Microelectrode Recording for Deep Brain Stimulation of the Subthalamic Nucleus in Patients with Advanced Parkinson's Disease:Advantage or Loss of Time?

AIM: To investigate the effect of using microelectrode recording (MER) on the length of time required to carry out a deep brain stimulation (DBS) procedure of the subthalamic nucleus in patients with Parkinson's disease (PD). MATERIAL and METHODS: The time required to include MER in the DBS operation was calculated for the first and second sides in 24 patients with PD. The number of microelectrodes used on each trajectory for the first and second sides, and the percentage of permanent electrodes implanted on each trajectory for the first and second sides, were quantified. RESULTS: The average times taken to use MER were 23.4 +/- 6.2 minutes, 17.4 +/- 6.5 minutes, and 41.2 +/- 6.3 minutes for the first side, second side and total procedure, respectively. In 75% of patients, the permanent electrode was implanted at the planned target site for the first side, and in 61% of patients for the second side. CONCLUSION: MER extends the time required to carry out the DBS procedure. However, during surgery, it provides real-time information on the electrodes' neurophysiological locations and helps the surgical team choose an alternative target if the planned target does not produce satisfying results

A remarkable new leaf-cutter bee from Thailand (Hymenoptera: Megachilidae)

This is the publisher's version, copyright by Akademie Verlag.A remarkable new species of leaf-cutter bee, Megachile trichorhytisma ENGEL sp. n., is described and figured from two males collected in northern Thailand. The species is placed in a new subgenus, Aethomegachile ENGEL & BAKER subgen. n., and is differentiated from previously known lineages of Megachile

Required reserves as a credit policy tool

This paper conducts a quantitative investigation of the role of reserve requirements as a macroprudential policy tool. We build a monetary DSGE model with a banking sector in which (i) an agency problem between households and banks leads to endogenous capital constraints for banks in obtaining funds from households, (ii) banks are subject to time-varying reserve requirements that countercyclically respond to expected credit growth, (iii) households face cash-in-advance constraints, requiring them to hold real balances, and (iv) standard productivity and money growth shocks are two sources of aggregate uncertainty. We calibrate the model to the Turkish economy which is representative of using reserve requirements as a macroprudential policy tool recently. We also consider the impact of financial shocks that affect the net worth of financial intermediaries. We find that (i) the time-varying required reserve ratio rule countervails the negative effects of the financial accelerator mechanism triggered by adverse macroeconomic and financial shocks, (ii) in response to TFP and money growth shocks, countercyclical reserves policy reduces the volatilities of key real macroeconomic and financial variables compared to fixed reserves policy over the business cycle, and (iii) a time-varying reserve requirement policy is welfare superior to a fixed reserve requirement policy. The credit policy is most effective when the economy is hit by a financial shock. Time-varying required reserves policy reduces the intertemporal distortions created by the credit spreads at expense of generating higher inflation volatility, indicating an interesting trade-off between price stability and financial stability

Required reserves as a credit policy tool

This paper conducts a quantitative investigation of the role of reserve requirements as a macroprudential policy tool. We build a monetary DSGE model with a banking sector in which (i) an agency problem between households and banks leads to endogenous capital constraints for banks in obtaining funds from households, (ii) banks are subject to time-varying reserve requirements that countercyclically respond to expected credit growth, (iii) households face cash-in-advance constraints, requiring them to hold real balances, and (iv) standard productivity and money growth shocks are two sources of aggregate uncertainty. We calibrate the model to the Turkish economy which is representative of using reserve requirements as a macroprudential policy tool recently. We also consider the impact of financial shocks that affect the net worth of financial intermediaries. We find that (i) the time-varying required reserve ratio rule countervails the negative effects of the financial accelerator mechanism triggered by adverse macroeconomic and financial shocks, (ii) in response to TFP and money growth shocks, countercyclical reserves policy reduces the volatilities of key real macroeconomic and financial variables compared to fixed reserves policy over the business cycle, and (iii) a time-varying reserve requirement policy is welfare superior to a fixed reserve requirement policy. The credit policy is most effective when the economy is hit by a financial shock. Time-varying required reserves policy reduces the intertemporal distortions created by the credit spreads at expense of generating higher inflation volatility, indicating an interesting trade-off between price stability and financial stability

The Effects of Additional Monetary Tightening on Exchange Rates

Since the global financial crisis, Central Banks have used various policy tools to sustain financial stability besides price stability. Additional Monetary Tightening is one of these tools that the Central Bank of the Republic of Turkey used in 2011-2012. The effects of this tool on the exchange rate are the main theme of this paper. Our analysis indicates that additional monetary tightening has a significant role in reducing volatility in the exchange rate. It is also shown that during the days of additional tightening Turkish Lira appreciated against the emerging market currencies

Effect of Anesthesia on Microelectrode Recordings During Deep Brain Stimulation Surgery:A Narrative Review

Deep brain stimulation (DBS) is an effective surgical treatment for patients with various neurological and psychiatric disorders. Clinical improvements rely on careful patient selection and accurate electrode placement. A common method for target localization is intraoperative microelectrode recording (MER). To facilitate MER, DBS surgery is traditionally performed under local or regional anesthesia. However, sedation or general anesthesia is sometimes needed for patients who are unable to tolerate the procedure fully awake because of severe motor symptoms, psychological distress, pain, or other forms of discomfort. The effect of anesthetic drugs on MER is controversial but likely depends on the type and dose of a particular anesthetic agent, underlying disease, and surgical target. In this narrative review, we provide an overview of the current literature on the anesthetic drugs most often used for sedation and anesthesia during DBS surgery, with a focus on their effects on MERs

Periaqueductal Grey Stimulation Induced Panic-Like Behaviour Is Accompanied by Deactivation of the Deep Cerebellar Nuclei

Until recently, the cerebellum was primarily considered to be a structure involved in motor behaviour. New anatomical and clinical evidence has shown that the cerebellum is also involved in higher cognitive functions and non-motor behavioural changes. Functional imaging in patients with anxiety disorders and in cholecystokinin tetrapeptide-induced panic-attacks shows activation changes in the cerebellum. Deep brain stimulation of the dorsolateral periaqueductal grey (dlPAG) and the ventromedial hypothalamus (VMH) in rats has been shown to induce escape behaviour, which mimics a panic attack in humans. We used this animal model to study the neuronal activation in the deep cerebellar nuclei (DCbN) using c-Fos immunohistochemistry. c-Fos expression in the DCbN decreased significantly after inducing escape behaviour by stimulation of the dlPAG and the VMH, indicating that the DCbN were deactivated. This study demonstrates that the DCbN are directly or indirectly involved in panic attacks. We suggest that the cerebellum plays a role in the selection of relevant information, and that deactivation of the cerebellar nuclei is required to allow inappropriate behaviour to occur, such as panic attacks

The role of the medial geniculate body of the thalamus in the pathophysiology of tinnitus and implications for treatment

Tinnitus is an auditory sensation in the absence of actual external stimulation. Different clinical interventions are used in tinnitus treatment, but only few patients respond to available options. The lack of successful tinnitus treatment is partly due to the limited knowledge about the mechanisms underlying tinnitus. Recently, the auditory part of the thalamus has gained attention as a central structure in the neuropathophysiology of tinnitus. Increased thalamic spontaneous firing rate, bursting activity and oscillations, alongside an increase of GABAergic tonic inhibition have been shown in the auditory thalamus in animal models of tinnitus. In addition, clinical neuroimaging studies have shown structural and functional thalamic changes with tinnitus. This review provides a systematic overview and discussion of these observations that support a central role of the auditory thalamus in tinnitus. Based on this approach, a neuromodulative treatment option for tinnitus is proposed