Effect of Botulinum Toxin Injection and Extracorporeal Shock Wave Therapy on Nerve Regeneration in Rats with Experimentally Induced Sciatic Nerve Injury.

This study was designed to compare the roles of botulinum neurotoxin A (BoNT/A) and extracorporeal shock wave therapy (ESWT) in promoting the functional recovery and regeneration of injured peripheral nerves. A total of 45 six-week-old rats with sciatic nerve injury were randomly divided into two experimental groups and one control group. The experimental groups received a single session of intranerve BoNT/A or ESWT immediately after a nerve-crushing injury. The control group was not exposed to any treatment. Differentiation of Schwann cells and axonal sprouting were observed through immunofluorescence staining, ELISA, real-time PCR, and Western blot at 3, 6, and 10 weeks post-nerve injury. For clinical assessment, serial sciatic functional index analysis and electrophysiological studies were performed. A higher expression of GFAP and S100ß was detected in injured nerves treated with BoNT/A or ESWT. The levels of GAP43, ATF3, and NF200 associated with axonal regeneration in the experimental groups were also significantly higher than in the control group. The motor functional improvement occurred after 7 weeks of clinical observation following BoNT/A and ESWT. Compared with the control group, the amplitude of the compound muscle action potential in the experimental groups was significantly higher from 6 to 10 weeks. Collectively, these findings indicate that BoNT/A and ESWT similarly induced the activation of Schwann cells with the axonal regeneration of and functional improvement in the injured nerve.

Association Between Latency of Dermatomal Sensory-Evoked Potentials and Quantitative Radiologic Findings of Narrowing in Lumbar Spinal Stenosis.

OBJECTIVE: To identify the difference of quantitative radiologic stenosis between a normal latency group and an abnormal latency group, and to investigate the association of dermatomal somatosensory-evoked potential (DSEP) with magnetic resonance imaging (MRI) findings of narrowing in patients with lumbar spinal stenosis (LSS). METHODS: We retrospectively reviewed the clinical records and P40 latencies of L5 DSEP of 40 patients with unilateral symptoms of LSS at the L4-5 disc level. Quantitative assessments of stenosis in lumbar spine MRI were performed with measurements of the anteroposterior diameter (APD), cross-sectional area (CSA) of the dural sac, ligamentous interfacet distance (LID), CSA of the neural foramen (CSA-NF), and subarticular zone width. Analyses were conducted through comparisons of radiologic severity between the normal and abnormal latency groups and correlation between radiologic severity of stenosis and latency of DSEP in absolute (APD <10 mm) and relative (APD <13 mm) stenosis. RESULTS: The radiologic severities of lumbar stenosis were not significantly different between the normal and abnormal latency groups. In absolute and relative stenosis, latency showed a significant negative correlation with APD (r=-0.539, r=-0.426) and LID (r=-0.459, r=-0.494). In patients with relative stenosis, a weak significant positive correlation was found between latency and CSA-NF (r=0.371, p=0.048). LID was the only significant factor for latency (ß=-0.930, p=0.011). CONCLUSION: The normal and abnormal DSEP groups showed no significant differences inradiologic severity. The latency of DSEP had a negative correlation with the severity of central stenosis, and LID was an influencing factor.

Tarlov Cysts Misdiagnosed as Adnexal Masses in Pelvic Sonography: A Literature Review.

Introduction: A Tarlov cyst (TC) is a perineural cyst filled with cerebrospinal fluid that originates from the dorsal ganglion or the spinal posterior nerve root. TCs are usually asymptomatic and incidentally found in the sacral region. Endopelvic extension of TCs is uncommon and can be misdiagnosed as an adnexal mass on gynecological ultrasound imaging. Methods: We performed a search for all clinical studies of TCs that mimicked adnexal masses that had been published through October 12, 2020. We placed no restrictions on language or year of publication in our search, and we performed searches with the following keywords: perineural cyst, Tarlov cyst, sclerotherapy, management, and prognosis. We included all misdiagnosed cases or cases considered as adnexal masses on pelvic sonography. Results: We identified 21 cases of TCs mimicking adnexal masses and conducted a comprehensive analysis of these 21 cases to assess the epidemiology, symptoms, initial diagnoses, provisional ultrasound diagnoses, confirmative modalities, sizes, locations, treatments, and outcomes. The 21 cases included 16 symptomatic cases (76%) and 5 cases with incidental findings (24%), and the average patient age was 41.3 years. The initial diagnosis was performed with ultrasonography in all cases. The most frequent misdiagnosis was unspecified adnexal mass. Confirmative diagnostic modalities were MRI only (67%), CT only (5%), and both MRI and CT (28%). Treatments were surgery (33%), conservative treatment (19%), percutaneous intervention (5%), and alcohol sclerotherapy (5%). In two symptomatic cases misdiagnosed as pelvic masses, cystectomy was performed and leakage of cerebrospinal fluid occurred, necessitating repair of the leak. In one of the asymptomatic patients, cauda equina syndrome occurred after alcohol sclerotherapy for misdiagnosed TC. However, the patient improved with no neurologic deficit after 18 months of conservative treatment. Conclusion: The possibility of large TCs should be considered when assessing adnexal masses in sonography. Since TCs can masquerade as pelvic masses, they should be considered if the mass appears tubular/cystic or multilocular/multiseptate, does not move with respiration, and originates from the sacrum in sonography with or without neurologic symptoms. Accurate diagnosis can prevent medical mismanagement and reduce patient discomfort.