Bilateral Upper-Extremity Acute Exertional Compartment Syndrome: A Case Report.

Introduction: Acute exertional compartment syndrome (AECS) is a condition with the potential for devastating outcomes if not promptly treated. Physicians must maintain a high index of suspicion when evaluating patients presenting with pain, swelling, decreased range of motion, and numbness within a muscle compartment. However, AECS is frequently misdiagnosed due to a multitude of factors, leading to a delay in treatment. In this case report, we would like to shed light on a rare case of bilateral upper-extremity AECS and suggest the treatment paradigm we believe will help prevent negative outcomes. Case Report: A previously healthy 33-year-old male presented with bilateral weakness, tingling, tenderness, swelling, and pain upon movement in the trapezius and deltoid muscles. The symptoms started after he performed "burpees" for 18 h following a 12-h forest-fire firefighting shift. The patient's rapidly developing clinical presentation warranted compartmental pressure checks for suspicion of AECS. Being able to quickly determine the elevated trapezius, deltoid, and supraspinatus compartmental pressures allowed us to perform immediate bilateral fasciotomies with delayed primary closure to relieve compartment pressure. Conclusion: The delay in treatment for patients presenting with AECS is multifactorial and may lead to devastating outcomes if not promptly addressed. The lack of literature regarding bilateral upper-extremity AECS makes the treatment for this condition even more difficult. For our patient, having a proper criterion for performing compartmental pressure checks played a vital role in ensuring an accurate diagnosis and timely medical intervention.

GABA receptors containing the alpha5 subunit mediate the trace effect in aversive and appetitive conditioning and extinction of conditioned fear.

A reduction in alpha5 subunit-containing gamma-aminobutyric acid (GABA)A receptors has been reported to enhance some forms of learning in mutant mouse models. This effect has been attributed to impaired alpha5 GABAA receptor-mediated inhibitory modulation in the hippocampus. The introduction of a point mutation (H105R) in the alpha5 subunit is associated with a specific reduction of alpha5 subunit-containing GABAA receptors in the hippocampus. The present study examined the modulation of associative learning and the extinction of conditioned response in these animals. The strength of classical conditioning can be weakened when a trace interval is interposed between the conditioned stimulus and unconditioned stimulus. Here we report that this 'trace effect' in classical conditioning was absent in the mutant mice--they were insensitive to the imposition of a 20-s trace interval. This effect of the mutation was most clearly in the female mice using an aversive conditioning paradigm, and in the male mice using an appetitive conditioning paradigm. These gender-specific phenotypes were accompanied by a resistance to extinction of conditioned fear response in the mutant mice that was apparent in both genders. Our results identify neuronal inhibition in the hippocampus mediated via alpha5 GABAA receptors as a critical control element in the regulation of the acquisition and expression of associative memory.

Repeated experience of social defeats increases serotonin transporter and monoamine oxidase A mRNA levels in raphe nuclei of male mice.

Serotonin transporter (SERT) and monoamine oxidase A (MAOA) mRNA levels in the raphe nuclei area of the midbrain were measured by the multiplex reverse transcription-polymerase chain reaction method in male mice with repeated experience of social victories (winners) and defeats (losers) in ten daily agonistic confrontations. Experiments revealed enhanced SERT and MAOA mRNA levels in the losers compared with the winners and controls. It has been supposed that SERT and MAOA genes are involved in enhancement of serotonin inactivation in response to the increase of serotonergic activity shown earlier in the losers. A positive correlation between MAOA and SERT mRNA levels in the raphe nuclei area of the midbrain was shown.