Value of Posterior circulation ASPECTS and Pons-Midbrain Index on non-contrast CT and CT Angiography Source Images in patients with basilar artery occlusion recanalized after mechanical thrombectomy. / Valor de la escala ASPECTS de circulación posterior y del índice puente-mesencéfalo en imágenes de TC sin contraste y angiografía por TC en pacientes con oclusiones de la arteria basilar recanalizados tras trombectomía mecánica.

PURPOSE: Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy. METHODS: Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.<8) and PMI (≥3vs.<3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate. RESULTS: CTASI pc-ASPECTS, dichotomized at <8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived. CONCLUSION: PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.

Manual acupuncture inhibits mechanical hypersensitivity induced by spinal nerve ligation in rats.

Manual acupuncture (MA) has presented analgesic activity against neuropathic pain in patients and animal models, yet a series of questions remain: Is MA effectiveness dependent of acupoint selection or combination? Is it equally efficient when treatment starts on the initial (acute) or sub-chronic phase of spinal nerve ligation (SNL)-induced neuropathy? Is MA effect related to the release of endogenous opioids? Does MA produce similar effects to gabapentin? To answer these questions rats submitted to the L5/L6 SNL injury were treated with unilateral MA (ST36 (Zusanli), SP6 (Sanyingjiao) or ST36+SP6 acupoint stimulation); or with gabapentin (30 mg/kg i.p., used as positive control). Both acupoints have been demonstrated to present analgesic activity and are used in clinical practice and basic science research. In addition, we investigated the influence of naloxone (1 mg/kg i.p., a nonselective opioid receptor antagonist) on MA treatment and also the effect of unilateral ST36+SP6 MA treatment beginning acutely (5 days) or sub-chronically (14 days) after SNL. Our results demonstrate that single or combined unilateral stimulation was able to reduce mechanical hypersensitivity with treatment beginning in both acute and sub-chronic phases of SNL-induced neuropathy; MA effect was blocked by naloxone, and finally; SP6+ST36 MA presented similar effect to gabapentin (30 mg/kg). In conclusion, our results demonstrate, for the first time, that unilateral MA (ST36, SP6 or ST36+SP6) reduces hypersensitivity induced by the SNL with effect dependent of the opioid system and comparable with the one obtained with gabapentin (used as positive control).

Peripheral kinin B(1) and B(2) receptor-operated mechanisms are implicated in neuropathic nociception induced by spinal nerve ligation in rats.

The kinin system can contribute distinctly to the sensory changes associated with different models of nerve injury-induced neuropathic pain. This study examines the roles of kinin B(1) and B(2) receptor-operated mechanisms in alterations in nociceptive responses of rats submitted to unilateral L5/L6 spinal nerve ligation (SNL) injury. Behavioural responses to ipsilateral hind paw stimulation with acetone (evaporation-evoked cooling), radiant heat (Hargreaves method) or von Frey hairs revealed that SNL rats developed long-lasting cold allodynia (from Days 3 to 40 post-surgery, peak on Day 6), heat hyperalgesia (stable peak from Days 9 to 36) and tactile allodynia (stable peak from Days 3 to 51). SNL rats manifested nocifensive responses to intraplantar injections on Day 12 of the selective B(1) receptor agonist des-Arg(9)-bradykinin (DABK) and augmented responses to the selective B(2) receptor agonist bradykinin (BK; each at 0.01-1nmol/paw). Systemic treatment of SNL rats with des-Arg(9)-Leu(8)-BK or HOE 140 (peptidic B(1) and B(2) receptor antagonists, respectively; 0.1-1mumol/kg, i.p.) selectively blocked responses triggered by DABK and BK (1nmol/paw) and alleviated partially and transiently established cold allodynia, heat hyperalgesia and (to a lesser extent) tactile allodynia. Western blot analysis revealed enhanced expression of kinin B(1) and B(2) receptor protein in ipsilateral L4-L6 spinal nerve and hind paw skin samples collected on Day 12 after SNL surgery. These results indicate that peripheral pronociceptive kinin B(1) and B(2) receptor-operated mechanisms contribute significantly to the maintenance of hind paw cold and mechanical allodynia and heat hyperalgesia induced by L5/L6 SNL in rats.

Importance of the vagus nerve for fever and neutrophil migration induced by intraperitoneal LPS injection.

OBJECTIVE: We investigated the importance of the vagus nerve in fever, neutrophil migration and neutrophilia simultaneously induced by intraperitoneal injection of endotoxin (lipopolysaccharide, LPS) and in terms of the production of pre-formed pyrogenic factor (PFPF) and of the fever induced by this factor. METHODS: Naïve, sham-operated or subdiaphragmatically vagotomized male Wistar rats received either LPS (i.p. or i.pl.) or PFPF (i.v., i.c.v., i.p.). The number of neutrophils was evaluated in peritoneal or pleural fluid and in blood. Fever was monitored using a rectal probe. RESULTS: In naïve animals, LPS (0.02-200 microg kg(-1), i.p.) induced dose-related neutrophilia and fever while on neutrophil migration it resulted in a bell-shaped curve. Vagotomy reduced the peritoneal resident cell population (56%), fever (71%) and neutrophil migration (43%) but not the neutrophilia or neutrophil migration to the pleural cavity. Vagotomy did not affect the PFPF production or PFPF-induced fever. CONCLUSIONS: Vagus nerve integrity is important not only for fever but also for the neutrophil influx to the peritoneal cavity by controlling the number of resident cells in this cavity.

Procainamide-induced myasthenia-like weakness in a patient with peripheral neuropathy.

Because procainamide hydrochloride (Pronestyl) may block neuromuscular transmission (NMT), this drug is contraindicated in cases of myasthenia gravis. Reduction of the safety factor of NMT is also seen in other conditions, including peripheral neuropathies. A patient with uremic peripheral neuropathy in whom myasthenia-like weakness developed during procainamide therapy is described. Procainamide should be given with caution in cases of peripheral neuropathies in which there may be a reduction of the safety factor of NMT.