Dynamic cervicomedullary cord compression and alterations in cerebrospinal fluid dynamics in children with achondroplasia: review of an 11-year surgical case series

2014 ◽  
Vol 14 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Debraj Mukherjee ◽  
Barry D. Pressman ◽  
Deborah Krakow ◽  
David L. Rimoin ◽  
Moise Danielpour

Object Achondroplasia may be associated with compression at the cervicomedullary junction. Determining which patients are at greatest risk for neurological complications of cervicomedullary compression can be difficult. In the current study the authors reviewed their records to determine the incidence and clinical significance of dynamic cervicomedullary stenosis and obstruction of CSF flow along with surgical outcomes following posterior fossa decompression. Methods The authors reviewed 34 consecutive cases involving symptomatic children with achondroplasia undergoing cervicomedullary decompression performed by a single surgeon over 11 years. Of these patients, 29 had undergone preoperative dynamic MRI of the cervicomedullary junction with cine (cinema) CSF flow studies; 13 of these patients underwent postoperative dynamic MRI studies. Clinical outcomes included changes in polysomnography, head circumference percentile, and fontanel characteristics. Radiographic outcomes included changes in dynamic spinal cord diameter, improvement in CSF flow at the foramen magnum, and change in the Evans ratio. Results Patients were predominantly female, with a mean age at presentation of 6.6 years and mean follow-up of 3.7 years (range 1–10 years). All patients had moderate to excellent improvement in postoperative polysomnography, slight decrease in average head circumference percentile (from 46.9th percentile to 45.7th percentile), and no subjective worsening of fontanel characteristics. The Evans ratio decreased by 2%, spinal cord diameter increased an average of 3.1 mm, 5.2 mm, and 0.2 mm in the neutral, flexed, and extended positions, respectively, and CSF flow improved qualitatively in all 3 positions. There were no postoperative infections, CSF leaks, or other major complications. None of the patients undergoing initial foramen magnum decompression performed at our medical center required reoperation. Conclusions Patients with achondroplasia and symptomatic cervicomedullary compression have increased risk of dynamic stenosis at the foramen magnum evident upon dynamic cine MRI. Operative decompression may be offered with low risk of complications or need for reoperation.

2015 ◽  
Vol 122 (5) ◽  
pp. 1068-1075 ◽  
Author(s):  
Aaron E. Bond ◽  
John A. Jane ◽  
Kenneth C. Liu ◽  
Edward H. Oldfield

OBJECT The authors completed a prospective, institutional review board–approved study using intraoperative MRI (iMRI) in patients undergoing posterior fossa decompression (PFD) for Chiari I malformation. The purpose of the study was to examine the utility of iMRI in determining when an adequate decompression had been performed. METHODS Patients with symptomatic Chiari I malformations with imaging findings of obstruction of the CSF space at the foramen magnum, with or without syringomyelia, were considered candidates for surgery. All patients underwent complete T1, T2, and cine MRI studies in the supine position preoperatively as a baseline. After the patient was placed prone with the neck flexed in position for surgery, iMRI was performed. The patient then underwent a bone decompression of the foramen magnum and arch of C-1, and the MRI was repeated. If obstruction was still present, then in a stepwise fashion the patient underwent dural splitting, duraplasty, and coagulation of the tonsils, with an iMRI study performed after each step guiding the decision to proceed further. RESULTS Eighteen patients underwent PFD for Chiari I malformations between November 2011 and February 2013; 15 prone preincision iMRIs were performed. Fourteen of these patients (93%) demonstrated significant improvement of CSF flow through the foramen magnum dorsal to the tonsils with positioning only. This improvement was so notable that changes in CSF flow as a result of the bone decompression were difficult to discern. CONCLUSIONS The authors observed significant CSF flow changes when simply positioning the patient for surgery. These results put into question intraoperative flow assessments that suggest adequate decompression by PFD, whether by iMRI or intraoperative ultrasound. The use of intraoperative imaging during PFD for Chiari I malformation, whether by ultrasound or iMRI, is limited by CSF flow dynamics across the foramen magnum that change significantly when the patient is positioned for surgery.


2014 ◽  
Vol 05 (S 01) ◽  
pp. S078-S082 ◽  
Author(s):  
Savitr Sastri Bhagavathula Venkata ◽  
Arivazhagan Arimappamagan ◽  
Spiros Lafazanos ◽  
Nupur Pruthi

ABSTRACTSyringomyelia secondary to cervical spondylosis is a rare entity to encounter in clinical practice. We discuss the case of a 53-year-old lady who presented with a syringomyelic syndrome and was found to have cervical spondylosis on imaging. Cine-MRI revealed an obstruction of cerebrospinal fluid (CSF) flow in the cervical spinal subarachnoid space. Decompression of the same led to clinical and radiological improvement. There is a potential causal association between cervical spondylosis and syringomyelia. MRI CSF flow studies may help in deciding the course of treatment in such cases. A subset of patients with cervical spondylosis and concurrent spinal cord signal intensity changes may show reversal of the same following intervention.


2013 ◽  
Vol 18 (5) ◽  
pp. 456-464 ◽  
Author(s):  
Yingsong Wang ◽  
Jingming Xie ◽  
Zhi Zhao ◽  
Ying Zhang ◽  
Tao Li ◽  
...  

Object 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. Methods 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 (VDmax) and maximum upflow velocities (VUmax) were measured. SPSS (version 14.0) was used for all statistical analysis. Results 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. Conclusions 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.


1994 ◽  
Vol 81 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Timothy C. Ryken ◽  
Arnold H. Menezes

✓ Six patients with achondroplasia and symptoms suggestive of cervicomedullary junction compression are reviewed; these included three females and three males, with an average age of 8 years (range 7 months to 30 years). The mean duration of symptoms prior to intervention was 1.9 years. Symptoms included occipitocervical pain, ataxia, incontinence, apnea, and respiratory arrest. Radiological investigations consisted of plain films with flexion and extension views, pluridirectional tomography, thin-section computerized tomography, and magnetic resonance imaging. Typical findings included marked foramen magnum stenosis, ventrolateral cervicomedullary junction compression secondary to central and paramesial basilar invagination, and dorsal cervicomedullary junction compression secondary to ligamentous hypertrophy and invagination of the posterior atlantal arch. All patients underwent posterior fossa decompression and atlantal laminectomy. Surgery consistently revealed marked dorsal and paramesial overgrowth of the rim of the foramen magnum, with thickening and invagination of the atlantal posterior arch and a dense fibrotic epidural band resulting in dorsal cervicomedullary compression. Intraoperative ultrasonography was used to determine the extent of decompression required. Three patients required duraplasty. Three patients had concurrent hydrocephalus, two of whom had undergone ventriculoperitoneal shunting prior to surgical decompression of the posterior fossa. One patient developed a pseudomeningocele postoperatively, requiring serial lumbar punctures before it resolved. No patient developed craniovertebral instability following decompression. Improvement or resolution of symptoms was noted in all patients, with an average follow-up period of 4.8 years. Thus, cervicomedullary compression in patients with achondroplasia can be successfully treated with dorsal decompression of the craniovertebral junction. Dense epidural fibrotic bands are frequently noted in these cases and must be aggressively released to ensure satisfactory decompression.


Author(s):  
Deborah L. Benzil ◽  
Mehran Saboori ◽  
Alon Y. Mogilner ◽  
Ronald Rocchio ◽  
Chitti R. Moorthy

Object. The extension of stereotactic radiosurgery treatment of tumors of the spine has the potential to benefit many patients. As in the early days of cranial stereotactic radiosurgery, however, dose-related efficacy and toxicity are not well understood. The authors report their initial experience with stereotactic radiosurgery of the spine with attention to dose, efficacy, and toxicity. Methods. All patients who underwent stereotactic radiosurgery of the spine were treated using the Novalis unit at Westchester Medical Center between December 2001 and January 2004 are included in a database consisting of demographics on disease, dose, outcome, and complications. A total of 31 patients (12 men, 19 women; mean age 61 years, median age 63 years) received treatment for 35 tumors. Tumor types included 26 metastases (12 lung, nine breast, five other) and nine primary tumors (four intradural, five extradural). Thoracic tumors were most common (17 metastases and four primary) followed by lumbar tumors (four metastases and four primary). Lesions were treated to the 85 to 90% isodose line with spinal cord doses being less than 50%. The dose per fraction and total dose were selected on the basis of previous treatment (particularly radiation exposure), size of lesion, and proximity to critical structures. Conclusions. Rapid and significant pain relief was achieved after stereotactic radiosurgery in 32 of 34 treated tumors. In patients treated for metastases, pain was relieved within 72 hours and remained reduced 3 months later. Pain relief was achieved with a single dose as low as 500 cGy. Spinal cord isodoses were less than 50% in all patients except those with intradural tumors (mean single dose to spinal cord 268 cGy and mean total dose to spinal cord 689 cGy). Two patients experienced transient radiculitis (both with a biological equivalent dose (BED) > 60 Gy). One patient who suffered multiple recurrences of a conus ependymoma had permanent neurological deterioration after initial improvement. Pathological evaluation of this lesion at surgery revealed radiation necrosis with some residual/recurrent tumor. No patient experienced other organ toxicity. Stereotactic radiosurgery of the spine is safe at the doses used and provides effective pain relief. In this study, BEDs greater than 60 Gy were associated with an increased risk of radiculitis.


Author(s):  
Tamer Belal ◽  
Abd-Elhalim Al Tantawy ◽  
Fatema Mohamed Sherif ◽  
Alshaimaa Ramadan

Abstract Background Idiopathic intracranial hypertension (IIH) mainly affects overweight women in the middle age period. The pathophysiology of IIH stays unclear, but suggested mechanisms include excess CSF production, reduced CSF absorption, increased brain water content, and increased cerebral venous pressure Objectives To assess the cerebrospinal fluid (CSF) flow dynamic changes in aqueduct of Sylvius in patients of idiopathic intracranial hypertension (IIH) with new MRI technique: phase contrast cine MRI (PCC-MRI). Methods Thirty patients diagnosed with idiopathic intracranial hypertension were divided into 3 groups according to treatment options (no treatment, medical treatment, and medical treatment with repeated lumbar tapping). CSF flow data were evaluated by phase contrast cine MRI. Results PCC-MRI parameters were significantly higher in group who was on medical treatment (group II) than other groups. The sensitivity of PCC MRI parameters ranged from 56.7 (stroke volume (SV) and mean flow (MF)) to 83.3% (peak systolic velocity (PSV)). A statistically significant difference was found for the mean flow value (p 0.039) between the control group and IIH patients. Conclusion The most specific CSF flowmetry parameter detected to help diagnosis of IIH is mean flow especially among early discovered patients. PCC MRI can be used as non-invasive technique for diagnosis of IIH and treatment follow-up.


1985 ◽  
Vol 143 (2) ◽  
pp. 84-85 ◽  
Author(s):  
John M. F. Grant ◽  
John D. Yeo ◽  
William R. Sears ◽  
Michael C. Copeman

2011 ◽  
Vol 31 (3) ◽  
pp. E5 ◽  
Author(s):  
Uwe Max Mauer ◽  
Andreas Gottschalk ◽  
Carolin Mueller ◽  
Linda Weselek ◽  
Ulrich Kunz ◽  
...  

Object The causal treatment of Chiari malformation Type I (CM-I) consists of removing the obstruction of CSF flow at the level of the foramen magnum. Cerebrospinal fluid flow can be visualized using dynamic phase-contrast MR imaging. Because there is only a paucity of studies evaluating CSF dynamics in the region of the spinal canal on the basis of preoperative and postoperative measurements, the authors investigated the clinical usefulness of cardiacgated phase-contrast MR imaging in patients with CM-I. Methods Ninety patients with CM-I underwent preoperative MR imaging of CSF pulsation. Syringomyelia was present in 59 patients and absent in 31 patients. Phase-contrast MR imaging of the entire CNS was used to investigate 22 patients with CM-I before surgery and after a mean postoperative period of 12 months (median 12 months, range 3–33 months). In addition to the dynamic studies, absolute flow velocities, the extension of the syrinx, and tonsillar descent were also measured. Results The changes in pulsation were highly significant in the region of the (enlarged) cistern (p = 0.0005). Maximum and minimum velocities (the pulsation amplitude) increased considerably in the region where the syrinx was largest in diameter. The changes of pulsation in these patients were significant in the subarachnoid space in all spinal segments but not in the syrinx itself and in the central canal. Conclusions The demonstration of CSF flow pulsation can contribute to assessments of surgical outcomes. The results presented here, however, raise doubts about current theories on the pathogenesis of syringomyelia.


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