Layer-specific diffusion weighted imaging in human primary visual cortex in vitro

One of the most prominent characteristics of the human neocortex is its laminated structure. The first person to observe this was Francesco Gennari in the second half the 18th century: in the middle of the depth of primary visual cortex, myelinated fibres are so abundant that he could observe them with bare eyes as a white line. Because of its saliency, the stria of Gennari has a rich history in cyto- and myeloarchitectural research as well as in magnetic resonance (MR) microscopy. In the present paper we show for the first time the layered structure of the human neocortex with ex vivo diffusion weighted imaging (DWI). To achieve the necessary spatial and angular resolution, primary visual cortex samples were scanned on an 11.7 T small-animal MR system to characterize the diffusion properties of the cortical laminae and the stria of Gennari in particular. The results demonstrated that fractional anisotropy varied over cortical depth, showing reduced anisotropy in the stria of Gennari, the inner band of Baillarger and the deepest layer of the cortex. Orientation density functions showed multiple components in the stria of Gennari and deeper layers of the cortex. Potential applications of layer-specific diffusion imaging include characterization of clinical abnormalities, cortical mapping and (intra)cortical tractography. We conclude that future high-resolution in vivo cortical DWI investigations should take into account the layer-specificity of the diffusion properties.     

Pigmented villonodular synovitis: a crowdsourcing study of two hundred and seventy two patients

Purpose

We aimed to ascertain the feasibility of crowdsourcing via Facebook for medical research purposes; by investigating surgical, oncological and functional outcome and quality-of-life (QOL) in patients with pigmented villonodular synovitis (PVNS) enrolled in a Facebook community (1112 members).

Methods

Patients completed online open surveys on demographics, surgery and clinical outcomes (group 1); and patient-reported outcome measures (PROMs) including knee-injury osteoarthritis outcome score (KOOS), hip-disability osteoarthritis outcome score (HOOS), Toronto extremity salvage score (TESS) and SF-36 (group 2). Mean follow-up was 70 months (12–374). Consistency checks were performed with Cohen’s kappa statistic for intra-rater agreement.

Results

The first survey was completed by 272 patients (group 1) and 72 patients completed the second (group 2). In group 1, recurrence-rate was 58 % (69/118) after arthroscopic, 36 % (35/97) after open and 50 % (5/10) after combined synovectomy (p?=?0.003). In group 2, recurrence-rate was 67 % (26/39) after arthroscopic and 51 % (17/33) after open synovectomy (p?=?0.19). Recurrence-risk was increased for diffuse disease (OR?=?16; 95%CI?=?3.2–85; p?<?0.001). Mean function and QOL did not differ after arthroscopic or open synovectomy: KOOS 49 vs. 58 (p?=?0.24), HOOS 62 vs. 53 (p?=?0.56), TESS 78 vs. 82 (p?=?0.86), SF-36 61 vs. 66 (p?=?0.41). Cohen’s kappa statistic for intra-rater agreement was good to outstanding (κ?=?0.68–0.95; p?<?0.001).

Conclusion

Local recurrence-risk was higher for diffuse-type disease and arthroscopic synovectomy. Functional outcome and QOL were comparable for both types of surgery. Gathering data via crowdsourcing seems a promising and innovative way of evaluating rare diseases including PVNS.

     

Therapy for Whipple's disease

Whipple's disease was first described in 1907, the genomic composition of the causative organism, Tropheryma whipplei, was unravelled in 2003 and its in vitro susceptibility to antibiotics started to be explored in 2004-05. Still today, this knowledge is not fully applied in the recommendations for the therapy of this disease. In this paper, we summarize the current recommendations on antimicrobial therapy for Whipple's disease and propose a shift in the maintenance therapy.