Reversible brainstem dysfunction from spinal arterio-venous fistula.

A 45-year-old man presented with subacute onset of ataxia, diplopia, urinary retention and paraparesis. MR scan of brain showed abnormal T2 hyperintense signal within the cervical cord, medulla and lower pons and vascular appearances suggesting an arterio-venous fistula. The fistula was surgically explored and successfully disconnected with good clinical outcome. Brainstem or cervical dural arterio-venous fistulae more typically present as a myelopathy; only a handful of cases have presented with brainstem dysfunction. This is a rare but reversible cause of subacute brainstem dysfunction.

Simple measurement of aneurysm residual after treatment: the SMART scale for evaluation of intracranial aneurysms treated with flow diverters.

BACKGROUND: Primary endovascular reconstruction with flow diversion represents a fundamental paradigm shift in the technique of endovascular aneurysm treatment. Unlike coil embolization, often there remains residual post-procedural filling within the aneurysm with flow diverters, the curative reconstruction presumably occurring over a period of weeks. Thus, conventional grading scales for post-procedural aneurysm occlusion and recanalization are inadequate. The aim of this paper is to propose a new angiographic grading scale that addresses this fundamentally new treatment option. METHOD: A five-point grading scale describes the location of residual flow within the aneurysm in the venous phase [grade 1: patent aneurysm with diffuse inflow; grade 2: residual filling of the aneurysm dome (saccular) or wall (fusiform); grade 3: only residual neck (saccular) or only intra-aneurysmal filling with former boundaries covered (fusiform); grade 4: complete occlusion]. FINDINGS: Grade 0 represents any aneurysm, regardless of occlusion rate with early phase, coherent inflow jet. Intra-aneurysmal flow stagnation is categorized into: (a) none, (b) capillary phase, and (c) venous phase. Prevailing parent vessel hemodynamics with in-stent stenosis (ISS) are divided into none (ISS0), mild (ISS1), moderate (ISS2), severe (ISS3), and total (ISS4) occlusion. The proposed grading scales allow assessment of the hemodynamic consequences of stent placement on endosaccular in-flow, stasis, and location of stasis as well as parent vessel hemodynamics. CONCLUSIONS: Further studies need to show the applicability and possible predictive value of this new grading scale on the efficacy of the stent in promoting intra-aneurysmal flow stagnation, thus creating the potential to harmonize the results of future papers. This may help to optimize treatment and future device design.

Decision-making in the scheduling of endovascular treatment after brain arteriovenous malformation haemorrhage: a retrospective single centre study.

The appropriate timing for endovascular intervention after brain arteriovenous malformation (bAVM) rupture is not known. This paper aims to determine factors that lead to early endovascular intervention and to investigate whether early intervention has the same complication rate as late intervention in a single centre. All patients who underwent endovascular treatment for a ruptured bAVM at our institution in the period January 2007 and July 2010 were included in this retrospective observational study. Of 50 patients, 33 had early endovascular intervention, defined as within 30 days of haemorrhage and the remaining 17 patients had endovascular treatment at day 30 or beyond. A greater proportion of patients treated within the first 30 days were in neuro-intensive care preoperatively (51.5% vs. 23.5%, p=0.07). A 'high-risk' angioarchitectural feature was identified in more patients who had acute intervention (78.8% vs. 11.8%, p<0.0001) and targeted embolization was also more frequent in this group (48.5% vs. 5.9%, p=0.004). Nidal aneurysms, venous varices and impaired venous outflow (venous stenosis) were the principal 'high risk' features. Clinically apparent complications occurred in 10.8% of procedures with permanent neurological deficit in 3.6%. There was no directly procedure-related mortality. There was no statistically significant difference in the complication rate of early procedures compared with delayed interventions (12.5% vs. 7.4%, p=0.71). Greater initial injury severity and the presence of high-risk lesion characteristics are the factors that lead to early endovascular intervention. Early intervention is associated with a higher complication rate, but this difference is not statistically significant.

Idiopathic aneurysms of distal cerebellar arteries: endovascular treatment after rupture.

INTRODUCTION: Idiopathic ruptured aneurysms of distal cerebellar arteries (DCAAs) are rare, and their endovascular therapy (EVT) has as yet not been extensively reported. They are usually assumed to result from local arterial wall disruption rather than infection, unlike distal supratentorial artery aneurysms. This study was performed to audit their frequency, potential aetiology and results of EVT. PATIENTS AND METHODS: Using strict inclusion criteria and a database of 1715 EVT patients, we identified ten idiopathic ruptured DCAAs (0.6%) over a 13-year period (1993-2006). The series comprised six males and four females with mean age of 64 years and solitary aneurysms located on posterior inferior cerebellar artery (five patients), anterior inferior cerebellar artery (three patients) and superior cerebellar artery (two patients). Nine aneurysms were fusiform and were treated by endovascular parent artery occlusion, and one was saccular and treated by endosaccular packing. Endovascular therapy was performed with coils in seven cases, n-butyl-2-cyanoacrylate (NBCA) in two cases and with both in one case. RESULTS: Primary EVT was successful in eight patients. One patient died following a procedure-related re-bleeding and one patient required re-treatment after failed endosaccular packing. Nine patients made good or excellent clinical recoveries (modified Rankin Scale 2 or less). Focal cerebellar infarctions were seen on computed tomography images after EVT in three patients, only one of whom was symptomatic with transient dysmetria, which resolved completely during follow up. No aneurysm recanalisation was detected on late follow-up imaging up to 24 months. CONCLUSION: Ruptured DCAAs are rare. The majority are fusiform in shape and their aetiology remains uncertain. Endovascular treatment is feasible and effective. It usually requires parent artery occlusion.

Association between cortical metabolite levels and clinical manifestations of migrainous aura: an MR-spectroscopy study.

Previous studies suggest an abnormal cerebral cortical energy metabolism in migraineurs. If causally related to the pathophysiology of migraine, these abnormalities might show a dose-response relationship with the duration and severity of aura symptoms. While such a trend has been suggested in phosphorus spectroscopy (31P-MRS) studies, it has not been considered in proton spectroscopy (1H-MRS) studies and it has not been studied in cerebral white matter. We aimed to determine whether for any of the metabolites measured by 31P-MRS or 1H-MRS there was a dose-response relationship with aura duration and severity, and whether such an association was also present in cerebral white matter. We studied patients with migraine with aura and healthy controls with 31P-MRS and with 1H-MRS. We measured metabolite ratios in grey and in white matter and in the patients, we related metabolite levels to the clinical characteristics and duration of the aura. In patients, the phosphocreatine/phosphate (PCr/Pi) ratio decreased significantly with increasing aura duration and was significantly lower in patients with hemiplegic migraine than in patients with non-motor aura. Overall the metabolite ratios did not differ significantly between patients and controls, but compared with controls the PCr/Pi ratio in patients with hemiplegic migraine and in patients with persistent aura >7 days was significantly lower. These changes were only present in grey matter. Results for 1H-MRS did not differ significantly between patients and controls, and they showed no association with duration or severity of symptoms. In this study, metabolite ratios differed significantly between patients with different aura phenotypes and with increasing aura duration. In addition, only in some patient subgroups were metabolite ratios significantly different from controls. These findings support the concept that migraine with aura is a heterogeneous disorder with distinct pathophysiological subtypes. They further suggest that rather than determining the susceptibility to developing a migraine attack, changes in cortical energy metabolism may determine the clinical manifestations of the migrainous aura once an attack has started.

Distal aneurysms of the unpaired ACA: embryologic and therapeutic aspects.

Anatomical variants of the cerebral arteries in general are frequent and due to the complex ontogenesis of these structures. Although encountered in many mammals, a single anterior cerebral artery (ACA) trunk is an infrequent finding in humans with an incidence of 3-5%. This vessel, giving rise to the arteries of both frontal lobes, is subjected to high flow volumes and distal arterial aneurysms have repetitively been encountered, mostly however before the introduction of endovascular treatment strategies. We report on five patients with acute SAH and arterial aneurysms of an unpaired ACA, who underwent coil embolisation. In all cases endovascular treatment using detachable platinum coils resulted in an at least satisfactory degree of aneurysm obliteration without parent artery occlusion or embolic infarcts. All patients had clinical and angiographic follow-up with median follow-up time of 29 months during which no aneurysm regrowth was encountered. In spite of a small patient group our results suggest, that altered flow dynamics due to enlarged single intracranial vessels may predispose to aneurysm formation and that endovascular embolisation is an appropriate treatment option in distal aneurysms of an unpaired ACA.

Beta-Interferon treatment does not always slow the progression of axonal injury in multiple sclerosis.

Progression of disability in multiple sclerosis (MS) appears related to axonal damage, which is at least in part associated with white matter lesions. Beta-interferon (BIFN) substantially reduces new inflammatory activity in MS and a recent report suggested that it may reverse a component of axonal injury. To test the generalisability of this conclusion, particularly in a population with relatively active disease, we used magnetic resonance spectroscopy measures to test whether BIFN can reverse or arrest progression of axonal injury in patients with MS. Eleven patients with a history of active (median, 1.5 relapses/year) relapsing-remitting MS were treated with BIFN and responses to treatment were monitored with serial MRI and single voxel magnetic resonance spectroscopic measurements of relative concentrations of brain N-acetylaspartate (NAA), a measure of axonal integrity from a central, predominantly white matter brain region. BIFN treatment was associated with a significant reduction in relapse rate (p = 0.007) and white matter water T2 relaxation time (p = 0.047) over 12 months. Also consistent with a treatment effect, white matter T2-hyperintense lesion loads did not increase. However, the central white matter NAA/creatine ratio (NAA/Cr, which was reduced over 16 % in patients relative to healthy controls at the start of treatment), continued to decrease in the patients over the period of observation (mean 6.2 % decrease, p = 0.02). For individual patients the magnitude of the NAA/Cr decrease was correlated with the frequency of relapses over the two years prior to treatment (r = -0.76, p = 0.006). These data suggest that reduction of new inflammatory activity with BIFN does not invariably halt progression of axonal injury. Nonetheless, there appears to be a relationship between the rate of progression of axonal injury and relapse rate over the previous two years. The consequences of reduced inflammation on pathological progression relevant to disability therefore may be present, but substantially delayed. Alternatively, distinct mechanisms may contribute to the two processes.

The in vitro and in vivo ultrasonographic appearances of the angio-seal percutaneous closure device.

PURPOSE: To assess the ultrasound appearances of the Angio-Seal device in an animal model and in twenty patients following catheterization of the femoral artery. MATERIALS AND METHODS: Ten patients were scanned within 8 hours of their procedure (early group) and 10 at two to four days (delayed group) using Acuson Aspen and Sequoia scanners. Colour flow images were taken and Doppler spectral analysis was performed proximal proximal to, at and distal to the Angio-Seal device. Early and delayed in vitro images were taken in a water bath in which the Angio-Seal device was deployed across a normal porcine aorta for comparison. RESULT: In the ten early patients colour and Doppler drop out were seen in 100 percent and 90 percent respectively compared with 90 percent and 60 percent in the delayed group. The device was seen in 30 percent and 90 percent in early and delayed groups respectively. In the in vitro study the components of the device were seen and a posterior acustic shadow noted. This shadow was less obvious and the polymer anchor more easily seen in the delayed group. CONCLUSION: The Angio-Seal device produces a consistent artifact when scanned soon after deployment. These appearances could potentially be mistaken for a vascular occlusion by the unwary in the appropriate clinical setting of acute post catheterisation lower limb ischaemia however an awareness of the normal sonographic appearances of this device would make this misinterpretation unlikely.

Abnormal cerebral blood volume in regions of contused and normal appearing brain following traumatic brain injury using perfusion magnetic resonance imaging.

Following traumatic brain injury, there may be secondary alterations in cerebrovascular parameters leading to ischemia and further cellular damage. To assess possible subacute hemodynamic disturbances following traumatic brain injury, we used conventional and perfusion magnetic resonance imaging (MRI) in 18 patients, on average 10 days following injury. Six of the 18 patients had focal contusions or edema visible on conventional MRI. These six patients had a significantly reduced normalized regional cerebral blood volume (rCBV) in the regions of focal pathology compared to equivalent areas in control subjects (patients 0.47 +/- 0.20 [means +/- SD], controls 1.02 +/- 0.11, p < 0.001). In addition, four of these six patients had an increased rCBV (outside control range) in the region of normal appearing brain immediately surrounding the contusion. These six patients were more significantly injured and had a worse clinical outcome compared to the remaining patients (p = 0.004,p = 0.03, respectively). There were five patients who had a region of reduced rCBV (outside control range) in a quadrant of normal appearing white matter, away from any visible abnormality, who were not more significantly injured than the remaining patients but went on to have a significantly poorer clinical outcome (p = 0.27, p = 0.01, respectively). Traumatic brain injury is a heterogeneous insult causing a variety of pathology, not all of which is visible using conventional imaging methods. The current study has shown that regions of both normal appearing and contused brain may have an abnormal rCBV and that alterations in rCBV may play a role in determining the clinical outcome of patients.

Altered cellular metabolism following traumatic brain injury: a magnetic resonance spectroscopy study.

Experimental studies have reported early reductions in pH, phosphocreatine, and free intracellular magnesium following traumatic brain injury using phosphorus magnetic resonance spectroscopy. Paradoxically, in clinical studies there is some evidence for an increase in the pH in the subacute stage following traumatic brain injury. We therefore performed phosphorus magnetic resonance spectroscopy on seven patients in the subacute stage (mean 9 days postinjury) following traumatic brain injury to assess cellular metabolism. In areas of normal-appearing white matter, the pH was significantly alkaline (patients 7.09 +/- 0.04 [mean +/- SD], controls 7.01 +/- 0.04, p = 0.008), the phosphocreatine to inorganic phosphate ratio (PCr/Pi) was significantly increased (patients 4.03 +/- 1.18, controls 2.64 +/- 0.71, p = 0.03), the inorganic phosphate to adenosine triphosphate ratio (Pi/ATP) was significantly reduced (patients 0.37 +/- 0.10, controls 0.56 +/- 0.19, p = 0.04), and the PCr/ATP ratio was nonsignificantly increased (patients 1.53 +/- 0.29, controls 1.34 +/- 0.19, p = 0.14) in patients compared to controls. Furthermore, the calculated free intracellular magnesium was significantly increased in the patients compared to the controls (patients 0.33 +/- 0.09 mM, controls 0.22 +/- 0.09 mM, p = 0.03)). Proton spectra, acquired from similar regions showed a significant reduction in N-acetylaspartate (patients 9.64 +/- 2.49 units, controls 12.84 +/- 2.35 units, p = 0.03) and a significant increase in choline compounds (patients 7.96 +/- 1.02, controls 6.67 +/- 1.01 units, p = 0.03). No lactate was visible in any patient or control spectrum. The alterations in metabolism observed in these patients could not be explained by ongoing ischemia but might be secondary to a loss of normal cellular homeostasis or a relative alteration in the cellular population, in particular an increase in the glial cell density, in these regions.

Early proton magnetic resonance spectroscopy in normal-appearing brain correlates with outcome in patients following traumatic brain injury.

The long-term clinical outcome following traumatic brain injury (TBI) can be difficult to predict. Proton magnetic resonance spectroscopy (MRS) has previously been used to demonstrate abnormalities in regions of white matter that appear normal on conventional imaging in patients following TBI. We report MRI and MRS studies of 26 patients performed at an early time point following injury (mean 12 days, n = 21) and at a later time point (mean 6.2 months, n = 15). The proton MRS was acquired from the posterior part of a normal-appearing frontal lobe containing predominantly white matter using stimulated echo acquisition mode to localize, with a relaxation time of 3000 ms and echo time of 30 ms. At both the early and late time points the N:-acetylaspartate/creatine ratio (NAA/Cr) was significantly reduced (P = 0.03, P = 0.005, respectively), the choline/creatine ratio (Cho/Cr) significantly increased (P = 0.001, P = 0.004, respectively) and the myo-inositol/creatine ratio (Ins/Cr) significantly increased (P = 0.03, P = 0.03, respectively) compared with controls. There was a small, but significant, further reduction (P = 0.02) in the NAA/Cr between the two studies in the 10 patients for whom data was available, at both time points. The NAA/Cr acquired at the early time point significantly correlated with the clinical outcome of the patients, assessed using either the Glasgow outcome scale (P = 0.005, n = 17) or the disability rating scale (P < 0.001, n = 17). We conclude that there is a sustained alteration in NAA and Cho. These findings provide possible evidence for cellular injury (NAA loss reflecting neuroaxonal cell damage and raised Cho and Ins reflecting glial proliferation) not visible by conventional imaging techniques. This may be relevant to understanding the extent of disability following TBI.

An unusual case of Lafora body disease.

A case is described in which non-convulsive status epilepticus (NCSE) prompted further investigation leading to the diagnosis of Lafora body disease (LBD). The onset of NCSE was temporally related to the withdrawal of sodium valproate and introduction of carbamazepine, which may have been precipitating factors. NCSE has not previously been reported in LBD. Implications for its drug management are discussed.

Normal pressure hydrocephalus: developments in determining surgical prognosis.

Research into normal pressure hydrocephalus has often focused on the clinical dilemma of selecting patients who will benefit from cerebrospinal fluid diversion. Recent developments in imaging and lumbar infusion tests are throwing light on the underlying pathophysiology, providing researchers with new avenues for the development of reliable investigative tools.