Neural response to lidocaine in healthy subjects

The Efficacy of Lidocaine in Disrupting Cocaine Cue-Induced Memory Reconsolidation

RATIONAL

Cue-induced craving memories, linked to drug-seeking behaviors, require key molecular processes for memory reconsolidation. Lidocaine, a sodium channel blocker, inhibits NMDA receptor activation and suppresses nitric oxide and ERK production. These processes are required for memory re-consolidation; inhibiting them may reduce cue-related craving memories in cocaine dependent subjects.

OBJECTIVES

To assess the efficacy of lidocaine in decreasing cue-induced cocaine craving and cocaine use.

METHODS

Treatment-seeking cocaine-dependent participants (n = 33, 25 men) were recruited. Personalized craving and relaxation scripts were developed. Participants were then randomly assigned in a double-blind design to either receive intravenous lidocaine immediately following a cocaine craving script (lidocaine/craving), saline following a craving script (saline/craving), or lidocaine following a relaxation script (lidocaine/relax). One week following the infusion, cue-induced craving was assessed in the same paradigm without an infusion. Cocaine use and craving were assessed for 4 weeks following infusion.

RESULTS

The administration of lidocaine during craving induction (lidocaine/craving) did not decrease cue-induced craving during craving reactivation one week later or craving and cocaine use over the 4-week follow-up period compared to the saline/craving group. There were no significant differences in craving and cocaine use between the lidocaine/relax and saline/craving groups.

CONCLUSION

Lidocaine administered following craving induction did not decrease subsequent cue-induced craving or cocaine use. Blocking the reconsolidation of craving-related memories with pharmacological agents remains an important area of investigation.

Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection

Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist. Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow. Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field. It is of paramount importance that the anesthesiologist shares this understanding. Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes.

[Langanhaltende Besserung von somatischen und psychovegetativen Störungen unter Procain-Infusionen: Eine multizentrische Anwendungsbeobachtung]

Hintergrund: Procain besitzt wie das strukturverwandte Cocain zentralnervöse Wirkungen unabhängig von seinem lokalanästhetischen Effekt. Procain-Infusionen werden Patienten mit psychovegetativen Störungen seit Jahrzehnten verabreicht, zumeist im Rahmen einer Neuraltherapie. Untersuchungen zur Wirksamkeit einer alleinigen Gabe von Procain im Praxisalltag stehen aus. Patienten und Methoden: Im Rahmen einer Anwendungsbeobachtung (AWB) wurde bei 56 Patienten aus 3 Arztpraxen die Wirkung von intravenösen Procain-Infusionen (1-3 Ampullen à 5 ml einer 2%igen Procain-Lösung in 250 ml Natriumchlorid pro Arztbesuch) auf das somatische und psychovegetative Befinden dokumentiert. Hierzu wurde ein validierter, 21 Fragen umfassender Befindlichkeitsskalierungsfragebogen verwendet, den die Patienten vor Beginn und nach 1, 2, 4 und 6 Monaten ausfüllten. Neben der laufenden Medikation waren keine weiteren therapeutischen Maßnahmen erlaubt. Ergebnisse: Nach 4 oder 6 Monaten zeigten 42 Patienten (75%) eine Verbesserung bei den 9 positiven Items (d.h. erfragte Eigenschaften) wie «Freude», «Genussfähigkeit» oder «Schlaf»; 35 Patienten (62,5%) verbesserten sich bei den 12 negativen Items wie «Stressbelastung», «Energielosigkeit» oder «Ängstlichkeit». Diese Veränderungen waren nach 2, 4 und 6 Monaten signifikant gegenüber dem Ausgangswert. Schlussfolgerungen: Procain ruft im zentralen Nervensystem nachweislich Veränderungen in der Aktivität spezifischer Kerngebiete wie des limbischen und kortikalen Systems hervor. Die Ergebnisse dieser AWB deuten auf eine langanhaltende Verbesserung von somatischen und psychovegetativen Störungen unter der Infusion von Procain.

Toxins and adverse drug reactions affecting the equine nervous system

This article provides an overview of the more common toxins and adverse drug reactions, along with more rare toxins and reactions (Table 1), that result in neurologic dysfunction in horses. A wide variety of symptoms, treatments, and outcomes are seen with toxic neurologic disease in horses. An in-depth history and thorough physical examination are needed to determine if a toxin or adverse drug reaction is responsible for the clinical signs. Once a toxin or adverse drug reaction is identified, the specific antidote, if available, and supportive care should be administered promptly.