[Hematomyelia complicating a spinal dural arteriovenous fistula. Report of a case]

We report a case of hematomyelia which led to sudden onset complete paraplegia in a 74-year-old man. Hematomyelia revealed a spinal dural arteriovenous fistula at level T8-T9. Spinal hemorrhage was observed in contact with a round-shaped aneurysmal like ectasia which undoubtedly ruptured. Treatment was embolization. Spinal atrophy followed and MRI one year after embolisation visualized the involution of the pathological vessels. We discuss the pathophysiology of this hemorrhagic accident and specific anomalies of the drainage veins in these malformations.

MRI and MR angiography of vertebral artery dissection

A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients.

Identification of the feeding arteries of spinal vascular lesions via phase-contrast MR angiography with three-dimensional acquisition and phase display

PURPOSE

To determine whether identification of the feeding arteries of spinal vascular lesions with phase-contrast MR angiography benefits from the higher spatial resolution of three-dimensional (volume) acquisitions and flow-direction information provided by the phase reconstruction of two-dimensional acquisitions.

METHODS

Fifteen patients with high- or low-flow spinal vascular lesions proved by spinal arteriography underwent MR angiography with phase-contrast techniques. Arteriographic and MR angiographic studies were reviewed to identify the arterial feeders of spinal vascular lesions.

RESULTS

On modulus reconstructions of coronal 2-D or 3-D acquisitions, three of four arteries feeding high-flow lesions and three of 14 arteries feeding low-flow lesions were identified as hypertrophic vessels joining the parent intercostal or cervical arteries. Of 11 intradural veins draining dural arteriovenous fistulas, three were identified on coronal 2-D acquisitions and six on coronal 3-D acquisitions as vessels that coursed from a neural foramen to a midline tangle of vessels. Phase reconstruction showed ascending and descending flow patterns in two patients with intramedullary arteriovenous malformations, and diverging flow in perimedullary veins draining a hemangioblastoma. In nine patients with dural arteriovenous fistulas, phase reconstruction provided information as to the level of the arterial feeders. Phase reconstruction in coronal plane acquisitions also provided evidence of centripetal flow.

CONCLUSION

Three-dimensional acquisitions and phase display of 2-D acquisitions improved the visibility of arterial pedicles of spinal vascular lesions at phase-contrast MR angiography.

Methylprednisolone delivery by Hyalobend corneal shields and its effects on rabbit ocular inflammation

Release of methylprednisolone from hyaluronic acid derivative corneal shields (Hyalobend), in vitro and in vivo, was evaluated as well as ocular anti-inflammatory activity in the rabbit eye. The release of methylprednisolone from Hyalobend corneal shields in vitro followed zero-order kinetics. After placing Hyalobend corneal shields in rabbit eye, aqueous and tear fluid methylprednisolone levels were detected up to 48 hours and compared with the levels obtained with methylprednisolone suspension. Hyalobend corneal shields maintained almost constant methylprednisolone levels in the rabbit tear fluid. On the contrary, the suspension gave very high tear values of steroid concentrations in the first 30 minutes but undetectable in less than 200 minutes. Hyalobend corneal shields ensured effective levels of methylprednisolone into the rabbit aqueous for up to 48 hours. Aqueous levels of drug, in the group treated with the suspension, decreased progressively and after 480 minutes were undetectable. Hyalobend corneal shields significantly reduced the conjunctival inflammation elicited by sodium arachidonate compared with control. Furthermore, Hyalobend corneal shields treatment significantly reduced the levels of PGE2 in the tear fluid. Hyalobend corneal shields increase the residence time of methylprednisolone in rabbit tear fluid and enhance the penetration into the aqueous humor as well as reduced the primary signs of ocular inflammation.

MR angiography of spinal vascular malformations

PURPOSE

To determine the potential and limitations of MR angiography in the evaluation of spinal vascular malformations.

METHODS

Eleven consecutive patients with spinal vascular malformations proved with spinal selective arteriography underwent two-dimensional phase-contrast MR angiography.

RESULTS

Abnormal vessels within the spinal canal were identified with MR angiography in 10 patients. In 1 patient with a dural arteriovenous fistula no definite vascular abnormality was seen with MR angiography. Correlation of MR angiography with spinal selective arteriography showed that the former allowed identification of the arterial feeder in 3 patients with intramedullary arteriovenous malformations and 2 with perimedullary arteriovenous fistula, whereas the source of intradural draining vein was seen in only 2 of 6 patients with dural arteriovenous fistula.

CONCLUSION

MR angiography is a promising complementary tool to MR imaging for detection and characterization of spinal vascular malformations.

Dementia with leucoaraiosis and dural arteriovenous malformation: clinical and PET case study

A case of rapidly progressive dementia with diffuse leucoaraiosis on CT was attributable to a supratentorial dural arteriovenous malformation. Positron emission tomography (PET) showed low cerebral blood flow and high oxygen extraction ratio throughout the cerebral hemispheres indicating a state of chronic haemodynamic compromise which could predispose to the development of a vascular dementia. CT images of dilated intracerebral veins suggested that a venous drainage overload rather than a vascular steal phenomenon might be involved in the pathophysiology of the dementia of vascular origin.

Effects of Mipragoside on ocular allergic inflammation in the rabbit

We evaluated the pharmacodynamic and pharmacokinetic profile of Mipragoside, a monosialoganglioside isopropyl-ester (as 0.5% w/w ophthalmic gel), on allergic inflammation of the eye induced by reverse passive Arthus reaction, on a non-immune mast cell degranulation elicited by compound 48/80 and on ocular inflammation produced by horse serum. Conjunctiva was sensitized by injection of rabbit antisera to bovine proteins and the allergic conjunctivitis was triggered by intravenous administration of bovine gamma globulin. The permeability of the blood-conjunctival barrier was evaluated by a fluorometric method. Compound 48/80 was topically administered at concentration of 50mg/ml and histological analysis of conjunctiva was performed. Horse serum was administered by intravenous injection at different days. The pharmacokinetic profile of topical 3H-Mipragoside on 48/80 model was investigated and compared with untreated animals. Mipragoside treatment significantly reduced (p < 0.05 vs placebo) the conjunctival vasopermeability induced by reverse passive Arthus reaction as well as successfully reduced the eosinophil levels in the conjunctival epithelium (p < 0.01 vs placebo) elicited by compound 48/80. Further, Mipragoside successfully reduced the primary signs of ocular inflammation produced by horse serum administration. A radiotracer technique was used to evaluate the disposition of 3H-Mipragoside in the rabbit ocular tissues. Disposition of the drug was monitored at 30, 60, 120 and 240 min. 3H-Mipragoside levels in the inflamed conjunctiva were significantly higher (p < 0.01) than in the control eye.

Effects of sodium naproxen eye drops on rabbit ocular inflammation induced by sodium arachidonate

Sodium naproxen, a reversible competitive inhibitor of cyclooxygenase, is widely used as an anti-inflammatory agent in clinical practice. The purpose of this study was to determine whether eye drops containing 0.5% (w/v) sodium naproxen reduce a number of inflammatory responses produced by sodium arachidonate in the rabbit's eye. Sodium naproxen eye drops successfully reduced the primary signs of ocular inflammation elicited by 0.5% sodium arachidonate on conjunctiva and iris. However, the drug was less effective in reducing conjunctival inflammation induced by 1% sodium arachidonate. Sodium naproxen treatment significantly reduced the levels of prostaglandin E2 (PGE2), polymorphonuclear leukocytes and protein concentration in aqueous humor samples obtained from the eyes of rabbits treated with 0.5% sodium arachidonate whereas aqueous humor levels of leukotriene B4(LTB4) were not found significantly different from control rabbits. Interestingly, PGE2 as well as LTB 4 "de novo" production by corneas and lenses obtained from rabbits sacrificed 2 h after arachidonate and incubation "in vitro" for 20 min were significantly higher in samples taken from controls than in tissues obtained from the eyes treated with sodium naproxen eye drops. Finally, this drug treatment significantly antagonized the rise in intraocular pressure induced by 0.5% sodium arachidonate. Present data suggest that sodium naproxen may be employed topically to prevent ocular inflammatory reactions where the arachidonic acid cascade is activated.

Simultaneous high-performance liquid chromatographic determination of antazoline phosphate and tetrahydrozoline hydrochloride in ophthalmic solution

A method for the determination of 2-[(N-phenyl)benzylaminomethyl]-2-imidazoline X H3PO4 (antazoline phosphate) and 2-(1,2,3,4-tetrahydro-1-naphthyl)-2-imidazoline X HCl (tetrahydrozoline hydrochloride) in ophthalmic solution is described. The pharmaceutical preparation is analysed directly by reversed-phase ion-pair high-performance liquid chromatography and the method is very rapid, selective and simple.

Sterols of Delphinium ajacis; production and metabolic relationships in whole plants and callus tissue

Sterols from whole nonsterile Delphinium ajacis plants and from sterile tissue cultures (callus) were identified and determined quantitatively. The major sterols in the whole plant tissues were sitosterol, campesterol and stigmasterol, whereas those in the callus tissue were stigmastanol, 24-ethylidenelophenol and Delta (7)-stigmastanol. Of the 21 compounds identified in callus tissue, 5 were not present in the whole plant, most notably Delta (7)-stigmastanol. For both sources of tissue, the sterol predominating in one was a minor component in the other (whole plant/tissue cultures: sitosterol 57%/5%; stigmastanol 2%/35%). On a tissue dry-weight basis, the amount of sterols isolated from callus tissue culture was ten to twenty times that obtained from the whole plant. Qualitatively the sterols from both sources fit into a metabolic scheme which proceeds from cycloartenol through 4,4-dimethylsterols and 4-methylsterols to sterols. A proposed metabolic pathway shows the differences in accumulation of sterols in the two types of tissue. The increase in sterol production in cultured cells, especially when favored by growth conditions, has promise for industrial application and in organic synthesis.