Surgical Ligation of Spinal CSF-Venous Fistulas after Transvenous Embolization in Patients with Spontaneous Intracranial Hypotension.

A spinal CSF-venous fistula is an increasingly recognized type of CSF leak that causes spontaneous intracranial hypotension. The detection of these fistulas requires specialized imaging such as digital subtraction myelography or dynamic CT myelography, and several treatment options are available. A novel treatment for these CSF-venous fistulas consisting of transvenous embolization with the liquid embolic agent Onyx has been described recently, but some patients require further treatment if embolization fails. The purpose of this study was to evaluate the safety and effectiveness of surgery following transvenous embolization. In a series of 6 consecutive patients who underwent surgical ligation of the fistula after endovascular embolization, there were no surgical complications. Postoperatively, complete resolution of symptoms was reported by 5 of the 6 patients, and brain MR imaging findings of spontaneous intracranial hypotension resolved in all patients. This study suggests that surgical ligation of spontaneous spinal CSF-venous fistulas after endovascular embolization is effective and safe.

Cerebral Venous Thrombosis: MR Black-Blood Thrombus Imaging with Enhanced Blood Signal Suppression.

BACKGROUND AND PURPOSE: The residual blood flow artifact is a critical confounder for MR black-blood thrombus imaging of cerebral venous sinus thrombosis. This study aimed to conduct a validation of a new MR black-blood thrombus imaging technique with enhanced blood signal suppression. MATERIALS AND METHODS: Twenty-six participants (13 volunteers and 13 patients) underwent conventional imaging methods followed by 2 randomized black-blood thrombus imaging scans, with a preoptimized delay alternating with nutation for tailored excitation (DANTE) preparation switched on and off, respectively. The signal intensity of residual blood, thrombus, brain parenchyma, normal lumen, and noise on black-blood thrombus images were measured. The thrombus volume, SNR of residual blood, and contrast-to-noise ratio for residual blood versus normal lumen, thrombus versus residual blood, and brain parenchyma versus normal lumen were compared between the 2 black-blood thrombus imaging techniques. Segmental diagnosis of venous sinus thrombosis was evaluated for each black-blood thrombus imaging technique using a combination of conventional imaging techniques as a reference. RESULTS: In the volunteer group, the SNR of residual blood (11.3 ± 2.9 versus 54.0 ± 23.4, P < .001) and residual blood-to-normal lumen contrast-to-noise ratio (7.5 ± 3.4 versus 49.2 ± 23.3, P < .001) were significantly reduced using the DANTE preparation. In the patient group, the SNR of residual blood (16.4 ± 8.0 versus 75.0 ± 35.1, P = .002) and residual blood-to-normal lumen contrast-to-noise ratio (12.4 ± 7.8 versus 68.8 ± 35.4, P = .002) were also significantly lower on DANTE-prepared black-blood thrombus imaging. The new black-blood thrombus imaging technique provided higher thrombus-to-residual blood contrast-to-noise ratio, significantly lower thrombus volume, and substantially improved diagnostic specificity and agreement with conventional imaging methods. CONCLUSIONS: DANTE-prepared black-blood thrombus imaging is a reliable MR imaging technique for diagnosing cerebral venous sinus thrombosis.

Diagnostic criteria for spontaneous spinal CSF leaks and intracranial hypotension.

BACKGROUND AND PURPOSE: Comprehensive diagnostic criteria encompassing the varied clinical and radiographic manifestations of spontaneous intracranial hypotension are not available. Therefore, we propose a new set of diagnostic criteria. MATERIALS AND METHODS: The diagnostic criteria are based on results of brain and spine imaging, clinical manifestations, results of lumbar puncture, and response to epidural blood patching. The diagnostic criteria include criterion A, the demonstration of extrathecal CSF on spinal imaging. If criterion A is not met, criterion B, which is cranial MR imaging findings of spontaneous intracranial hypotension, follows, with at least one of the following: 1) low opening pressure, 2) spinal meningeal diverticulum, or 3) improvement of symptoms after epidural blood patch. If criteria A and B are not met, there is criterion C, the presence of all of the following or at least 2 of the following if typical orthostatic headaches are present: 1) low opening pressure, 2) spinal meningeal diverticulum, and 3) improvement of symptoms after epidural blood patch. These criteria were applied to a group of 107 consecutive patients evaluated for spontaneous spinal CSF leaks and intracranial hypotension. RESULTS: The diagnosis was confirmed in 94 patients, with use of criterion A in 78 patients, criterion B in 11 patients, and criterion C in 5 patients. CONCLUSIONS: A new diagnostic scheme is presented reflecting the wide spectrum of clinical and radiographic manifestations of spontaneous spinal CSF leaks and intracranial hypotension.

Frequency of spontaneous intracranial hypotension in the emergency department.

Spontaneous intracranial hypotension is considered a rare disorder. We conducted a study on the frequency of spontaneous intracranial hypotension in the emergency department (ED). We identified patients with spontaneous intracranial hypotension evaluated in the ED of a large urban hospital between 1 January 2003 and 31 December 2006. For comparison, we also identified all patients with spontaneous subarachnoid haemorrhage (SAH). Eleven patients with previously undiagnosed spontaneous intracranial hypotension were evaluated in the ED during the four-year time period. All patients presented with positional headaches and the duration of symptoms varied from one day to three months. None of the patients were correctly diagnosed with spontaneous intracranial hypotension in the ED. During the same time period, 23 patients with aneurysmal SAH were evaluated. Spontaneous intracranial hypotension is more common than previously appreciated and the diagnosis in the ED remains problematic.

Spontaneous retroclival hematoma presenting as a thunderclap headache. Case report.

An excruciating headache of instantaneous onset, or thunderclap headache, may be caused by a variety of serious disorders, including aneurysmal subarachnoid hemorrhage, cerebral venous sinus thrombosis, pituitary apoplexy, and carotid artery or vertebral artery dissection. The authors describe a patient with this type of headache who was found to have a spontaneous retroclival hematoma. A 49-year-old woman experienced an instantaneous excruciating headache. Results of computerized tomography (CT) scans of the head were normal, but on examination of the cerebrospinal fluid xanthochromia was found. Magnetic resonance (MR) imaging of the cervical spine revealed a retroclival hematoma. Three cerebral angiographic studies did not reveal the source of the hemorrhage and a repeated MR image demonstrated resolution of the hematoma. The patient made an uneventful recovery. Spontaneous retroclival hematoma is an exceedingly rare type of intracranial hemorrhage and may be associated with normal findings on CT scans. Spontaneous retroclival hematoma should be included in the differential diagnosis of thunderclap headache.

Cross-species amplification of cassava (Manihot esculenta) (Euphorbiaceae) microsatellites: allelic polymorphism and degree of relationship.

Microsatellite amplification was performed on cassava (Manihot esculenta) and six other different species (all wild) of the Manihot genus. We used ten pairs of microsatellite primers previously developed from cassava, detecting 124 alleles in a sample of 121 accessions of the seven species. The number of alleles per locus ranged from four to 21 alleles, and allelic diversity was greater in the wild species than in cassava. Seventy-nine alleles, including unique ones, were detected in the wild species but were not found in the crop. The lower level of heterozygosity in some wild species probably resulted from a combination of fine-scale differentiation within the species and the presence of null alleles. Overall, microsatellite primers worked across the genus, but, with increasing genetic distance, success in amplifying loci tended to decrease. No accession of M. aesculifolia, M. carthaginensis, and M. brachyloba presented a banding pattern at locus Ga-140; neither did one appear for M. aesculifolia at locus Ga-13. Previous work with amplified fragment length polymorphism (AFLP) markers and this microsatellite analysis show that these three wild taxa are the most distant relatives of the crop, whereas the wild forms M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana appear to be the closest.

Jacobson's nerve schwannoma presenting as middle ear mass.

Schwannoma is one of the common benign middle ear space tumors. Middle ear space schwannomas may originate from the nerves of the tympanic cavity or by extensions from outside the middle ear space. In the English-language literature, the facial nerve and chorda tympani nerve, but not yet the tympanic branch of glossopharyngeal nerve (Jacobson's nerve), have been reported as the origins of intrinsic middle ear space schwannomas. We present the clinical and radiologic features of a middle-space schwannoma originating from Jacobson's nerve, and suggest that such a tumor be included in the differential diagnosis of middle ear tumors.

Orbital CT. Current use in the MR era.

The additional advantages of spiral CT have further cemented CTs role as the screening examination of choice for the orbit. The shorter scan times permit ideal enhancement yet reduce the contrast load, providing the optimal postcontrast studies that routine imaging of the orbit requires. This article is not a comprehensive study of orbital CT, but a general review emphasizing CTs strengths, especially the evaluation of childhood leukocoria (calcification), proptosis screening, and trauma.

Purification and properties of a DNA primase from Nicotiana tabacum.

A DNA primase was isolated from a nuclear fraction from leaves of tobacco (Nicotiana tabacum L. cv. Samsun) and from purified nuclei prepared from tobacco suspension culture cells. The DNA primase was purified to homogeneity (i) for preparations from leaves, by ammonium sulphate fractionation, followed by chromatography on columns of phosphocellulose, Q-Sepharose, heparin-Sepharose and single-stranded DNA cellulose, and sedimentation in a glycerol gradient, or (ii) for preparations from cells, by chromatography on single-stranded DNA cellulose, followed by ammonium sulphate precipitation and chromatography on columns of High Q, heparin-Sepharose and Mono Q. In glycerol gradients, the DNA primase sedimented at a rate corresponding to a molecular mass of about 120 kDa. In SDS-polyacrylamide gel electrophoresis, the primase was resolved into two polypeptide subunits of 63 kDa and 53 kDa, which are similar in size to the primase subunits of animal and yeast DNA polymerase alpha-primase complexes. On poly(dT) or phage M13 single-stranded DNA templates, the DNA primase catalysed the synthesis of oligoribonucleotides up to 20 nucleotides in length, which could serve as primers for DNA synthesis catalysed by Escherichia coli DNA polymerase. Primase activity was dependent on a template, magnesium ions and ATP; it was resistant to aphidicolin and rifampicin, but was strongly inhibited by N-ethylmaleimide. This is the first report of the purification to homogeneity of a plant DNA primase.

Isolation and characterization of replication protein A (RP-A) from tobacco cells.

Replication protein A (RP-A) was isolated from tobacco suspension cells and purified to near homogeneity by a procedure involving isolation of protoplasts, preparation of nuclei, nuclear lysis, binding to a column of single-stranded (ss) DNA cellulose and elution at different salt concentrations. The purified protein contained three subunits with molecular masses of 70, 34 and 14 kDa, and was free from nuclease activity. Tobacco RP-A had a high affinity for ssDNA. Binding competition experiments indicated only a weak affinity for double-stranded DNA and no detectable affinity for ssRNA. Photochemical cross-linking experiments indicated that the 70 kDa subunit has the ssDNA-binding activity. Tobacco RP-A was able to stimulate the activity of a tobacco alpha-like DNA polymerase about 4-fold. This is the first isolation of RP-A from a plant and the procedure may be generally applicable to other plant species.

Intestinal lymphangiectasia: ultrasound evaluation of a case simulating appendicitis.

Intestinal lymphangiectasia is a disorder of the lymphatics of the gastrointestinal system that usually manifests itself with protein-losing enteropathy, malabsorption, and ascites. We report an adult patient with this disorder with an unusual presentation simulating an acute abdomen.

Urinary bladder leiomyoma: magnetic resonance imaging findings.

Benign urinary bladder tumors are very rare, leiomyoma being the most common among them. We wish to report a case and discuss the radiological findings with special emphasis on magnetic resonance (MR) imaging.