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Background context The presentation of a tumor due to torsion, with hemorrhage from presumed reperfusion injury as a result of infarction of the lesion, is extremely rare and may be different than typical tumor presentation. Purpose The aim was to describe a patient with a rare case of twisted intradural nerve sheath myxoid Schwannoma. Study design This was a case report and a review of literature. Methods A patient presented with acute onset of severe pain was found to have minimally enhanced intradural extramedullary cystic lesion. The patient underwent bilateral L2 and L3 laminectomy and microsurgically assisted intradural exploration. Results At laminectomy and intradural exploration, it was found to be a Schwannoma, which had rotated above and below, with obvious color change consistent with either infarction or hemorrhage. Because the color change ceased abruptly at the site of the torsion, we presumed that the mechanism of the hemorrhage in and around the Schwannoma found at pathologic evaluation was due to the torsion. The torsion caused vascular insufficiency (likely venous) and produced subsequent reperfusion-related hemorrhage, because of the compression of the vascular supply coming from the proximal and distal ends of the root of origin. The patient did well with complete resolution of his symptoms and 11 years of pain relief. Conclusions This acute infarction of the tumor and the associated nerve caused the acute pain syndrome that is not commonly associated with lumbar Schwannomas. Patients with acute onset of severe radiating pain may have torsion of a benign tumor arising from the nerve in question. [ABSTRACT FROM AUTHOR]

Background & Aims: Hand2 is a basic helix-loop-helix transcription factor required for terminal differentiation of enteric neurons. We studied Hand2 haploinsufficient mice, to determine whether reduced expression of Hand2 allows sufficient enteric neurogenesis for survival, but not for development of a normal enteric nervous system (ENS). Methods: Enteric transcripts that encode Hand2 and the neuron-specific embryonic lethal abnormal vision proteins HuB, HuC, and HuD were quantified. Immunocytochemistry was used to identify and quantify neurons. Apoptosis was analyzed with the terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling procedure. Intracellular microelectrodes were used to record inhibitory junction potentials. Gastrointestinal transit and colonic motility were measured in vivo. Results: Levels of of enteric Hand2 transcripts were associated with genotypes of mice, in the following order: Hand2 +/+ > Hand2 LoxP/+ > Hand2 +/− > Hand2 LoxP/− . Parallel reductions were found in expression of HuD and in regional and phenotypic manners. Numbers of neurons, numbers of neuronal nitric oxide synthase+ and calretinin+, but not substance P+ or vasoactive intestinal peptide+ neurons, decreased. No effects were observed in stomach or cecum. Apoptosis was not detected, consistent with the concept that Hand2 inhibits neuronal differentiation, rather than regulates survival. The amplitude of inhibitory junction potentials in colonic circular muscle was similar in Hand2 wild-type and haploinsufficient mice, although in haploinsufficient mice, the purinergic component was reduced and a nitrergic component appeared. The abnormal ENS of haploinsufficient mice slowed gastrointestinal motility but protected mice against colitis. Conclusions: Reduced expression of factors required for development of the ENS can cause defects in the ENS that are subtle enough to escape detection yet cause significant abnormalities in bowel function. [Copyright &y& Elsevier]

Background & Aims: Enteric neurons have been reported to be increased in inflamed regions of the bowel in patients with inflammatory bowel disease or intestinal neurogangliomatosis. It is impossible to determine whether this hyperinnervation predates intestinal inflammation, results from it, or contributes to its severity in humans, so we studied this process in mice. Methods: To determine whether the density of enteric neurons determines the severity of inflammation, we studied transgenic mice that have greater than normal (NSE-noggin mice, which overexpress noggin under the control of the neuron-specific enolase promoter) or fewer than normal (Hand2 +/− mice) numbers of neurons in the enteric nervous system. Colitis was induced with trinitrobenzene sulfonic acid or dextran sulfate sodium, and the intensity of the resulting inflammation in Hand2 +/− and NSE-noggin mice was compared with that of wild-type littermates. Results: Severity of each form of colitis (based on survival, symptom, and histologic scores; intestinal expression of genes that encode proinflammatory molecules; and levels of neutrophil elastase and p50 nuclear factor κB) were significantly reduced in Hand2 +/− mice and significantly increased in NSE-noggin animals. Neither mouse differed from wild-type in the severity of delayed-type hypersensitivity (edema, T-cell and neutrophil infiltration, or expression of interleukin-1β, interferon-γ, or tumor necrosis factor–α) induced in the ears using 2,4-dinitro-1-fluorobenzene. Transgene effects on inflammation were therefore restricted to the gastrointestinal tract. Conclusions: The severity of intestinal inflammation is associated with the density of the enteric innervation in mice. Abnormalities in development of the enteric nervous system might therefore contribute to the pathogenesis of inflammatory bowel disease. [ABSTRACT FROM AUTHOR]