Functional long-term outcome following endovascular thrombectomy in patients with acute ischemic stroke

Endovascular thrombectomy (EVT) is the most effective treatment for acute ischemic stroke caused by large vessel occlusion (LVO). Yet, long-term outcome (LTO) and health-related quality of life (HRQoL) in these patients have rarely been addressed, as opposed to modified Rankin scale (mRS) recordings. We analysed demographic data, treatment and neuroimaging parameters in 694 consecutive stroke patients in a maximum care hospital. In 138 of these patients with respect on receipt of written informed consent, LTO and HRQoL were collected over a period of 48 months after EVT using a standardised telephone survey (median 2.1 years after EVT). Age < 70 years (OR 4.82), lower NIHSS on admission (OR 1.11), NIHSS ≤ 10 after 24 h (OR 11.23) and complete recanalisation (mTICI3) (OR 7.79) were identified as independent predictors of favourable LTO. Occurrence of an infection requiring treatment within the first 72 h was recognised as a negative predictor for good long-term outcome (OR 0.22). Patients with mRS > 2 according to the telephone survey more often had complaints regarding mobility, self-care, and usual activity domains of the HRQoL. Our results underline a sustainable positive effect of effective EVT on the quality of life in LVO stroke. Additionally, predictive parameters of outcome were identified, that may support clinical decision making in LVO stroke.

Case report: Cerebral amyloid angiopathy-related inflammation in a patient with granulomatosis with polyangiitis

Background

Cerebral amyloid angiopathy-related inflammation (CAA-ri) defines a subacute autoimmune encephalopathy, which is presumably caused by increased CSF concentrations of anti-Aβ autoantibodies. This autoinflammatory reaction is temporally and regionally associated with microglial activation, inflammation and radiological presence of vasogenic edema. Clinical characteristics include progressive demential development as well as headache and epileptic seizures. In the absence of histopathologic confirmation, the criteria defined by Auriel et al. allow diagnosis of probable resp. possible CAA-ri. CAA-ri shows responsiveness to immunosuppressive therapies and a possible coexistence with other autoinflammatory diseases.

Methods

We present a case report and literature review on the diagnosis of CAA-ri in a patient with known granulomatosis with polyangiitis (GPA).

Results

Initially, the presented patient showed neuropsychiatric abnormalities and latent arm paresis. Due to slight increase in CSF cell count, an initial antiviral therapy was started. MR tomography showed a pronounced frontotemporal edema as well as cerebral microhemorrhages, leading to the diagnosis of CAA-ri. Subsequent high-dose steroid treatment followed by six intravenous cyclophosphamide pulses resulted in decreased CSF cell count and regression of cerebral MRI findings.

Conclusion

The symptoms observed in the patient are consistent with previous case reports on CAA-ri. Due to previously known GPA, we considered a cerebral manifestation of this disease as a differential diagnosis. However, absence of pachymeningitis as well as granulomatous infiltrations on imaging made cerebral GPA less likely. An increased risk for Aβ-associated pathologies in systemic rheumatic diseases is discussed variously.

Transient Global Amnesia (TGA): Sex-Specific Differences in Blood Pressure and Cerebral Microangiopathy in Patients with TGA

Transient global amnesia (TGA) is defined by an acute memory disturbance of unclear aetiology for a period of less than 24 h. Observed psychological, neuroanatomical and hormonal differences between the sexes in episodic memory suggest sex-specific differences in memory disorders such as TGA. The aim of this study was to determine sex-specific differences in cardiovascular risk profiles, recurrences and magnetic resonance imaging (MRI). In total, 372 hospitalised TGA patients between 01/2011 and 10/2021 were retrospectively analysed. Comparisons were made between female and male TGA patients and compared to 216 patients with acute stroke. In our sample, women were overrepresented (61.8%), especially compared to the general population in the 65−74 age category (χ2 = 10.6, p < 0.02). On admission, female TGA patients had significantly higher systolic blood pressure values and a higher degree of cerebral microangiopathy compared to male TGA patients, whereas acute stroke patients did not. No sex-specific differences were observed with respect to recurrences or hippocampal DWI lesions. Our data demonstrate sex-specific differences in TGA. The higher blood pressure on admission and different degree of cerebral microangiopathy in female TGA patients supports the theory of blood pressure dysregulation as a disease trigger. Distinct precipitating events in female and male patients could lead to differences in the severity and duration of blood pressure abnormalities, possibly explaining the higher incidence in female patients.

Mechanical thrombectomy for acute ischemic stroke in COVID-19 patients: multicenter experience in 111 cases

BACKGROUND

Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience.

METHODS

A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted.

RESULTS

We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis.

CONCLUSION

Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

Differentiating Progressive Supranuclear Palsy and Parkinson's Disease With Head-Mounted Displays

Background: Progressive supranuclear palsy (PSP) is a neurodegenerative disorder that, especially in the early stages of the disease, is clinically difficult to distinguish from Parkinson's disease (PD). Objective: This study aimed at assessing the use of eye-tracking in head-mounted displays (HMDs) for differentiating PSP and PD. Methods: Saccadic eye movements of 13 patients with PSP, 15 patients with PD, and a group of 16 healthy controls (HCs) were measured. To improve applicability in an inpatient setting and standardize the diagnosis, all the tests were conducted in a HMD. In addition, patients underwent atlas-based volumetric analysis of various brain regions based on high-resolution MRI. Results: Patients with PSP displayed unique abnormalities in vertical saccade velocity and saccade gain, while horizontal saccades were less affected. A novel diagnostic index was derived, multiplying the ratios of vertical to horizontal gain and velocity, allowing segregation of PSP from PD with high sensitivity (10/13, 77%) and specificity (14/15, 93%). As expected, patients with PSP as compared with patients with PD showed regional atrophy in midbrain volume, the midbrain plane, and the midbrain tegmentum plane. In addition, we found for the first time that oculomotor measures (vertical gain, velocity, and the diagnostic index) were correlated significantly to midbrain volume in the PSP group. Conclusions: Assessing eye movements in a HMD provides an easy to apply and highly standardized tool to differentiate PSP of patients from PD and HCs, which will aid in the diagnosis of PSP.

Transient Global Amnesia (TGA): Younger Age and Absence of Cerebral Microangiopathy Are Potentially Predisposing Factors for TGA Recurrence

Background: Transient global amnesia (TGA) is defined by an acute memory disturbance of unclear etiology for a period of less than 24 h. TGA occurs as a single event in most cases. Prevalence rates of recurrent TGA vary widely from 5.4 to 27.1%. This retrospective study aimed to determine predictors for TGA recurrence.

Methods: Cardiovascular risk profile and magnetic resonance imaging (MRI) of 340 hospitalized TGA patients between 2011 and 2020 were retrospectively analyzed. The median follow-up period amounted to 4.5 ± 2.7 years. Comparisons were made between TGA patients with and without subsequent recurrence.

Results: TGA patients with subsequent recurrence were significantly younger (recurrent vs. single episode, 63.6 ± 8.6 years vs. 67.3 ± 10.5 years, p = 0.032) and showed a lower degree of cerebral microangiopathy compared to TGA patients without recurrence. The mean latency to recurrence was 3.0 years ± 2.1 years after the first episode. In a subgroup analysis, patients with at least five years of follow-up (N = 160, median follow-up period 7.0 ± 1.4 years) had a recurrence rate of 11.3%. A 24.5% risk of subsequent TGA recurrence in the following five years was determined for TGA patients up to 70 years of age without microangiopathic changes on MRI (Fazekas' score 0).

Conclusion: Younger TGA patients without significant microangiopathy do have an increased recurrence risk. In turn, pre-existing cerebrovascular pathology, in the form of chronic hypertension and cerebral microangiopathy, seems to counteract TGA recurrence.

Postvaccinal Encephalitis after ChAdOx1 nCov-19

The global SARS-CoV-2 pandemic has contributed to more than 163 million confirmed infections and 3.3 million deaths worldwide. The severity of the pandemic has led to an unprecedented effort to develop multiple effective vaccines. Due to excellent safety and efficacy data from clinical trials, several vaccines were approved. We report a case series of postvaccinal encephalitis in temporal correlation to vaccination with ChAdOx1 nCov-19. The diagnostic criteria for possible autoimmune encephalitis were fulfilled. Our patients responded well to immunosuppressive therapy with corticosteroids. The incidence has been estimated to be approximately 8 per 10 million vaccine doses. Complication of postvaccinal encephalitis after ChAdOx1 nCoV-19 vaccination still appear to be very rare, but need to be diagnosed and treated adequately. Large pooled data from observational epidemiologic studies are necessary to verify causality. ANN NEUROL 2021.

Transient Global Amnesia (TGA): Influence of Acute Hypertension in Patients Not Adapted to Chronic Hypertension

Objective: Transient global amnesia (TGA) is defined by an acute memory disturbance of unclear etiology for a period of <24 h. Several studies showed differences in vascular risk factors between TGA compared to transient ischemic attack (TIA) or healthy controls with varying results. This retrospective and cross-sectional study compares the cardiovascular risk profile of TGA patients with that of acute stroke patients.

Methods: Cardiovascular risk profile and MR imaging of 277 TGA patients was retrospectively analyzed and compared to 216 acute ischemic stroke patients (26% TIA).

Results: TGA patients were significantly younger and predominantly female compared to stroke patients. A total of 90.6% of TGA patients underwent MRI, and 53% of those showed hippocampal diffusion-weighted imaging (DWI) lesions. Scores for cerebral microangiopathy were lower in TGA patients compared to stroke patients. After statistical correction for age, TGA patients had higher systolic and diastolic blood pressure, higher cholesterol levels, lower HbA1c, as well as blood glucose levels, and lower CHA₂DS₂-VASc scores. Stroke patients initially displayed higher CRP levels than TIA and TGA patients. TGA patients without DWI lesions were older and showed higher CHA₂DS₂-VASc scores compared to TGA patients with DWI lesions.

Conclusion: This study revealed significant differences between TGA and stroke patients in regard to the cardiovascular risk profile. Our main findings show a strong association between acute hypertensive peaks and TGA in patients not adapted to chronic hypertension, indicating a vascular cause of the disease.

Severe drug-induced liver injury caused by levetiracetam - A case report and review of the literature

Levetiracetam (LEV) is a broad-spectrum, second-generation anti-seizure medication, which has quickly become one of the most commonly prescribed drugs for people with epielpsy due to its good tolerability, rapid up-dosing capability, with both parenteral and enteral routes of administration. Considering the frequent prescriptions and predominant excretion by the kidney with minimal hepatic metabolism, severe liver injury is very rarely a complication associated with LEV. An analysis of this reported case and further published cases was performed with respect to indication, relevant previous liver diseases, concomitant medication, and both the dosage as well as the duration of LEV when drug-induced liver injury (DILI) was noted. DILI occurs after a few days to a maximum of five months after initiation of therapy with LEV and, in the worst case, may require liver transplantation or result in death. Monitoring of serum transaminase values may be helpful. Discontinuing LEV is the first therapeutic measure. In addition, immunosuppression with cortisone can be considered for serious cases.

Psychiatric symptoms and cognitive dysfunction caused by Epstein–Barr virus-induced encephalitis

Epstein-Barr virus (EBV) encephalitis is rare and shows a wide range of clinical manifestations. We report an immunocompromised patient with EBV encephalitis diagnosed by EBV-specific PCR and antibody testing in the cerebrospinal fluid who presented with psychiatric symptoms and cognitive dysfunction in the absence of any neurological impairments or infectious signs. Clinical recovery and clearance of cerebrospinal fluid EBV DNA appeared following ganciclovir treatment within 6 weeks.

Sphenopalatine Ganglion Stimulation to Augment Cerebral Blood Flow

Background and Purpose—

Many patients with acute ischemic stroke are not eligible for thrombolysis or mechanical reperfusion therapies due to contraindications, inaccessible vascular occlusions, late presentation, or large infarct core. Sphenopalatine ganglion (SPG) stimulation to enhance collateral flow and stabilize the blood-brain barrier offers an alternative, potentially more widely deliverable, therapy.

Methods—

In a randomized, sham-controlled, double-masked trial at 41 centers in 7 countries, patients with anterior circulation ischemic stroke not treated with reperfusion therapies within 24 hours of onset were randomly allocated to active SPG stimulation or sham control. The primary efficacy outcome was improvement beyond expectations on the modified Rankin Scale of global disability at 90 days (sliding dichotomy), assessed in the modified intention-to-treat population. The initial planned sample size was 660 patients, but the trial was stopped early when technical improvements in device placement occurred, so that analysis of accumulated experience could be conducted to inform a successor trial.

Results—

Among 303 enrolled patients, 253 received at least one active SPG or sham stimulation, constituting the modified intention-to-treat population (153 SPG stimulation and 100 sham control). Age was median 73 years (interquartile range, 64–79), 52.6% were female, deficit severity on the National Institutes of Health Stroke Scale was median 11 (interquartile range, 9–15), and time from last known well median 18.6 hours (interquartile range, 14.5–22.5). For the primary outcome, improved 3-month disability beyond expectations, rates in the SPG versus sham treatment groups were 49.7% versus 40.0%; odds ratio, 1.48 (95% CI, 0.89–2.47); P =0.13. A significant treatment interaction with stroke location (cortical versus noncortical) was noted, P =0.04. In the 87 patients with confirmed cortical involvement, rates of improvement beyond expectations were 50.0% versus 27.0%; odds ratio, 2.70 (95% CI, 1.08–6.73); P =0.03. Similar response patterns were observed for all prespecified secondary efficacy outcomes. No differences in mortality or serious adverse event safety end points were observed.

Conclusions—

SPG stimulation within 24 hours of onset is safe in acute ischemic stroke. SPG stimulation was not shown to statistically significantly improve 3-month disability above expectations, though favorable outcomes were nominally higher with SPG stimulation. Beneficial effects may distinctively be conferred in patients with confirmed cortical involvement. The results of this study need to be confirmed in a larger pivotal study.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03767192.

Effect of MRI-based semiautomatic size-assessment in cerebral metastases on the RANO-BM classification

AIM

Evaluation of a semiautomatic software algorithm for magnetic resonance imaging (MRI)-based assessment of cerebral metastases in cancer patients.

MATERIAL AND METHODS

Brain metastases (n = 131) in 38 patients, assessed by contrast-enhanced MRI, were retrospectively evaluated at two timepoints (baseline, follow-up) by two experienced neuroradiologists in a blinded manner. The response assessment in neuro-oncology (RANO) criteria for brain metastases (RANO-BM) were applied by means of a software (autoRANO-BM) as well as manually (manRANO-BM) at an interval of 3 weeks.

RESULTS

The average diameter of metastases was 12.03 mm (SD ± 6.66 mm) for manRANO-BM and 13.97 mm (SD ± 7.76 mm) for autoRANO-BM. Diameter figures were higher when using semiautomatic measurements (median = 11.8 mm) as compared to the manual ones (median = 10.2 mm; p = 0.000). Correlation coefficients for intra-observer variability were 0.993 (autoRANO-BM) and 0.979 (manRANO-BM). The interobserver variability (R1/R2) was 0.936/0.965 for manRANO-BM and 0.989/0.998 for autoRANO-BM. A total of 19 lesions (15%) were classified differently when using semiautomatic measurements. In 14 cases with suspected disease progression by manRANO-BM a stable course was found according to autoRANO-BM.

CONCLUSION

Computerized measuring techniques can aid in the assessment of cerebral metastases by reducing examiner-dependent effects and may consequently result in a different classification according to RANO-BM criteria.

Assessment of the arteriovenous cerebrovascular system by multi-slice CT: A single-bolus, monophasic protocol

Purpose: We present a protocol for the non-invasive angiographic assessment of the arterial and venous cerebrovascular (CV) system by multi-slice CT.

Material and Methods: Data acquisition was performed in a multi-slice CT scanner with a scan range from the carotid bifurcation to the vertex and manual scan start following i.v. administration of 120 ml iodinated contrast medium with a flow rate of 4 ml/s. This protocol was applied in 12 patients with symptoms of acute CV insuffiency.

Results: In all patients, comprehensive imaging of the arteriovenous CV system was achieved including the common carotid bifurcation, the third segment of the major cerebral arteries, the dural sinus and the internal cerebral veins. Various CV pathologies, such as a territorial artery occlusion, a thrombotic obstruction of the internal carotid artery, an intracranial arteriovenous malformation and a sinus vein thrombosis, were successfully evaluated.

Conclusion: Comprehensive assessment of the arteriovenous CV system is possible by the use of a single-bolus, monophasic multi-slice scan technique.

Visualization of inner ear dysplasias in patients with sensorineural hearing loss: High-resolution MR imaging and volume-rendered reconstructions

Purpose: We evaluated a data acquisition and post-processing protocol for inner ear (IE) assessment by MR imaging in patients, suffering from various labyrinth malformations.

Material and Methods: MR IE studies of 158 consecutive patients (316 IEs) suffering from sensorineural hearing loss without evidence of an acoustic neurinoma were reviewed for pathologies of the IE and internal acoustic meatus. High-resolution MR data of all abnormal IE studies (n=45) were post-processed to previously standardized 3D volume rendered (VR) reconstructions.

Results: In 9 patients (5.7%) the following IE dysplasias were detected: malformation of the cochlea (6 IEs), vestibulum (4 IEs), semicircular canals (12 IEs) and vestibular aqueduct/endolymphatic sac (10 IEs). One patient showed evidence of an aplasia of the vestibulocochlear nerve. In 4 patients multiple IE dysplasias were encountered. Comprehensive 3D visualization of all labyrinthine dysplasias was achieved by the use of two VR reconstructions. The overall time for bilateral IE assessment amounted to 30-35 min.

Conclusion: The imaging protocol allows for rapid and comprehensive visualization of various IE dysplasias, based on a limited number of VR reconstructions.

Volumetric assessment of optic nerve sheath and hypophysis in idiopathic intracranial hypertension

BACKGROUND AND PURPOSE

Idiopathic intracranial hypertension is a headache syndrome characterized by increased CSF pressure. Compression of the hypophysis and distension of the optic nerve sheath are reliable imaging signs. The purpose of the study was to validate, in patients with idiopathic intracranial hypertension, MR imaging-based volumetric measurements of the optic nerve sheath and hypophysis as an objective observation method for more accurate diagnosis and posttreatment follow-up.

MATERIALS AND METHODS

Twenty-three patients with idiopathic intracranial hypertension as well as age-, sex-, and body mass index-matched controls underwent volumetric measurements of the optic nerve, optic nerve sheath, and hypophysis on high-resolution T2-weighted MR images by using a 7-cm surface coil, followed by correlation with CSF opening pressures and clinical symptom scores of visual disturbances and headache.

RESULTS

Mean values of optic nerve sheath (341.86 ± 163.69 mm(3) versus 127.56 ± 53.17 mm(3), P < .001) and hypophysis volumes (554.59 ± 142.82 mm(3) versus 686.60 ± 137.84 mm(3), P < .05) differed significantly between healthy and diseased subjects. No significant differences between mean optic nerve volumes were observed. Receiver operating characteristic analysis showed optic nerve sheath volumes of >201.30 mm(3) (sensitivity, 86.96%; specificity, 91.30%) and hypophysis volumes of <611.21 mm(3) (sensitivity, 78.26%; specificity, 69.57%) to be indicative of idiopathic intracranial hypertension diagnosis. In patients with idiopathic intracranial hypertension, no correlations were found between optic nerve sheath and hypophysis volumes and CSF opening pressures or clinical scores of visual disturbances and headache.

CONCLUSIONS

Semiautomated volumetric measurement of optic nerve sheath and hypophysis has the potential to more accurately diagnose and follow patients with idiopathic intracranial hypertension.

Morphometric and volumetric MRI changes in idiopathic intracranial hypertension

Objective

We aimed at validating established imaging features of idiopathic intracranial hypertension (IIH) by using state-of-the-art MR imaging together with advanced post-processing techniques and correlated imaging findings to clinical scores.

Methods

Twenty-five IIH patients as well as age-, sex- and body mass index (BMI)-matched controls underwent high-resolution T1w and T2w MR imaging in a 1.5 T scanner, followed by assessment of optic nerve sheaths, pituitary gland, ventricles and Meckel's cave. Imaging findings were correlated with cerebrospinal fluid (CSF) opening pressures and clinical symptom scores of visual disturbances (visual field defects or enlarged blind spot), headache, tinnitus (pulsatile and non-pulsatile) and vertigo. CSF as well as ventricle volumes were determined by using an automated MRI volumetry algorithm.

Results

So-called ‘empty sella’ and optic nerve sheath distension were identified as reliable imaging signs in IIH. Posterior globe flattening turned out as a highly specific but not very sensitive sign. No abnormalities of the lateral ventricles were observed. These morphometric results could be confirmed using MR volumetry (VBM). Clinical symptoms did not correlate with an increase in lumbar opening pressure.

Conclusions

Our study results indicate that lateral ventricle size is not affected in IIH. In contrast, abnormalities of the pituitary gland and optic nerve sheath were reliable diagnostic signs for IIH.

Large positive effect of lithium on prefrontal cortex N-acetylaspartate in patients with bipolar disorder: 2-centre study

BACKGROUND

Neuroprotective effects of lithium (Li) have been well documented in tissue cultures and animal models, whereas human data continue to be limited. Previous studies investigating the association between Li treatment and brain N-acetylaspartate (NAA), a putative neuronal marker, showed mixed results because of methodological heterogeneity.

METHODS

To investigate the effects of Li on prefrontal cortex NAA levels, we compared patients with bipolar disorder from specialized Li clinics in Berlin and Halifax with at least 2 years of ongoing Li treatment (Li group), patients with lifetime Li exposure of less than 3 months more than 2 years ago (non-Li group) and healthy controls. Participants in both patient groups had at least 10 years of illness and 5 episodes. We measured left prefrontal NAA levels using 1.5-T magnetic resonance spectroscopy.

RESULTS

We enrolled 27 participants in the Li, 16 in the non-Li and 21 in the healthy control groups. The non-Li group had lower prefrontal NAA levels than the Li group (t41 = -3.44, corrected p < 0.01) or control participants (t35 = -2.91, corrected p < 0.05), who did not differ from the Li group (t46 = -0.14, p = 0.89). The same pattern of prefrontal NAA differences was replicated in both sites. In addition, there was a negative correlation between prefrontal NAA and duration of illness in the non-Li group (r = -0.60, p = 0.019) but not in the Li group (r = 0.07, p = 0.74).

LIMITATIONS

Study limitations include the crosssectional design and exposure to other medications.

CONCLUSION

Whereas patients with bipolar disorder, substantial illness burden and limited lifetime Li exposure had significantly lower prefrontal NAA levels than controls, Li-treated patients with similar illness burden showed prefrontal NAA levels comparable to those of healthy controls. These findings provide indirect support for neuroprotective effects of Li and for negative effects of illness burden on prefrontal NAA levels in patients with bipolar disorder.

MTR abnormalities in subjects at ultra-high risk for schizophrenia and first-episode schizophrenic patients compared to healthy controls

BACKGROUND

Neuroimaging studies have suggested gray (GM) and white matter (WM) abnormalities in early stages of schizophrenia. We aimed at evaluating subtle parenchymal alterations in individuals at ultra-high risk (UHR) for transition into psychosis and first-episode schizophrenic (FES) patients by measuring the magnetization transfer ratio (MTR).

METHODS AND MATERIAL

In a cross-sectional study magnetization transfer images and high-resolution volumetric T1-weighted images were acquired in 70 age- and gender-matched subjects (25 UHR subjects, 16 FES patients and 29 controls) in a 1.5Tesla scanner. Following normalization of MTR-maps the intensity histograms were analyzed by performing a Kruskal-Wallis-test.

RESULTS

Gray matter MTR decreases were depicted in UHR subjects solely, involving the cingulate gyrus and precentral cortex. WM MTR alterations were more pronounced in FES than in UHR patients and exclusively affected the frontal lobe bilaterally. In addition, UHR subjects showed bilateral MTR decreases at the stria terminalis though statistically significant only on the left side (p=0.018.)

CONCLUSION

Our results indicate GM affection earlier on during disease progression as well as cumulative WM affection within frontal lobes during transition from UHR to FES. MTR reductions at the stria terminalis of UHR patients points to the involvement of the extended amygdala in the prodromal disease stage.

Structural olfactory nerve changes in patients suffering from idiopathic intracranial hypertension

Background

Complications of idiopathic intracranial hypertension (IIH) are usually caused by elevated intracranial pressure (ICP). In a similar way as in the optic nerve, elevated ICP could also compromise the olfactory nerve system. On the other side, there is growing evidence that an extensive lymphatic network system around the olfactory nerves could be disturbed in cerebrospinal fluid disorders like IIH. The hypothesis that patients with IIH suffer from hyposmia has been suggested in the past. However, this has not been proven in clinical studies yet. This pilot study investigates whether structural changes of the olfactory nerve system can be detected in patients with IIH.

Methodology/Principal Findings

Twenty-three patients with IIH and 23 matched controls were included. Olfactory bulb volume (OBV) and sulcus olfactorius (OS) depth were calculated by magnetic resonance techniques. While mean values of total OBV (128.7±38.4 vs. 130.0±32.6 mm³, p=0.90) and mean OS depth (8.5±1.2 vs. 8.6±1.1 mm, p=0.91) were similar in both groups, Pearson correlation showed that patients with a shorter medical history IIH revealed a smaller OBV (r=0.53, p<0.01). In untreated symptomatic patients (n=7), the effect was greater (r=0.76, p<0.05). Patients who suffered from IIH for less than one year (n=8), total OBV was significantly smaller than in matched controls (116.6±24.3 vs. 149.3±22.2 mm³, p=0.01). IIH patients with visual disturbances (n=21) revealed a lower OS depth than patients without (8.3±0.9 vs. 10.8±1.0 mm, p<0.01).

Conclusions/Significance

The results suggest that morphological changes of the olfactory nerve system could be present in IIH patients at an early stage of disease.

Magnetic resonance imaging in transient global amnesia: lessons learned from 198 cases

PURPOSE

Patients with transient global amnesia (TGA) present with a characteristic clinical syndrome although other differential diagnoses have to be considered. Diffusion-weighted imaging (DWI) represents a highly specific diagnostic tool in the context of TGA; however, standard clinical DWI often fails to detect the small characteristic hippocampal lesions. The diagnostic success of DWI sequences in TGA patients was analyzed with respect to slice thickness and time interval between symptom onset.

METHODS

Magnetic resonance imaging (MRI) studies of 198 patients with clinically diagnosed TGA were retrospectively analyzed. All DWI studies were grouped according to the slice thickness applied (3 mm, 5 mm and 6 mm). The three groups were assessed for group-specific detection rates of hippocampal lesions with diffusion restriction. In addition the detection rates were evaluated with respect to the time interval between TGA symptom onset and MRI examination.

RESULTS

A significant increase in detection rates (about 8.4% per mm) was found when thinner slices were acquired (44.7% for 3 mm, 27.1% for 5 mm and 19.6% for 6 mm slice thickness). The detection rate was highest (up to 80%) when MRI was performed 2 days after TGA symptom onset.

CONCLUSIONS

The MRI protocol in patients with TGA should include a DWI sequence with a slice thickness of 3 mm or less. The examination should be performed on day 2 after symptom onset to fully exploit the diagnostic value of DWI which represents a sensitive and specific diagnostic tool for patients with TGA.

Compulsivity predicts fronto striatal activation in severely anorectic individuals

Anorexia nervosa is a severe illness and shows one of the highest death rates among psychiatric or psychosomatic diseases. However, despite several lines of research, the etiology of this disease is still unknown. One of those features is the rigidity of behaviors, for example, controlling of weight and pursuing of thinness, that often meets the criteria for obsessive-compulsive behavior. In this study, it was investigated whether the clinical feature of compulsivity in anorexia nervosa patients relates to regional brain activation. Using functional magnetic resonance imaging, 12 severely anorectic women were compared to 12 normal-weight female individuals following a cue-reactivity paradigm. Cues comprised food cues of high and low calorie content as well as eating-related utensils. Voxel-based morphometric analysis indicated significantly overall reduced gray matter volume and significantly increased cerebrospinal fluids in anorexia nervosa (AN) patients, which was controlled for in subsequent analyses. Following the high-calorie stimulation, AN patients activated the right caudate body and right precuneus, whereas control subjects did not show significant regional activations. In both other conditions, low-calorie foods and eating utensils, regional brain activations did not survive FDR thresholds. During the high-calorie condition, compulsivity, that is, the subscore "obsessive thoughts," predicted activation of the superior frontal gyrus [Brodmann areas (BA) 10], inferior frontal gyrus, anterior cingulate cortex (BA 32), cingulate gyrus (BA 24), caudate body, cuneus, pre- and postcentral gyrus. The subscore "compulsive acts" correlated with activation of the claustrum during the high-calorie condition and predicted a number of deactivations of frontal and temporal regions. We conclude that in severely anorectic individuals, the degree of compulsivity predicts activation and deactivation of the fronto-striatal pathway.

Reduction of claustrophobia with short-bore versus open magnetic resonance imaging: a randomized controlled trial

BACKGROUND

Claustrophobia is a common problem precluding MR imaging. The purpose of the present study was to assess whether a short-bore or an open magnetic resonance (MR) scanner is superior in alleviating claustrophobia.

METHODS

Institutional review board approval and patient informed consent were obtained to compare short-bore versus open MR. From June 2008 to August 2009, 174 patients (139 women; mean age = 53.1 [SD 12.8]) with an overall mean score of 2.4 (SD 0.7, range 0 to 4) on the Claustrophobia Questionnaire (CLQ) and a clinical indication for imaging, were randomly assigned to receive evaluation by open or by short-bore MR. The primary outcomes were incomplete MR examinations due to a claustrophobic event. Follow-up was conducted 7 months after MR imaging. The primary analysis was performed according to the intention-to-treat strategy.

RESULTS

With 33 claustrophobic events in the short-bore group (39% [95% confidence interval [CI] 28% to 50%) versus 23 in the open scanner group (26% [95% CI 18% to 37%]; P = 0.08) the difference was not significant. Patients with an event were in the examination room for 3.8 min (SD 4.4) in the short-bore and for 8.5 min (SD 7) in the open group (P = 0.004). This was due to an earlier occurrence of events in the short-bore group. The CLQ suffocation subscale was significantly associated with the occurrence of claustrophobic events (P = 0.003). New findings that explained symptoms were found in 69% of MR examinations and led to changes in medical treatment in 47% and surgery in 10% of patients. After 7 months, perceived claustrophobia increased in 32% of patients with events versus in only 11% of patients without events (P = 0.004).

CONCLUSIONS

Even recent MR cannot prevent claustrophobia suggesting that further developments to create a more patient-centered MR scanner environment are needed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00715806.

In vivo viscoelastic properties of the brain in normal pressure hydrocephalus

Nearly half a century after the first report of normal pressure hydrocephalus (NPH), the pathophysiological cause of the disease still remains unclear. Several theories about the cause and development of NPH emphasize disease-related alterations of the mechanical properties of the brain. MR elastography (MRE) uniquely allows the measurement of viscoelastic constants of the living brain without intervention. In this study, 20 patients (mean age, 69.1 years; nine men, 11 women) with idiopathic (n = 15) and secondary (n = 5) NPH were examined by cerebral multifrequency MRE and compared with 25 healthy volunteers (mean age, 62.1 years; 10 men, 15 women). Viscoelastic constants related to the stiffness (µ) and micromechanical connectivity (α) of brain tissue were derived from the dynamics of storage and loss moduli within the experimentally achieved frequency range of 25-62.5 Hz. In patients with NPH, both storage and loss moduli decreased, corresponding to a softening of brain tissue of about 20% compared with healthy volunteers (p < 0.001). This loss of rigidity was accompanied by a decreasing α parameter (9%, p < 0.001), indicating an alteration in the microstructural connectivity of brain tissue during NPH. This disease-related decrease in viscoelastic constants was even more pronounced in the periventricular region of the brain. The results demonstrate distinct tissue degradation associated with NPH. Further studies are required to investigate the source of mechanical tissue damage as a potential cause of NPH-related ventricular expansions and clinical symptoms.

Tension pneumocephalus with diplegia and deterioration of consciousness

Tension pneumocephalus results from intracranial air under pressure as a rare complication after head injury or craniofacial surgery. A 58-year-old man underwent ethmoid sinus surgery and subsequently developed rapidly progressive global headache, restlessness, diplegia with sensory loss, and deterioration of the conscious level. A head CT demonstrated extensive pneumocephalus with gross compression of the brain. The frontal retention of air caused widening of the interhemispheric fissure leading to a peaked appearance of the frontal poles, referred to as the ‘Mount Fuji sign’. Surgical revision of a dural air leak resulted in rapid improvement and full clinical resolution. Early diagnosis of tension pneumocephalus and emergent surgical treatment are crucial to prevent life-threatening deterioration.

Reduction of claustrophobia during magnetic resonance imaging: methods and design of the "CLAUSTRO" randomized controlled trial

Background

Magnetic resonance (MR) imaging has been described as the most important medical innovation in the last 25 years. Over 80 million MR procedures are now performed each year and on average 2.3% (95% confidence interval: 2.0 to 2.5%) of all patients scheduled for MR imaging suffer from claustrophobia. Thus, prevention of MR imaging by claustrophobia is a common problem and approximately 2,000,000 MR procedures worldwide cannot be completed due to this situation. Patients with claustrophobic anxiety are more likely to be frightened and experience a feeling of confinement or being closed in during MR imaging. In these patients, conscious sedation and additional sequences (after sedation) may be necessary to complete the examinations. Further improvements in MR design appear to be essential to alleviate this situation and broaden the applicability of MR imaging. A more open scanner configuration might help reduce claustrophobic reactions while maintaining image quality and diagnostic accuracy.

Methods/Design

We propose to analyze the rate of claustrophobic reactions, clinical utility, image quality, patient acceptance, and cost-effectiveness of an open MR scanner in a randomized comparison with a recently designed short-bore but closed scanner with 97% noise reduction. The primary aim of this study is thus to determine whether an open MR scanner can reduce claustrophobic reactions, thereby enabling more examinations of claustrophobic patients without incurring the safety issues associated with conscious sedation. In this manuscript we detail the methods and design of the prospective "CLAUSTRO" trial.

Discussion

This randomized controlled trial will be the first direct comparison of open vertical and closed short-bore MR systems in regards to claustrophobia and image quality as well as diagnostic utility.

Trial Registration

ClinicalTrials.gov: NCT00715806

Infectious vasculopathy of intracranial large- and medium-sized vessels in neurological intensive care unit: a clinico-radiological study

BACKGROUND

Infections are a well-known cause of cerebral vasculopathy and vasculitis. We aimed to analyze the frequency of intracranial vasculopathy attributable to infection, the spectrum of causative microorganisms, imaging, and cerebrospinal fluid (CSF) characteristics as well as clinical course and outcome.

METHODS

We used our institution's medical record system to identify all patients diagnosed with nonatherosclerotic central nervous system vasculopathy from January 1, 1999 through February 28, 2009. We reviewed their clinical charts, imaging data, and results of CSF studies.

RESULTS

Twenty-five adult patients with nonatherosclerotic cerebral vasculopathy of large- and medium-sized intracranial vessels were identified. Eight patients had vasculopathy attributable to infection (32%). The underlying pathologies were acute bacterial meningitis (n = 4), varicella zoster virus (VZV) infection (n = 2), borreliosis (n = 1), and syphilis (n = 1). In six patients, magnetic resonance angiography was performed and showed vasculopathic changes in all patients examined (100%). In both patients with VZV-associated vasculopathy, the arterial wall enhanced on magnetic resonance imaging. The CSF examination of the patients with infectious vasculopathy showed a significantly higher white blood cell count. The outcome of the infectious cohort was unfavorable with one death, two patients with locked-in syndrome, and five patients discharged from intensive care with severe neurological deficits.

CONCLUSION

In this cohort, one-third of all cases of nonatherosclerotic vasculopathy were due to infectious vasculopathy of large and medium intracranial vessels.

Image quality and radiation exposure in 320-row temporal bone computed tomography

OBJECTIVES

The aim was to define image quality and radiation exposure in the recently introduced 320-row CT of the temporal bone (tb) in comparison to a 16-row tb CT.

METHODS

A cadaveric head phantom was used for repeated tb volume CT studies (80-120 kV, 25-150 mAs), performed in a 320-row scanner (single rotation, 0.5 mm slice thickness, kernel FC 51) in comparison to 16-row helical CT using standard acquisition parameters (SAP) of 120 kV and 75 mAs (kernel FC 53). Qualitative image evaluation was performed by two radiologists using a 5-point visual analogue scale. Image noise (D(SD)) was determined by region of interest (ROI) based measurements in cadaveric as well as water phantom studies. Dosimetric measurements of the effective dose (ED) and organ dose (OD) of the lens were performed.

RESULTS

Image quality of 320-row tb CT was equivalent to 16-row CT for SAP scans, resulting in image noise levels (D(SD) 16-/320-row) of 109/237 and 206/446 for air and bone respectively. D(SD) differences were predominantly (>90%) attributable to the different kernels available for tb studies in 16- and 320-row CT. Radiation exposure for 16-/320-row SAP scans amounted to 0.36/0.30 mSv (ED) and 10.0/8.4 mGy (lens dose).

CONCLUSION

320-row volume acquisition in tb CT delivers equivalent image quality to 16-row CT while decreasing radiation exposure figures by one sixth. Image noise increase in 320-row CT is negligible with respect to image quality.

Tumor volume of growth hormone-secreting pituitary adenomas during treatment with pegvisomant: a prospective multicenter study

CONTEXT

Clinical and biochemical remission in acromegaly can frequently be achieved with the recombinant GH receptor antagonist pegvisomant, even when other treatments fail. However, increases in tumor volume have been reported.

OBJECTIVE

Because previous studies suffer from inhomogenous magnetic resonance imaging (MRI) protocols, this prospective study examined the long-term course of adenoma volume during pegvisomant therapy by standardized MRI.

DESIGN

Five centers in Germany participated. High-resolution MRI was performed at baseline and 6, 12, and 24 months after enrollment.

SETTING/PATIENTS

Patients were outpatients, and pegvisomant is third-line therapy in most of the cases.

MAIN OUTCOME MEASURES

The primary end point was tumor volume at 24 month follow-up, measured by a single, double-blinded rater.

RESULTS

Forty-five of 61 patients completed 24 months' follow-up (73.8%). Tumor volume increase greater than 25% during the study was observed in three of 61 patients (4.9%), all during the first year of enrollment. All three patients had had octreotide treatment before initiation of pegvisomant; none of them had had radiotherapy. All volumetric findings were comparable with clinical radiological interpretations. ANOVA revealed no significant change in tumor volume after 24 months (n = 45).

CONCLUSIONS

This study shows that pegvisomant therapy infrequently coincides with tumor growth during long-term treatment of acromegaly. Because all significant tumor volume increases occurred during the first year, these changes might correlate to the change of medication and thus be the result of a rebound from somatostatin-induced shrinkage.

Dose exposure of patients undergoing comprehensive stroke imaging by multidetector-row CT: comparison of 320-detector row and 64-detector row CT scanners

BACKGROUND AND PURPOSE

Recently introduced 320-detector row CT enables whole brain perfusion imaging compared to a limited scanning area in 64-detector row CT. Our aim was to evaluate patient radiation exposure in comprehensive stroke imaging by using multidetector row CT consisting of standard CT of the head, CTA of cerebral and cervical vessels, and CTP.

MATERIAL AND METHODS

Organ doses were measured by using LiF-TLDs located at several organ sites in an Alderson-Rando phantom. Effective doses were derived from these measurements. Stroke protocols including noncontrast head CT, CTA of cerebral and cervical vessels, and CTP were performed on 320- and 64-detector row scanners.

RESULTS

Measured effective doses for the different scanning protocols ranged between 1.61 and 4.56 mSv, resulting in an effective dose for complete stroke imaging of 7.52/7.54 mSv (m/f) for 64-detector row CT and 10.56/10.6 mSv (m/f) for 320-detector row CT. The highest organ doses within the area of the primary beam were measured in the skin (92 mGy) and cerebral hemispheres (69.91 mGy). Use of an eye-protection device resulted in a 54% decrease of the lens dose measured for the combo protocol for whole-brain perfusion with the 320-detector row CT scanner.

CONCLUSIONS

Phantom measurements indicate that comprehensive stroke imaging with multidetector row CT may result in effective radiation doses from 7.52 mSv (64-detector row CT) to 10.6 mSv (320-detector row CT). The technique of 320-detector row CT offers additional information on the time course of vascular enhancement and whole-brain perfusion. Physicians should weigh the potential of the new technique against the higher radiation dose that is needed. Critical doses that would cause organ damage were not reached.

Hippocampal subdivision and amygdalar volumes in patients in an at-risk mental state for schizophrenia

BACKGROUND

Accumulating evidence from postmortem and magnetic resonance imaging (MRI) studies suggests that abnormalities of medial temporal lobe structures are critically involved in the pathogenesis of schizophrenia. It is still unclear, however, whether certain abnormalities are already present in individuals at ultra high-risk (UHR) for transition into psychosis. Recent studies involving patients at UHR showed contradictory results for hippocampal volume, and only 1 study reported that amygdalar volume was unchanged between healthy patients and those at UHR. Furthermore, no subregions of the hippocampus have been investigated in people at UHR.

METHODS

We recruited 29 UHR patients, 23 first-episode patients and 29 age- and sex-matched healthy controls. We measured hippocampal and amygdalar volumes from MRI scans by use of BRAINS2 to manually trace the regions of interest. The hippocampi were divided in 2 regions: head and corpus/tail.

RESULTS

Patients at UHR had significantly smaller volumes of the hippocampus corpus and tail bilaterally, but not of the head, compared with healthy controls. Group differences for the right hippocampus corpus and tail volume remained significant after we controlled for whole brain volume and other covariates. We found that UHR patients who later developed psychosis had smaller right hippocampus corpus and tail volumes than did those who did not develop psychosis. First-episode patients had significantly smaller left amygdalar volumes than did healthy individuals or those at UHR.

LIMITATIONS

Our study had a small sample size, and we were unable to control for the effects of medication.

CONCLUSION

Our findings suggest that parts of the hippocampal-amygdalar complex are involved in the pathogenesis of schizophrenia. Reduction of hippocampus corpus and tail volumes may be indicative of the prodromal phase of schizophrenia and represent risk factors for transition into psychosis. Further investigations are needed to determine whether structural changes of the left amygdala play a role during transition from the prodromal phase to the first manifest episode of schizophrenia.