Diminished appetitive startle modulation following targeted inhibition of prefrontal cortex.

From an evolutionary perspective the startle eye-blink response forms an integral part of the human avoidance behavioral repertoire and is typically diminished by pleasant emotional states. In major depressive disorder (MDD) appetitive motivation is impaired, evident in a reduced interference of positive emotion with the startle response. Given the pivotal role of frontostriatal neurocircuitry in orchestrating appetitive motivation, we hypothesized that inhibitory transcranial magnetic stimulation (TMS) would reduce appetitive neuromodulation in a manner similar to MDD. Based on a pre-TMS functional MRI (fMRI) experiment we selected the left dorsolateral and dorsomedial prefrontal cortices as target regions for subsequent sham-controlled inhibitory theta-burst TMS (TBS) in 40 healthy male volunteers. Consistent with our hypothesis, between-group comparisons revealed a TBS-induced inhibition of appetitive neuromodulation, manifest in a diminished startle response suppression by hedonic stimuli. Collectively, our results suggest that functional integrity of left dorsolateral and dorsomedial prefrontal cortex is critical for mediating a pleasure-induced down-regulation of avoidance responses which may protect the brain from a depressogenic preponderance of defensive stress.

Treatment of lumbar disc herniations by interventional fluoroscopy-guided endoscopy.

The neurointerventional transforaminal endoscopic approach to sequestered disk herniation is a minimally invasive alternative to established microsurgical techniques. In addition to those techniques approaching the nucleus like APLD, the transforaminal approach allows the removal of dislocated sequesters in the epidural space. The main steps of the procedure are fluoroscopy-guided, so a good experience with fluoroscopy based interventional techniques is helpful, but the technique has a significant learning curve. If familiar with the different steps, it allows nearly every lumbar disk herniation to be treated with a very short hospital stay and short rehabilitation time. The paper describes in detail the steps of the procedure, the difficulties and advantages and gives a short review of the relevant literature.

Nicotinic acetylcholine receptors contribute to learning-induced metaplasticity in the hippocampus.

Hippocampal learning is thought to induce metaplasticity, which can facilitate subsequent learning. Administered at single low doses, the N-methyl-d-aspartate-type glutamate receptor antagonist memantine predominantly blocks α7 nicotinic acetylcholine receptors (α7 nAChRs). Placebo-controlled administration of a single low dose of memantine in a pharmaco-fMRI experiment may thus help characterize the role of α7 nAChRs in hippocampal metaplasticity. We hypothesized that if α7 nAChRs contribute to learning-induced metaplasticity in the hippocampus, blockade of these receptors with low-dose memantine would selectively interfere with a facilitation of subsequent learning without impairing hippocampal learning per se. To specifically test this hypothesis, we devised a randomized controlled trial in which healthy volunteers were administered a 20-mg single oral dose of memantine or placebo and scanned on three subsequent runs of a hippocampal learning task. Our results indicate no discrepancies in behavioral learning between low-dose memantine- and placebo-treated participants in the first and second run of this task. In the third run, however, only the placebo-treated group showed facilitated behavioral learning, an effect paralleled by decreased neural responses in the hippocampal cornu ammonis region. Our findings suggest that blockade of α7 nAChRs selectively interfered with a learning-induced facilitation of subsequent learning while leaving unimpaired hippocampal learning per se. Taken together, our results provide support for a relevant contribution of α7 nAChRs to learning-associated metaplasticity in the hippocampus.

Immediate and 30-day clinical outcome of patients treated with the TwinOne cerebral protection system: multicenter experience in 217 cases.

There are several cerebral protection devices used for carotid artery stenting (CAS). All of them require manipulation and exchange of two separate materials (cerebral protection device ? dilatation balloon), making the procedure longer and posing possible complications such as vasospasm and embolism. The new system described here is an evolution of the cerebral protection concept and allows temporary occlusion of the distal internal carotid during CAS procedures with both materials in one device. We present our experience using this new device. Between January 2007 and March 2008, consecutive patients sent for CAS (symptomatic, with stenosis C50%, or asymptomatic, with stenosis C70%) were treated using TwinOne as a cerebral protection system. All patients were treated using the "simplified" CAS technique, limiting cerebral protection to the poststenting angioplasty phase. Two hundred nine patients have been treated at our institutions; eight underwent bilateral CAS, for a total of 217 CAS procedures performed using the TwinOne for cerebral protection. There have been four periprocedural (within 3 h of procedure) cases of complications (1.8%): three disabling strokes (one in-stent thrombosis, one presumed clotting, one ipsilateral stroke with uncertain root cause) and one transient ischemic attack attributable to heart failure. There have been two in-hospital complications (0.92%): one disabling stroke of unclear origin and one contralateral transient ischemic attack. No additional adverse event has been reported at 30 days after the CAS procedure. In conclusion, this cerebral protection system is simple to use, allows a quick intervention and short occlusion time, and has a low rate of complications.