Short circuit in deep brain stimulation.

OBJECT: The authors undertook this study to investigate the incidence, cause, and clinical influence of short circuits in patients treated with deep brain stimulation (DBS). METHODS: After the incidental identification of a short circuit during routine follow-up, the authors initiated a policy at their institution of routinely evaluating both therapeutic impedance and system impendence at every outpatient DBS follow-up visit, irrespective of the presence of symptoms suggesting possible system malfunction. This study represents a report of their findings after 1 year of this policy. RESULTS: Implanted DBS leads exhibiting short circuits were identified in 7 patients (8.9% of the patients seen for outpatient follow-up examinations during the 12-month study period). The mean duration from DBS lead implantation to the discovery of the short circuit was 64.7 months. The symptoms revealing short circuits included the wearing off of therapeutic effect, apraxia of eyelid opening, or dysarthria in 6 patients with Parkinson disease (PD), and dystonia deterioration in 1 patient with generalized dystonia. All DBS leads with short circuits had been anchored to the cranium using titanium miniplates. Altering electrode settings resulted in clinical improvement in the 2 PD cases in which patients had specific symptoms of short circuits (2.5%) but not in the other 4 cases. The patient with dystonia underwent repositioning and replacement of a lead because the previous lead was located too anteriorly, but did not experience symptom improvement. CONCLUSIONS: In contrast to the sudden loss of clinical efficacy of DBS caused by an open circuit, short circuits may arise due to a gradual decrease in impedance, causing the insidious development of neurological symptoms via limited or extended potential fields as well as shortened battery longevity. The incidence of short circuits in DBS may be higher than previously thought, especially in cases in which DBS leads are anchored with miniplates. The circuit impedance of DBS should be routinely checked, even after a long history of DBS therapy, especially in cases of miniplate anchoring.

The effect of probiotics on gastric mucosal permeability in humans administered with aspirin.

OBJECTIVE: To examine whether a probiotic strain, Lactobacillus gasseri OLL2716 (LG21), can protect the gastric mucosal integrity from aspirin using urinary sucrose excretion (USE) test. MATERIALS AND METHODS: In the study using high-dose aspirin, the USE tests were carried out in 29 volunteers before and after LG21 treatment for 4 weeks. In the study using patients undergoing low-dose aspirin therapy, USE tests were performed in 37 subjects who took LG21 for 16 weeks. Stool occult blood was examined by the guaiac method. RESULTS: In the former study, the elevation in the USE value after aspirin loading significantly decreased after LG21 treatment (Median ± SD; 0.244 ± 0.237 vs. 0.208 ± 0.112%, p = 0.018). In the latter study, the USE value significantly decreased in the period with LG21 treatment (p = 0.033), while no significant difference was found in the period without LG21 (p = 0.113). The number of positive occult blood tests decreased during LG21 treatment. CONCLUSIONS: The regular ingestion of LG21 may protect the integrity of the gastric mucosal permeability against aspirin.

Inferior temporal sulcus approach for amygdalohippocampectomy guided by a laser beam of stereotactic navigator.

OBJECTIVE: To describe a surgical technique for a minimally invasive transcortical transventricular amygdalohippocampectomy via the inferior temporal sulcus (ITS) using a stereotactic navigator. METHODS: Seven patients with medically intractable mesial temporal lobe epilepsy underwent an amygdalohippocampectomy via the ITS. By use of a laser-guided navigation system, the epileptogenic foci of the mesial temporal lobe were resected through a small linear operative route that was made by a brain speculum inserted from the ITS to the anterolateral floor of the temporal horn in the lateral ventricle. RESULTS: All patients completed at least a 1-year follow-up (range, 14-45 mo) after surgery and had improved neuropsychological parameters as a result of the operation. All patients became seizure-free after surgery. A Humphrey visual field perimeter detected no hemianopsia. CONCLUSION: Combined with the stereotactic navigation system, the ITS approach provides the least invasive amygdalohippocampectomy that preserves optic radiation. This approach seems beneficial especially in patients in whom the epileptic lesions are limited to the anterior mesial temporal lobe.