A Challenging Case of Oral Ulcers and Gastrointestinal Bleeding: Crohn's or Behçet's Disease.

Introduction. Differentiating Crohn's disease (CD) and Behçet's disease (BD) with gastrointestinal (GI) manifestations can be clinically challenging, as current diagnostic criteria are not clear between both conditions and multiple symptoms could overlap. Case Presentation. The patient is an 8-year-old boy of Brazilian descent, who initially presented with a 1-year history of painful oral ulcers. Before presenting to the hospital, he had been treated for periodic fever, aphthous stomatitis, pharyngitis, and adenitis and placed on steroids, with relapsing symptoms on attempts to wean the doses. The initial workup was largely unremarkable. Buccal biopsies showed no granulomas, and the ophthalmologic exam was normal. Infectious and rheumatological tests were negative. Prometheus IBD sgi testing showed a pattern consistent with CD; however, the patient had multiple negative endoscopies, colonoscopies, and capsule endoscopies. He developed intermittent bloody stools and severe malnutrition and did not respond to infliximab, colchicine, or methotrexate. After a large GI bleed, a 4th colonoscopy was performed, which showed large round ulcers in the terminal ileum, and no granulomas. He was started on ustekinumab with clinical improvement. One month later, he developed bilateral hip effusion and meningismus, being diagnosed with aseptic meningitis secondary to COVID-19. He improved, but in one month developed worsening symptoms, and MRV showed extensive venous sinus thrombosis. The patient was started on enoxaparin, methylprednisolone, and colchicine, with resolution of the thrombus on a 3-month follow-up. The patient's overall symptoms remained controlled with clinical and biochemical remission on monthly ustekinumab. Discussion and Conclusion. Our patient had a challenging clinical course, with nonspecific systemic and intestinal manifestations which proved difficult to differentiate between BD and CD. Given endoscopic findings and the worsening of an auto-inflammatory reaction in the central nervous system after COVID-19 in a patient with controlled GI symptoms, the most likely diagnosis is BD.

Cortical Neuroprosthesis Merges Visible and Invisible Light Without Impairing Native Sensory Function.

Adult rats equipped with a sensory prosthesis, which transduced infrared (IR) signals into electrical signals delivered to somatosensory cortex (S1), took approximately 4 d to learn a four-choice IR discrimination task. Here, we show that when such IR signals are projected to the primary visual cortex (V1), rats that are pretrained in a visual-discrimination task typically learn the same IR discrimination task on their first day of training. However, without prior training on a visual discrimination task, the learning rates for S1- and V1-implanted animals converged, suggesting there is no intrinsic difference in learning rate between the two areas. We also discovered that animals were able to integrate IR information into the ongoing visual processing stream in V1, performing a visual-IR integration task in which they had to combine IR and visual information. Furthermore, when the IR prosthesis was implanted in S1, rats showed no impairment in their ability to use their whiskers to perform a tactile discrimination task. Instead, in some rats, this ability was actually enhanced. Cumulatively, these findings suggest that cortical sensory neuroprostheses can rapidly augment the representational scope of primary sensory areas, integrating novel sources of information into ongoing processing while incurring minimal loss of native function.