Medicolegal aspect of loss of smell and olfactory event-related potentials.

Background: It is not straightforward to objectively evaluate the olfactory dysfunction that occurs following forensic incidents. The olfactory event-related potentials method, based on electrophysiological records, may provide objective data in the evaluation of posttraumatic anosmia cases from the medicolegal perspective. This study, where a quantitative evaluation of the cases with the complaints of olfactory sensation disorder was performed using the olfactory event-related potentials test, aims to identify the factors that should be considered in the evaluation of olfactory dysfunction from the medicolegal perspective. Results: This study first evaluated the complaints of 98 patients admitted because of posttraumatic impaired smell and then administered electrophysiological odor tests on the patients. Because of this, the relationship between the EEG responses of the cases and the olfactory disorder was examined. Of the 98 cases that participated in the study, 68 (69.4%) were male and 30 (30.6%) were female. Of all cases, 53 (54.1%) had complaints of not being able to smell at all, 14 (14.3%) had complaints of reduced smell, whereas, in addition to the existing complaints of olfactory dysfunction, 44 (44.9%) of them had complaints of taste perception and 18 (18.3%) reported having vision disorders. 21 of 37 cases who reported being unable to smell during the test turned out to be anosmic. Furthermore, 16 cases stated that, though having had a response in the odor test, they had no sense of smell following the test. Conclusions: Although it seems possible to prove that there is a relationship between the olfactory event-related potential test and the diagnosis of anosmia, there is still ongoing research on its use in clinical practice. Performing both subjective and electrophysiological tests together to detect olfactory dysfunctions that occur after a forensic incident enable provide more reliable results in diagnosis.

Analytical Performance Evaluation of Siemens Sysmex CS-2500 and Sekisui CP-3000.

BACKGROUND: Automatic coagulation analyzers have been used in the last 50 years and have been developed considerably. Newly developed tests and methods cannot be conducted in routine laboratories without evaluating their performance. Therefore, their performance must be evaluated and approved before being used routinely. The aim of this study is to evaluate the analytical performance of Sysmex Coagulation System-2500 (CS-2500) and Sekisui CP-3000 automatic coagulation analyzer (CP-3000). METHODS: For APTT, PT, and D-dimer tests, reference range verification study, a method comparison study was performed in both analyzers in accordance with CLSI protocols, and precision and accuracy were evaluated using internal and external quality control samples. In the evaluation of precision and accuracy, CV% and bias% values were calculated. Bland-Altman, Passing-Bablok regression analysis, and correlation coefficient were used in the comparison study. RESULTS: The CV% values calculated for APTT and PT in both analyzers were found to be below the CLSI recommendation of 5%. D-dimer test results meet the quality criteria recommended by CLSI. Accuracy for both analyzers was within the acceptable limits. The reference ranges recommended by the manufacturer have been veryfied. Regression equations for APTT, PT, and D-dimer are y = -3.313 + 1.188x, y = -0.0399 + 1.048x, and y = 0.155 + 0.655x, respectively, and r values were 0.904, 0.978, and 0.974, respectively. CONCLUSIONS: CS-2500 and CP-3000 analyzers are suitable for laboratory use for routine coagulation. Since the CP-3000 device is newly used in our country, it needs to be supported by more comparison studies.

Is the Reference Electrode Location Important for the Electromyography Evaluation of the Pelvic Floor in Urodynamic Studies?

PURPOSE: Perineal electromyography (EMG) is a crucial part of urodynamic studies. Many researchers focused on the standardization of techniques in urodynamics, but no study has yet evaluated the differences with various reference electrode placements. The aim of this study was to determine the optimal placement of the reference electrode for recording pelvic floor activity in urodynamic studies. METHODS: Children over 6 years of age without anatomic or neurological abnormalities were invited to participate in the study. Four reference electrodes were placed on the right kneecap, the inner surface of the right inner thigh, the right anterior iliac spine (AIS), and the skin over the left gluteal muscles for simultaneous recording. The EMG signal formed by pelvic contraction during forceful straining was recorded both in the supine and sitting positions. The root mean square (RMS) value of each muscle contraction signal was calculated. RESULTS: Twenty-one participants (10 boys and 11 girls) were included. The mean age was 10.19±3.20 years. The highest RMS values were obtained with the reference electrode on the thigh in the supine position and the AIS in the sitting position. Significant differences were found between the mean RMS values of the knee and other locations of reference electrodes in the supine position, as well as between mean RMS values in all regions except the thigh and gluteus in the sitting position. The minimum mean RMS values in both positions were obtained with the reference electrode on the knee. CONCLUSION: During urodynamic studies, reference electrodes shall be placed on AIS in the sitting and on the inner thigh in the supine position. The knee is not a suitable option for reference electrode placement. This information may help improve EMG recordings in the evaluation of pelvic floor muscles.

Responses of human soleus motor units to low-threshold stimulation of the tibial nerve.

The peristimulus frequencygram (PSF) has recently been shown to illustrate postsynaptic potentials of motoneurones much more reliably than the peristimulus time histogram (PSTH). The aim of this investigation was to examine the profile of the postsynaptic potential (PSP) in soleus motoneurones in response to an H-reflex with and without accompanying M waves of different magnitude by using PSTH and PSF profiles of single motor units. Nine men and five women healthy subjects participated in this study. Electrical stimuli were delivered to the tibial nerve in the popliteal fossa. The reflex response of the soleus muscle was recorded using both surface electromyogram and single motor unit potentials. The PSTH analysis demonstrated that there were four different synaptic events following low-intensity stimulation of the tibial nerve: primary enhancement in firing probability (H-reflex or E1), primary reduction in firing probability (primary silent period or SP1), secondary reduction in firing probability (secondary silent period or SP2), and secondary enhancement in firing probability (E2). On the other hand, the PSF analysis indicated only two reflex responses, long-lasting enhancement in discharge rate including the H-reflex (LLE) and long-lasting decrease in discharge rate (LLD). The results of the two analyses methods are compared and contrasted. While the PSTH demonstrated that there was a silent period (SP1) immediately following the H-reflex, the PSF indicated an increase in discharge rate during the same period. The PSF also indicated that, during SP2 and E2, the discharge rate actually decreased (LLD). It was therefore suggested that LLD involved activation of several inhibitory pathways including the autogenic inhibition of units via the Golgi tendon organs. It was concluded that the PSF could indicate the details of the postsynaptic potentials and is very useful for bringing out previously unknown effects of electrical stimulation of muscle nerves.

Laryngoaltimeter: a new ambulatory device for laryngeal height control, preliminary results.

The vertical larynx position has significant effects on vocal tract resonances and on the biomechanical properties of the vocal folds. It is generally agreed that the larynx should be kept in a comfortably low position during singing, and voice problems are often associated with a habitually raised larynx. A new method, and a battery operated portable device called Laryngoaltimeter, was developed to control laryngeal height continuously for therapeutic or educational purposes. Two similar condenser microphones attached on the suprasternal notch and supraglottic region were used to capture corresponding vibrations during phonation. The microphone signals were then filtered through a band pass filter (90-240 Hz), digitized, and compared to each other by detection algorithms of the Laryngoaltimeter. When the supraglottic microphone received subglottic resonance related vibrations due to laryngeal elevation, auditory and visual signals were produced as a biofeedback by the device. Waterfall amplitude spectrograms of the microphone signals verified that the frequencies captured by each microphone were dissimilar before and similar after laryngeal elevation. The accuracy of the device was found to be 87% on 13 subjects having different voice classifications as a demonstration of its use. Laryngoaltimeter is a prototype device and needs to be developed. Further research may also be established to investigate the habitual effects of keeping vertical position low by using Laryngoaltimeter as a biofeedback device during therapy exercises or voice lessons.

The comparison of therapeutic effects of atropine and pralidoxime on cardiac signs in rats with experimental organophosphate poisoning.

Organophosphate poisoning causes disturbances in cardiac conduction and potentially fatal severe cardiac rhythm abnormalities. This study investigated the cardiac effects of atropine and pralidoxime in the treatment of organophosphate poisoning in rats. Three groups of 10 adult male Wistar rats were anesthetized with an intraperitoneal injection of ketamine 100 mg/kg and xylazine 10 mg/kg and connected to a computerized electrocardiographic monitor. Each rat was then injected intraperitoneally with the pesticide dichlorvos 70 mg/kg. Sixty seconds after the injection, 10 rats were injected with saline, 10 with pralidoxime mesylate 20 mg/kg, and 10 with atropine 10 mg/kg. During the computerized electrocardiographic monitoring, each rat's heart rate and QT(c) intervals were recorded and analyzed as the injections were administered. The heart rates in all 3 groups did not differ before the dichlorvos was administered, nor at 60 seconds afterward, but in the atropine group, the time elapsed before the first decline in heart rate was significantly longer than that in the control group (P<.05). In addition, the interval before death was significantly longer in the atropine group than in either the control group or the pralidoxime group (P<.05 for both). The QT(c) was almost identical in each of the groups. Atropine has beneficial effects on the heart rate, prolongs the time before the heart rate declines, and delays death but has no effect on the QT(c) interval. Further research about the toxic effects of organophosphate compounds on myocardial cells is warranted.