Spontaneous subarachnoid hemorrhage and negative initial vascular imaging--should further investigation depend upon the pattern of hemorrhage on the presenting CT?

BACKGROUND: Multiple investigations are usually performed in patients with spontaneous SAH who have negative initial angiography. This study aimed to evaluate the most appropriate use of additional imaging studies and how this may be influenced by the findings of the initial CT. METHODS: A retrospective analysis was performed on a prospectively collected cohort of patients referred with spontaneous SAH and negative initial angiography. The patients were divided into four categories based upon the distribution of blood on the initial CT: perimesencephalic (pSAH), diffuse (dSAH), sulcal (sSAH) and CT negative (CSF positive for xanthochromia) (nCT-pLP). The number and nature of the subsequent imaging investigations were reviewed, and the results were correlated with the findings of the presenting CT. RESULTS: One hundred fourteen patients were included in the study. Repeat imaging found five relevant abnormalities. Three cases of vasculitis were diagnosed on the first DSA following a negative CTA. A case of dissecting aneurysm was revealed on the third neurovascular study. A hemorrhagic spinal tumor presented with xanthochromia. No subsequent abnormality was found on the third DSA or MRI head. No case of pSAH had a subsequent positive finding if the initial CTA was negative. CONCLUSIONS: Certain patterns of SAH are associated with a low yield of abnormalities on repeat imaging if the initial angiography is normal. The authors believe that the pattern of hemorrhage on the presenting CT should be used to guide the most appropriate use of further imaging modalities and present a diagnostic algorithm for this purpose.

Near fatal haemorrhage 35 years after radiation for laryngeal cancer: emergency embolisation of a vertebral artery aneurysm.

The authors report a rare case of a 75 year old man who presented 35 years after radiotherapy for carcinoma of the larynx, with catastrophic bleeding through the mouth. Both the time and mode of presentation were unusual. The patient required emergency sacrifice of the left vertebral artery to stop the bleeding. The literature has been reviewed.

Quantitative MR diffusion mapping and cyclosporine-induced neurotoxicity.

Apparent diffusion coefficient maps of two patients with cyclosporine-induced neurotoxicity showed areas of increased diffusion that corresponded to the characteristic regions of signal change on routine T2-weighted sequences. The majority of lesions subsequently resolved without residual T2 or diffusion signal alteration. These findings suggest that, in our patients, the neurotoxic effects of cyclosporine resulted in a partially reversible extravasation of fluid into the cerebral interstitium and were not associated with acute ischemia.

Onchocerca cervicalis in horses: dermal histopathology.

A histopathological study of ventral midline skin from midwestern U.S. horses with and without onchocerciasis due to Onchocerca cervicalis found perivascular mononuclear dermatitis as the most consistent difference between the two groups. Seasonal variation in parasite numbers or cellular influxes was not observed. Eosinophilic dermatitis was observed in horses with onchocerciasis and dermatitides of unknown etiology.

Effects of timing of coil embolization after aneurysmal subarachnoid hemorrhage on procedural morbidity and outcomes.

OBJECTIVE: To elucidate the effect of treatment timing on procedural clinical outcomes after aneurysmal subarachnoid hemorrhage (SAH) for patients treated by endosaccular coil embolization. METHODS: A group of 327 patients who were consecutively treated, during a 46-month period, for ruptured intracranial aneurysms by coil embolization within 30 days after SAH were evaluated. Outcomes were assessed by comparing immediate pretreatment World Federation of Neurological Surgeons (WFNS) grades, 72-hour posttreatment WFNS grades, and modified Glasgow Outcome Scale scores at 6 months for patients treated within 48 hours (Group 1), 3 to 10 days (Group 2), or 11 to 30 days (Group 3) after SAH. RESULTS: The three interval-to-treatment groups included 33, 38, and 29% of the patients, respectively. Before treatment, 70% of the patients in Group 1, 78% of those in Group 2, and 83% of those in Group 3 were in good clinical grades (i.e., WFNS Grade 1 or 2). After coil embolization, the WFNS grades were either unchanged or improved for 93.5% of the patients in Group 1, 89.5% of those in Group 2, and 91.5% of those in Group 3. After 6 months, 81.3% of the patients in Group 1 experienced good outcomes (modified Glasgow Outcome Scale scores of 1 or 2), as did 84% of those in Group 2 and 80% of those in Group 3. No statistical difference was demonstrated between the three groups when they were compared for these two variables. CONCLUSION: The interval between endovascular treatment and SAH did not affect periprocedural morbidity rates or 6-month outcomes. Coil embolization should therefore be performed as early as possible after aneurysmal SAH, to prevent aneurysmal rerupture.

Embolization of spinal cord arteriovenous malformations with an ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide (Onyx liquid embolic system). Report of two cases.

In this paper the authors describe the first use of a new liquid embolic agent (Onyx) to treat spinal cord arteriovenous malformations (AVMs). Because its properties make it more predictable to use than currently available liquid agents, the authors believe that this material has great potential in the endovascular management of both spinal cord and brain AVMs. This very promising agent merits further clinical study.

Equine alternative pathway activation by unsensitized rabbit red blood cells.

The equine alternative complement pathway has been partially characterized and compared to the equine classical activation pathway. A dose-dependent lysis of RbRBC was observed with peak lytic values noted within 10 minutes at 37 degrees C when rabbit red blood cells (RbRBC) were used as an alternative pathway activator. Sheep red blood cells (SRBC) sensitized with rabbit hemolysin or partially purified equine IgM antibodies were equally sensitive to lysis. Dilution of the commercial hemolysin by 1/5 reduced lysis from 90% to 38% in the presence of constant cell numbers. Hemolysis of SRBC peaked at 10 minutes and the majority of lysis occurred within 10 minutes. Dilution of equine sera by as little as 1/5 decreased hemolytic activity for SRBC to 21.5% from greater than 90% with undiluted sera. The alternative pathway protein, equine factor B, was tested using RbRBC and monitored by its differential susceptibility to heat treatment at 50 degrees C. This treatment led to almost complete inactivation after a 15-minute incubation. An apparent heat-dependent decay of certain classical pathway components was also observed after 50 degrees C treatment. This sensitivity was indicated by a reduction in the lytic activity for sensitized SRBC. Treatment for 15 minutes at 56 degrees C with either RbRBC or SRBC was sufficient to abolish hemolytic activity in all equine sera tested. Chelation of cations with 0.04 M EDTA blocked expression of alternative and classical pathway activation; however, chelation of Ca++ ions with 10 mM EGTA containing 1 mM Mg++ ions permitted lysis of the RbRBC but not the SRBC. A dose-related Mg++-ion dependence for RbRBC hemolytic activity was observed as the concentration of Mg++ was increased to 1.0 mM. In addition, our results obtained with pre-colostral foal serum strongly suggest that natural antibody to RbRBC was of little importance in the lysis observed with these cells. These results also show that the equine alternative pathway activation may require Ca++ ions. If Ca++ ions are required, the equine alternative pathway is quite different from any other mammalian complement system so far described. Our results suggest that the alternative pathway of activation is of major importance in the equine complement system. Confirmation of this hypothesis requires both purification of the components involved as well as further characterization.

Dissecting vertebral artery aneurysm: diagnosis and coil embolization.

Dissecting aneurysm of the intradural vertebral artery, a rare cause of stroke and sub-arachnoid haemorrhage, is associated with a poor neurological outcome if the disease is unrecognized and remains untreated. Clinical manifestations may be delayed or overlooked and non-invasive radiological investigations demonstrate little or no abnormality. We describe the diagnosis and successful endovascular occlusion of a dissecting vertebral artery aneurysm using detachable microcoils; a novel technique that has advantages over conventional therapeutic procedures.

The performance of three portable infusion-pump devices set to deliver 2 mL/hr.

The performance of three portable infusion-pump devices set to deliver 2 mL/hr was studied. Portable infusion-pump devices (CADD-1, Paragon, and Singleday Infusor) were set to deliver 5% or 25% dextrose in water at 2 mL/hr for 24 hours at two environmental temperatures (25 and 35 degrees C). There were a total of 12 types of experimental runs, and each run was performed in triplicate. Flow rate accuracy and flow continuity were measured by a computerized gravimetric technique; effusate weights were measured and recorded at 30-second intervals for two hours at the beginning and two hours at the end of each run. Mean flow rates among the three devices did not differ significantly. Mean flow rate was significantly higher for the 5% dextrose solution than for the 25% dextrose solution, for the 35 degree C temperature than for the 25 degree C temperature, and during the first two hours of delivery than during the last two hours. The CADD-1 units showed an interruption of flow lasting about 30 seconds and recurring every 60 seconds; the other devices had fairly constant flow. Mean flow continuity differed significantly among the three devices. Mean flow continuity was significantly higher for the 5% dextrose solution and for the 25 degree C temperature. Flow continuity differed among three representative portable infusion-pump devices set to deliver 2 mL/hr, but flow rate accuracy did not. Fluid viscosity, environmental temperature, and elapsed time affected flow rate accuracy and flow continuity.

Chemical composition of lipid droplets isolated from larvae of Taenia taeniaeformis.

Young developing larvae of Taenia taeniaeformis contain large deposits of osmiophilic droplets. These droplets are spherical, approximately 1.5 micron in diameter and are primarily localized in the tegument. After cellular disruption of the parasite, followed by centrifugation, the lipid droplets were found in a floating layer of lipid. The lipid droplets in the lipid layer resembled the droplets as seen in situ. The isolated lipid droplets mainly consisted of neutral lipids with triglycerides, sterol esters, sterols and free fatty acids being the major components. Smaller amounts of other neutral lipids were also present, as were glycolipids, phospholipids and protein. The lipid droplets were not membrane bound. The relationship between lipid droplets, lipid utilization and membrane synthesis during parasite growth is discussed.

Lipid and protein composition of the surface tegument from larvae of Taenia taeniaeformis.

A tegumental fraction from fully developed larvae of Taenia taeniaeformis was recovered by low speed centrifugation following incubation of the parasites in a 0.1% solution of digitonin. Scanning electron microscopy of the parasite carcass revealed no surface microtrichs, and transmission electron microscopy indicated that the subtegumental layer was undamaged. The tegumental fraction, judging from the distribution of 3H-Concanavalin A, was enriched for surface components, exhibited low succinic dehydrogenase activity, and an electron microscopic examination of the pellet showed a slightly expanded but intact distal tegumental layer. The fraction, which made up 3.0% of the dry weight of the parasite, consisted of 52% protein and 32% lipid. Thirty-three proteins, ranging in Mr from 9,000 to 276,000 daltons, were detected after sodium dodecyl sulfate solubilization and polyacrylamide gel electrophoresis. Seven of these proteins were glycoproteins. Cholesterol, phosphatidylethanolamine, phosphatidylserine, and glycosphingolipids were the major lipids.

Equine ocular onchocerciasis: histopathologic study.

Equine eyes (368) were examined clinically and histologically for abnormalities associated with the presence of ocular microfilariae of naturally occurring Onchocerca sp infection. Forty of the eyes had microfilariae in the conjunctiva, but distinguishing clinical abnormalities were not associated with their presence. In 1 horse with ocular microfilariae that was treated with diethylcarbamazine daily for 2 weeks, ocular tissue samples were obtained before, during, and after the horse was treated, and the samples were compared histologically. During treatment of the horse, microfilariae apparently moved from the conjunctival stroma into the perilimbal corneal stroma; inflammatory cells were more abundant in the perilimbal tissues. The tissue samples obtained before and after the treatment appeared similar.

Giant aneurysm of the petrous internal carotid artery: diagnosis and treatment.

We report the case of a giant fusiform aneurysm of the petrous internal carotid artery in a 15-year-old patient who had presented with headache, hearing loss and Horner's syndrome. Definitive radiological diagnosis was made by non-invasive imaging techniques, including magnetic resonance angiography (MRA). The aneurysm was obliterated by endovascular balloon occlusion following successful tolerance of test occlusion of the internal carotid artery.

Delayed massive epistaxis due to traumatic intracavernous carotid artery pseudoaneurysm.

Recurrent epistaxes after head injury may rarely be due to a traumatic intracavernous carotid artery pseudoaneurysm. The head injury is usually associated with fracture of the skull base and the epistaxes are severe with the first episode generally occurring one to three months after the initial trauma. We present a case which illustrates the role of high resolution computed tomography (CT) scanning and also magnetic resonance angiography (MRA) in achieving the diagnosis.

3.0 T MRI of 2000 consecutive patients with localisation-related epilepsy.

OBJECTIVES: Clinical guidelines suggest that all patients diagnosed with localised seizures should be investigated with MRI to identify any epileptogenic structural lesions, as these patients may benefit from surgical resection. There is growing impetus to use higher field strength scanners to image such patients, as some evidence suggests that they improve detection rates. We set out to review the detection rate of radiological abnormalities found by imaging patients with localised seizures using a high-resolution 3.0 T epilepsy protocol. METHODS: Data were reviewed from 2000 consecutive adult patients with localisation-related epilepsy referred between January 2005 and February 2011, and imaged at 3.0 T using a standard epilepsy protocol. RESULTS: An abnormality likely to be related to seizure activity was identified in 403/2000 (20.2%) patients, with mesial temporal sclerosis diagnosed in 211 patients. 313/2000 (15.6%) had lesions potentially amenable to surgery. Abnormalities thought unrelated to seizure activity were found in 324/2000 (16.1%), with 8.9% having evidence of ischaemic disease. CONCLUSIONS: Since the introduction of the then National Institute for Clinical Excellence guidelines in 2004, the detection rate of significant pathology using a dedicated 3.0 T epilepsy protocol has not fallen, despite the increased numbers of patients being imaged. This is the largest study of epilepsy imaging at 3.0 T to date and highlights the detection rates of significant pathology in a clinical setting using a high-strength magnet. The prevalence of ischaemic disease in this population is significantly higher than first thought, and may not be incidental, as is often reported.

Spontaneous closure of a type 2a dural arteriovenous fistula following late recanalization of the occluded sinus.

We describe the rare spontaneous resolution of a type 2a dural AVF that coincided with recanalization of the previously thrombosed sigmoid sinus after ten years of conservative management. The factors potentially responsible for spontaneous fistula obliteration are discussed and the therapeutic implication of this observation is considered.

Symptomatic perianeurysmal edema following bare platinum embolization of a small unruptured cerebral aneurysm.

There is considerable interest in the development of symptomatic inflammatory reactions following coil embolization of cerebral aneurysms. Patients have experienced a range of adverse events, usually after treatment of moderately large aneurysms with modified "bioactive" coils. More recently, it has been recognized that adverse inflammatory reactions can be associated with the use of "nonbioactive" coils, and we present a case of symptomatic perianeurysmal edema after treatment of a small unruptured aneurysm with bare platinum coils.