Coil migration through two flow-diverting stents.

We report a case of a patient who initially presented with a subarachnoid haemorrhage secondary to a ruptured supraclinoid internal carotid artery (ICA) blister aneurysm. The patient was treated successfully with a flow diverter stent (FD) and coiling; however, a large aneurysm recurrence via a feeding posterior communicating artery (PCOM) was noted on the 1-year follow-up angiogram. During the retreatment, a second FD in the ICA resulted in insufficient aneurysm stasis. Therefore, the decision was made to coil sacrifice the PCOM via posterior circulation access. During the first coil deployment, the distal coil end migrated through the mesh of two overlapping FD into the middle cerebral artery. This complication was a previously unrecognised possibility given the composition of the FD. This case report aims to discuss this process as a potential complication during neurointerventional procedures using these devices.

Admission Perfusion CT for Classifying Early In-Hospital Mortality of Patients With Severe Traumatic Brain Injury: A Pilot Study.

OBJECTIVE. The purposes of this study were to assess the feasibility and safety of perfusion CT of patients with severe traumatic brain injury (TBI) at hospital admission and to examine whether early in-hospital mortality could be characterized with perfusion CT (PCT). The hypothesis was that PCT can be used to characterize brain death, when present, in patients with severe TBI at hospital admission. SUBJECTS AND METHODS. In this prospective cohort pilot study, PCT was performed on patients with severe TBI at first imaging workup at hospital admission. PCT images were processed at the end of the study and assessed for features of brain death. The PCT features were then compared with the clinical outcome of in-hospital mortality. RESULTS. A total of 19 patients (13 men [68.4%]; six women [31.6%]; mean age, 36.4 years; median, 27.5 years) had a mean hospital stay longer than 1 month. No complications of PCT were found. In the first 48 hours after admission, four patients (21%) died. Admission PCT changes suggesting brainstem death were sensitive (75%) and specific (100%) and had high positive (100%) and negative (93.75%) predictive value for correct classification early in-hospital mortality. CONCLUSION. Admission PCT of patients with severe TBI was feasible and safe. Admission PCT findings helped in correctly classifying early in-hospital mortality in the first 48 hours of hospital admission.

Computed Tomography Perfusion Aids in the Prognostication of Comatose Postcardiac Arrest Patients.

Early assessment of the potential for neurologic recovery in comatose cardiac arrest patients (CCAP) has been a challenge despite significant evolution in management and imaging techniques. The purpose of study was to determine if the use of computed tomography perfusion (CTP) in CCAPs is feasible and if this technique can predict the likelihood that CCAPs will have a devastating outcome at hospital discharge. We prospectively enrolled 10 newly admitted comatose adults who had an out-of-hospital cardiac arrest and were treated with standard therapeutic hypothermia protocols. Patients underwent CTP of the head within 6 hours after finishing therapeutic hypothermia treatment. The imaging findings were compared with the results of a clinical assessment, as well as the modified Rankin Scale (mRS) score at hospital discharge. Sensitivity, specificity, and positive and negative predictive values for CTP were calculated to predict clinical outcome. Eight patients had an mRS score of ≥5, and 2 patients had an mRS score of ≤2 at hospital discharge. CTP predicted a good clinical outcome in both patients with an mRS score of ≤2. The area under the curve (AUC) for plain computed tomography of the head, computerized tomography angiogram 4-point scale, computerized tomography angiogram 7-point scale, CTP of the whole brain, and CTP of the brainstem for predicting the results of the immediate clinical assessment were 0.76, 0.83, 0.67, 0.83, and 1.0, respectively. The AUCs for predicting outcome at discharge were 0.69, 0.63, 0.56, 0.63, 0.63, and 0.69, respectively. In conclusion, our pilot study showed that CTP is feasible and had a very high AUC for predicting the results of immediate clinical assessment in CCAP.

Canadian Expert Panel Recommendations for MRI Use in MS Diagnosis and Monitoring.

BACKGROUND: A definitive diagnosis of multiple sclerosis (MS), as distinct from a clinically isolated syndrome, requires one of two conditions: a second clinical attack or particular magnetic resonance imaging (MRI) findings as defined by the McDonald criteria. MRI is also important after a diagnosis is made as a means of monitoring subclinical disease activity. While a standardized protocol for diagnostic and follow-up MRI has been developed by the Consortium of Multiple Sclerosis Centres, acceptance and implementation in Canada have been suboptimal. METHODS: To improve diagnosis, monitoring, and management of a clinically isolated syndrome and MS, a Canadian expert panel created consensus recommendations about the appropriate application of the 2010 McDonald criteria in routine practice, strategies to improve adherence to the standardized Consortium of Multiple Sclerosis Centres MRI protocol, and methods for ensuring effective communication among health care practitioners, in particular referring physicians, neurologists, and radiologists. RESULTS: This article presents eight consensus statements developed by the expert panel, along with the rationale underlying the recommendations and commentaries on how to prioritize resource use within the Canadian healthcare system. CONCLUSIONS: The expert panel calls on neurologists and radiologists in Canada to incorporate the McDonald criteria, the Consortium of Multiple Sclerosis Centres MRI protocol, and other guidance given in this consensus presentation into their practices. By improving communication and general awareness of best practices for MRI use in MS diagnosis and monitoring, we can improve patient care across Canada by providing timely diagnosis, informed management decisions, and better continuity of care.

Evolving role of MRI in optimizing the treatment of multiple sclerosis: Canadian Consensus recommendations.

BACKGROUND: Magnetic resonance imaging (MRI) is increasingly important for the early detection of suboptimal responders to disease-modifying therapy for relapsing-remitting multiple sclerosis. Treatment response criteria are becoming more stringent with the use of composite measures, such as no evidence of disease activity (NEDA), which combines clinical and radiological measures, and NEDA-4, which includes the evaluation of brain atrophy. METHODS: The Canadian MRI Working Group of neurologists and radiologists convened to discuss the use of brain and spinal cord imaging in the assessment of relapsing-remitting multiple sclerosis patients during the treatment course. RESULTS: Nine key recommendations were developed based on published sources and expert opinion. Recommendations addressed image acquisition, use of gadolinium, MRI requisitioning by clinicians, and reporting of lesions and brain atrophy by radiologists. Routine MRI follow-ups are recommended beginning at three to six months after treatment initiation, at six to 12 months after the reference scan, and annually thereafter. The interval between scans may be altered according to clinical circumstances. CONCLUSIONS: The Canadian recommendations update the 2006 Consortium of MS Centers Consensus revised guidelines to assist physicians in their management of MS patients and to aid in treatment decision making.

Evaluation of whole brain health in aging and Alzheimer's disease: a standard procedure for scoring an MRI-based brain atrophy and lesion index.

BACKGROUND: The Brain Atrophy and Lesion Index (BALI), a semi-quantitative rating scale, has been developed to evaluate whole brain structural changes in aging and Alzheimer's disease (AD). OBJECTIVE: This study describes a standard procedure to score the BALI and train new raters for reliable BALI evaluation following this procedure. METHODS: Structural MRI of subjects in the Alzheimer's Disease Neuroimaging Initiative dataset who had 3.0T, T1, and T2 weighted MRI scans at baseline and at 6, 12, and 24 month follow-ups were retrieved (n = 122, including 24 AD, 51 mild cognitive impairment patients, and 47 healthy control subjects). Images were evaluated by four raters following training with a step-by-step BALI process. Seven domains of structural brain changes were evaluated, and a total score was calculated as the sum of the sub-scores. RESULTS: New raters achieved >90% accuracy after two weeks of training. Reliability was shown in both intra-rater correlation coefficients (ICC ≥ 0.92, p < 0.001) and inter-rater correlation coefficients (ICC ≥0.88, p < 0.001). Mean BALI total scores differed by diagnosis (F ≥ 2.69, p ≤ 0.049) and increased consistently over two years. CONCLUSION: The BALI can be introduced using a standard procedure that allows new users to achieve highly reliable evaluation of structural brain changes. This can advance its potential as a robust method for assessing global brain health in aging, AD, and mild cognitive impairment.

Teaching NeuroImages: neurodegeneration with brain iron accumulation in aceruloplasminemia.

A 55-year-old African Canadian man with insulin-dependent diabetes mellitus and alcohol abuse presented with diabetic ketoacidosis. Progressive cognitive decline over the previous 5 years resulted in long-term care placement. Aside from pigmentary retinopathy, general examination was unremarkable. MRI demonstrated iron accumulation in the brain (figure 1) and liver (figure 2A). Ceruloplasmin, a ferroxidase enzyme important in iron homeostasis, was undetectable and associated with low serum iron, low serum copper, and 10-fold increase in serum ferritin. Liver biopsy confirmed increased hepatocyte iron storage (figure 2B). Aceruloplasminemia was diagnosed.(1,2) Iron chelation was not administered given advanced dementia at presentation.

SILK flow diverter for treatment of intracranial aneurysms: initial experience and cost analysis.

BACKGROUND: The flow diverting stent is a new and expansive tool in the endovascular therapy of complex intracranial aneurysms. We present our experience using SILK flow diverter (SFD) in patients with complex intracranial aneurysms, and a cost analysis. METHODS: Between September 2010 and May 2012, 19 consecutive patients with 29 complex intracranial aneurysms were treated with SFD without the adjunctive use of coils. We retrospectively evaluated the technical aspects, thromboembolic events, adjunctive therapies, and short term results in patients with complex intracranial aneurysms treated with SFD. A cost analysis of patients who were treated with SFD was performed and compared with similar sized aneurysms coiled with stent assisted coiling. RESULTS: The primary technical success rate was 100%. An adjunctive device was required in two of our patients. The technique related complication rate and the 30 day mortality and morbidity rates were 5% (1/20) and 10% (2/20), respectively. We had a total of 263 patient months of clinical and 166 patient months of imaging follow-up. Follow-up imaging revealed two asymptomatic occlusions of the parent artery. Complete occlusion of the aneurysm with fully patent parent artery was observed in 59% of patients where follow-up images were available. The cost analysis showed that the mean cost of treatment with SFD was significantly cheaper compared with the presumed cost of stent assisted coiling (p<0.001). CONCLUSIONS: The SFD provides a very feasible, efficient, relatively safe, and cost effective method to treat complex intracranial aneurysms without the use of adjunct coiling.

A longitudinal study on the effects of typical versus atypical antipsychotic drugs on hippocampal volume in schizophrenia.

BACKGROUND: Previous studies have reported that hippocampal volumes correlate with symptom severity in schizophrenia. This longitudinal study measured changes in symptoms and hippocampal volume in patients switched from typical antipsychotics to olanzapine. METHODS: MRI scans were acquired from patients with chronic schizophrenia (n=10) and healthy volunteers (n=20). At baseline, patients were treated with typical antipsychotics for at least one year, then switched to olanzapine, and rescanned approximately one year later. RESULTS: Olanzapine treatment resulted in no significant change in right or left hippocampal volume. Individual changes in right hippocampal volume correlated significantly with changes in symptoms. CONCLUSIONS: Hippocampal volume change may serve as a marker of symptom change in patients on olanzapine.

Reduced thalamic volume in patients with chronic schizophrenia after switching from typical antipsychotic medications to olanzapine.

OBJECTIVE: The authors performed a longitudinal study of the effects on thalamic volume of switching from typical to atypical antipsychotic medications. METHOD: Magnetic resonance imaging scans were acquired from 10 subjects with chronic schizophrenia taking typical antipsychotics and 20 healthy volunteers. Subjects with schizophrenia were switched to olanzapine; both groups were rescanned. RESULTS: At baseline, thalamic volumes in subjects with chronic schizophrenia were 5.8% greater than those of healthy volunteers. At follow-up, there was no significant difference between groups. Additional analysis revealed a significant positive correlation between baseline thalamic volume and dosage of typical antipsychotic medication. Higher dosages at baseline were correlated with larger reductions in volume after the switch to olanzapine. CONCLUSIONS: Antipsychotic medication effects may be a factor in the wide range of thalamic volume differences reported between subjects with schizophrenia and healthy volunteers.

Clinical and radiographic subtypes of vascular cognitive impairment in a clinic-based cohort study.

BACKGROUND AND PURPOSE: There is a need for empirical studies to define criteria for vascular cognitive impairment (VCI) subtypes. In this paper, we report the predictive validity of a subtype classification scheme based on clinical and radiographic features. METHODS: Nine Canadian memory clinics participated in the Consortium to Investigate Vascular Impairment of Cognition. This cohort consisted of 1347 patients, of whom 324 had VCI, and was followed for up to 30 months. RESULTS: Clinical and neuroimaging features defined three subtypes: vascular cognitive impairment, no dementia, (n=97), vascular dementia (n=101) and mixed neurodegenerative/vascular dementia (n=126). Any ischemic lesion on neuroimaging increased the odds (odds ratio=9.31; 95% confidence interval 6.46, 13.39) of a VCI diagnosis. No VCI subtype, however, was associated with a specific neuroimaging abnormality. Compared to those with no cognitive impairment, patients with each VCI subtype had higher rates of death and institutionalization (hazard ratio for combined adverse events=6.08, p<0.001). CONCLUSIONS: Both clinical features and radiographic features help establish a diagnosis of VCI. The outcomes of VCI subtypes, however, are more strongly associated with clinical features than with radiographic ones.

Reduced basal ganglia volumes after switching to olanzapine in chronically treated patients with schizophrenia.

OBJECTIVE: A follow-up study of patients with schizophrenia was conducted to examine change in striatal volumes and extrapyramidal symptoms after a change in medication. METHOD: Thirty-seven patients with schizophrenia and 23 healthy volunteers were examined. Patients at baseline receiving typical antipsychotics (N=10) or risperidone but exhibiting limited response (N=13) were switched to treatment with olanzapine. Patients receiving risperidone and exhibiting a good response (N=14) continued treatment with risperidone. Caudate, putamen, and pallidal volumes were assessed with magnetic resonance imaging. The Extrapyramidal Symptoms Rating Scale was used to assess clinical signs and symptoms. RESULTS: At baseline, basal ganglia volumes in patients treated with typical antipsychotics were greater than in healthy subjects (putamen: 7.0% larger; globus pallidus: 20.7% larger). After the switch to olanzapine, putamen and globus pallidus volumes decreased (9.8% and 10.7%, respectively) and did not differ from those of healthy subjects at the follow-up evaluation. Akathisia was also reduced. In the patients receiving risperidone at baseline, basal ganglia volumes did not differ between those exhibiting good and poor response, and no significant volume changes were observed in subjects with poor risperidone response after the switch to olanzapine treatment. CONCLUSIONS: Olanzapine reversed putamen and globus pallidus enlargement induced by typical antipsychotics but did not alter volumes in patients previously treated with risperidone. Changes in striatal volumes related to typical and atypical antipsychotics may represent an interactive effect between individual medications and unique patient characteristics.

Delineation of lateral tentorial sinus with contrast-enhanced MR imaging and its surgical implications.

BACKGROUND AND PURPOSE: The lateral tentorial sinus (LTS) has not been well described in the imaging literature. The aim of this study was to investigate the value of MR imaging in assessing the LTS, which may provide guidance for preoperative planning. METHODS: Fifty-five adult patients underwent MR imaging of the brain. Four neuroradiologists evaluated the studies for delineation of the LTS and its branches. Presence of arachnoid granulation and dominance of the venous drainage also were reported. RESULTS: An LTS was detected in 104 of 110 lobes. The LTS in each lobe was classified as type I (candelabra) in 30 (28.8%), type II (independent veins) in 22 (21.1%), and type III (venous lakes) in 37 (35.5%); in 15 (14.4%) of the lobes, the LTS was indeterminate. LTS branches were inconsistently detected, with the exception of the vein of Labbé (VL). Five of eight branches were seen in approximately half of the cases. The VL was identified in 94 (85.4%) lobes. Among these, 53 (56.4%) were draining into the LTS and 22 (23.4%) into the transverse sinus; in 19 (20.2%) cases, the terminal portion was not visualized. The right transverse sinus was dominant in 19 (34.5%) patients and the left in 18 (32.7%); codomination was present in 18 (32.7%) cases. At least one arachnoid granulation was seen in the transverse sinus in 27 (49.1%) patients. CONCLUSION: In many instances, the LTS and VL drainage patterns were well delineated on routine MR images. For selected cases, this information may be crucial during lateral skull base surgery to avoid venous infarct.

Neuroanatomy of coprolalia in Tourette syndrome using functional magnetic resonance imaging.

OBJECTIVE: To determine the neural substrates of phonic tics in Tourette syndrome (TS) using functional magnetic resonance imaging (fMRI) and compare with a proposed tic-generating network (TGN). PATIENTS: One with TS and one normal control. METHODS: fMRI scans were obtained on the TS patient during which numerous unsuppressed phonic tics occurred and, along with the scanner noise, were recorded on audiotape. The control underwent the same functional MRI sequence but mimicked the tics within predetermined, on-off time blocks. Fuzzy clustering (FC) methods were used to generate the activation maps. RESULTS: The TS patient and control showed fMRI activation in the left middle frontal gyrus and right precentral gyrus. The TS patient also had activity in the caudate nucleus, cingulate gyrus, cuneus, left angular gyrus, left inferior parietal gyrus, and occipital gyri. CONCLUSIONS: fMRI, using an FC analysis, is a viable technique for studying TS patients with phonic tics. These results give further support to the hypothesis of a tic-generating circuit model. Further studies are required to confirm our data.

Gradients of detection in neglect: comparison of peripersonal and extrapersonal space.

Previous studies of target-cancellation performance in visuospatial neglect patients have reported lateral (left-right) and radial (near-far) gradients of attentional ability. The purpose of the present study was to replicate the reported attentional gradients in peripersonal space (within arms reach) and to examine whether lateral gradients of detection also appear in extrapersonal space (beyond arms reach), using equivalent tasks with no manual requirement. The relationship between radial gradients in peripersonal space and neglect severity (degree of lateral gradient) in extrapersonal space was also of interest. Right-hemisphere stroke subjects, with and without neglect, and healthy control subjects named visual targets on scanning sheets placed in peripersonal and extrapersonal space. The neglect group showed lateral gradients of increasing target detection from left to right in both peripersonal and extrapersonal space, which were not evident in the performance of either of the control groups. Double dissociations of neglect severity in peripersonal and extrapersonal space were also found in analyses of individual performance. Lesion analyses showed that peripersonal neglect was related to dorsal stream damage and extrapersonal neglect was related to ventral stream damage. Group analyses showed no significant radial gradients in peripersonal space in the three groups. In addition, while analyses of some individuals found significant near-far and far-near radial gradients, there was no correlation between radial gradients in peripersonal space and neglect severity in extrapersonal space. These results are discussed in terms of theorised hemispheric mechanisms of spatial attention and the relationship of neglect in the two co-ordinate spaces to the extent and location of damaged neurons in the right hemisphere.

The Consortium to Investigate Vascular Impairment of Cognition: methods and first findings.

BACKGROUND: The Consortium to Investigate Vascular Impairment of Cognition (CIVIC) is a Canadian, multi-centre, clinic-based prospective cohort study of patients with Vascular Cognitive Impairment (VCI). We report its organization and the impact of diagnostic criteria on the study of VCI. METHODS: Nine memory disability clinics enrolled patients and recorded their usual investigations and care. A case report form included all vascular dementia (VaD) individual criteria for each of four sets (National Institute of Neurological Disorders and Stroke (NINDS-AIREN), Alzheimer's Disease Diagnostic Treatment Centers (ADDTC), the ICD-10 Classification of Mental and Behavioural Disorders (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)) of consensus-based diagnostic criteria and for the Hachinski Ischemia Score (HIS). Investigators, having completed the case report form, were asked to make a clinical judgement about the cognitive diagnosis based on the best available information, including neuroimaging. RESULTS: Of 1,347 patients (mean age 72 years; 56% women), 846 (63%) were diagnosed with dementia and 324 (24%) were diagnosed with VCI. The proportion of patients diagnosed with VaD by the diagnostic criteria was: 23.9% (n = 322) by DSM-IV, 10.2% (n = 137) by HIS, 4.3% (n = 58) by ICD-10, 3.8% (n = 51) by ADTCC, and 3.6% (n = 48) by NINDS-AIREN. Judged against a clinical diagnosis of VaD, the sensitivity/specificity of each was: DSM-IV (0.77/0.80); HIS (0.41/0.92); ICD-10 (0.29/0.98); ADTCC (0.24/0.98); NINDS-AIREN (0.42/0.995). Compared with a clinical diagnosis of VCI, sensitivities were lower for the diagnostic criteria, reflecting the exclusion of patients who did not have dementia. CONCLUSIONS: Consensus-based criteria for VaD omit patients who do not meet dementia criteria that are modeled on Alzheimer's disease. Even for patients who do, the proportion identified with VaD varies widely. Criteria based on empirical analyses need to be developed and validated.