A patient with optic pathway glioma, scoliosis, Chiari type I malformation and syringomyelia: is it Neurofibromatosis type 1?
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A 22 years old girl had features of optic pathway glioma, scoliosis, Chiari type 1 malformation and cervical syringomyelia. She had no cutaneous lesions. We considered this combination to be more than coincidental and argue in favour of considering the case as a variant form of Neurofibromatosis type 1. The relevent literature in favour of our contention has been reviewed. (+info)
Hypothesis on the pathophysiology of syringomyelia based on simulation of cerebrospinal fluid dynamics.
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OBJECTIVES: Despite many hypotheses, the pathophysiology of syringomyelia is still not well understood. In this report, the authors propose a hypothesis based on analysis of cerebrospinal fluid dynamics in the spine. METHODS: An electric circuit model of the CSF dynamics of the spine was constructed based on a technique of computational fluid mechanics. With this model, the authors calculated how a pulsatile CSF wave coming from the cranial side is propagated along the spinal cord. RESULTS: Reducing the temporary fluid storage capacity of the cisterna magna dramatically increased the pressure wave propagated along the central canal. The peak of this pressure wave resided in the mid-portion of the spinal cord. CONCLUSIONS: The following hypotheses are proposed. The cisterna magna functions as a shock absorber against the pulsatile CSF waves coming from the cranial side. The loss of shock absorbing capacity of the cisterna magna and subsequent increase of central canal wall pressure leads to syrinx formation in patients with Chiari I malformation. (+info)
Peak systolic and diastolic CSF velocity in the foramen magnum in adult patients with Chiari I malformations and in normal control participants.
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BACKGROUND AND PURPOSE: Abnormal flow of CSF through the foramen magnum has been implicated in the pathogenesis of clinical deficits in association with Chiari I malformation. The purpose of this study was to test the hypothesis that peak CSF velocities in the foramen magnum are increased in patients with Chiari I malformations. METHODS: Eight adult patients with symptomatic Chiari I malformations and 10 adult volunteers were studied with cardiac gated, phase-contrast MR imaging in the axial plane at the foramen magnum. The spatial uniformity of flow velocity in the foramen magnum was assessed at 14 time frames within the R-R interval. The velocity in each of the voxels at each of the time frames was calculated, and the peak systolic and diastolic velocities were tabulated for the patients and controls. RESULTS: For the normal volunteers, the CSF velocities in the subarachnoid space were relatively uniform throughout the subarachnoid space at each of the time frames. Peak systolic velocity ranged from 1.2 to 3.3 cm/s, and peak diastolic velocity ranged from 1.6 to 4.5 cm/s. In symptomatic patients with Chiari I, velocities in the foramen magnum did not appear as uniform throughout the subarachnoid space in the phase-contrast images. Peak systolic velocities ranged from 1.8 to 4.8 cm/s, and peak diastolic velocities ranged from 2.5 to 5.3 cm/s. Peak systolic velocity was significantly higher (P =.01) in the patients than in the control volunteers. CONCLUSION: Patients with Chiari I malformations have significant elevations of peak systolic velocity in the CSF in the foramen magnum. (+info)
A novel nonsense mutation in the ABC1 gene causes a severe syringomyelia-like phenotype of Tangier disease.
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Tangier disease is a rare autosomal recessive disorder caused by mutations in the recently identified ATP-binding cassette transporter 1 gene (ABC1). A typical clinical manifestation of Tangier disease is peripheral neuropathy. Former studies differentiated between two manifestations: the more frequent mono- or polyneuropathic form and a syringomyelia-like type. It is unknown whether specific mutations in the ABC1 gene or a particular genetic background are responsible for either of these forms. A family is presented comprising a case with a severe syringomyelia-like phenotype of Tangier disease and absence of cardiovascular disease. Sequencing analysis of the ABC1 gene was performed. A new homozygous C-->T transition in exon 18 was found in the index patient. This mutation results in a stop codon at position 909 (R909X) leading to premature termination of translation. Her clinically asymptomatic daughters, her sister and one of her nieces were heterozygous. Sural nerve biopsies were studied in the index patient at the age of 45 and 54 years; both revealed a severe neuropathy, characterized by a subtotal and finally complete loss of nerve fibres. The entire loss of Schwann cells resulted in an extraordinary form of endoneurial sclerosis. Only rare capillaries, lipid-laden macrophages and fibroblasts had survived in the endoneurium. This case appears to be unique in respect to the underlying novel mutation in the ABC1 gene and its association with complete endoneurial sclerosis of all fascicles in the sural nerve and absence of cardiovascular disease. (+info)
Fluid flow in an animal model of post-traumatic syringomyelia.
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More than a quarter of patients with spinal cord injury develop syringomyelia, often with progressive neurological deficit. Treatment options remain limited and long-term failure rates are high. The current poor understanding is impeding development of improved therapies. The source and route of fluid flow into syringes has been investigated using cerebrospinal fluid (CSF) tracers. Previous work using a model of canalicular syringomyelia has shown that fluid enters the dilated central canal from perivascular spaces. The aim of this study was to determine the source and route of fluid flow in an animal model of extracanalicular (post-traumatic) syringomyelia. A model of post-traumatic syringomyelia was established in 25 Sprague-Dawley rats with intraparenchymal injections of quisqualic acid and kaolin-induced arachnoiditis. Rats survived for 6 weeks before injection of the CSF tracer horseradish peroxidase into the cisterna magna. Examination of the spatial distribution of horseradish peroxidase at 0, 3, 5, 10, or 20 min after injection was used to determine the route of fluid flow. Horseradish peroxidase rapidly spread to the ventromedian fissure, perivascular spaces, central canal, and extracanalicular syrinx. Flow occurred into the syrinx prior to significant perivascular flow in the rostral spinal cord. Preferential flow into the syrinx occurred from the perivascular spaces of the central penetrating branches of the anterior spinal artery in the grey matter. Transparenchymal flow into the syrinx was less prominent than perivascular flow. This is the first report of fluid flow within the spinal cord in a model of post-traumatic syringomyelia. Fluid from perivascular spaces moves preferentially into extracanalicular syringes and the surrounding parenchyma. Obstruction to CSF flow and loss of compliance from traumatic arachnoiditis might potentiate fluid flow in the perivascular space. (+info)
Secondary holocord syringomyelia with spinal hemangioblastoma: a report of two cases.
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Intramedullary spinal hemangioblastoma is well known to be accompanied by syringomyelia. However, holocord secondary syringomyelia is uncommon. We present 2 cases of spinal hemangioblastoma, one in the conus medullaris and the other in midthoracic region, accompanied by holocord syrinx. In both the cases the secondary syrinx resolved following successful total tumor excision with good neurological recovery. (+info)
Basilar impression, Chiari malformation and syringomyelia: a retrospective study of 53 surgically treated patients.
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The present study shows the results of 53 patients who have been treated surgically for basilar impression (BI), Chiari malformation (CM), and syringomyelia (SM). The patients were divided into two groups. Group I (24 patients) underwent osteodural decompression with large inferior occipital craniectomy, laminectomy from C 1 to C 3, dural opening in Y format, dissection of arachnoid adhesion between the cerebellar tonsils, medulla oblongata and spinal cord, large opening of the fourth ventricle and dural grafting with the use of bovine pericardium. Group II patients (29 patients) underwent osteodural-neural decompression with the same procedures described above plus dissection of the arachnoid adherences of the vessels of the region of the cerebellar tonsils, and tonsillectomy (amputation) in 10 cases, and as for the remainning 19 cases, intrapial aspiration of the cerebellar tonsils was performed. The residual pial sac was sutured to the dura in craniolateral position. After completion of the suture of the dural grafting, a thread was run through the graft at the level of the created cisterna magna and fixed to the cervical aponeurosis so as to move the dural graft on a posterior- caudal direction, avoiding, in this way, its adherence to the cerebellum. (+info)
Preoperative radiological and electrophysiological evaluation in 100 adolescent idiopathic scoliosis patients.
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This is a prospective study of spinal magnetic resonance imaging (MRI), electrophysiological recordings, and neurological examinations of 100 patients admitted for surgery for adolescent idiopathic scoliosis (AIS), which was conducted to assess the prevalence of structural and functional abnormalities within the spinal cord in patients with clinically normal neurologic condition. In all patients the clinical diagnosis and intact neurological condition was ascertained by a spinal orthopedic surgeon. Full-length spinal axis MRI studies (T1/T2 sequences) and somato-sensory evoked potentials of the tibial nerves (tSSEPs) were preoperatively assessed by independent evaluators blinded to the patients' medical histories. Structural spinal cord abnormalities were found in three of 100 AIS patients on MR imaging. In one patient a Chiari malformation type 1 with an accompanying syringomyelia was diagnosed, which required a suboccipital decompression. In the other two patients small thoracic syringomyelias were diagnosed. Abnormalities of spinal cord function were detected in 68% of the 100 patients: tSSEP latencies corrected for body height were increased in 56% of the patients; pathological differences between tSSEPs on the left and right sides were present in 17% (12% in combination with a prolongation of the latency). The findings of this study indicate that MRI and electrophysiological examinations are essential to assess spinal cord abnormalities that are clinically not detectable in AIS patients. Even in patients with intact neurologic condition and clinically typical right-curved thoracic scoliosis, the possibility of intraspinal pathologies should be ruled out by MRI. It is especially important to detect structural pathologies like syringomyelia and Chiari malformation before proceeding with scoliosis surgery, as these conditions are associated with a higher neurological risk during scoliosis surgery. The electrophysiological recordings made in the present study, with the high number of pathological tSSEPs, are indicative of functional abnormalities with a subclinical involvement of the recorded neuronal pathways. The relevance of the latter findings is not yet clear, but pre-operative tSSEP examinations offer the possibility of assessing alterations in spinal cord function that are undetectable by clinical examination. (+info)