Pain levels of examined muscles and gender differences in pain during electromyography.

OBJECTIVES: The aim of this study was to evaluate the pain level of each muscle during an EMG study and also search for any association between the pain levels and gender. METHODS: Two hundred and twenty-seven subjects (166 females and 111 males) participated in the present study. Numeric analogue scale (NAS) was obtained from the patients after needle EMG for each muscle. RESULTS: In total, 1242 muscles were examined. The highest pain levels among examined muscles were found on Abductor Pollicis Brevis (APB) (5.8 ± 2.6), First Dorsal Interosseous (4.2 ± 2.6) and Vastus Lateralis (4.0 ± 2.6). NAS levels of the female patients (4.3 ± 2.7) were apparently higher than those of the male patients (2.8 ± 2.3) (p<0.01). CONCLUSION: First Dorsal Interosseous muscle was found less painful than APB muscle for the patients. Our study displayed greater pain sensitivity among females compared with males during the needle EMG; however, the pain levels of examined muscles were not higher than moderate for both genders.

Expected and Experienced Pain Levels in Electromyography.

INTRODUCTION: The aim of the present study was to assess pain using a visual analogue scale (VAS) in patients awaiting an EMG procedure (i.e., expected VAS) and after an EMG procedure (i.e., experienced VAS). METHODS: Expected and experienced pain in response to nerve conduction studies (NCS) and needle EMG were assessed in 108 patients (61 females, 47 males; mean age 43.2±11.6) using a VAS. RESULTS: No significant correlations were noted between the expected or the experienced VAS in response to EMG and demographic features of the patients. The expected VAS was significantly higher than the experienced VAS in response to needle EMG (p=0.005). The highest VAS level was noted in the expected VAS in response to needle EMG (4.7±2.2). The lowest VAS level was noted in the experienced VAS in response to NCS (3.6±2.5). CONCLUSION: The present study demonstrated that neither the expected nor the experienced pain associated with EMG exceeded a moderate level. Interestingly, we found that expected pain levels in response to needle EMG were significantly higher than experienced pain levels. Therefore, it may be possible to increase compliance if patients are provided with this information before undergoing electrophysiological procedures.

Diffusion tensor imaging in carpal tunnel syndrome.

PURPOSE: We aimed to investigate the efficacy of diffusion tensor imaging in the diagnosis of carpal tunnel syndrome and to obtain a quantitative parameter that may contribute to the diagnosis. MATERIALS AND METHODS: The median nerves in 57 wrists of 38 patients diagnosed as carpal tunnel syndrome and 30 wrists of 24 normal subjects were prospectively evaluated with a 3T Philips scanner, using standard 8-channel SENSE head coil. Diffusion tensor imaging was performed using spin echo-echo planar imaging. For anatomical reference, a T1-weighted sequence was acquired. Fractional anisotropy and apparent diffusion coefficient measurements were done focally at the carpal tunnel level and from whole median nerve. RESULTS: In carpal tunnel syndrome patients, both focal carpal tunnel and whole nerve measurements demonstrated statistically significantly lower fractional anisotropy values than normal subjects (P < 0.001). No statistically significant difference was observed in apparent diffusion coefficient measurements. The cut-off value obtained by receiver operator characteristics analysis was 0.554 for focal carpal tunnel fractional anisotropy (sensitivity, 80%; specificity, 80%) and 0.660 for whole nerve fractional anisotropy (sensitivity, 82%; specificity, 80%) measurement. CONCLUSION: Diffusion tensor imaging may contribute to the diagnosis of carpal tunnel syndrome on the basis of fractional anisotropy measurements.

The utility of high b-value DWI in evaluation of ischemic stroke at 3T.

PURPOSE: The utility of DWI with high b-value in ischemic stroke is still unsettled. The purpose of this study is to compare high b-value (3000) and standard b-value (1000) diffusion-weighted images in patients with ischemic stroke at 3T. MATERIALS AND METHODS: 27 patients with acute stroke who were admitted to the hospital during the first 24h after symptom onset were included in this study. All patients had a brain MRI study with stroke protocol including standard (b=1000) DWI and high b-value (b=3000) DWI sequences at 3T MR scanner. Number and localization of the lesions were assessed MR signal intensities (SI), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contrast ratio (CR) and apparent diffusion coefficient (ADC) values of the lesions and normal parenchyma on DWI with b=1000 and b=3000 sequences were measured. RESULTS: All patients with acute stroke revealed hyperintense lesions due to restricted diffusion on DWI with both b-values. However, lesions of restricted diffusion were more conspicuous in b=3000 value DWI than b=1000, and additional 4 ischemic lesions were detected on b=3000 DWI. SNR, CNR, SI and also ADC values in both stroke area and normal parenchyma were lower at b=3000 than the value at b=1000. At b=3000, CR was significantly greater than b=1000 images. CONCLUSIONS: Although quantitative analysis shows higher SI, SNR and CNR values with standard b-value (b=1000) diffusion-weighted imaging, using higher b-value may still be beneficial in detecting additional subtle lesions in patients whose clinical findings are not correlated with standard b-value DWI in stroke.

The analgesic effect of gabapentin as a prophylactic anticonvulsant drug on postcraniotomy pain: a prospective randomized study.

BACKGROUND: Gabapentin is an anticonvulsant drug that has analgesic properties for acute postoperative pain. However, the analgesic effect of gabapentin as an antiepileptic prophylactic drug on patients undergoing craniotomy is unclear. In this study, we evaluated the postoperative effectiveness of gabapentin on acute postoperative pain when it is used for antiepileptic prophylaxis in patients undergoing craniotomy for supratentorial tumor resection. METHODS: Eighty patients undergoing craniotomy for supratentorial tumor resection were randomly assigned into two groups. Patients in Group G (n = 40) received oral gabapentin (3 x 400 mg), and patients in Group P (n = 40) received oral phenytoin (3 x 100 mg) for 7 days before the operation and postoperatively. An identical anesthesia protocol was performed for both the groups. Anesthesia was maintained with propofol and remifentanil infusion. Patient-controlled analgesia with morphine was used, and pain levels were measured. The antiepileptic-related side effects, anesthetic consumption, duration of anesthesia and surgery, tracheal extubation time, postoperative pain scores, morphine consumption, and sedation scores were recorded. RESULTS: Thirty-seven patients in Group G and 38 patients in Group P completed the study. During the preoperative period in Group G, one patient had severe fatigue, one had severe dizziness, and one patient's surgical procedure was changed. The median plasma levels of gabapentin were 34 micromol/mL (range, 23-51 micromol/mL) in 34 patients. In Group P, one patient withdrew from the study preoperatively and one developed transient neurological symptoms postoperatively. The demographic data and mean duration of anesthesia and surgery were similar in both the groups. The total propofol and remifentanil consumption in Group G (1847 +/- 548 mg/3034 +/- 1334 microg) was significantly less than that of Group P (2293 +/- 580 mg/4287 +/- 1282 microg) (P = 0.01). However, tracheal extubation could be done earlier in Group P (4.5 +/- 2 min) than in Group G (16.6 +/- 22 min) (P < 0.001). Pain scores were significantly higher in Group P at 15 min, 30 min, and 1 h (P < 0.001). The total morphine consumption was also significantly higher in Group P (33 +/- 17 mg vs 24 +/- 19 mg) (P = 0.01). The postoperative sedation scores were significantly higher in Group G at 15 min, 30 min, 1 h, and 2 h (P < 0.001). CONCLUSIONS: The administration of gabapentin to patients undergoing craniotomy for supratentorial tumor resection was effective for acute postoperative pain. It also decreased analgesic consumption after surgery. However, it may lead to side effects such as delayed tracheal extubation and increased sedation postoperatively.

Electrodiagnosis of ulnar nerve entrapment at the elbow.

OBJECTIVE: To evaluate the different localizing electrodiagnostic techniques of ulnar nerve entrapment at the elbow (UNE), particularly, comparison of the sensitivities of long segment stimulation across the elbow, versus short segment stimulation. METHODS: Patients who were referred to the Neurophysiology Laboratory of Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey between 2000-2004 with a preliminary diagnosis of UNE were retrospectively evaluated. We compared the sensitivity of studying long segments (8-12 cm) versus short segments (3 cm) for the diagnosis of UNE in 93 limbs. RESULTS: The study group consisted of 55 females and 31 males. Slowing of the conduction velocity (<50 m/sn) across the elbow was recorded in 48.4% of the limbs with long segment studies, and 73% of the limbs with short segment studies. In 82% of cases, an amplitude drop of the compound muscle action potential (CMAP) was also recorded. A CMAP amplitude drop of 10-30% between the wrist and elbow was recorded in 35 limbs (37.6%), while a drop of more than 50% was only recorded in 5 limbs (5.4%). CONCLUSION: Short segment studies are sensitive for the electrodiagnosis of UNE, and although a CMAP amplitude drop is recorded in most patients, an amplitude drop consistent with a conduction block (>50%) is rare.

Spinal accessory nerve monitoring in posterior fossa surgery.

The role of intraoperative monitoring of lower cranial nerves is not well established. In this study, the authors retrospectively analyzed the intraoperative monitoring data and the clinical outcome of the spinal accessory nerve (SAN) in patients who have undergone posterior fossa surgery. SAN was monitored in 19 patients. Subcutaneous needle electrodes were placed in the trapezius, and any abnormal spontaneous activity was documented for duration and amplitude. A bipolar stimulation probe was used for triggered electromyogram, with a maximum stimulation intensity of 3 mA. All patients were clinically evaluated for SAN dysfunction postoperatively 24 hours and 7 days. Neurotonic discharges, lasting between 3 and 90 minutes were seen in 84% of the patients. Continuous discharges lasting longer than 5 minutes were seen in 36% of the patients. The SAN was stimulated in 57.8% of the patients. With clinical examination, none of our patients had postoperative SAN dysfunction. Long lasting dense neurotonic discharges and high stimulation thresholds have been correlated with postoperative facial nerve injury; however, this does seem be true in the case of SAN monitoring. Neurotonic discharges are commonly false-positive and stimulation intensity up to 3 mA can be related with a good outcome. The intraoperative monitoring of SAN may not be valuable as much as facial nerve monitoring.

Does prior aspirin use reduce stroke mortality?

BACKGROUND: Millions of people around the world regularly consume aspirin, but its value in determining stroke severity is still not clear. It has been stated that prior aspirin use might reduce the severity of ischemic stroke by reducing the size of fibrin-platelet emboli or by ameliorating platelet hyperaggregability that occurs in the microcirculation. However there are only few large studies focusing on the early outcome of stroke patients including both ischemic stroke and primary intracerebral hemorrhage patients with prior aspirin therapy. REVIEW SUMMARY: We retrospectively analyzed the medical records of 2509 consecutive stroke patients who were hospitalized in the 2nd Neurology Clinic of Haydarpasa Numune Education and Research Hospital, Istanbul, Turkey, during the period of 1993-2003. We compared the early mortality rates in the patients with prior aspirin use versus the patients without. Of the patients without prior aspirin use, 20.1% died during the first 3 weeks of the stroke, while only 11.5% of the patients with prior aspirin use died during the same period. The difference in early mortality rate between 2 groups was extremely significant (P = 0.0008). Logistic regression analysis indicated that aspirin use was a significant (P < 0.01) and independent predictor of early stroke mortality. CONCLUSION: Daily low dose (100-300 mg) aspirin has a protective effect in reducing the risk of early death in stroke.