Enhanced anxiety-like behavior induced by chronic neuropathic pain and related parvalbumin-positive neurons in male rats.

Anxiety commonly co-occurs with and exacerbates pain, but the interaction between pain progression and anxiety, and its underlying mechanisms remain unclear. Inhibitory interneurons play a crucial role in maintaining normal central nervous system function and are suggested to be involved in pain-induced anxiety. This study aimed to elucidate the time-dependent effects of neuropathic pain on the developmental anxiety-like behaviors and related inhibitory interneurons; parvalbumin (PV)- and cholecystokinin (CCK)-positive neurons in corticolimbic regions. Using an 8-week-old male Wistar rat model with partial sciatic nerve ligation (pSNL), anxiety-like behaviors were biweekly assessed post-surgery through open field (OF) and elevated plus maze (EPM) tests. From 4 weeks post-surgery, pSNL rats exhibited reduced OF center time, rearing, and initial activity, along with diminished EPM open-arm activities (time spent, head dips, movement, and rearing), which correlated with the paw withdrawal threshold. These effects were absent at 2 weeks post-surgery. At 8 weeks post-surgery, specific behaviors (decreased total rearing and increased inactive time in EPM) were observed in the pSNL group. Immunohistochemistry revealed changes in PV- and CCK-positive neurons in specific corticolimbic subregions of pSNL rats at 8 weeks post-surgery. Notably, PV-positive neuron densities in the basolateral amygdaloid complex (BLC) and hippocampal cornu ammonis areas 1 and 2 correlated with anxiety-like behavioral parameters. PV-positive neurons in the BLC of pSNL rats were predominantly changed in large-cell subtypes and were less activated. These findings indicate that anxiety-like behaviors emerge in the late phase of neuropathic pain and relate to PV-positive neurons in corticolimbic regions of pSNL rats.

Acute myocardial infarction in patient without cardiac risk factors during emergence from general anesthesia: a case report.

BACKGROUND: Perioperative myocardial infarction is a rare but highly fatal complication, which often occurs in patients with poor preoperative cardiac conditions undergoing high-risk surgery. We report a case of acute myocardial infarction in a patient without cardiac risk factors during emergence from general anesthesia for removal of spinal screws. CASE PRESENTATION: A 37-year-old, 60 kg, and 160 cm man, who had no history of cardiovascular diseases, underwent removal of loosen spinal plug screws at L4-L5. The preoperative investigations revealed no abnormality and the patient was ASA I. The surgery was uneventful. During aspiration of the endotracheal tube, the patient suddenly experienced paroxysmal atrial fibrillation and ST segment elevation in DII lead. He was treated with oxygenation, optimal hemodynamics, minimize cardiac work, antiarrhythmias, and anticoagulation. The clinical conditions improved. Sinus rhythm was regained after 24 h and discharged without complications. CONCLUSIONS: Myocardial infarction can occur suddenly and unexpectedly in patients without risk factors after a low-risk surgery in any period of general anesthesia. Close monitoring and prompt treatment with this condition is important for improving outcomes.