Thestages ofintegration leading fromlocal feature analysis toobject recognition wereexplored inhuman visual cortex byusing thetechnique offunctional magnetic resonance imaging. Herewereport evidence forobject-related activation. Suchactivation waslocated atthelateral-posterior aspect oftheoccipital lobe, just abutting theposterior aspect ofthemotion-sensitive areaMT/V5,inaregion termed the lateral occipital complex (LO). LOshowedpreferential acti- vation toimages ofobjects, compared toawiderangeof texture patterns. Thisactivation wasnotcaused byaglobal difference intheFourier spatial frequency content ofobjects versus texture images, since object images produced enhanced LOactivation compared totextures matched inpowerspectra butrandomized inphase. Thepreferential activation toob- jects alsocould notbeexplained bydifferent patterns ofeye movements: similar levels ofactivation wereobserved when subjects fixated ontheobjects andwhentheyscanned the objects withtheir eyes. Additional manipulations suchas spatial frequency filtering anda4-fold change invisual size didnotaffect LO activation. Theseresults' suggest thatthe enhanced responses toobjects werenotamanifestation of low-level visual processing. A striking demonstration that activity inLOisuniquely correlated toobject detectability was produced bythe"Lincoln" illusion, inwhichblurring of objects digitized intolarge blocks paradoxically increases their recognizability. Suchblurring ledtosignificant en- hancement ofLOactivation. Despite thepreferential activa- tion toobjects, LO didnotseemtobeinvolved inthefinal, "semantic," stages oftherecognition process. Thus,objects varying widely intheir recognizability (e.g., famous faces, commonobjects, andunfamiliar three-dimensional abstract sculptures) activated ittoasimilar degree. Theseresults are thusevidence foranintermediate linkinthechainofpro- cessing stages leading toobject recognition inhumanvisual cortex.

/pdf/object-related-activity-revealed-byfunctional-magnetic-1a8vllt6eu.pdf

Object-related activity revealed byfunctional magnetic resonance imaging inhumanoccipital cortex

Anatomy and White Matter Connections of the Lingual Gyrus and Cuneus

Radiation therapy (RT), an integral component of curative treatment for many malignancies, can be administered via an increasing array of techniques. In this review, we summarize the properties and application of different types of RT, specifically, conventional therapy with x-rays, stereotactic body RT, and proton and carbon particle therapies. We highlight how low-linear energy transfer (LET) radiation induces simple DNA lesions that are efficiently repaired by cells, whereas high-LET radiation causes complex DNA lesions that are difficult to repair and that ultimately enhance cancer cell killing. Additionally, we discuss the immunogenicity of radiation-induced tumor death, elucidate the molecular mechanisms by which radiation mounts innate and adaptive immune responses and explore strategies by which we can increase the efficacy of these mechanisms. Understanding the mechanisms by which RT modulates immune signaling and the key players involved in modulating the RT-mediated immune response will help to improve therapeutic efficacy and to identify novel immunomodulatory drugs that will benefit cancer patients undergoing targeted RT.

https://www.mdpi.com/1422-0067/21/21/8151/pdf

Immunomodulatory Effects of Radiotherapy.

Anatomy and White Matter Connections of the Middle Frontal Gyrus.

Inter-individual differences can inform treatment procedures and - if accounted for - can significantly improve patient outcomes. However, when studying brain anatomy, these inter- individual variations are largely unaccounted for, despite reports of differences in gross anatomical features, cross-sectional and connectional anatomy. Brain connections are essential to mediate brain functional organisation and, when severed, cause functional impairments or complete loss of function. Hence the study of cerebral white matter may be an ideal compromise to capture inter-individual variability in structure and function. Here we reviewed the wealth of studies that associate functions and clinical symptoms with individual tracts using diffusion tractography. Our systematic review indicates that tractography has proven to be a sensitive method in neurology, psychiatry and healthy populations to identify variability and its functional correlates. However, the literature may be biased, as we identified that the most commonly reported tracts are not necessarily those with the highest sensitivity to cognitive functions and pathologies. Finally, we demonstrate that tracts, as we define them, are not usually correlated with only one, but rather multiple cognitive domains or pathologies. While our systematic review identified some methodological caveats, it also suggests that tract-function correlations might be a promising biomarker for precision medicine as it characterises variations in brain anatomy, differences in functional organisation and predict resilience or recovery in patients.

/pdf/white-matter-variability-cognition-and-disorders-a-37bs2i6uyi.pdf

White matter variability, cognition, and disorders: a systematic review

Shunt failure requiring reintervention remains a common complication of hydrocephalus treatment. Here, we report a novel cause of mechanical shunt obstruction in an adult patient: position-dependent intermittent occlusion via an infusion port catheter. A 51-year-old woman with a grade II oligodendroglioma presented in a delayed fashion following surgery with a pseudomeningocele. She underwent ventriculoperitoneal shunt placement due to communicating hydrocephalus, resolving her pseudomeningocele. Shortly thereafter, she underwent placement of a subclavian infusion port at an outside institution. Her pseudomeningocele returned. Imaging demonstrated close proximity of her port catheter to the shunt catheter overlying the clavicle. Her shunt was tapped demonstrating a patent ventricular catheter with normal pressure. She underwent shunt exploration after her pseudomeningocele did not respond to valve adjustment. Intraoperative manometry demonstrated head position-dependent distal catheter obstruction. Repeat manometry following distal catheter revision demonstrated normal runoff independent of position. Her pseudomeningocele was resolved on follow-up. To our knowledge, this is the only reported case of intermittent, position-dependent distal catheter obstruction. Shunted patients with concern for malfunction following subclavian infusion port placement should be evaluated for possible dynamic obstruction of their distal catheter when the two catheters are in close proximity along the clavicle.

/pdf/dynamic-occlusion-of-distal-ventriculoperitoneal-shunt-32ff9sm4uf.pdf

Kyle P. O'Connor

Papers

Dynamic Occlusion of Distal Ventriculoperitoneal Shunt Catheter after Infusion Port Placement: A New Shunt Malfunction

Use of Pterional Craniotomy for Removal of Penetrating Object: Case Report and Surgical Video.

Combined Multi-portal “Pull-Through” Keyhole Craniotomy

In Reply to "The Extradural Minipterional Approach: 'Think Small, Play Wider' ".

Viabahn stent extrusion into the airway in association with nasopharyngeal squamous cell carcinoma