Acute dural venous sinus thrombosis without brain parenchymal abnormality: assessment with cerebral blood volume using dynamic susceptibility contrast magnetic resonance imaging.

We report results applying the dynamic susceptibility contrast (DSC) magnetic resonance (MR) technique to a patient with dural venous sinus thrombosis (DVST) of the right transverse-sigmoid sinus without brain parenchymal abnormality. The DSC-MR technique clearly demonstrated increased regional cerebral blood volume of the right temporo-parieto-occipital region adjacent to a right transverse-sigmoid sinus thrombosis in a patient with DVST without cerebral edema or hemorrhage.

Subdural hematoma (SDH): assessment of macrophage reactivity within the dura mater and underlying hematoma.

OBJECTIVES: Macrophages are an inherent component of the dura mater, and can be characterised in cases of subdural hematoma (SDH) by their progressive and varying accumulation within areas of damage. Gross and histological methods used to determine the age of SDH are inexact. These are in part due to the active nature of such lesions and the diverse manner in which trauma victims respond to injury. Correct diagnosis has obvious medico-legal implications. However, there is as yet no specific diagnostic method that allows the age of SDH to be reliably determined. This study investigated the progressive and orderly pattern of reactivity of resident and infiltrating dural macrophages that occurs in response to injury associated with SDH. MATERIALS: 26 postmortem cases of traumatic SDH were examined with survival times (onset of trauma to death) ranging from a few hours and up to 31 days. METHODS: Macrophage reactivity associated with the dura mater and the underlying hematoma was determined using CD68 and MHC class II immunohistochemistry and the qualitative and quantitative findings compared with the presence of iron detected using conventional Perl's Prussian blue method. RESULTS: The results show that CD68 and MHC class II are differentially expressed within the dura mater and hematoma in SDH, and that the expression of MHC class II is markedly upregulated in the inner aspect of the dura mater within the initial 24 hours following injury. CD68 expression can be detected quantitatively in the hematoma, 24-48 hours after SDH, and within the dura following this period. Linear regression analysis further revealed a significant and positive association between the expression of MHC class II or CD68 antigens and the progressive survival of SDH up to 31 days post-injury, which was not seen with Perl's histochemical method. The expression of MHC class II antigen was a distinguishing, and quantifiable feature particularly localized within the inner aspect of the dura from a very early stage in the progression of SDH. Widespread, diffuse and cellular MHC class II reactivity was particularly noted within the inner aspect of the dura mater in cases of SDH with survival > 10 days. Since only a proportion of this widespread immunoreactivity was accounted for by macrophages (considering CD68 immunoreactivity), a large component of this activity was more likely to be due to the reorganisation and activation of fibroblasts within inner dural layers (dural border layer), known to upregulate expression of MHC class II molecules. CONCLUSIONS: The expression of CD68 and MHC class II antigens provides a more informative picture of the progression of pathology associated with SDH, and may be used in conjunction with other clinicopathological factors, in further investigations that attempt to date SDH according to defined histopathological characteristics.

Haemodynamic assessment in patients with dural arteriovenous fistulae: dynamic susceptibility contrast-enhanced MRI.

Cerebral haemodynamics in patients with dural arteriovenous fistulae (DAVF) have not been fully investigated and their effects are not clear. Our purpose was to assess impaired haemodynamics in patients with DAVF using dynamic susceptibility contrast-enhanced MRI (DSC-MRI). We used this technique in eight control subjects (group I) and 17 patients with DAVF who were scheduled to undergo or had already undergone endovascular embolisation and/or surgical excision. There were seven patients with cavernous sinus DAVF (CSDAVF) and the other ten had unilateral transverse/sigmoid sinus DAVF. All patients with CSDAVF underwent DSC-MRI preoperatively (group II) and those with transverse/sigmoid sinus DAVF underwent preoperative DSC-MRI (group III) and postoperative (group IV) assessment. The ratios of relative cerebral blood volume (rCBV), cerebral blood flow (rCBF) and mean transit time (rMTT) were calculated relative to contralateral values. Patients in group II had no significant haemodynamic impairment in grey (GM) or white matter (WM), but cerebellar rMTT were significantly prolonged ( P<0.05). Group III showed haemodynamic impairment characterised by significant increase in rCBV, prolongation of rMTT and decrease in rCBF in GM ( P<0.05). Significantly increased rCBV and prolonged rMTT in the GM ( P<0.05) were obvious in group III patients irrespective of retrograde leptomeningeal venous drainage (RLVD). In group IV, rCBV and rCBF returned to normal values, whereas rMTT was still significantly prolonged in GM ( P<0.05). Our study indicates that patients with CSDAVF may have impaired cerebellar perfusion, and that those with transverse/sigmoid sinus DVAF can have disturbed cerebral haemodynamics, even in the absence of RLVD.

Surgical and endovascular treatment of spinal dural arteriovenous fistulas: long-term disability assessment and prognostic factors.

OBJECT: The authors assessed clinical outcomes of patients with treated spinal dural arteriovenous fistulas (DAVFs) and investigated prognostic factors. METHODS: Thirty consecutive patients with spinal DAVFs were treated at the authors' institution during the past 15 years: seven underwent surgery; seven underwent surgery after failed embolization: and 16 underwent embolization alone. The outcomes of gait and micturition disability, were analyzed. Follow up averaged 3.4 years (range 1 month-11.8 years). Age, duration of symptoms, pre- and postintervention magnetic resonance (MR) imaging findings, and preintervention disability were correlated with outcome. Seventeen patients (57%) experienced improved gait, 12 (40%) were unchanged, and one (3%) was worse. In 11 patients (37%) micturition function was improved, in 15 (50%) it was unchanged, and in four (13%) it was worse. Gait disability, as measured by the Aminoff-Logue Scale, was significantly improved after treatment, from 3.4+/-1.4 (average +/- standard deviation) to 2.7+/-1.5 (p = 0.007). Mean micturition disability scores decreased, but not significantly, from 1.9+/-1 to 1.6+/-1.1 (p = 0.20). Preintervention gait disability was not associated with improvement except for patients with Aminoff-Logue Scale Grade 4 disability (eight of nine improved; p = 0.024). For patients treated within 13 months of symptom onset, mean micturition disability decreased (p = 0.035). No association was found between clinical improvement and age, a symptom duration less than 30 months, or pre- and postintervention MR imaging-documented spinal cord edema. CONCLUSIONS: Spinal DAVF treatment significantly improved patients' mean gait disability score by almost one grade at last follow up. The mean micturition disability score was not significantly improved, unless treatment was performed within 13 months of symptom onset. Longer and more uniform follow-up study is needed to determine if improved and stabilized clinical outcomes are sustained.

Importance of dural ectasia in phenotypic assessment of Marfan's syndrome.

BACKGROUND: Early identification of Marfan's syndrome is fundamental in the prevention of aortic dilatation, but the wide phenotypic expression of the disorder makes the clinical diagnosis very difficult. Dural ectasia has been classified as a major diagnostic criterion; however, its prevalence is not known. We aimed to identify the true prevalence of dural ectasia in Marfan's syndrome, and to investigate its relation to aortic pathology. METHODS: A magnetic-resonance-imaging (MRI) study of the thoracic aorta and of the lumbosacral spine was done in an inclusive series of 83 patients with Marfan's syndrome to assess the presence and degree of dural ectasia and aortic involvement; 12 patients were younger than 18 years. 100 individuals who underwent MRI of the lumbar spine for routine clinical indications represented the control group; none of them had any potential causes for dural ectasia. FINDINGS: Dural ectasia was identified in 76 (92%) patients and none of the control group. The severity of dural ectasia was related to age; the mean (SD) age of patients with mild dural ectasia was 26 years (14) whereas that of those with severe disease (meningocele) was 36 years (9) (p=0.038). 11 of 12 patients younger than 18 years had dural ectasia. No association was found between aortic dilatation and dural ectasia. INTERPRETATION: Dural ectasia is a highly characteristic sign of Marfan's syndrome, even at an early age.

Assessment of CSF dynamics and venous flow in the superior sagittal sinus by MRI in idiopathic intracranial hypertension: a preliminary study.

A velocity-sensitive magnetic resonance imaging (MRI) phase-mapping method was used for non-invasive study of cerebrospinal fluid (CSF) flow in the cerebral aqueduct, for indirect calculation of supratentorial CSF production, and for measurement of blood flow in the superior sagittal sinus (SSS). We examined 12 patients with idiopathic intracranial hypertension (IIH; pseudotumour cerebri), and 10 healthy volunteers. The peak caudal and rostral CSF flow in the aqueduct during the cardiac cycle did not differ significantly between the patients and the volunteers. A significant correlation was found between the CSF volume flow amplitude and the resistance to cerebrospinal fluid outflow in the patients (p < 0.05). The calculated mean supratentorial CSF production rate was 0.79 ml/min in the patients and 0.70 ml/min in the controls, but this difference was not statistically significant. However, the MRI measurements suggested CSF hypersecretion in three patients, whereas increased transependymal passage of CSF could have been the cause of negative calculated CSF production rates in two others. A tendency towards lower mean blood flow in the SSS (mean 345 ml/min) in the patients than in the controls (mean 457 ml/min) was found, and in two patients showed very low values. We showed that MRI phase-mapping may be used to study the relative importance of the pathophysiological factors thought to play a role in the development of IIH.

Epidural venous system (meningorachidian venous plexus) in juvenile amyotrophy of distal upper extremity: assessment with GD-DTPA enhanced volumetric MR study.

The epidural venous system (meningorachidian venous plexus) was analyzed utilizing gadolinium-diethylenetriamine pentaacetic acid (DTPA) (Gd-DTPA) enhanced volumetric magnetic resonance (MR) images in 11 patients with focal cervical spinal cord atrophy, clinically consistent with juvenile amyotrophy of distal upper extremity. In our series, all of the patients showed unusual posterior epidural venous enhancement at the C5-6 level, suggesting posterior epidural venous dilatation. Three patients also showed prominent dilatation of cervico-thoracic epidural veins surrounding the thecal sac. These MR findings were also demonstrated by spinal phlebography. Gd-DTPA enhanced MR images, especially high resolutional volumetric MR images, were efficient for evaluating these vessels. The observation of meningorachidian venous plexus along the disease course should be necessary for searching the pathogenesis of this disease.

MRI assessment of unsuspected dural sinus thrombosis.

In three patients with clinically unsuspected diagnosis, MRI has afforded a positive and conspicuous demonstration of dural sinus thrombosis, allowing specific treatment and followed by improvement in the patients' condition. Even in retrospect, CT examinations were nondiagnostic. Presenting symptoms were usual and nonspecific. CT and radionuclide scanning have proved valuable when performed on a clinically oriented basis. Angiography cannot be carried out without clear indications. MRI offers advantages in being a non-invasive technique without ionising radiation, allowing direct visualization and accurate delineation of the thrombus. MRI is definitely the method of choice to assess clinically suspected cerebral venous occlusion. As MRI diagnosis relies on a routine examination protocol, we believe that it will detect other unsuspected cases of dural sinus thrombosis.

The value of the external carotid circulation in the assessment of intracranial disease.

The external carotid circulation often contributes a vascular supply in intracranial disease. Adequate radiological evaluation of this circulation is important and may alter the surgical management in these patients.