Central motor conduction was assessed as a predictor of mortality and functional outcome in a longitudinal study of 118 patients with first-ever stroke. Investigations commenced 12-72 hours after stroke and were repeated up to death or 12 months. The results were compared with normal data, validated assessments of motor function, detailed neurological examinations and CT scans. Responses were recorded in the surface electromyogram from proximal and distal muscles of both upper limbs following percutaneous electromagnetic stimulation of the motor cortex (muscles contracted) and spinal motor roots (muscles relaxed). Central Motor Conduction Time (CMCT) was estimated by subtracting the latencies of spinal root evoked responses from those of cortical evoked responses. The durations and thresholds of the responses were recorded. Investigations 12-72 hours after stroke identified patients with 1) normal CIVICT, 2) delayed CIVICT, and 3) absent responses. Sequential investigations up to 12 months after stroke revealed 1) CIVICT may remain unchanged, 2) delayed CIVICT may become normal 3) responses may reappear with shortened duration, with delayed or normal CIVICT, 4) responses were lost if the stroke extended, 5) initially high thresholds to stimulation decreased. Absent responses 12-72 hours after stroke initially correlated with reduced power, hand dexterity and functional ability, and with large infarctions, mass effect and cortical lesions on CT scans. Normal CIVICT correlated with a high probability of survival and significantly better functional recovery at 12 months. Absent responses correlated with a high probability of stroke-related death. Survivors had poor outcome for muscle power, hand dexterity, activities of daily living, functional outcome and duration of stay in hospital. Results from the thenar muscles alone provided accurate prognostic information. If results from all the muscles were considered and the test repeated seven days after the first assessment, the sensitivity of the test increased. Electromagnetic stimulation is a safe prognostic investigation that is complementary to clinical examination and imaging patients with stroke.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Nonsurgical root canal therapy procedures aim to reduce the total microbial load within an infected root canal system through chemomechanical debridement of the root canal system via instrumentation in conjunction with an antibacterial irrigating solution. The most commonly used irrigant is sodium hypochlorite, often at concentrations toxic to human cells. Electromagnetic wave irradiation is a novel method of disinfection that has been shown to be bactericidal against planktonic microorganisms in solution, but its efficacy against an established biofilm is unknown. Pilot studies have demonstrated a synergistic killing effect with sodium hypochlorite through a process termed electromagnetic stimulation (EMS). If confirmed, lower concentrations of the current gold standard of 6.0-percent sodium hypochlorite could be used to irrigate infected root canals during endodontic treatment, resulting in less toxicity to human cells. There are also regenerative implications as EMS could be used to disinfect the root canals of immature teeth using 1.5-percent sodium hypochlorite, as recommended by the American Association of Endodontists. Objectives: The purpose of this in-vitro study was to evaluate the anti-biofilm effect of EMS against an established biofilm of Enterococcus faecalis. Materials and Methods: Single rooted teeth were cut to a standardized length (12 mm) and instrumented with a 45.05 Wave One Gold reciprocating file. Specimens were sterilized and inoculated with E. faecalis, which grew for two weeks to form an established biofilm. There were five treatment groups: 1) 6.0-percent sodium hypochlorite; 2) 1.5-percent sodium hypochlorite; 3) 1.5-percent sodium hypochlorite with EMS; 4) 0.9-percent saline with EMS and 5) 0.9-percent saline. Samples were collected, plated, and incubated for two days. The number of CFUs/mL was determined and converted to log10. The effect of treatment group on bacterial counts was made using Wilcoxon Rank Sums Test. One sample per group was scored and split for confocal imaging. Null Hypothesis: Teeth treated with EMS in combination with 1.5-percent sodium hypochlorite or 0.9-percent saline will not demonstrate a significant anti-biofilm effect in comparison to those treated with 6.0-percent sodium hypochlorite alone. Results: 0.9-percent saline and 0.9-percent saline with EMS were significantly higher than 6.0-percent NaOCl, 1.5-percent NaOCl, and 1.5-percent NaOCl with EMS. 0.9-percent saline was significantly higher than 0.9-percent saline with EMS. The three groups that included treatment with NaOCl were not significantly different from each other. Confocal imaging confirmed the CFU findings. Conclusion: Because there was no growth in any of the NaOCl groups, the null hypothesis cannot be rejected. However, there was an antibiofilm effect when comparing the two saline groups, demonstrating that EMS has an antibiofilm effect. Future studies should focus on determining what concentration of NaOCl is most effective in combination with EMS.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Elimination of bacteria and active infection within an infected root canal system is one of the primary objectives of nonsurgical root canal treatment. One of the measures of successful root canal treatment is subsequent bone healing of periapical lesions caused by previous infection. A previous study by Yumoto et al. showed that electromagnetic wave stimulation can increase proliferation of osteoblastic cells with no cytotoxicity, and it can also up-regulate growth factors such as vascular endothelial growth factor and platelet-derived growth factor.18 They also showed increased proliferation of an immortalized osteoblastic MC3T3-E1 cell line 3 days following electromagnetic stimulation (EMS).18 Previously, Pauly et al. found increased alkaline phosphatase (ALP) activity with 10 mA EMS application to primary murine calvaria-derived osteoblastic cells with 5 pulses at 1 second per pulse, but no significant differences were found for MTS proliferation nor mineral deposition compared to a negative control group.82 Optimization of the different variables including post-treatment incubation time, current delivery, and number of pulses per treatment may be necessary to improve osteogenic activity. The use of mesenchymal stem cells from murine bone marrow may also offer a physiologically relevant model for osteoblastic regeneration of periapical lesions. Objectives: The goal of this study was to investigate and optimize the effects of electromagnetic wave stimulation (EMS) on murine bone marrow mesenchymal stem cells (MSCs) by evaluating the proliferation and differentiation of the cells after exposure to different EMS treatment regimens. Materials and Methods: 5 x104 stromal osteoblasts (SOBs) were cultured in 24-well plates in α-MEM containing 10% fetal bovine serum. Cells were then subjected to pulsed EMS treatments of 1 mA, 10 mA, and 50 mA. EMS was generated using an electromagnetic apical treatment (EMAT) device created by J. Morita MFG Corp. Proliferation was assessed via MTS assay 1 days after treatment. For osteogenic differentiation, ascorbic acid and β-glycerol phosphate were added to the culture media, and SOBs were cultured for 14 days. Afterwards, alkaline phosphatase (ALP) activity and Alizarin-red S mineral deposition were quantified as measures of osteoblast activity. Cells grown in osteogenic media without EMS treatment served as the negative control. Results: Although MSC proliferation was unaffected by different EMS treatment regimens, 50 mA EMS resulted in a decrease in ALP activity and mineral deposition by osteoblasts. Conclusions: Our findings suggest bone healing by EMS may involve a different cellular mechanism, that is not reproduced in vitro in our studies. Utilizing different amperage and EMS regimens may improve osteogenic differentiation.