Jeffrey A. Strakowski

Acute common peroneal neuropathy due to hand positioning in normal labor and delivery.

BACKGROUND: Foot drop has been described as an infrequent complication from common peroneal nerve injury related to external compression and forceful knee flexion while pushing during vaginal delivery. Past recommendations include placing the hands at the posterior thighs rather than the legs to avoid this complication. CASE: A 32-year-old woman developed unilateral foot drop after vaginal delivery. Electromyography was diagnostic for an acute compression neuropathy of the common peroneal nerve above the knee. CONCLUSION: The patients likely mechanism of injury occurred during delivery from external compression by the patients dominant hand to the distal posterior thigh while under epidural anesthesia. Labor and delivery teams should be aware that nerve injury is also possible at the distal thigh with excessive external pressure.

Poster 186 Sonographic Visualization of the Thenar Motor Branch of the Median Nerve: A Cadaveric Validation Study.

Case/Program Description: Thirty-one-year-old woman with chronic right lateral elbow pain for three years was referred to our hospital for surgical treatment after previous standard conservative managements and extracorporeal shock-wave therapy (ESWT) had failed. Tenderness was prominent over the right lateral epicondyle and the pain was aggravated by resisted wrist extension. Laboratory findings were normal. Plain x-ray and T2-weighted fat-suppressed magnetic resonance imaging (MRI) showed the curvilinear calcification around lateral epicondyle of elbow. Numeric rating scale (NRS) was 7 and Roles-Maudsley score (RMS) “poor” grade. The patient received USguided barbotage and additional 3 sessions of ESWT (0.15 mJ/mm, 600 shocks, weekly). Setting: Tertiary care hospital. Results: After US-guided barbotage combined ESWT, pain and tenderness started to dramatically decrease. Two months after, additional three sessions of ESWT were given to reduce residual pain (NRS 3). At 8 months and 12 months follow-up, pain scores were NRS 1 and NRS 0, and RMSs were good and excellent, respectively. Calcific deposits nearly disappeared on X-ray at 8 months follow-up. Discussion: This is the first reported case, to our knowledge, of chronic intractable calcific tendinitis of the common extensor tendon which was successfully treated with US-guided barbotage combined with ESWT. Conclusions: US-guided barbotage combined with ESWT may be a good non-surgical therapeutic option for managements of chronic intractable calcific tendinitis of the common extensor tendon. Level of Evidence: Level V

Is the Combined Sensory (Robinson) Index Routinely Indicated for All Cases of Suspected Carpal Tunnel Syndrome Undergoing Electrodiagnostic Evaluation

M.N. is a 35-year-old otherwise healthy female software engineer with a 2-year history of intermittent right hand numbness that has worsened in the past 2-3 months. She endorses numbness in the hand, worse in the thumb, index, and middle fingers. Typing and driving aggravate her symptoms, and she frequently wakes up at night with numbness in the hand. She also endorses intermittent neck pain that she believes is unrelated and occasional numbness in the forearm. She denies any weakness or history of dropping items. On examination, she had normal strength, sensation, and reflexes in the upper limbs bilaterally. She has a negative Tinnel sign at the wrists and elbows bilaterally, and a negative Spurling Maneuver. She does have a positive Phalen sign at the right wrist. She has not improved with 8 weeks of wearing wrist splints, receiving hand therapy, and undergoing workplace ergonomic upgrades. She presents to you for electrodiagnostic evaluation for suspected carpal tunnel syndrome (CTS) before referral to a hand surgeon. Needle electromyography of the upper limb showed no abnormalities in a 7-muscle radiculopathy screen, which included the abductor pollicis brevis. Motor nerve conduction studies of the median and ulnar nerves were normal. The transpalmar sensory nerve conduction studies of the ulnar and median nerve showed a difference in latency of 0.8 ms, with the median nerve slower than the ulnar nerve. Lawrence Robinson, MD, will argue for the need to complete a full combined sensory index, whereas Jeffrey Strakowski, MD will argue that a full combined sensory index is not needed. Guest Discussants:

Poster 46: Ultrasound Visualization of Torsional Anatomic Changes from External Rotation of the Posterior Shoulder

Disclosures: Nancey Tsai: I Have No Relevant Financial Relationships To Disclose Objective: Assess changes in blink reflex at baseline, at play, and after impact in Division I athletes using novel, non-invasive device. Design: Prospective, non-randomized Setting: Division I college Participants: Athletes Interventions: N/A Main Outcome Measures: 1. Evaluate changes in blink reflex parameters between baseline, at play, and after head impact; 2. Compare data to previously published EMG blink reflex data Results: The baseline latency, differential latency, and duration of the images from the device were compared with those from published EMG literature. The baseline median latency was 51ms (SD 12) compared with the published range of 40-70ms. The differential latency was 4ms (SD 7ms) compared to w12ms in prior publications. The duration measured using the device was 177ms (SD 94) compared to w200ms using EMG data. During active play, the latency was increased latency (P1⁄4 <.001, decreased differential latency (P1⁄4<.017), and fewer oscillations (P+.002). After head-impact or concussive event, there were decreases in latency (P1⁄4<0.017), increased differential latency (P1⁄4<.001), and increased oscillations (P1⁄4<.008). Conclusions: This study demonstrates that the device is a viable tool to obtain fast, objective, quantitative metrics of a blink reflex that has promise as a non-invasive diagnostic assessment of neurological health. Level of Evidence:

Poster 210: Superficial Radial Sensory Neuropathy from Heterotopic Ossification Diagnosed with Dynamic Ultrasound: A Case Report

Disclosures: Gerard Limerick: I Have No Relevant Financial Relationships To Disclose Case/Program Description: The patient presented with chronic right arm pain and decreased range of motion in both elbows (right greater than left) for the last 10 years. The elbows were tender to palpation, with no associated erythema, edema or warmth. Setting: University Hospital Outpatient Clinic Results: The patient was sent for bilateral elbow x rays that demonstrated large single osteochondral bodies posterior to the distal humerus measuring 1.7 cm on the right and 1.4 cm on the left. Diagnostic ultrasound was used to better define these calcifications with relation to the surrounding tissues and demonstrated that the right osteochondral body was 1.4 cm L 1.2 cm W and 3.55 cm proximal to the olecranon while the left osteochondral body was 1.7 cm L 1.33 cm W and 5.37 cm proximal to the olecranon. The patient was sent for a right elbow MRI, as part of further evaluation. However, it could not be completed as the patient was claustrophobic. Discussion: Osseous bodies are typically formed in intra-articular spaces following disruption to the articular surface. This disruption may occur as the result of direct/indirect trauma, or chronic disease processes such as osteoarthritis, Charcot’s disease or synovial chondromatosis. In the case of this patient, the osseous bodies were identified within the muscle fibers, rather than the joint space. Years of repetitive subclinical trauma from the jackhammer vibrations, as opposed to a single inciting event or a classic disease process, likely spurred the development of these bodies. Conclusions: Osseous bodies are usually found in joint spaces where they cause symptoms of pain and reduced range of motion. However, long-term subclinical trauma can cause these bodies to occur within the tendinous structures where they can cause a similar syndrome. Level of Evidence: Level V

Accuracy and Reliability of Peripheral Nerve Diameter Measurement in Long Axis

Disclosures: J. L. Zaremski, No Disclosures: I Have Nothing To Disclose. Objective: Lacrosse forward passing has some joint motion components similar to that of a baseball throw. However, glenohumeral range of motion patterns have not yet been studied in lacrosse players. As high school lacrosse participation increases in in the United States, it is expected that injuries, including shoulder injuries, will increase. We currently understand little about the shoulder range of motion and its relationship to pain and arm dominance in high school lacrosse players. Our objective was to determine the differences in dominant (D) versus non-dominant (ND) shoulder external (ER) and internal (IR) range of motion (ROM), whether ROM is different in presence of shoulder pain. Design: Cross sectional study. Setting: High school lacrosse field. Participants: High school male lacrosse players (N1⁄418; 5.2 1.8 years of play, 14-19 years old). Interventions: Not Applicable. Main Outcome Measures: D and ND ER and IR of shoulder. Results or Clinical Course: Passive ER and IR in the D shoulder were 98.4 and 60.4 , respectively (total arc of motion 158.8 ). Passive ER and IR in the ND shoulder were 96.1 and 64.8 , respectively (total arc of motion 160.9 ). In three players with shoulder pain (average pain severity 1⁄4 3 points out of 10), ER was less than in players without pain (ND ER1⁄482 versus 98.9 , p 1⁄4.026). D ER with pain was 95.7 compared to 99 in ND ER without pain (p>.05). Conclusions: During an overhead lacrosse shot, there was an increase in D shoulder ER while maintaining total arc of motion. This pattern was similar to that reported in the baseball throwing literature. Players with shoulder pain had a lower ER than those without pain. These data infer that a pre-participation examination period and pre-habilitation programs to address ROM and strength asymmetries might be useful to prevent shoulder injury in lacrosse.

Poster 96: Ultrasonography to Assess an Isolated Sural Neuropathy Due to a Ganglion Cyst: A Case Report

and lower limb delayed motor distal latencies, slow conduction velocities, low compound muscle action potential (CMAP) amplitudes and universal absence of sensory action potentials (SNAP). Electromyography (EMG)-added followups at 2 and 4 months: left peroneal and tibial CMAP amplitude major new drop in first, total loss in second, with no response in foot/toes dorsiflexors to peroneal nerve, very small response in plantarflexors to tibial nerve knee level, and direct to muscles up-to 500s duration supramaximal stimulations. Findings static in remaining nerves. Initial EMG: marked proximal and distal denervation potentials in both legs, somewhat worse proximally and on the left, reduced but still fair number motor unit (MU) recruitment; normal in arms. Second EMG: persistent florid denervation activity, very few or no MU recruitment in left leg, in contrast to denervation potentials decline and MU recruitment gain in the right. Discussion: WNV neuropathy is known as an asymmetric motor neuronopathy of variable distribution and recovery course quite like polio. Also reported, a demyelinating variant. This case may be the first with electrodiagnostic evidence of one limb MU loss progression over 4 months, while expected gradual recovery is proceeding in contralateral one. Given its one-extremity limitation and deterioration speed, diabetes should be playing no role, while explaining the absent SNAPs. Conclusions: WNV neuropathy can show localized subacute progression.

Poster 37: Sural neuropathy from chronic leg crossing: a case report1

Abstract Setting: Outpatient electromyography clinic. Patient: A 33-year-old male computer programmer. Case Description: The patient presented with a 6-month history of pain in the right calf with numbness affecting the right lateral aspect of the ankle and foot. He denied history of trauma or known precipitating event. He had no history of systemic illness. He displayed decreased sensation in the right sural nerve distribution, but otherwise had a normal physical examination. An electrodiagnostic study was performed. The right sural sensory nerve action potential (SNAP) displayed a distal latency of 3.8ms, but an amplitude of 6μV at the ankle and 3μV near the knee. The nerve conduction velocity (NCV) in the leg was mildly slowed at 40m/s. The unaffected left sural SNAP had a 3.8ms distal latency and was 17μV at the ankle and 10μV near the knee, with an NCV of 52m/s. The remainder of the electrodiagnostic study was unremarkable. Further inquiry revealed that the patient would sit with his feet propped and legs crossed, right over left, on his desk for long periods of time. After discontinuing this activity, he returned 3 months later with no significant symptoms and with improvement in his sural nerve conduction study. Discussion: The sural nerve is commonly studied in electrodiagnostic evaluations, however, mononeuropathies are rare. Most sural abnormalities encountered are related to manifestations of systemic illness and most mono-neuropathies are related to penetration trauma. To our knowledge, localized compressive neuropathy due to leg crossing has not been reported in the literature. Conclusion: Clinicians should be aware of this potential mechanism of sural compressive neuropathy in the area of the posterior calf. Nerve conduction studies, with stimulation both proximal and distal to this site, can be helpful with the assessment.