Frequency of Automatic Stimulations in Responsive Vagal Nerve Stimulation in Patients With Refractory Epilepsy

BackgroundIn vagal nerve stimulation (VNS) therapy, the release of VNS model 106 (AspireSR) allowed for responsive VNS (rVNS). rVNS utilizes a cardiac-based seizure detection algorithm to detect seizure-induced tachycardia to trigger additional stimulation. There are some studies suggesting clinical benefits of rVNS over traditional VNS, but the performance and significance of autostimulation mode in clinical practice are poorly understood.ObjectivesTo assess the effect of initiation of rVNS therapy and altered stimulation settings on the number of daily stimulations and energy consumption in VNS therapy and to compare autostimulation performance in different epilepsy types.Materials and MethodsRetrospective follow-up of 30 patients with drug-resistant epilepsy treated with rVNS including 17 new implantations and 13 battery replaces at a single center in Finland. Our data consist of 208 different stimulation periods, that is, episodes with defined stimulation settings and both autostimulation and total stimulation performance-related data along with clinical follow-up.ResultsThe variation in autostimulation frequency was highly dependent on the duration of the OFF-time and autostimulation threshold (p < 0.05). There was a large additional effect of autostimulation mode on therapy time and energy consumption with longer OFF-times, but a minor effect with shorter OFF-times. Significantly more autostimulations were triggered in the temporal lobe and multifocal epilepsies than in extratemporal lobe epilepsies.ConclusionsThe initiation of autostimulation mode in VNS therapy increased the total number of stimulations. Shortening the OFF-time leads to a decreased number and share of automatic activations. Epilepsy type may affect autostimulation activity.     

Higher Preimplantation Opioid Doses Associated With Long‐Term Spinal Cord Stimulation Failure in 211 Patients With Failed Back Surgery Syndrome

ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation.     

Salbutamol‐induced Decrease in Augmentation Index is Related to the Parallel Increase in Heart Rate

The change in augmentation index following salbutamol inhalation has been applied to evaluate endothelial function. We examined the contribution of salbutamol‐induced increase in heart rate to the observed decrease in augmentation index. Haemodynamics were recorded using whole‐body impedance cardiography and continuous pulse wave analysis from tonometric radial blood pressure. All subjects (n = 335, mean age 46, body mass index 26, 48% men) were without medications with cardiovascular influences. The effects of salbutamol inhalation (0.4 mg) versus the endothelium‐independent agent nitroglycerin resoriblet (0.25 mg) were examined during passive head‐up tilt, as the haemodynamic influences of these compounds depend on body position. Salbutamol decreased augmentation index by ~3‐4% units in supine and upright positions. Although salbutamol moderately increased cardiac index (+4.5%) and decreased systemic vascular resistance (?8.5%), the significant haemodynamic explanatory factors for decreased augmentation index in multivariate analysis were increased supine heart rate, and increased upright heart rate and decreased ejection duration (p < 0.001 for all, r² = 0.36–0.37). Sublingual nitroglycerin decreased supine and upright augmentation index by ~15% units and ~23% units, respectively. The haemodynamic explanatory factors for these changes in multivariate analysis were increased heart rate, reduced ejection duration and reduced systemic vascular resistance (p ≤ 0.021 for all, r² = 0.22–0.34). In conclusion, the lowering influence of salbutamol on augmentation index may be largely explained by increased heart rate, suggesting that this effect may not predominantly reflect endothelial function.     

Conceptions of Finnish people about the etiology and prevention of dental caries and periodontal disorders

Conceptions among the general public in Finland regarding the etiology and prevention of dental caries and periodontal disorders were surveyed in two interviews in 1971 and 1972. Both population samples interviewed comprised about 1,000 people aged 15 years and over. Inadequate oral hygiene was the most common (65%) possible cause chosen by the subjects among the causes of dental caries. Only 44% of the interviewees considered sugar to be a cause of cariers. Thorough cleaning of the teeth (83%) and dentist's check-ups twice a year (67%) were the factors most frequently chosen in caries prevention. Avoidance of sugar (56%) ranked as the third in frequency. As regards symptoms of periodontal disorders, tender gingiva, gingival bleeding, and loosening of the teeth were correctly suggested as symptoms by 62, 61 and 45%, respectively. Poor oral hygiene (77%) was the cause of gingivitis most commonly chosen by the interviewees, while simultaneous systemic disease (37%) was considered more important than, for example, dental calculus (31%). As regards treatment of periodontal disorders, careful toothcleaning (73%) received most support. However, this factor was closely followed by misconceptions regarding the supposed advantageous value of drug and rinses (50%), chewing of fibrous foods (45%), and vitamin therapy (38%).     

The width of attached gingiva on supraerupted teeth

On basis of earlier results it seems justified to assume that the antomical width of the attached gingiva, i.e. the distance from the mucogingival junction to the cemento-enamel junction in human type of teeth is in direct proportion to the amount of past tooth eruption. For experimental verification of this hypothesis a study was designed to assess the anatomical width of attached gingiva on supraerupted teeth in man. The material of the sutdy comprised 28 first and second maxillary mucogingival junction was marked with short pieces of metal wire, orthopantomograms were taken, and the distances from the mucongingival junction to the floor of the nasal cavity and to the cemento-enamel junction used as controls. A comparision wa also made between the supraerupted teeth and previously measured normally occluding teeth. The results indicated that even during pronounced supraeruption the teeth tend to erupt with their investing tissues while the location of the mucogingival junction remains constant. This finding is of special interest as it should make it possible to treat the problem of a too narrow zone of attached gingiva by grinding the tooth out of occlusion and allowing it and its gingival margin to erupt.