The Cortical Signature of Central Poststroke Pain: Gray Matter Decreases in Somatosensory, Insular, and Prefrontal Cortices.

It has been proposed that cortical structural plasticity plays a crucial role in the emergence and maintenance of chronic pain. Various distinct pain syndromes have accordingly been linked to specific patterns of decreases in regional gray matter volume (GMV). However, it is not known whether central poststroke pain (CPSP) is also associated with cortical structural plasticity. To determine this, we employed T1-weighted magnetic resonance imaging at 3 T and voxel-based morphometry in 45 patients suffering from chronic subcortical sensory stroke with (n = 23) and without CPSP (n = 22), and healthy matched controls (n = 31). CPSP patients showed decreases in GMV in comparison to healthy controls, involving secondary somatosensory cortex (S2), anterior as well as posterior insular cortex, ventrolateral prefrontal and orbitofrontal cortex, temporal cortex, and nucleus accumbens. Comparing CPSP patients to nonpain patients revealed a similar but more restricted pattern of atrophy comprising S2, ventrolateral prefrontal and temporal cortex. Additionally, GMV in the ventromedial prefrontal cortex negatively correlated to pain intensity ratings. This shows for the first time that CPSP is accompanied by a unique pattern of widespread structural plasticity, which involves the sensory-discriminative areas of insular/somatosensory cortex, but also expands into prefrontal cortex and ventral striatum, where emotional aspects of pain are processed.

8p deletion is strongly linked to poor prognosis in breast cancer.

Deletions of chromosome 8p occur frequently in breast cancers, but analyses of its clinical relevance have been limited to small patient cohorts and provided controversial results. A tissue microarray with 2,197 breast cancers was thus analyzed by fluorescence in-situ hybridization using an 8p21 probe in combination with a centromere 8 reference probe. 8p deletions were found in 50% of carcinomas with no special type, 67% of papillary, 28% of tubular, 37% of lobular cancers and 56% of cancers with medullary features. Deletions were always heterozygous. 8p deletion was significantly linked to advanced tumor stage (P < 0.0001), high-grade (P < 0.0001), high tumor cell proliferation (Ki67 Labeling Index; P < 0.0001), and shortened overall survival (P < 0.0001). For example, 8p deletion was seen in 32% of 290 grade 1, 43% of 438 grade 2, and 65% of 427 grade 3 cancers. In addition, 8p deletions were strongly linked to amplification of MYC (P < 0.0001), HER2 (P < 0.0001), and CCND1 (p = 0.001), but inversely associated with ER receptor expression (p = 0.0001). Remarkably, 46.5% of 8p-deleted cancers harbored amplification of at least one of the analyzed genes as compared to 27.5% amplifications in 8p-non-deleted cancers (P < 0.0001). In conclusion, 8p deletion characterizes a subset of particularly aggressive breast cancers. As 8p deletions are easy to analyze, this feature appears to be highly suited for future DNA based prognostic breast cancer panels. The strong link of 8p deletion with various gene amplifications raises the possibility of a role for regulating genomic stability.

Levetiracetam in patients with central neuropathic post-stroke pain--a randomized, double-blind, placebo-controlled trial.

BACKGROUND AND PURPOSE: Central post-stroke pain (CPSP) is a severe chronic neuropathic pain condition defined as a spontaneous pain or allodynia corresponding to a vascular lesion. It usually evolves weeks after stroke, and can distinctively impair the quality of life. Treatment is complex and mostly unsatisfactory. We hypothesized that the anti-epileptic drug levetiracetam (LEV) improves CPSP compared with placebo. The purpose of this study was to examine the efficacy and tolerability of LEV in patients with CPSP. METHODS: In a double-blind, placebo-controlled, crossover study design patients with CPSP lasting at least 3 months and a pain score ≥ 4 on the 11-point Likert scale were treated over two 8-week periods with a maximum dose up to 3000 mg LEV or placebo. Primary endpoint was a median pain lowering ≥ 2 in the final treatment week compared with the last baseline week. Secondary outcome measures comprised additional pain ratings, depression, sleep quality, quality of life and patients' global impression of change. RESULTS: Of 42 patients, 33 [61.5 years (40-76); 38% women] completed the study. Side effects and withdrawals were more frequent in the LEV (n = 5) group than in the placebo group (n = 1). Patients treated with LEV did not show any improvement of pain or changes in secondary outcome parameters compared with placebo. CONCLUSIONS: LEV is not effective in treatment for CPSP. The mode of action of LEV does not exert an analgesic effect in chronic CPSP.

Dipole source localization and fMRI of simultaneously recorded data applied to somatosensory categorization.

In this study, the feasibility of dipole source localization (DSL) and coregistration with functional magnetic resonance imaging (fMRI) activation patterns on the basis of simultaneously acquired data is demonstrated. Brain activity was mapped during the performance of a somatosensory single reaction and a choice reaction task at high spatiotemporal resolution in six healthy subjects. The choice reaction task required a categorization of two different stimulus intensities, whereas for the single reaction task merely the perception of a tactile stimulus had to be confirmed by the subjects. An offline artifact correction algorithm was applied to 32-channel EEG data that were acquired between subsequent MRI scans. Using a multiple dipole approach, five distinct dipole sources were identified within areas of the somatosensory system. Coregistration of fMRI and DSL showed consistent spatial activation patterns with a mean distance of 9.2 +/- 6.8 mm between dipole sources and fMRI activation maxima. However, since the number of fMRI activation sites exceeded the number of cerebral dipole sources, it was not possible to assign a dipole source to each fMRI activation site. Dipole moment time courses were consistent with previously reported results of similar experiments. A comparison of brain activation patterns during the two tasks with both fMRI and DSL indicated an involvement of the contralateral secondary somatosensory cortex in somatosensory categorization.