Altered somatosensory processing in trigeminal neuralgia.

Trigeminal neuralgia (TN) is a pain state characterized by intermittent unilateral pain attacks in one or several facial areas innervated by the trigeminal nerve. The somatosensory cortex is heavily involved in the perception of sensory features of pain, but it is also the primary target for thalamic input of nonpainful somatosensory information. Thus, pain and somatosensory processing are accomplished in overlapping cortical structures raising the question whether pain states are associated with alteration of somatosensory function itself.

Abnormal myelination in Angelman syndrome.

Patients with Angelman syndrome (OMIM # 105830) are generally thought to have normal brain imaging studies except for occasional minor cerebral atrophy. We report 9 patients with genetically proven Angelman syndrome, who were examined by magnetic resonance imaging (MRI) between the ages of 7.5 months and 5 years.

Evidence against a perihemorrhagic penumbra provided by perfusion computed tomography.

Background And Purpose: Several recent studies analyzing perfusion changes in acute intracerebral hemorrhage fed the debate whether there is secondary ischemic tissue damage in the vicinity of intracerebral hemorrhage. We used perfusion CT to address this question.

Methods: We examined 36 patients between 2001 and 2002 with acute intracerebral hemorrhage (within 24 hours after symptom onset).

fMRI reflects functional connectivity of human somatosensory cortex.

Unilateral sensory stimulation reliably elicits contralateral somatotopic activation of primary (SI) and secondary (SII) somatosensory cortex. There is an ongoing debate about the occurrence and nature of concomitant ipsilateral SI and SII activation. Here we used functional magnetic resonance imaging (fMRI) in healthy human subjects with unilateral tactile stimulation of fingers and lips, to compare somatosensory activation patterns from distal and proximal body parts.

Localizing and lateralizing language in patients with brain tumors: feasibility of routine preoperative functional MR imaging in 81 consecutive patients.

Purpose: To prospectively assess the feasibility of standardized presurgical functional magnetic resonance (MR) imaging for localizing the Broca and Wernicke areas and for lateralizing language function.

Materials And Methods: The study was approved by the responsible ethics commission, and patients gave written informed consent. Eighty-one patients (36 female and 45 male patients; age range, 7-75 years) with different brain tumors underwent blood oxygen level-dependent functional MR imaging at 1.

Age- and tooth-related pulp cavity signal intensity changes in healthy teeth: a comparative magnetic resonance imaging analysis.

Objective: To determine if it is possible to measure age-related pulp cavity signal intensity changes by using magnetic resonance imaging (MRI).

Study Design: Dental pulp cavity signal intensities were assessed in 92 test subjects on the basis of MRI signal intensity measurements at freely defined regions of interest by using T1 gradient echo sequences before and after contrast-agent administration. Relative signal intensity differences were calculated and provided the basis for age- and tooth-related comparisons.

Global activation of primary motor cortex during voluntary movements in man.

Unilateral voluntary movements are accompanied by robust activation of contralateral primary motor cortex (M1) in a somatotopic fashion. Occasionally, coactivation of M1 (M1-CoA) ipsilateral to the movement was described. In a study with brain tumor patients, we consistently observed additional somatotopic M1-CoAs and hypothesized that they might represent a basic feature of movement execution.

Volumetric measurement of the pontomesencephalic cistern in patients with trigeminal neuralgia and healthy controls.

Objective: Most so-called idiopathic trigeminal neuralgias (TN) are caused by neurovascular compression. Does the size of the cerebellopontine cistern play a role in favoring a neurovascular conflict? The aim of this prospective study was to measure the volume of the parapontine cistern in patients with idiopathic TN and to perform a comparison with healthy controls.

Methods: In 25 patients with unilateral idiopathic TN and 17 healthy participants, high-resolution 1.

Degenerative spine disorders in the context of clinical findings.

Hardly any other structure in the human body is held responsible for so many complaints, pain, and costs as the spine and its degenerative disorders. In the following article, the role of imaging procedures in diagnosing disorders of the spine is presented. Due to the fact that disk herniation represents the most frequent cause for degenerative disorders the anatomy of the intervertebral disk and the pathology of the entities that can cause diseases of the disks are described.

Evolution of apparent diffusion coefficient and transverse relaxation time (T2) in the subchronic stage of global cerebral oligemia in different rat models.

Using magnetic resonance imaging techniques, we examined the time course of apparent diffusion coefficient (ADC), T2, and T2* relaxation times in 1-year-old rats after different forms of cerebral oligemia had been induced by (1) transient systemic hypotension, (2) permanent bilateral carotid artery occlusion (BCCAO), and (3) combined hypotension and BCCAO over a time period of 14 days after the oligemic event. These groups were compared with a group of sham-operated adult rats (controls, 4) to rule out a drift of the parameters over time. The animals were examined in a 2.

MR imaging-based volumetry in patients with early-treated phenylketonuria.

Background And Purpose: Our purpose was to specify the most severely affected brain structures in early treated phenylketonuria regarding volume loss and establish possible correlations between volume loss and plasma levels of phenylalanine (Phe).

Methods: In 31 patients with early treated phenylketonuria and in 27 healthy volunteers, we acquired volumetric MR imaging data. Serum Phe concentrations at different times were measured as well.

Time-efficient localization of the human secondary somatosensory cortex by functional magnetic resonance imaging.

Standardized, robust and time-efficient localization of the human secondary somatosensory cortex (S2) is a challenge in clinical blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). A fully automated tactile stimulation was optimized in seven right-handed volunteers at 1.5 T for minimum scan time, high BOLD signals and robust localization of S2 by systematically varying the applied block-design.

MRI volumetry for the preoperative diagnosis of trigeminal neuralgia.

To assess whether quantitative measuring methods can help improve the reliability of MRI-based evaluations of the pathological role of a neurovascular conflict between an artery and the trigeminal nerve. In a prospective study, magnetic resonance images were obtained from 62 patients with unilateral facial pain and 50 healthy test subjects. In coronal T1- and T2-weighted sequences volume measurements were performed by regions of interest and compared intraindividually (healthy versus affected side in the patient populations and right versus left side in the group of test subjects) and on the basis of the different clinical pictures (t test for dependent and independent samples, p<0.

Fully automated localization of the human primary somatosensory cortex in one minute by functional magnetic resonance imaging.

A clinical functional magnetic resonance imaging (fMRI) protocol based on a fully automated tactile stimulation was optimized in 10 right-handed volunteers at 1.5 T for minimum scan time, high BOLD-signals and robust localization of the primary somatosensory cortex (S1) by systematically varying the applied block design. All volunteers had six different fMRI measurements of 5 stimulation/baseline cycles each with equal block duration that was changed between the measurements from 6 to 30 s.

Comparison of perfusion computed tomography and computed tomography angiography source images with perfusion-weighted imaging and diffusion-weighted imaging in patients with acute stroke of less than 6 hours' duration.

Background And Purpose: We aimed to determine the diagnostic value of perfusion computed tomography (PCT) and CT angiography (CTA) including CTA source images (CTA-SI) in comparison with perfusion-weighted magnetic resonance imaging (MRI) (PWI) and diffusion-weighted MRI (DWI) in acute stroke <6 hours.

Methods: Noncontrast-enhanced CT, PCT, CTA, stroke MRI, including PWI and DWI, and MR angiography (MRA), were performed in patients with symptoms of acute stroke lasting <6 hours. We analyzed ischemic lesion volumes on patients' arrival as shown on NECT, PCT, CTA-SI, DWI, and PWI (Wilcoxon, Spearman, Bland-Altman) and compared them to the infarct extent as shown on day 5 NECT.

Stroke magnetic resonance imaging is accurate in hyperacute intracerebral hemorrhage: a multicenter study on the validity of stroke imaging.

Background And Purpose: Although modern multisequence stroke MRI protocols are an emerging imaging routine for the diagnostic assessment of acute ischemic stroke, their sensitivity for intracerebral hemorrhage (ICH), the most important differential diagnosis, is still a matter of debate. We hypothesized that stroke MRI is accurate in the detection of ICH. To evaluate our hypotheses, we conducted a prospective multicenter trial.

Bell palsy: quantitative analysis of MR imaging data as a method of predicting outcome.

Purpose: To assess the prognostic value of quantitative analyses of region-of-interest (ROI) magnetic resonance (MR) imaging data in patients with acute facial nerve palsy.

Materials And Methods: In a single-blinded study, MR images were obtained in 39 patients (32 men and seven women; age range, 18-75 years; average age, 37.9 years) with acute facial nerve palsy.

Image stacking with entropy values in conventional angiography: initial experience.

The entropy method for stacking a series of angiographic images is presented and compared with the maximum opacity method, which is already established. The entropy method comprises calculation of the entropy of the time course for each image pixel. This accentuates image areas where a contrast agent bolus is passing.

Small-vessel stents for intracranial angioplasty: in vitro comparison of different stent designs and sizes by using CT angiography.

Background And Purpose: Our purpose was to evaluate whether CT angiography is a suitable alternative to conventional angiography in the evaluation of small-vessel stents for intracranial angioplasty.

Methods: CT angiographic appearances of 23 stents of different designs and sizes (2.0, 3.

Robust localization and lateralization of human language function: an optimized clinical functional magnetic resonance imaging protocol.

An optimized clinical functional magnetic resonance imaging (fMRI) protocol with a total scanning time of 8 min is presented that localizes Broca's and Wernicke's areas robustly and determines hemispheric dominance. Language function was visualized using two different sentence generation (SG) and word generation (WG) tasks. Block designed blood oxygenation level dependent (BOLD) fMRI was applied in 14 right-handed volunteers at 1.

Stroke MRI in intracerebral hemorrhage: is there a perihemorrhagic penumbra?

Background And Purpose: Cerebral ischemia has been proposed as a contributing mechanism to secondary neuronal injury after intracerebral hemorrhage (ICH). The search for surrogate parameters that allow treatment stratification for spontaneous ICH continues. We sought to assess the presence and prognostic effect of perihemorrhagic ischemic changes and hypoperfusion in a prospective stroke MRI study.

Local intra-arterial fibrinolysis of thromboemboli occurring during neuroendovascular procedures with recombinant tissue plasminogen activator.

Background And Purpose: There is a lack of systematic data regarding local intra-arterial fibrinolysis (LIF) of thromboemboli occurring during neuroendovascular procedures with the use of recombinant tissue plasminogen activator (rtPA). We report our technique for treating LIF of intracerebral thromboemboli occurring during neuroendovascular procedures.

Methods: Nine of 723 patients (1.

Differentiating primary central nervous system lymphoma from glioma in humans using localised proton magnetic resonance spectroscopy.

In order to characterise primary central nervous system lymphomas (PCNSL) and to evaluate if 1H spectroscopy improves the preoperative differential diagnosis of PCNSL and glioma, seven immunocompetent patients with PCNSL and 21 patients with glioma were examined using single voxel, short echo time magnetic resonance spectroscopy (MRS; 1.5 T, STEAM 1500/20). All PCNSL demonstrated massively elevated lipid resonances and markedly elevated choline.

Differentiation of white, mixed, and red thrombi: value of CT in estimation of the prognosis of thrombolysis phantom study.

Purpose: To test with serial computed tomographic (CT) scans whether white, mixed, and red thrombi could be differentiated according to their CT attenuation.

Materials And Methods: Platelet-enriched plasma and whole blood were mixed to produce samples with hematocrit levels of 0, 0.005, 0.

Distinguishing of primary cerebral lymphoma from high-grade glioma with perfusion-weighted magnetic resonance imaging.

To assess the usefulness of perfusion-weighted echo-planar magnetic resonance imaging in the differential diagnosis of primary supratentorial lymphoma (PCNSL) and glioblastoma (GBM), 12 patients with a PCNSL and 12 with a GBM were examined using a 1.5 T magnetic resonance (MR) imager. With dynamic-susceptibility contrast MR imaging the intensity-time curves of each tumor were analyzed, and we determined the relative regional cerebral blood volume ratios (rrCBV [tumor/contralateral white matter (WM)]) to find out whether these parameters could be used to separate PCNSL from GBM.