients receiving BD (n = 14.6) and DOPD (n = 14.5), but lower in patients with DOWD (n = 12). Post-operative complications were noted in 7 DOWD patients (41%) and 3 DOPD patients (17.6%). Conclusions: BD is a safe and effective procedure with comparable clinical and radiological outcomes to DOPD in children with CM1. The risk of post-operative complications and worse clinical outcome was noted to be higher when performing a DOWD.

Closing the dura: dural hitching versus surgicel and tisseel overlay graft in craniocervicaldecompression for Chiari 1 malformation

Background: This study compares dural hitching to surgicel and tisseel overlay graft following craniocervical decompression and C1 laminectomy with simple durotomy for Chiari I malformation. Outcome measures were syrinx decompression, headache resolution and complication rates.Methods: A retrospective analysis of case notes was conducted. Patients who had undergone craniocervical decompression (CCD) were grouped by method of dural closure. Outcomes compared were rates of syrinx decompression, headache resolution, and post-operative complications. Statistical analysis was conducted using SPSS v20.Results: We identified 32 adult patients for inclusion in this study. 53.1% (n = 17) had asyrinx, and 78.1% (n = 25) had a pre-operative headache. All were treated with suboccipital craniectomy, C1 laminectomy (with or without C2 laminectomy), and durotomy. The dura was either left open by dural hitching (n = 23) or closed with surgicel and tisseel overlay graft (n = 9). We found a statistically significant association between the method of dural closure and the rate of syrinx resolution. Resolution occurred in 91.7% (n = 11) of the hitching group, compared to 20.0% (n = 1) of the overlay graft group: Χ2(1) = 5.6, p = .018. There were no statistically significant differences between the two groups in the rates of headache resolution or other complications.Conclusions: In patients with symptomatic Chiari I malformation and associated syringomyelia, syrinx resolution is more likely if the dura is hitched open rather than closed bysurgicel and tisseel overlay graft after durotomy.

Shunting of Syringomyelic Cavities by Using a Myringotomy Tube: Technical Note and Long-Term Results

Syringomyelia is a progressive cerebrospinal fluid disorder that can lead to irreversible spinal cord injury. To date, the optimal management of syringomyelic cavities remains controversial. Multiple studies have emphasized the importance of the craniocervical decompression or shunting procedures; however, except for syrinx related to Chiari malformation, nearly one-half of patients need to undergo reoperation. The purpose of the present study was to describe a simple and efficient surgical technique and to report the long-term radioclinical outcomes. We report a series of 17 consecutive patients (10 male, 7 female) with symptomatic syringomyelia treated by myringotomy tube between January 1999 and January 2014. The mean follow-up was 43.6 months (5-118). For each case, a laminectomy was carried out at the level of the most expanded part of the syrinx. The myringotomy tube was then placed through a puncture myelotomy. Clinical examination showed disappearance of symptoms in 3 cases, a significant improvement in 8 cases, stabilization in 5 patients, and continuation of neurologic deterioration in 1 case. Thus, favorable long-term outcomes were observed in two-thirds of patients. No permanent postoperative complication was reported. The postoperative imaging showed complete or almost complete disappearance of the syrinx in 11 cases and a reduction over 80% in 4 cases. In 2 cases, the cavity remained stable. Moreover, just 2 patients had to undergo reoperation with the placement of a syringoperitoneal shunt. A myringotomy tube is a simple surgical technique that seems to be an efficient and safe treatment for syringomyelic cavities.

Efficacy and Safety of Duraplasty in Chiari Malformation Type-I Patients Associated With Syringomyelia

Background Data: Chiari malformation type-I (CM-I) is a challenging subject to wrap our hands around table. Chiari symptoms often range from, unexplained, and/or occipital Valsalva type headache, chronic fatigue syndrome, tolower cranial nerve abnormalities, or brain stem compression, till severe neurological insult which augmented by syringomyelia, or syringobulbia. Exact diagnostic and prognostic tools carry a great controversy which ranged from simple MRI study to MR imaging–based CSF velocity measurements, morphological, dynamic craniocervical junction assessments, subarachnoid pressure recordings, and compliance calculations were compared before and after surgical treatment.Purpose: This study aimed to estimate the efficacy and safely of duraplasty in CM-I patients associated with yringomyelia. Study Design: A retrospective descriptive clinical case study. Patients and Methods: The study was conducted on 23 consecutive adults patients with CM-I associated with syringomyelia. They underwent surgicaltreatments at Sohag University Hospital from February 2012 to May 2015. Results: The current study was applied to 23 patients; 10 males (43.5%) and 13 females (56.5%), aged 18-64 with a mean age of 41 years. The durationof symptoms before presentation varied from 1 month to 20 years. Clinical outcome was classified according to Glasgow outcome scale, 21 patients (91.3%) were graded V, 2 patients (8.7%) were grade IV, and no patient gradedI. Radiologically MRI craniocervical junction suggested that decompression of the posterior fossa was achieved in all patients. Post-operative reports showed that no deterioration occurred in any of our patients. Improvement occurred and increased gradually on post-operative period. Conclusion: Craniocervical decompression with duraplasty is effective in treating patients with Chiari Malformation type-I with syringomyelia. Both clinical and radiologic improvement was documented on the follow up period. (2015ESJ099)

Management of Syringohydromyelia Associated with Basilar Impression and Osteogenesis Imperfecta

Objective: Syringomyelia associated with osteogenesis imperfecta and basilar impression is a rarely seen pathology. We herein report our management experiences of patients with this rare condition. Methods: We overlook 4 patients with osteogenesis imperfecta, basilar impression and syringohydromyelia. All patients were symptomatic at presentation. One patient received a syringosubarachnoid shunt at the craniocervical junction and 2 patients underwent cranio-cervical decompression with duraplasty. One patient was followed conservatively. Follow up periods of these patients ranged up to 14 years. Results: Two patients that received a cranio-cervical decompression showed complete remission of clinical symptoms through the followup period. One patient who was treated by a syringo-subarachnoid microcatheter shunt had early regression of spinal cord symptoms, but died 6 weeks after surgery. One conservatively treated patient remained neurologically unchanged and therefore surgery was not advocated. Conclusions: Cranio-cervical decompression and duraplasty is a treatment option for symptomatic patients with syringohydromyelia and basilar impression accompanying osteogenesis imperfecta resulting in acceptable perioperative morbidity.

Surgical management of syringomyelia unrelated to Chiari malformation or spinal cord injury.

Syringomyelia is a misleading disease since the problem always lies elsewhere. Arachnoiditis, because it is radiographically difficult to discern, is an especially insidious cause. To better guide selection from among surgical treatment options for syringomyelia, we reviewed our case series of patients without Chiari malformation or spinal injury. Excluding syringomyelia due to Chiari malformation, spinal cord injury, and tumors, 32 patients (mean age 44years) were operated on between 1995 and 2013 and followed up for a mean of 53.8months. Presumed causes at diagnosis, clinical and radiological findings, type of operation, clinical and radiological outcome were reviewed. Duration of clinical history varied widely (range 6-164months). Clinical assessment was based on the McCormick classification (15 independent, 17 dependent). Causes included birth trauma, pyogenic meningitis, tuberculous meningitis, postoperative scarring, dysraphism, and basilar impression. Treatment was local decompression with arachnoid lysis and shunts. Hindbrain-related syringomyelia was differentiated from non hindbrain-related syringomyelia. Hindbrain arachnoiditis was significantly associated with radiological findings at the foramen magnum (p=0.01) and craniocervical decompression (p<0.03), with good clinical and radiological outcome at 6months and later follow-up controls (p=0.02), whereas uneven results were observed in cases of non-hindbrain arachnoiditis. To remove the cause of syringomyelia, surgical planning will rely on thorough clinical history and accurate imaging to determine the site of cerebrospinal fluid obstruction. Craniocervical decompression to dissect basal arachnoiditis in the posterior fossa can be recommended in hindbrain syringomyelia. Treatment of non-hindbrain arachnoiditis is more controversial, probably owing to uncertainties about the extent of adhesions.

Chiari type I malformation with high foramen magnum anomaly.

A 14-year-old male with a neck pain and hypoesthesia in the upper extremities was diagnosed with Chiari type I malformation (CMI) and syringomyelia. The posterior part of the occipital bone was removed via cranio-cervical decompression. The accuracy of measuring the posterior cranial fossa (PCF) and foramen magnum (FM) dimensions were evaluated and compared with the literature. The linear PCF and FM dimensions as well as volumes were measured using computed tomography (CT) images with different techniques. The volume data were compared with similar data from literature. Use of the posterior fossa approach remains controversial when treating patients with minor little brain stem dislocation, small PCF, and or incomplete C1, but the approach can easily be applied if FM and PCF sizes are known. Linear measurements that were assessed for concordance with CT measurements had the best agreement. Quantification of PCF volume and high FM should be taken into consideration for differential diagnosis of tonsillar herniation and prediction of surgical outcome in CMI.

Craniocervical decompression with duraplasty and cerebellar tonsillectomy as treatment for Chiari malformation-I complicated with syringomyelia.

This study aimed to investigate the therapeutic effects of craniocervical decompression with duraplasty and cerebellar tonsillectomy for the treatment of Chiari malformation-I with syringomyelia (CM I-SM). From January 2005 to December 2011, 127 patients with CM I-SM underwent craniocervical decompression with duraplasty and cerebellar tonsillectomy and the therapeutic effects of these surgeries were evaluated using Tator scores. No patient in this study died or showed disease deterioration after the surgery. Re-examination by magnetic resonance imaging (MRI) showed that the cisterna magna was obviously larger after the operation in all but one patient. Moreover, syringomyelia (SM) was reduced in 76 patients. CM I-SM symptoms disappeared or decreased in 112 patients after following discharge. Follow-up was conducted in 84 of the patients and 79 of these patients exhibited improved symptoms. A second MRI re-examination showed that the cisterna magna was successfully constructed in 44 patients; 42 of these patients showed further eliminated or obviously reduced SM. Craniocervical decompression with duraplasty and cerebellar tonsillectomy achieved favorable therapeutic effects. Thus, craniocervical decompression with duraplasty and cerebellar tonsillectomy is a rational surgical approach with beneficial clinical effects. The proposed approach may have useful applications in the treatment of CM I-SM.

Prognostic value of newborn hearing screening in patients with myelomeningocele.

Brainstem dysfunction occurs in a minority of patients with myelomeningocele (MMC), most of whom have Chiari Type II malformation. Some surgeons advocate early identification of these patients for craniocervical decompression to avoid significant mortality. The auditory brainstem response has been found to be abnormal in most children with MMC. The present study examines whether failure of routine newborn hearing screening (NHS) predicts brainstem dysfunction in MMC patients. The charts of 40 newborns with MMC and 50 newborns without MMC who stayed in the neonatal intensive care unit were reviewed. Results of NHS, brainstem symptoms, birth demographics, and surgical history were retrospectively examined. Differences in the presence and onset of brainstem symptoms by NHS result were assessed. Failure of NHS was more common among newborns with MMC who developed brainstem symptoms (31%, 4 of 13 patients) than among newborns without MMC (0%, 0 of 50 patients; p = 0.001). Among the 40 newborns with MMC, brainstem symptoms were more common in those who failed NHS (80%, 4 of 5 patients) than in those who passed (26%, 9 of 35 patients; p = 0.031). Respiratory symptom onset occurred later in patients who failed NHS (median 16 months) than among those who passed (median 0 months; p = 0.022). The positive and negative predictive values of NHS for brainstem dysfunction in MMC were 0.80 and 0.74, respectively. Results of NHS may help predict future brainstem dysfunction in patients with MMC and may be useful to incorporate into prognostic assessment and surgical decision making.

Titanium mesh-assisted dural tenting for an expansile suboccipital cranioplasty in the treatment of Chiari 1 malformation

Cerebellar ptosis and dural prolapse are known complications after posterior craniocervical decompression of Chiari 1 malformation (CM1), and are associated with larger craniectomies, epidural scarring and intradural adhesions. Although management of these complications has been well documented, little has been reported in regards to their prevention. We describe our variation of the posterior fossa decompression technique for CM1 using a titanium mesh-assisted dural tenting expansile cranioplasty to prevent both cerebellar ptosis and dural prolapse. A watertight dural augmentation patch is performed after posterior craniocervical decompression. A titanium mesh cranioplasty is performed to cover the superior aspect of the craniectomy. The duraplasty is then tented to the titanium mesh plate with several interrupted sutures. The titanium mesh plate was intended to prevent postoperative cerebellar ptosis or sag, while the dural tenting was performed to prevent delayed collapse and restenosis of the cistern magna. Four patients with CM1 underwent this technique without complication. Postoperative MRI did not demonstrate cerebellar ptosis, restenosis or collapse of the cisterna magna. The expansile suboccipital cranioplasty with titanium mesh-assisted dural tenting technique is a simple and efficient strategy that may be useful to prevent cerebellar ptosis and dural prolapse and maintain the patency of the surgically created neo-cisterna magna.

Atypical Cerebellar Slump Syndrome and External Hydrocephalus following Craniocervical Decompression for Chiari I Malformation: Case Report

Symptomatic cerebellar slump (CS) and external hydrocephalus (EH) are amongst the rarer complications of foramen magnum decompression (FMD) for Chiari I malformation (CM). CS typically presents with delayed onset headache related to dural traction or with neurological deficit offsetting the benefit of FMD. EH, consisting of ventriculomegaly along with subdural fluid collection(s) (SFCs), has been related to cerebrospinal fluid egress from a tiny breach in an otherwise intact arachnoid. We describe the case of a 21-year-old man with CM and syringomyelia who presented with impaired gag, spastic quadriparesis, and raised intracranial pressure 1 week following an uneventful FMD during which the arachnoid had been widely fenestrated. Magnetic resonance imaging (MRI) showed an infratentorial SFC, dilated aqueduct and triventriculomegaly, features of CS, and a residual but resolving syrinx. His symptoms resolved following a high pressure ventriculo-peritoneal shunt. At a 6-month follow-up visit, he was asymptomatic and demonstrated partial resolution of the syrinx, with no recurrence of the SFC. The unusual features in the clinical course of this patient were an atypical CS syndrome presenting with concomitantly resolving syringomyelia, and the development of EH after a wide arachnoidal fenestration. This is the first case in indexed literature describing such a combination of unusual postoperative complications of a FMD. A hypothesis is presented to explain the clinico-radiological findings of the case.

Cervical spinous process reconstruction

Posterior neck deformity with an unsightly crater-like defect may result after cervicothoracic laminectomies. The authors present a new technique, spinous process reconstruction, to address this problem. A 64-year-old man presented with progressive quadriparesis secondary to cervical spondylotic myelopathy. Previously he had undergone multiple neck surgeries including cervicothoracic decompressive laminectomy. Postoperatively, he developed severe craniocervical spinal deformity and a large painful concave surgical defect in the neck. The authors performed craniocervical decompression and craniocervicothoracic instrumented stabilization. At the same time, cervicothoracic spinous process reconstruction was performed using titanium mesh to address the defect. Cervicothoracic decompressive laminectomy results in varying degrees of neck defect with resulting unsightly and an often painful surgical wound defect despite an appropriate multilayer closure. The presented spinous process reconstruction is a simple technique to address this problem with good clinical outcome.

Primary and secondary management of the Chiari II malformation in children with myelomeningocele

Chiari malformation type II is almost exclusively found in patients with open spinal dysraphism. Etiology and pathophysiology are not yet completely understood, and management guidelines regarding the best follow-up and treatment of this pathological entity do not exist. In order to assess essential management aspects, literature and a series of secondary neurosurgical interventions in Chiari II patients have been reviewed. A literature review regarding etiology, diagnostics, pathophysiology, and management of Chiari malformation type II (CMII) and a retrospective evaluation of a series (2009-2012) of secondary interventions in Chiari II patients have been performed. Inclusion criteria were ICD for myelomeningocele with or without hydrocephalus and ICD for Chiari malformation and neurosurgical OR procedure. Evaluated parameters were: patient demographics, primary management, secondary neurosurgical operations (cranio-cervical decompression, shunt revision, myelolysis) as well as specific findings pre- and postoperatively. Essential results from literature review and patients' series are compiled in order to define management recommendations. Fifty patients (28 f, 22 m; mean age, 7.1 years (range, 0.5-26 years)) with myelomeningocele-associated Chiari malformation type II were operated on between 2009 and 2012. Twenty-four patients had syringomyelia and scoliosis each, and 12 suffered from both. Orthopedic surgery for scoliosis or kyphosis had been performed in 13 cases. Shunt revision was performed in 38 cases, myelolysis in 17, and decompression of the foramen magnum in 14 (28 %). After a mean follow-up of 1.9 years, syringomyelia decreased from 24 to 16 cases. There was a postoperative reduction of neck pain (one third), sensorimotor (two fifths), and cranial nerve deficits (one half). CSF flow at the foramen magnum did not change visibly after surgery. Ventricular size improved in about half of the patients. Slit-like ventricles were found in nine (6 pre-surgical) and enlarged ventricles in nine (23 pre-surgical). Complication rate was 6 % (3/50) per cases, and no patient died or deteriorated neurologically after surgery. CMII-related management guidelines are not well defined, since clinical constellations and presentations are varying. Often associated findings are syringomyelia, hydrocephalus, and scoliosis, and symptomatic CMII may be triggered by more than one underlying condition. According to literature and clinical experience, management recommendations can be defined. The most important finding is that hydrocephalus is often involved in symptomatic CMII and must always be considered first in any symptomatic patient. Intrinsic brain stem dysfunctions cannot be treated surgically, and monitoring of vital functions is sometimes the only clinical means that can be offered to the patient. Knowledge of the complex background has led to improved follow-up programs for the affected children and thus also improved longtime survival.

Changes in CSF flow after one-stage posterior vertebral column resection in scoliosis patients with syringomyelia and Chiari malformation Type I

Phase contrast-cine MRI (PC-cine MRI) studies in patients with syringomyelia and Chiari malformation Type I (CM-I) have demonstrated abnormal CSF flow across the foramen magnum, which can revert to normal after craniocervical decompression with syrinx shrinkage. In order to investigate the mechanisms leading to postoperative syringomyelia shrinkage, the authors studied the hydrodynamic changes of CSF flow in the craniocervical junction and spinal canal in patients with scoliosis associated with syringomyelia after one-stage deformity correction by posterior vertebral column resection. Preoperative and postoperative CSF flow dynamics at the levels of the foramen magnum, C-7, T-7 (or apex), and L-1 were assessed by electrocardiogram-synchronized cardiac-gated PC-cine MRI in 8 adolescent patients suffering from severe scoliosis with syringomyelia and CM-I (scoliosis group) and undergoing posterior vertebral column resection. An additional 8 patients with syringomyelia and CM-I without spinal deformity (syrinx group) and 8 healthy volunteers (control group) were also enrolled. Mean values were obtained for the following parameters: the duration of a CSF cycle, the duration of caudad CSF flow (CSF downflow [DF]) and cephalad CSF flow (CSF upflow [UF]), the ratio of DF duration to CSF cycle duration (DF%), and the ratio of UF duration to CSF cycle duration (UF%). The ratio of the stationary phase (SP) duration to CSF cycle duration was calculated (SP%). The maximum downflow velocities (VD max) and maximum upflow velocities (VU max) were measured. SPSS (version 14.0) was used for all statistical analysis. Patients in the scoliosis group underwent one-stage posterior vertebral column resection for deformity correction without suboccipital decompression. The mean preoperative coronal Cobb angle was 102.4° (range 76°-138°). The mean postoperative Cobb angle was 41.7° (range 12°-75°), with an average correction rate of 59.3%. During the follow-up, 1 patient with hypermyotonia experienced a significant decrease of muscle tension and 1 patient with reduced anal sphincter tone manifested recovery. A total of 5 patients demonstrated a significant decrease (> 30%) in syrinx size. With respect to changes in CSF flow dynamics, the syrinx group was characterized by slower and shorter downflow than the control group, and the difference was more significant at the foramen magnum and C-7 levels. In patients with scoliosis, CSF downflow at the foramen magnum level was significantly restricted, and a prolonged stationary phase indicated increased obstruction of CSF flow. After posterior vertebral column resection, the peak velocity of CSF flow at the foramen magnum increased, and the downflow phase duration was markedly prolonged. The parameters showed a return to almost normal CSF dynamics at the craniocervical region, and this improvement was maintained for 6-12 months of follow-up. There were distinct abnormalities of CSF flow at the craniocervical junction in patients with syringomyelia. Abnormal dynamics of downflow could be aggravated by associated severe spinal deformity and improved by correction via posterior vertebral column resection.

Craniocervical decompression in patients with mucopolysaccharidosis VI: development of a scoring system to determine indication and outcome of surgery

To analyse diagnostic value of somato-sensory evoked potentials (SEP), magnetic resonance imaging (MRI), and clinical neurological examination in the decision for decompression surgery in mucopolysaccharidosis (MPS) VI patients with craniocervical cord compression (CCJ). We retrospectively analysed neurological examination, SEP of the median nerve and MRI outcomes from 31 MPS VI patients. Individual scores for each test (based on severity of findings) and a sum of scores of all three procedures (CCJ score) were evaluated for their potential to measure the need for and improvement after surgery. Differences between rapidly and slowly progressive patients were also evaluated. Fourteen patients (45 %) aged 4-34 years underwent decompression surgery. Median age at first operation was lower in rapidly than in slowly progressive patients (12 vs. 24 years; P = 0.008). Neurological and SEP findings but not MRI results differed significantly between non-operated and operated patients (P < 0.001, P = 0.003 and P = 0.08, respectively). A significant relationship was found between MRI and clinical neurological examination (P < 0.001) and between SEP and clinical neurological examination (P = 0.01) but not between MRI and SEP (P = 0.06). The CCJ score discriminated between operated and non-operated patients (4-9 points vs. 0-3 points; P < 0.001) and decreased in 61.5 % of patients after surgery. CCJ is common in rapidly and slowly progressive MPS VI patients. The CCJ score is an objective and transparent tool for assessing pathology of the CCJ, the need for surgery, and improvement after surgery.

Cranio-cervical decompression and expansile duroplasty for isolated fourth ventricle in a patient with Chiari II malformation

The management of isolated fourth ventricle in Chiari II malformation remains a complex challenge. Commonly accepted treatment options have been associated with high rates of complications and failure. Cranio-cervical decompression and autologous expansile duroplasty may be an effective primary intervention for this condition.

Normalization of hindbrain morphology after decompression of Chiari malformation Type I

Chiari malformation Type I (CM-I) is characterized by hindbrain deformity. We investigated the effects of craniocervical decompression surgery on the anatomical features of hindbrain deformity with a prospective MRI study of patients with CM-I. A prospective longitudinal study was conducted in 48 patients with CM-I (39 with syringomyelia) treated with craniocervical decompression. Clinical examinations and cervical MRI were performed before surgery and 1 week, 3-6 months, and annually after surgery. Hindbrain deformity was defined by tonsillar ectopia, pointed cerebellar tonsils, and/or cervicomedullary protuberance. The length of the clivus, basiocciput (sphenooccipital synchondrosis to basion), supraocciput (internal occipital protuberance to opisthion), and anteroposterior (AP) width of CSF pathways at the foramen magnum were measured and compared with those from 18 healthy volunteers (control group). Before surgery, the patients' posterior fossa bones were short and their CSF pathways were narrow. All patients had tonsillar ectopia (mean [± SD] 12.3 ± 5.1 mm; normal 0.3 ± 1.0). The majority of patients had pointed tonsils and more than two-thirds exhibited a cervicomedullary protuberance. Clivus and basiocciput lengths were significantly shorter than the values obtained in the control group. However, the supraocciput length did not differ significantly from control measurements. The mean bulbopontine sulcus distance superior to the basion was 9.5 ± 2.6 mm (vs 13.6 ± 2.8 mm in controls; p < 0.0001). The AP widths of the CSF pathways at the level of the foramen magnum were significantly narrowed. After surgery, CSF pathways significantly expanded both ventrally and dorsally. By 3-6 months after surgery, pointed tonsils became round, cervicomedullary protuberance disappeared, and tonsillar ectopia diminished by 51% (to 6.0 ± 3.3 mm; p < 0.0001). The cerebellar tonsils and brainstem assumed a normal appearance within 6 months after craniocervical decompression. These findings support the concept that the CM-I is not a congenital malformation of the neural elements but rather an acquired malformation that arises from pulsatile impaction of the cerebellar tonsils into the foramen magnum. Clinical trial registration no.: NCT00001327.

Lung function, diagnosis, and treatment of sleep‐disordered breathing in children with achondroplasia

Children with achondroplasia are at risk of sleep-disordered breathing. The aim of the study was to evaluate lung function and sleep-disordered breathing in children with achondroplasia. An interview, clinical examination, lung function tests with blood gases, and a polygraphic sleep study were obtained as part of routine annual evaluation in consecutive children with achondroplasia. We included 30 children (median age 3.0 years, range: 0.4-17.1) over a period of 21 months. Habitual snoring and witnessed apneas were observed in 77% and 33% of the patients, respectively. Prior to the sleep study, 10/29 (34%) patients had undergone upper airway surgery and 5/29 (17%) craniocervical decompression operation. Arterial blood gases were abnormal in two (7%) patients. Sleep findings were abnormal in 28/30 (93%) patients. Eleven (37%) patients had an apnea index≥1 event/hr and 26 (87%) had an apnea-hypopnea index≥5 events/hr. The ≥3% desaturation index was >5/hr in 22 (73%) patients. Sixteen (53%) patients had a minimal pulse oximetry<90% but only two (7%) patients had a maximal transcutaneous carbon dioxide pressure>50 mmHg during sleep. As a consequence, the following therapeutic interventions were performed: upper airway surgery in four patients and noninvasive positive pressure ventilation (NPPV) in five other patients, resulting in an improvement in sleep studies in all nine patients. Systematic sleep studies are recommended in children with achondroplasia because of the high prevalence of sleep-disordered breathing. Upper airway surgery and NPPV are effective treatments of sleep-disordered breathing.