Negative BOLD Responses Surpass Positive Responses in Task Specificity, Reflecting Neural Reconfigurations Better Than Functional Connectivity.

Objective: To investigate whether the Negative BOLD Response (NBR) is more task-specific than the Positive BOLD Response (PBR) during cognitive tasks and to determine whether task-evoked activity reflects brain reconfigurations during different tasks better than functional connectivity.

Methods: Functional Magnetic Resonance Imaging (fMRI) data were collected from 214 participants under 50 years old (152 in Dataset 1 and 62 in Dataset 2) performing twelve cognitive tasks spanning vocabulary, speed of processing, fluid reasoning, and memory domains. Data analysis included subject-level and group-level analyses, focusing on comparing the spatial patterns and task specificity of NBR and PBR through similarity measures using Dice coefficients.

Bagel sign in neuro Behçet's disease myelitis: neuroimages.

Neuro-Behçet's disease (NBD) is a chronic heterogenous autoimmune disorder. It may involve central or pripheral nervous system but rarely shows spinal cord involvement (SCI). Bagel Sign is a unique sign of SCI due to NBD.

Brainstem and upper cervical cord involvement in a patient with posterior reversible encephalopathy syndrome: Neuro-images.

Introduction: Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological syndrome with acute heterogeneous neurological symptoms. It is usually preceded by hypertension or chemotherapy. Brain magnetic resonance imaging (MRI) shows vasogenic edema over the cortex and subcortex of parieto-occipital lobes.