Effect of craniocervical decompression on peak CSF velocities in symptomatic patients with Chiari I malformation.
BACKGROUND AND PURPOSE: Peak CSF velocities detected in individual voxels in the subarachnoid space in patients with Chiari I malformations exceed those in similar locations in the subarachnoid space in healthy subjects. The purpose of this study was to test the hypothesis that the peak voxel velocities are decreased by craniocervical decompression. METHODS: A consecutive series of patients with symptomatic Chiari I malformations was studied before and after craniocervical decompression with cardiac-gated, phase contrast MR imaging. Velocities were calculated for each voxel within the foramen magnum at 14 time points throughout the cardiac cycle. The greatest velocities measured in a voxel during the cephalad and caudad phases of CSF flow through the foramen magnum were tabulated for each patient before and after surgery. The differences in these velocities between the preoperative and postoperative studies were tested for statistical significance by using a single-tailed Student's t test of paired samples. RESULTS: Eight patients with a Chiari I malformation, including four with a syrinx, were studied. Peak caudad velocity diminished after craniocervical decompression in six of the eight patients, and the average diminished significantly from 3.4 cm/s preoperatively to 2.4 cm/s postoperatively (P =.01). Peak cephalad velocity diminished in six of the eight cases. The average diminished from 6.9 cm/s preoperatively to 3.9 cm/s postoperatively, a change that nearly reached the significance level of.05 (P =.055). CONCLUSION: Craniocervical decompression in patients with Chiari I malformations decreases peak CSF velocities in the foramen magnum. The study supports the hypothesis that successful treatment of the Chiari I malformation is associated with improvement in CSF flow patterns. (+info)
Spinal dysraphism: MR imaging rationale.
Spinal cord development occurs through the three consecutive periods of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal cord malformations derive from defects in these early embryonic stages, and are collectively called spinal dysraphisms. Spinal dysraphisms may be categorized clinically into open and closed, based on whether the abnormal nervous tissue is exposed to the environment or covered by skin. Open spinal dysraphisms include myelomeningocele and other rare abnormalities such as myelocele, hemimyelomeningocele, and hemimyelocele, and are always associated with a Chiari II malformation. Closed spinal dysraphisms are further divided into two subsets based on whether a subcutaneous mass is present in the low back. Closed spinal dysraphisms with mass comprise lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category involves abnormal notochordal development, either in the form of failed midline integration (ranging from complete dorsal enteric fistula to neurenteric cysts and diastematomyelia) or of segmental agenesis (caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging is the imaging modality of choice for evaluation of this complex group of disorders. (+info)
Clinical evidence for cervical myelopathy due to Chiari malformation and spinal stenosis in a non-randomized group of patients with the diagnosis of fibromyalgia.
OBJECTIVE: While patients with fibromyalgia report symptoms consistent with cervical myelopathy, a detailed neurological evaluation is not routine. We sought to determine if patients with fibromyalgia manifest objective neurological signs of cervical myelopathy. METHODS: Two hundred and seventy patients, 18 years and older, who carried the diagnosis of fibromyalgia but who had no previously recognized neurological disease underwent detailed clinical neurological and neuroradiological evaluation for the prevalence of objective evidence of cervical myelopathy and radiological evidence of cerebellar tonsillar herniation (Chiari 1 malformation) or cervical spinal canal stenosis. RESULTS: Patients were primarily women (87%), of mean age 44 years, who had been symptomatic for 8 years (standard deviation, 6.3 years). The predominant complaints were neck/back pain (95%), fatigue (95%), exertional fatigue (96%), cognitive impairment (92%), instability of gait (85%), grip weakness (83%), paresthesiae (80%), dizziness (71%) and numbness (69%). Eighty-eight percent of patients reported worsening symptoms with neck extension. The neurological examination was consistent with cervical myelopathy: upper thoracic spinothalamic sensory level (83%), hyperreflexia (64%), inversion of the radial periosteal reflex (57%), positive Romberg sign (28%), ankle clonus (25%), positive Hoffman sign (26%), impaired tandem walk (23%), dysmetria (15%) and dysdiadochokinesia (13%). MRI and contrast-enhanced CT imaging of the cervical spine revealed stenosis. The mean antero-posterior (AP) spinal canal diameter at C2/3, C3/4, C4/5, C5/6, C6/7 and C7/T1 was 13.5 mm, 11.8 mm, 11.5 mm, 10.4 mm, 11.3 mm and 14.5 mm respectively, (CT images). In 46% of patients, the AP spinal diameter at C5/6 measured 10 mm, or less, with the neck positioned in mild extension, i.e., clinically significant spinal canal stenosis. MRI of the brain revealed tonsillar ectopia >5 mm in 20% of patients (mean=7.1+/-1.8 mm), i.e., Chiari 1 malformation. CONCLUSION. Our findings indicate that some patients who carry the diagnosis of fibromyalgia have both signs and symptoms consistent with cervical myelopathy, most likely resulting from spinal cord compression. We recommend detailed neurological evaluation of patients with fibromyalgia in order to exclude cervical myelopathy, a potentially treatable condition. (+info)
Endovascular treatment of a ruptured giant serpentine aneurysm of the superior cerebellar artery in a patient with a Chiari II malformation.
We present a case of a ruptured giant serpentine aneurysm (GSA) of the superior cerebellar artery in a patient with a Chiari II malformation. The fusiform aneurysm was successfully treated with endovascular parent artery occlusion of the GSA by using detachable coils. (+info)
Results of the treatment of syringomyelia associated with Chiari malformation: analysis of 60 cases.
We analyze the results of surgical treatment of 60 patients presenting syringomyelia (SM) associated with Chiari malformation (CM) who were operated in the period 1982-2000. For each case, analysis covered 15 signs and 16 symptoms included in a protocol that separated SM signs and symptoms from those of CM. A score system was established in parallel with the protocol to make the evaluation of treatment results easier. All cases were submitted to craniovertebral decompression by C1 and eventually C2 laminectomy and cerebellar tonsillectomy with duramater graft. To evaluate the results, statistical proportion difference tests and variance analyses were made to a reliability index of 95% (p=0.05). We conclude that the statistical improvement of CM signs and symptoms was very significant (p=0). Syringomyelia signs and symptoms also improved significantly, except for "upper limb hyporeflexia", which did not improve. No statistical difference in the improvement of SM symptoms as compared to CM symptom was found. Syringomyelia signs improved statistically more than CM signs. In half of patients, the percent improvement of signs and symptoms ranged between 40% and 60%. (+info)
Factors influencing the outcome in symptomatic Chiari I malformation.
BACKGROUND: To study the clinico-radiological determinants of outcome in patients with Chiari I malformation (CIM). MATERIALS AND METHODS: The disability assessment of 48 patients with C I M who underwent posterior decompression was done by modified Klekamp and Samii scoring system. The outcome was regarded as good when the patient was ambulant without any aid with an improvement in the disability score; and, poor when (a) there was postoperative deterioration or lack of improvement; (b) the patient was non-ambulant without aid, irrespective of the improvement in the clinical score; or, (c) there was a perioperative mortality. Patients with hydrocephalus; those who underwent syringo-subarachnoid or syringo-peritoneal shunt as the primary procedure; and, patients with atlanto-axial dislocation were excluded from the study. STATISTICAL METHODS USED: Categorical data were expressed in proportions and analyzed with Chi square test. Analysis of factors predicting clinical outcome at 6 months was done utilizing logistic regression analysis. RESULTS: The outcome assessed at six months showed that 30 patients (62.5%) had good outcome while 18 patients (37.5%; including two perioperative mortalities) had a poor outcome. CONCLUSIONS: Significant predictors of outcome in patients with CIM include the duration of symptoms (P value=0.006), respiratory distress (P value=0.001), and basilar invagination (P value=0.048). The effect of syringomyelia in predicting the clinical outcome could not be determined due to the differences in the number of patients in the groups with or without syringomyelia. (+info)
Inherited occipital hypoplasia/syringomyelia in the cavalier King Charles spaniel: experiences in setting up a worldwide DNA collection.
Inherited diseases commonly emerge within pedigree dog populations, often due to use of repeatedly bred carrier sire(s) within a small gene pool. Accurate family records are usually available making linkage analysis possible. However, there are many factors that are intrinsically difficult about collecting DNA and collating pedigree information from a large canine population. The keys to a successful DNA collection program include (1) the need to establish and maintain support from the pedigree breed clubs and pet owners; (2) committed individual(s) who can devote the considerable amount of time and energy to coordinating sample collection and communicating with breeders and clubs; and (3) providing means by which genotypic and phenotypic information can be easily collected and stored. In this article we described the clinical characteristics of inherited occipital hypoplasia/syringomyelia (Chiari type I malformation) in the cavalier King Charles spaniel and our experiences in establishing a pedigree and DNA database to study the disease. (+info)
Orthostatic intolerance and syncope associated with Chiari type I malformation.
The Chiari type I malformation (CM1) is characterized by herniation of cerebellar tonsils to at least 3-5 mm below the plane of foramen magnum and can present with a wide variety of clinical symptoms, frequently including occipital headaches, secondary to bulbar and/or medullary distress. Rarely, syncopal episodes have also been described and attributed to either compression of the midbrain ascending reticular system, or vascular compromise (vertebrobasilar artery compression, hypotension). We report the first case of a CM1 patient with frequently recurring syncope due to postural orthostatic tachycardia syndrome (POTS), a form of orthostatic intolerance, whose symptoms resolved completely after surgical intervention. It is important to stress that it is not clear whether the described association of POTS and CM1 in our patient is a fortuitous finding in an isolated case or a reflection of a more systematic association between the two pathologies. (+info)