Paraspinal arteriovenous fistula: Stuttgart classification based on experience and a review of the literature.

The term "paraspinal arteriovenous shunts" (PAVSs) summarizes an inhomogeneous variety of rare vascular disorders. PAVSs have been observed as congenital or acquired lesions. The clinical course of PAVSs may be asymptomatic or present with life-threatening symptoms. Based on a collection of individual cases from three institutions and a literature evaluation, we propose the following classification: PAVSs that are part of a genetic syndrome are separated from "isolated" PAVSs. Isolated PAVSs are subdivided into "acquired", "traumatic" and "congenital" without an identifiable genetic hereditary disorder. The subgroups are differentiated by the route of venous drainage, being exclusively extraspinal or involving intraspinal veins. PAVSs associated to a genetic syndrome may either have a metameric link or occur together with a systemic genetic disorder. Again extra-vs intraspinal venous drainage is differentiated. The indication for treatment is based on individual circumstances (e.g. myelon compression, vascular bruit, high volume output cardiac failure). Most PAVSs can be treated by endovascular means using detachable coils, liquid embolic agents or stents and derivates.

Morphological and tissue characterization of the medicinal fungus Hericium coralloides by a structural and molecular imaging platform.

In this study the potential of new imaging techniques such as Magnetic Resonance Imaging (MRI), Matrix-Assisted Laser Desorption/Ionization (MALDI) profiling mass spectrometry ("MALDI Profiling") and Fourier Transform Infrared (FTIR) spectroscopic imaging was evaluated to study morphological and molecular patterns of the potential medicinal fungus Hericium coralloides. For interpretation, the MALDI profiling, FTIR imaging and MRI results were correlated with histological information gained from Scanning Electron Microscopy (SEM) and Light Microscopy (LM). Additionally we tested several evaluation processes and optimized the methodology for use of complex FTIR images to monitor molecular patterns. It is demonstrated that the combination of these spectroscopic methods enables to gain a more distinct picture concerning morphology and distribution of active ingredients. We were able to obtain high quality FTIR imaging and MALDI-profiling results and to distinguish different tissue types with their chemical ingredients. Beside this, we have created a 3-D reconstruction of a mature Hericium basidioma, based on the MRI dataset: analyses allowed, for the first time, a realistic approximation of the "evolutionary effectiveness" of this bizarrely formed basidioma type, concerning the investment of sterile tissue and its reproductive output (production of basidiospores).

[Anesthesiology and palliative medicine. Structured results of a prospective questionnaire-based survey in German hospitals]. / Anästhesiologie und Palliativmedizin. Strukturelle Ergebnisse einer prospektiven Umfrage in deutschen Kliniken.

BACKGROUND: Anesthesiology departments were often integrated into the primary formation of palliative activities in Germany. The aim of this study was to present the current integration of anesthesiology departments into palliative care activities in Germany. METHODS: The objective was to determine current activities of anesthesiology departments in in-hospital palliative care. A quantitative study was carried out based on a self-administered structured questionnaire used during telephone interviews. RESULTS: A total of 168 out of 244 hospitals consented to participate in the study and the response rate was 69%. In-hospital palliative care activities were reported for most of the surveyed hospitals. Only two hospitals in the maximum level of care reported no activities. Participation in these activities by anesthesiology departments was described in up to 92%. Historically, most activities are due to the commitment of individuals, whereas the development of palliative care of cancer pain services and hospital support teams took place in the university hospitals by 2005. CONCLUSIONS: Until 2005 many university palliative care activities had their origins in cancer pain services. These were often integrated into anesthesiology departments. Currently, anesthesiology departments work as an integrative part of palliative medicine. However, it appears from the present results that there is a domination of internal medicine (especially hematology and oncology) in palliative activities in German hospitals. This allows the focus of palliative activities to be formed by subjective specialist interests. Such a state seems to be reduced by the integration of anesthesiology departments because of their neutrality with respect to faculty-specific medical interests. Advantages or disadvantages of these circumstances are not considered by the present investigation.

Isometric non-machine-based prevention training program: effects on the cross-sectional area of the paravertebral muscles on magnetic resonance imaging.

PURPOSE: The purpose of this study was to determine potential effects of isometric non-machine-based training on the cross-sectional area (CSA) of the paravertebral muscles in volunteers who were participants in a prevention program. An increase in the CSA of back muscles after various machine-based exercises have been reported but non-machine-based training programs have not been adressed before. MATERIALS AND METHODS: In the study 14 volunteers, who were participants of a company internal prevention program, underwent a magnetic resonance (MR) examination before and after a 3 months training program to improve back muscle strength. The MRI protocol consisted of T1-weighted and T2-weighted images aligned to the intervertebral disc spaces. The CSAs of the erector spinae and quadratus lumborum muscles were assessed twice by 2 operators at the levels L3/4, L4/5 and L5/S1. RESULTS: Out of 14 subjects 11 completed the training. The recorded CSA values exhibited an intrarater and intrarater correlation coefficient ranging from 0.949 to 0.989. There was an increase in CSA in all subjects after the training period (mean increase 8%). CONCLUSIONS: A 3-month isometric training program is sufficient to effect measurable increases in back muscles volume. The study demonstrated the usefulness of MRI to quantify such changes as a measure of training efficacy and compliance into the training program. These results represent a rationale for further studies to determine the effect of different training methods on the CSA of back muscles and to correlate structural changes with clinical symptoms in chronic low back pain syndrome.

Hippocampal abnormalities in malformations of cortical development: MRI study.

OBJECTIVES: Hippocampal abnormalities may coexist with malformations of cortical development (MCD). This cross-sectional MRI study aimed at categorizing hippocampal abnormalities in a large group of MCD and comparing MCD patients with (group W) and without (group W/O) hippocampal abnormalities. METHODS: Hippocampal anatomy, rotation, size, internal structure, and MRI signal alterations were assessed visually by 3 independent raters in patients with MCD and epilepsy. Four types of hippocampal abnormalities were examined in 220 patients (116 women, mean age 31 +/- 16.6, range 2-76 years): partially infolded/hypoplastic hippocampus (HH), hippocampal sclerosis (HS), malrotated hippocampus (MH), and enlarged hippocampus (EH). The commonest MCD in the cohort were focal cortical dysplasia (27%), polymicrogyria (PMG) (21%), developmental tumors (15%), and periventricular nodular heterotopia (PNH) (14%). RESULTS: Hippocampal abnormalities were seen in 69/220 (31%) patients: HH in 34/69 (49%); HS in 18/69 (26%); MH in 15/69 (22%); and EH in 2/69 (3%). PNH (21/30 [70%]) and PMG (22/47 [47%]) were most commonly associated with hippocampal abnormalities. Compared to the W/O group, patients in the W group had a higher rate of learning disability (W 41/69 [59%] vs W/O 56/151 [37%]; p = 0.003) and delayed developmental milestones (W 36/69 [52%] vs W/O 53/151 [35%]; p = 0.025); groups did not differ otherwise with regard to clinical presentation. HH was associated with symptomatic generalized epilepsies (11/34 [32%]) and high rate of learning disability (27/34 [79%]), neurologic deficits (25/34 [73%]), and delayed developmental milestones (23/34 [68%]). CONCLUSIONS: About a third of patients with malformations of cortical development had hippocampal abnormalities. Patients with hypoplastic hippocampus had the most severe clinical phenotype.

Peripheral neuropathy as the sole initial finding in three children with infantile metachromatic leukodystrophy.

Metachromatic leukodystrophy (MLD) is a progressive white matter disease caused by arylsulfatase A deficiency. Demyelination in the nervous system is detected by cerebral magnetic resonance imaging (MRI) and neurophysiological studies. We present three children with infantile MLD, who had difficulties in standing and walking with absent reflexes. Protein levels in cerebral spinal fluid (CSF) were elevated and nerve conduction studies revealed slowing down of motor nerve conduction velocity. Initial cerebral MRIs showed no white matter changes. Consecutively, all three children developed clinical symptoms of neurodegenerative disease. Follow-up MRI and arylsulfatase A testing led to diagnosis of MLD. We conclude, that in young children who present with an acute/subacute demyelinating polyneuropathy, MLD is a differential diagnosis.

Variability of BOLD response evoked by foot vibrotactile stimulation: influence of vibration amplitude and stimulus waveform.

The aim of the present was study to evaluate cortical and subcortical neural responses on vibrotactile stimulation of the food and to assess somatosensory evoked BOLD responses in dependence of vibration amplitude and stimulus waveform. Sixteen healthy male subjects received vibrotactile stimulation at the sole of the right foot. The vibration stimulus was delivered through a moving magnet actuator system (MMAS). In an event-related design, a series of vibration stimuli with a duration of 1 s and a variable interstimulus interval was presented. Four stimulation conditions were realized using a 2 (amplitudes 0.4 mm or 1.6 mm) x 2 (waveform sinusoidal or amplitude modulated) factorial design. Stimulating with 0.4 mm amplitude compared to 1.6 mm stimulus amplitude more strongly activated the pre- and postcentral gyrus bilaterally and the right inferior, medial and middle frontal gyrus. In the reverse comparison significant differences were observed within the left inferior parietal lobule, the left superior temporal gyrus, and the left temporal transverse gyrus. In the comparison of sinusoidal versus modulated waveform and vice versa no significant activation differences were obtained. The inter-subject variability was high but when all four stimulation conditions were jointly analyzed, a significant activation of S1 was obtained for every single subject. This study demonstrated that the BOLD response is modulated by the amplitude but not by the waveform of vibrotactile stimulation. Despite high inter-individual variability, the stimulation yielded reliable results for S1 on the single-subject level. Therefore, our results suggest that vibrotactile testing could evolve into a clinical tool in functional neuroimaging.

Does caffeine modulate verbal working memory processes? An fMRI study.

To assess the effect of caffeine on the functional MRI signal during a 2-back verbal working memory task, we examined blood oxygenation level-dependent regional brain activity in 15 healthy right-handed males. The subjects, all moderate caffeine consumers, underwent two scanning sessions on a 1.5-T MR-Scanner separated by a 24- to 48-h interval. Each participant received either placebo or 100 mg caffeine 20 min prior to the performance of the working memory task in blinded crossover fashion. The study was implemented as a blocked-design. Analysis was performed using SPM2. In both conditions, the characteristic working memory network of frontoparietal cortical activation including the precuneus and the anterior cingulate could be shown. In comparison to placebo, caffeine caused an increased response in the bilateral medial frontopolar cortex (BA 10), extending to the right anterior cingulate cortex (BA 32). These results suggest that caffeine modulates neuronal activity as evidenced by fMRI signal changes in a network of brain areas associated with executive and attentional functions during working memory processes.

Electroclinical and imaging findings in ulegyria and epilepsy: a study on 25 patients.

PURPOSE: Ulegyria refers to cerebral cortex scarring, which results from a perinatal ischaemic brain injury. It presents with a characteristic gyral pattern: small circumvolutions with atrophy at sulci bottom and spared apex. Ulegyria is frequently associated with epilepsy, cerebral palsy and mental disability. We analysed electroclinical and MRI features in patients with ulegyria and epilepsy. PATIENTS AND METHODS: We reviewed 25 patients (14 males/11 females) with ulegyria and epilepsy from the database (about 5000 patients with epilepsy) of our unit. Patients were examined clinically, underwent high resolution MRI, EEG recordings, positron emission tomography, single photon emission computed tomography and neuropsychological testing. Two patients with refractory seizures underwent epilepsy surgery. RESULTS: Mean age of patients was 34 years (5-66) at the reassessment time. The majority (16/25, 64%) had a history of perinatal asphyxia. 15 patients had delayed developmental milestones; 20 had learning disabilities and five patients were severely disabled. Mean age at seizure onset was 4.2 years (1-18). 17 patients (68%) had medically intractable epilepsy. 11 patients (44%) had occipital lobe seizures. The majority (n = 24, 96%) had parieto-occipital lesions on MRI. In 13 patients (52%), ulegyria was bilateral. 12 patients (48%) had hippocampal sclerosis. Two patients underwent epilepsy surgery with an excellent postoperative outcome (Engel class IA and IC). CONCLUSION: Patients with ulegyria often have a history of perinatal asphyxia and present with pharmacoresistant seizures. Their presurgical assessment is complicated because of frequent dual pathology (hippocampal sclerosis) and bilateral lesions.

Unilateral polymicrogyria with ipsilateral cerebral hemiatrophy: a distinct syndrome?

INTRODUCTION: There are sporadic reports of unilateral polymicrogyria with ipsilateral hemiatrophic cerebri associated with epilepsy, focal neurological deficit and mental retardation. The mechanisms which cause this condition are not well understood. The aim of our study was to delineate further, clinical and neuroimaging features of this malformation of cortical development and to explore its possible etiological background. PATIENTS AND METHODS: Four patients (two males and two females), aged from 23 to 31 years (mean age range 27.5 years) were evaluated. Subjects underwent clinical, electrophysiological, neuropsychological and high resolution magnetic resonance imaging assessment. RESULTS: No significant perinatal event or exposure to intrauterine infection was noted. None suffered from birth asphyxia or ischemic injury. The parents of two patients were first cousins. Every subject had delayed developmental milestones, mental disability and congenital, non-progressive, spastic hemiparesis. They had epilepsy with seizure-onset ranging from three months to 17 years (mean 6.8 years); two had intractable seizures. In all patients, unilateral, right-sided polymicrogyria was associated with ipsilateral cerebral hemiatrophy. Polymicrogyria involved mainly anterior perisylvian areas; occipital regions were relatively spared. CONCLUSION: The evaluated patients showed homogenous clinical and neuroimaging characteristics. We support the idea that the disorder could constitute a clinical entity with an underlying genetic cause.

Recanalization after thrombolysis in stroke patients: predictors and prognostic implications.

OBJECTIVE: To estimate rates, predictors, and prognostic importance of recanalization in an unselected series of patients with stroke treated with IV thrombolysis. METHODS: We performed a CT angiography or transcranial Doppler (TCD) follow-up examination 24 hours after IV thrombolysis in 64 patients with documented occlusion of the intracranial internal carotid or middle cerebral artery (MCA). Complete recanalization was defined by a rating of 3 on the Thrombolysis in Myocardial Infarction or 4/5 on the Thrombolysis in Brain Ischemia grading scales. Information about risk factors, clinical features, and outcome was prospectively collected by standardized procedures. RESULTS: Complete recanalization was achieved in 36 of the 64 patients (56.3%). There was a nonsignificant trend of recanalization rates to decline with a more proximal site of occlusion: 68.4% (M2 segment of MCA), 53.1% (M1 segment), and 46.2% (carotid T) (p for trend = 0.28). Frequencies of vessel reopening were markedly reduced in subjects with diabetes (9.1% vs 66.0% in nondiabetics, p < 0.001) and less so in subjects with additional extracranial carotid occlusion (p = 0.03). Finally, complete recanalization predicted a favorable stroke outcome at day 90 independently of the information provided by age, NIH Stroke Scale, and onset-to-needle time. CONCLUSIONS: We found a high rate of vessel recanalization after IV thrombolysis occlusion. However, recanalization was infrequent in patients with diabetes and extracranial carotid occlusion. Information on recanalization was a powerful, early predictor for clinical outcome.

Cortical motor activation patterns following hand transplantation and replantation.

We studied cortical activation patterns by functional MRI in a patient who received bilateral hand transplantation after amputation 6 years ago and in a patient who had received unilateral hand replantation within 2 hours after amputation. In the early postoperative period, the patient who had had the hand transplantation revealed strong activation of a higher motor area, only weak activation of the primary sensorimotor motor cortex and no activation of the primary somatosensory cortex. At 1-year follow-up, a small increase in primary sensorimotor motor cortex activation was observed. Activation of the primary somatosensory cortex was only seen at the 2 year follow-up. By contrast, after hand replantation, the activation pattern was similar to that of the uninjured hand within 6 weeks. This included activation of the primary sensorimotor motor cortex, higher motor areas and primary somatosensory cortex. Transplantation after long-standing amputation results in cortical reorganization occurring over a 2-year period. In contrast, hand replantation within a few hours preserves a normal activation pattern.

Learning by strategies and learning by drill--evidence from an fMRI study.

The present fMRI study investigates, first, whether learning new arithmetic operations is reflected by changing cerebral activation patterns, and second, whether different learning methods lead to differential modifications of brain activation. In a controlled design, subjects were trained over a week on two new complex arithmetic operations, one operation trained by the application of back-up strategies, i.e., a sequence of arithmetic operations, the other by drill, i.e., by learning the association between the operands and the result. In the following fMRI session, new untrained items, items trained by strategy and items trained by drill, were assessed using an event-related design. Untrained items as compared to trained showed large bilateral parietal activations, with the focus of activation along the right intraparietal sulcus. Further foci of activation were found in both inferior frontal gyri. The reverse contrast, trained vs. untrained, showed a more focused activation pattern with activation in both angular gyri. As suggested by the specific activation patterns, newly acquired expertise was implemented in previously existing networks of arithmetic processing and memory. Comparisons between drill and strategy conditions suggest that successful retrieval was associated with different brain activation patterns reflecting the underlying learning methods. While the drill condition more strongly activated medial parietal regions extending to the left angular gyrus, the strategy condition was associated to the activation of the precuneus which may be accounted for by visual imagery in memory retrieval.

[Spinal fibrocartilaginous embolism]. / Fibrokartilaginäre Embolie des Rückenmarks.

Fibrocartilaginous embolism (FCE) of the spinal cord is a rare cause of ischemic myelopathy. We describe a 13-year-old patient with probable post-traumatic FCE. History of disease, clinical presentation, diagnostic workup, and disease course are outlined. Diagnosing FCE in the living often seems to be merely conjectural. Therefore, vertebral edema adjacent to the level of the spinal lesion is a possibly valuable diagnostic hint of spinal ischemia. Furthermore, exclusion of systemic embolism and other etiologies of myelopathy is necessary to corroborate the diagnosis of FCE. The postulated pathomechanism, diagnostic procedures, therapy, and prognosis of FCE are discussed in this article.

Modulatory effects on human sensorimotor cortex by whole-hand afferent electrical stimulation.

OBJECTIVE: To investigate the effect of electrical stimulation of the nerve afferents of the hand on cortical activity elicited by whole-hand subthreshold stimulation for sensation in healthy human subjects. METHODS: Ten healthy volunteers were studied using BOLD-fMRI with 1) a test motor-task with finger-to-thumb tapping of the left hand, 2) a whole-hand afferent electrical stimulation of the left hand below the sensory level for sensation for 30 minutes, 3) a second fMRI run with the same paradigm as in the test motor-task immediately after electrical stimulation, and 4) a final identical fMRI run 2 hours post-stimulation to test the cortical changes induced by electrical stimulation. Experiments were carried out on a 1.5 T MR scanner and for fMRI echoplanar sequences were used. Data analysis was performed with SPM99. RESULTS: An increase of movement-related responses was seen within the primary motor and primary somatosensory areas of both hemispheres when comparing the test motor-task with the motor-task after electrical stimulation relative to the baseline or sham stimulation. Two hours post-stimulation the modulatory effects of mesh-glove stimulation diminished to baseline level except within the contralateral primary motor region. CONCLUSIONS: The increased BOLD response spatially localized within the sensorimotor cortex reflects an increase in neuronal activity that may provide augmented neuronal excitability.

In vitro and in vivo Studies of the Extent of Electrothrombotic Deposition of Blood Elements on the Surface of Electrolytically Detachable Coils.

SUMMARY: Endovascular treatment of intracranial aneurysms with electrolytically detachable coils is often claimed to be based on electrothrombosis, i.e. intra-aneurysmal thrombus formation through applied direct current. Despite the fact that this concept was described more than a century ago, the significance of electrothrombosis in the endovascular treatment of aneurysms remains debatable. Apart from electrothrombosis, mechanical obliteration of the aneurysmal lumen might be one of the many possible mechanisms to explain why and how detachable coils are effective in preventing aneurysms from (re-)rupture. The purpose of this experimental study was to investigate to what extent direct current comparable to that used for coil detachment would influence the adhesion of cellular and liquid blood components to the surface of electrolytically detachable platinum coils. For the in vitro study, electrolytically detachable platinum coils of various types were exposed to stagnant heparinised blood for a total of 16 h, without or with applied direct current for 30 or 90 s (1 mA, 4-6 V, coil as anode). For the in vivo study, electrolytically detachable platinum coils were exposed to flowing blood for 180 s, without or with applied direct current (2 mA, 4-6 V, coil as either anode or cathode), without anti-coagulation and after intravenous administration of 5000 U Heparin and again after the intravenous administration of 500 mg Aspisol in addition to Heparin. After exposure to blood according to these different experimental protocols, the coils were fixed in formalin solution, gold coated and examined by scanning electron microscopy. Thrombus formation on the surface of all unfibred coils was thin and highly variable both from coil to coil, and on different areas of any given coil. The application of direct current minimally enhanced thrombus formation in stagnant blood in vitro, but not in vivo. The cellular and fibrin adhesions on the coil surfaces without and with applied current did not effectively increase the diameter or volume of unfibred coils. Coils with attached nylon fibres, however, proved to be highly thrombogenic without or with application of current. In fibred coils, surface adhesions without and with applied current were voluminous enough to effectively increase the diameter of the coil, potentially important for the process of endosaccular aneurysm occlusion. Electrothrombosis plays no role in the endovascular treatment of intracranial aneurysms with electrolytically detachable coils. This explains why platinum coils with non-electrolytic detachment mechanisms show a similar efficiency and recurrence rate.

Brain activation pattern during a verbal fluency test in healthy male and female volunteers: a functional magnetic resonance imaging study.

Sex differences in executive speech tasks, favoring women, have been noted in behavioral studies and functional imaging studies. In the present study ten female and ten male volunteers underwent functional magnetic resonance imaging in a conventional block design. All subjects were selected on the basis of high performance on the verbal fluency task. Regions of activation were detected after performance of a covert lexical verbal fluency task inside the scanner. Men and women who did not differ significantly in verbal fluency task performance showed a very similar pattern of brain activation. Our data argue against genuine between-sex differences in cerebral activation patterns during lexical verbal fluency activities when confounding factors like performance differences are excluded.

Sex differences in brain activation pattern during a visuospatial cognitive task: a functional magnetic resonance imaging study in healthy volunteers.

Sex differences in mental rotation tasks, favoring men, have been noted in behavioral studies and functional imaging studies. In the present study ten female and ten male volunteers underwent functional magnetic resonance imaging in a conventional block design. Regions of activation were detected after performance of a mental rotation task inside the scanner. In contrast to previous studies, confounding factors such as performance differences between genders or high error rates were excluded. Men showed significantly stronger parietal activation, while women showed significantly greater right frontal activation. Our results point to gender specific differences in the neuropsychological processes involved in mental rotation tasks.

The natural course of Sneddon syndrome: clinical and magnetic resonance imaging findings in a prospective six year observation study.

Sneddon syndrome (SS) is increasingly recognised as a cause of ischaemic stroke in young adults. As the natural course of SS is not well defined, the authors performed a prospective six year clinical and neuroradiological follow up study. Thirteen patients with definite diagnosis of SS (livedo racemosa, characteristic skin biopsy, and history of stroke) entered a follow up programme that consisted of clinical examinations, two magnetic resonance imaging (MRI) investigations, and a comprehensive laboratory follow up protocol. The most frequent clinical findings during follow up had been headache (62%) and vertigo (54%). Seven patients (54%) suffered from transient ischaemic attacks, however, completed stroke has not been obtained during follow up. Progression of white matter lesions detected in MRI were present in 10 of 13 patients. Laboratory follow up protocol revealed transient antiphospholipid antibodies in two subjects. This prospective six year follow up study suggests a low incidence of territorial stroke but outlines progressive leucencephalopathy in patients with SS.

A novel microcatheter-delivered, highly-flexible and fully-retrievable stent, specifically designed for intracranial use. Technical note.

SUMMARY: A new microcatheter-delivered, highly-flexible, fully-retrievable intracranial stent has been developed in order to facilitate the endovascular treatment of wide-necked aneurysms, though it might also prove useful for other intracranial pathology. The nitinol stent has radiopaque proximal and distal markers, is available in a wide range of sizes and is as flexible as a micro-guidewire. It is electrolytically detached, allowing retrieval even after full deployment. The stent is compatible with all currently available embolic agents and does not degrade MR images.