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Hereditary spastic paraparesis (HSP) is a heterogeneous group of neurodegenerative disorders with progressive lower limb spasticity, categorized into pure (p-HSP) and complicated forms (c-HSP). The purpose of this study was to evaluate if brain volumes in HSP were altered compared with a control population. Brain volumes were determined in patients suffering from HSP, including both p-HSP (n = 21) and c-HSP type (n = 12), and 30 age-matched healthy controls, using brain parenchymal fractions (BPF) calculated from 3D MRI data in an observer-independent procedure. In addition, the tissue segments of grey and white matter were analysed separately. In HSP patients, BPF were significantly reduced compared with controls both for the whole patient group (P < 0.001) and for both subgroups, indicating considerable brain atrophy. In contrast to controls who showed a decline of brain volumes with age, this physiological phenomenon was less pronounced in HSP. Therefore, global brain parenchyma reduction, involving both grey and white matter, seems to be a feature in both subtypes of HSP. Atrophy was more pronounced in c-HSP, consistent with the more severe phenotype including extramotor involvement. Thus, global brain atrophy, detected by MRI-based brain volume quantification, is a biological marker in HSP subtypes.

Purpose Focal cortical dysplasia (FCD), a frequent cause of partial epilepsy, is often associated with blurring of the gray–white matter junction in magnetic resonance images (MRI). To improve the recognition and delineation of FCD we developed a novel voxel-based image post-processing method for enhanced visualization of blurred gray–white matter junctions. Methods Using standard algorithms of statistical parametric mapping software (SPM99) a T1-weighted MRI volume data set is normalized and segmented. The distribution of gray and white matter is analyzed on a voxelwise basis and compared with a normal database. Based on this analysis, a three-dimensional feature map is created which highlights brain areas with blurred gray–white matter transition. This method was applied to the MRI data of 25 epilepsy patients with histologically proven FCD. Results In 18/25 patients the new feature maps clearly showed that the dysplastic lesions were accompanied by blurring of the gray–white matter junction. Combined with a formerly published method of voxel-based 3D MRI analysis, 21/25 FCD lesions were shown to be associated with either blurring or abnormal extension of gray matter beyond the normal cortical ribbon, including four cases with lesions not or incompletely recognized on conventional MRI. Conclusions The MRI post-processing presented here improves the visualization of FCD and may increase the diagnostic yield of MRI. Thereby, it provides a valuable additional diagnostic tool in the presurgical evaluation of epilepsy patients.

Die Bestimmung der zerebralen Sprachreprasentation ist wesentlicher Bestandteil der prachirurgischen Diagnostik vor Operationen in potentiell sprachrelevanten Regionen, insbesondere vor elektiven epilepsiechirurgischen Eingriffen. Die etablierten Verfahren Wada-Test und kortikale Stimulation sind invasiv und belastend. Seit ca. 10 Jahren steht die funktionelle Magnetresonanztomographie (fMRT) als nichtinvasive Alternative zur Verfugung. Obwohl in zahlreichen Untersuchungen eine gute Ubereinstimmung der Ergebnisse von fMRT und Wada-Test gezeigt werden konnte, gibt es keine allgemein akzeptierten Empfehlungen, in welchen Fallen auf einen Wada-Test verzichtet werden kann. In der vorliegenden Zusammenstellung untersuchten die Autoren, wie sich das diagnostische Procedere seit der klinischen Einfuhrung der Sprach-fMRT an ihrer Institution verandert hat. Seit 1999 wurden in Freiburg 208 Sprach-fMRTs bei 198 Patienten durchgefuhrt. Im gleichen Zeitraum reduzierte sich der relative Anteil der Patienten der Sektion Prachirurgische Epilepsiediagnostik, bei denen ein Wada-Test durchgefuhrt wurde, um ca. 50%. Der Anteil der Sprach-fMRTs, der vorwiegend aufgrund mangelhafter Kooperationsfahigkeit der Patienten nicht verwertbar war, lag in den vergangenen 2 Jahren < 10%. Nach Ansicht der Autoren besteht lediglich noch in den Fallen eine zwingende Indikation fur einen Wada-Test, in denen keine Sprach-fMRT durchfuhrbar ist oder die fMRT therapeutisch entscheidende Fragen nicht beantworten kann.

Functional and structural damage in postanoxic persistent vegetative state (PVS) was analysed using 18fluorodeoxyglucose PET (FDG-PET) coregistered to 3-D MRI in combination with morphometric 3-D MRI analysis (voxel-based morphometry, VBM). In five patients in late stages of non-traumatic PVS, combined analysis using statistical parametric mapping (SPM2) was performed to compare metabolic impairment and structural loss. FDG-PET showed widespread hypometabolism at p

Patients with symptomatic epilepsy due to hypothalamic hamartomas often are compromised not only by pharmacoresistant epileptic seizures but also by behavioral disturbances and cognitive dysfunction. We report the effect of successful treatment with stereotactic interstitial radiosurgery by intrahypothalamic implantation of 125I seeds on behavior and subjective handicap. In all patients rendered seizure-free or suffering only from auras, improvement of behavior was reported by parents and colleagues or schoolteachers. Parents' ratings according to the Child Behavior Checklist showed improvements with respect to social problems and attention. Self-ratings of quality of life by adult patients showed improvements in activities, working situation, and self-perception. These improvements were not observed in patients in whom clinically manifest seizures and interictal EEG discharges persisted after radiosurgery.

Summary: Purpose: Focal cortical dysplasia (FCD) is a frequent cause of partial epilepsy. Its diagnosis by visual evaluation of magnetic resonance images (MRIs) remains difficult. The purpose of this study was to apply a novel automated and observer-independent voxel-based technique for the analysis of 3-dimensional (3-D) MRI to detect and localize FCD. Methods: The technique was based on algorithms of the SPM99 software and included the spatial normalization of 3-D MRI data sets to a common stereotaxic space and the segmentation of cortical grey matter. The resulting data sets represented grey-matter density maps where each voxel encoded the grey-matter concentration at the corresponding position in the original MRI. A normal database was set up by calculating and averaging the grey-matter density maps of 30 healthy volunteers. The MRI data sets of seven epilepsy patients with FCD were evaluated retrospectively for dysplastic lesions by voxelwise subtraction of the mean grey-matter density map of the normal database and searching automatically for local and global maxima in the resulting data set. Results: In all patients, the results of voxel-based 3-D MRI analysis corresponded both to the location of the dysplastic lesions in conventional MRI and to seizure semiology and EEG findings. In one case, surgery was performed, and the diagnosis FCD was supported by histology. Conclusions: The technique of voxel-based 3-D MRI analysis and comparison with a normal database seems to provide a valuable additional screening tool for the detection of FCD.

Summary: Purpose: To report on the occurrence of myoclonus in patients receiving pregabalin (PGB) for the treatment of focal epilepsy. Methods: Clinic records of 19 patients who were consecutively enrolled at a tertial referral epilepsy center in a randomized, double-blind and/or open add-on study with PGB were reviewed. Results: In four patients treated with PGB, focal myoclonus newly developed. The side effect appeared with PGB doses of 50–600 mg/day; the intensity showed some dose dependency. All patients had medically refractory focal epilepsy and received other antiepileptic drugs (AEDs) besides the study medication. One patient showed focal myoclonic jerks of the left arm, whereas the other patients developed multifocal myoclonus. Polygraphic studies including electromyogram (EMG)-triggered back-averaging of the EEG in the patient with the highest frequency of myoclonic jerks showed no visible correlate of the myoclonus. In this patient, frequency and intensity of myoclonic jerks significantly decreased after dose reduction of PGB. In the other cases, myoclonus was only subtle and did not significantly interfere with daily activities, so that a dose reduction of PGB was not considered necessary. Conclusions: These data indicate a relatively high incidence (four of 19) of myoclonus associated with PGB therapy. The rate seems to be at least as high as reported in patients receiving the structurally similar anticonvulsant gabapentin.

Objectives: We developed a method to register EEG and MRI data used for the source reconstruction of electric brain activity. Methods: The method is based on matching of the head surfaces as obtained by 3D scanning after the EEG recording, and by segmentation of MRI data. The registration accuracy was estimated by calculating the residual error of the surface matching and its intra-individual and inter-individual variability. In addition, the test-retest reliability concerning the transformation of electrode positions was studied, to estimate how inaccuracies resulting from the 3D scanning of the head surface translate into registration uncertainty. Results: For 61 measurements, performed on 20 subjects, the average root mean square of the Euclidean distances between the 3D-scanned and the MRI-derived head surfaces amounted to 3.4 mm. An inter-individual standard deviation of 0.24 mm, and an intra-individual standard deviation of 0.003–0.31 mm proved a high inter- and intra-subject stability of the surface matching technique. The variation of transformation results when studying the test-retest reliability amounted to 1.6 mm on average. The maximum error of transformation was smaller than the diameter of the electrodes. Conclusions: The findings suggest that the surface matching technique is a precise method for determination of the transformation of electrode positions and MRI data into a single co-ordinate system and can successfully be used in a routine laboratory setting.

High Spatial Resolution electromyography (HSR-EMG), a new kind of noninvasive surface EMG based on a spatial filtering technique, was evaluated with respect to the diagnosis of neuromuscular diseases. HSR-EMG measurements were recorded from 61 healthy subjects and 72 patients with different neuromuscular diseases and analyzed quantitatively. The results indicate that a few parameters such as muscular conduction velocity, dwell time over root mean square, autocorrelation function, and chi-value are sufficient to recognize and classify specific signal alterations due to neuromuscular disorders. A diagnostic evaluation procedure calculating automatically the most probable diagnosis from the parameter results could assign the correct diagnosis to about 81% of the investigated patients and healthy subjects. Myopathic disorders were recognized with a sensitivity of 85% (specificity: 97%), neuropathic disorders with a sensitivity of 68% (specificity: 98%). We conclude that HSR-EMG shows a diagnostic validity similar to that described in literature for needle EMG. Moreover, the noninvasive technique provides the advantage of a simple and painless application.

Summary: For rapid visualization of subdural electrodes with respect to cortical and subcortical structures, we describe a novel and fully automated method based on coregistration, normalization, optional cerebellum masking, and volume rendering of 3D MR imaging data taken before and after implantation. The key step employs the skull-stripped preimplantation image as a mask to also remove the skull in the postimplantation image. The extracted brain is presented in 3D with the electrodes directly visible by their susceptibility artifacts. Compared with alternative methods, ours is based on freely available software and does not require manual intervention.