Utility of ultrasound-guided near-nerve needle recording for lateral femoral cutaneous sensory nerve conduction study: does it increase reliability compared with surface recording?

INTRODUCTION: The aim of this study was to assess the reliability of a near-nerve needle recording technique in lateral femoral cutaneous nerve (LFCN) sensory nerve conduction studies (NCS). METHODS: Bilateral LFCN sensory nerve action potentials (SNAPs) were recorded from 10 healthy volunteers using surface and near-nerve needle recording electrodes. Absolute amplitudes were compared side-to-side in each subject and between the 2 techniques. RESULTS: Near-nerve needle electrode recording amplitude was significantly higher when compared with surface electrode recording (surface 9 µV, needle 58 µV; P < 0.0001), whereas side-to-side variability did not differ (surface 37%, needle 37%; P = 0.94). CONCLUSIONS: We propose that near-nerve needle recording is a simple technique to employ for clinicians with experience in ultrasound-guided needle placement, especially when evaluation is critical and responses are difficult to obtain. However, given the degree of side-to-side variability in healthy subjects, we recommend caution when interpreting side-to-side differences.

Inflammatory hypertrophic cauda equina following intrathecal neural stem cell injection.

INTRODUCTION: Potential benefit from stem cell treatments has more patients seeking treatment without understanding possible risks. METHODS: We describe a woman who presented with progressive bilateral leg pain, numbness, and gait difficulties. A prior stroke, macular degeneration, osteoarthritis, and depression, led her to receive intrathecal neural stem cell therapy overseas 1 year before onset of symptoms. RESULTS: Imaging showed marked enlargement of lumbosacral roots of the cauda equina, which was not seen before stem cell treatment. Electrodiagnostic studies confirmed chronic multiple lumbosacral radiculopathies. Biopsy of a lumbar dorsal sensory root showed myelinated fiber degeneration and loss, with endoneurial inflammation. The hypertrophic inflammatory cauda equina syndrome was potentially triggered by the prior intrathecal neural stem cell injection. CONCLUSIONS: Safety of intrathecal stem cell treatments is not routinely regulated in overseas stem cell facilities. We wish to bring this potential complication to the attention of health care providers.

Endurance training increases skeletal muscle LKB1 and PGC-1alpha protein abundance: effects of time and intensity.

Recent research suggests that LKB1 is the major AMP-activated protein kinase kinase (AMPKK). Peroxisome-proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) is a master coordinator of mitochondrial biogenesis. Previously we reported that skeletal muscle LKB1 protein increases with endurance training. The purpose of this study was to determine whether training-induced increases in skeletal muscle LKB1 and PGC-1alpha protein exhibit a time course and intensity-dependent response similar to that of citrate synthase. Male Sprague-Dawley rats completed endurance- and interval-training protocols. For endurance training, rats trained for 4, 11, 25, or 53 days. Interval-training rats trained identically to endurance-trained rats, except that after 25 days interval training was combined with endurance training. Time course data were collected from endurance-trained red quadriceps (RQ) after each time point. Interval training data were collected from soleus, RQ, and white quadriceps (WQ) muscle after 53 days only. Mouse protein 25 (MO25) and PGC-1alpha protein increased significantly after 4 days. Increased citrate synthase activity, increased LKB1 protein, and decreased AMPKK activity were found after 11 days. Maximal increases occurred after 4 days for hexokinase II, 25 days for MO25, and 53 days for citrate synthase, LKB1, and PGC-1alpha. In WQ, but not RQ or soleus, interval training had an additive effect to endurance training and induced significant increases in all proteins measured. These results demonstrate that LKB1 and PGC-1alpha protein abundances increase with endurance and interval training similarly to citrate synthase. The increase in LKB1 and PGC-1alpha with endurance and interval training may function to maintain the training-induced increases in mitochondrial mass.