Stimulus duration and pain in nerve conduction studies

Introduction: It is generally believed that a shorter stimulus duration is less painful in nerve conduction studies (NCS). We investigated whether a shorter duration stimulus is actually less painful when the same physiological effect, such as supramaximal stimulation, is achieved in motor NCS. Methods: The tibial nerve was stimulated at the ankle in 14 control subjects and the median nerve at the wrist in 20 subjects. Two stimulations of different durations were given blindly, and each subject was asked to report which was more painful. Results: A 0.2‐ms‐duration stimulus was significantly less painful than those with longer or shorter durations for the tibial nerve. For the median nerve, the 0.05‐ and 0.2‐ms durations were equally less painful than a 1‐ms‐duration stimulus. Conclusions: As a common duration for motor NCS, 0.2 ms seems appropriate, because the tibial nerve stimulation was more painful than the median nerve stimulation. Muscle Nerve, 2013     

Whole plantar nerve conduction study with disposable strip electrodes

Introduction: A new method to evaluate whole plantar nerve conduction with disposable strip electrodes (DSEs) is described. Methods: Whole plantar compound nerve action potentials (CNAPs) were recorded at the ankle. DSEs were attached to the sole for simultaneous stimulation of medial and lateral plantar nerves. We also conducted medial plantar nerve conduction studies using an established method and compared the findings. Results: Whole plantar CNAPs were recorded bilaterally from 32 healthy volunteers. Mean baseline to peak amplitude for CNAPs was 26.9 ± 11.8 μV, and mean maximum conduction velocity was 65.8 ± 8.3 m/s. The mean amplitude of CNAPs obtained by our method was 58.2% higher than that of CNAPs obtained by the Saeed method (26.9 μV vs. 17.0 μV; P < 0.0001). Conclusions: The higher mean amplitude of whole plantar CNAPs obtained by our method suggests that it enables CNAPs to be obtained easily, even in elderly people. Muscle Nerve 53: 209–213, 2016     

Recommendations regarding the requirements and applications for long-term recordings in epilepsy

The purpose of this paper is to update the state of knowledge with respect to long-term monitoring (LTM) in epilepsy and to formulate recommendations regarding the application of LTM in clinical practice. LTM is an established technique in use both in a hospital setting and, increasingly, in an ambulatory and more recently in a community-based setting. There has been sufficient evidence to substantiate the claim that LTM is of crucial importance in documenting electroclinical correlations both in epilepsy and in paroxysmally occurring behavioral changes often mistaken for epilepsy. Internationally recognized neurophysiological equipment standards, data acquisition and data transfer protocols and widely accepted safety standards have made widespread access to LTM facilities in epilepsy possible. Recommendations on efficient and effective use of resources as well as regarding training and competencies for personnel involved in LTM in epilepsy have been formulated. The DMC Neurophysiology Subcommittee of the ILAE recommends use of hospital-based LTM in the documentation of seizures including its application for assessing seizure type and frequency, in the evaluation of status epilepticus, in noninvasive and invasive video/EEG investigations for epilepsy surgery and for the differential diagnosis between epilepsy and paroxysmally occurring nonepileptic conditions, in children and in adults. Ambulatory outpatient and community-based LTM may be used as a substitute for inpatient LTM in cases where the latter is not cost-effective or feasible or when activation procedures aimed at increasing seizure yield are not indicated. However, outpatient ambulatory monitoring may be less informative than is inpatient monitoring in some cases because: (1) reduction of medication to provoke seizures may not be safe as an outpatient; (2) faulty electrode contacts cannot quickly be noticed and repaired; (3) the patient may move out of video surveillance; and (4) duration of ambulatory monitoring can be limited by technical constraints.     

Variations in the distal branches of the superficial fibular sensory nerve

Introduction: We evaluated anatomic variations of distal branches of the superficial fibular sensory nerve electrophysiologically. Methods: Orthodromic nerve conduction studies (NCS) of the first and third branches (M‐I, M‐III) of the medial dorsal cutaneous nerve and the fourth and fifth branches (I‐IV, I‐V) of the intermediate dorsal cutaneous nerve (IDCN) were performed. To find anomalous innervations from the dorsal sural nerve (DSN) in the IDCN territory, NCS of the fourth and fifth branches (S‐IV, S‐V) of the DSN were also performed. Results: All sensory nerve action potentials (SNAPs) of M‐I and M‐III could be obtained bilaterally from 31 healthy Japanese volunteers. SNAPs of I‐IV and I‐V were recordable in 85.5% and 43.5% of feet, respectively. Anomalous innervations from the DSN were confirmed in 71.0% of S‐IV and 93.5% of S‐V. Conclusion: These results suggest that anatomical variations in the IDCN territory are very frequent in Japanese subjects. Muscle Nerve 55 : 74–76, 2017     

Pre‐close technique of percutaneous closure for delayed hemostasis of large‐bore femoral sheaths

Advancement of coronary interventions and portable hemodynamic device requires placement of large bore sheaths. Access for large caliber sheaths, its placement, maintenance, and hemostasis is very challenging and one of the key ailments for successful procedures. Traditional hemostasis method is manual compression, which is unattractive due to its own limitations and subsequent complications. Single closure device for sheath size larger than 8 French (Fr) is not available. We performed retrospective analysis of large cohort of patients with 13, 14 Fr sheaths (Impella device [ABIOMED]) percutaneous closure with the use of two Perclose devices. Two perclose devices were placed in a “Preclose” fashion and hemostasis was obtained few days later once hemodynamic support was weaned off by deployment of perclose sutures.