Diagnosing ulnar neuropathy at the elbow using magnetic resonance neurography.

INTRODUCTION: Early diagnosis of ulnar neuropathy at the elbow is important. Magnetic resonance neurography (MRN) images peripheral nerves. We evaluated the usefulness of elbow MRN in diagnosing ulnar neuropathy at the elbow. METHODS: The MR neurograms of 21 patients with ulnar neuropathy were reviewed retrospectively. MRN was performed prospectively on 10 normal volunteers. The MR neurograms included axial T1 and axial T2 fat-saturated and/or axial STIR sequences. The sensitivity and specificity of MRN in detecting ulnar neuropathy were determined. RESULTS: The mean ulnar nerve size in the symptomatic and normal groups was 0.12 and 0.06 cm(2) (P < 0.001). The mean relative signal intensity in the symptomatic and normal groups was 2.7 and 1.4 (P < 0.01). When using a size of 0.08 cm(2), sensitivity was 95% and specificity was 80%. DISCUSSION: Ulnar nerve size and signal intensity were greater in patients with ulnar neuropathy. MRN is a useful test in evaluating ulnar neuropathy at the elbow.

Neurohospitalists: an emerging model for inpatient neurological care.

Over the past decade, the hospitalist model has become a dominant system for the delivery of general adult and pediatric inpatient care. Similar forces, including national mandates to improve safety and quality and intense pressure to safely reduce length of hospital stays, that led to the remarkable growth of hospitalist medicine are now exerting pressure on neurologists. A neurohospitalist model, in which inpatient neurology specialists deliver high-quality and efficient care to neurology patients, is emerging to meet these challenges. Benefits of this system may include more frequent, timely neurology consultations in the hospital and emergency department, as well as improved quality of inpatient neurological education for residents and medical students. Challenges will involve defining the relationship of neurohospitalists with primary stroke centers, the economic feasibility of such neurohospitalist systems, and how to train members of this new field. A neurohospitalist model of care is an emerging idea in neurology that would overcome many regulatory, educational, and economic challenges facing neurologists; further research is needed to gauge the effects of this innovative approach.

Predicting success: What medical student measures predict resident performance in neurology?

OBJECTIVE: Many medical school metrics are used by residency programs to differentiate residency applicants. The importance of each metric in the field of neurology is unclear. MATERIALS AND METHODS: This is a single-site retrospective evaluation of characteristics that predict resident quality. Several measures from all 57 adult neurology residents over 8 years were obtained including Step I scores, college and medical school rankings, in-service training examination scores, advanced degrees, and number of publications during residency. Two program directors, blinded to these data and each other's ratings, rated the quality of all residents at the end of the residency. The data were then anonymized for all analyses. RESULTS: There was no significant relationship between Step I scores and resident quality, though Step I scores correlated significantly with in-service training examination scores. Medical students with PhDs did not perform differently in terms of resident quality, number of publications in residency, or in-service training examination scores. Resident quality was correlated with the ranking of each applicant's undergraduate college, but not the ranking of their medical school. CONCLUSIONS: While Step I is used by many residency programs in ranking potential residents, it does not correlate with overall resident quality, although Step I scores may predict success on future standardized medical examinations. Students with PhDs do not differ from other residents across several metrics. Applicants from highly selective colleges, though not highly selective medical schools, had significantly higher quality ratings. Further research is needed to determine characteristics of medical students that predict performance during neurology residency.

A comparison of ultrasonographic and electrophysiologic 'inching' in ulnar neuropathy at the elbow.

OBJECTIVE: The present study aimed to clarify the relationship between structural ulnar nerve changes and electrophysiological nerve dysfunction in patients with ulnar neuropathy at the elbow (UNE). METHODS: High-resolution ultrasonography of the ulnar nerve was performed on 17 limbs with clinically and electrophysiologically confirmed UNE, and 52 control subjects at four standardised sites proximal and distal to the medial epicondyle (P2, P1, D1, D2), corresponding to segments of ulnar short-segment nerve conduction studies ("inching studies"). RESULTS: Ulnar nerve cross-sectional area (CSA) and hypoechoic fraction were significantly increased in patients with UNE immediately distal (D1) and proximal (P1) to the medial epicondyle (p<0.01). In patients with UNE, hypoechoic fraction was similar in asymptomatic and symptomatic limbs. Motor nerve conduction velocity across the elbow correlated with CSAmax and the maximum hypoechoic fraction (R=0.6, p<0.05). CSA and hypoechoic fraction of individual segments did not correlate with corresponding latencies on inching studies, but latencies across the D1 segment correlated with CSA at P1 (R=0.80, p<0.0001) and D2 (R=0.65, p<0.01). CONCLUSIONS: Sonographic abnormalities in UNE may not be maximal at the site of electrophysiological nerve dysfunction. SIGNIFICANCE: Sonographic abnormalities may reflect secondary pathophysiological changes in segments adjacent to regions of nerve compression.

International electives in neurology training: a survey of US and Canadian program directors.

OBJECTIVE: To ascertain the current status of global health training and humanitarian relief opportunities in US and Canadian postgraduate neurology programs. BACKGROUND: There is a growing interest among North American trainees to pursue medical electives in low- and middle-income countries. Such training opportunities provide many educational and humanitarian benefits but also pose several challenges related to organization, human resources, funding, and trainee and patient safety. The current support and engagement of neurology postgraduate training programs for trainees to pursue international rotations is unknown. METHODS: A survey was distributed to all program directors in the United States and Canada (December 2012-February 2013) through the American Academy of Neurology to assess the training opportunities, institutional partnerships, and support available for international neurology electives. RESULTS: Approximately half of responding programs (53%) allow residents to pursue global health-related electives, and 11% reported that at least 1 trainee participated in humanitarian relief during training (survey response rate 61%, 143/234 program directors). Canadian programs were more likely to allow residents to pursue international electives than US programs (10/11, 91% vs 65/129, 50%, p = 0.023). The number of trainees participating in international electives was low: 0%-9% of residents (55% of programs) and 10%-19% of residents (21% of programs). Lack of funding was the most commonly cited reason for residents not participating in global health electives. If funding was available, 93% of program directors stated there would be time for residents to participate. Most program directors (75%) were interested in further information on global health electives. CONCLUSIONS: In spite of high perceived interest, only half of US neurology training programs include international electives, mostly due to a reported lack of funding. By contrast, the majority of Canadian programs that responded allow international electives, likely due to clearer guidelines from the Royal College of Physicians and Surgeons of Canada compared to the Accreditation Council of Graduate Medical Education. However, the number of both Canadian and US neurology trainees venturing abroad remains a minority. Most program directors are interested in learning more information related to global health electives for neurology residents.

Dual reinnervation of biceps muscle after side-to-side anastomosis of an intact median nerve and a damaged musculocutaneous nerve.

Traumatic peripheral nerve injury can lead to significant long-term disability for previously healthy persons. Damaged nerve trunks have been traditionally repaired using cable grafts, but nerve transfer or neurotization procedures have become increasingly popular because the axonal regrowth distances are much shorter. These techniques sacrifice the existing nerve pathway, so muscle reinnervation depends entirely on the success of the repair. Providing a supplemental source of axons from an adjacent intact nerve by using side-to-side anastomosis might reinnervate the target muscle without compromising the function of the donor nerve. The authors report a case of biceps muscle reinnervation after side-to-side anastomosis of an intact median nerve to a damaged musculocutaneous nerve. The patient was a 34-year-old man who had sustained traumatic injury primarily to the right upper and middle trunks of the brachial plexus. At 9 months after the injury, because of persistent weakness, the severely damaged upper trunk of the brachial plexus was repaired with an end-to-end graft. When 8 months later biceps function had not recovered, the patient underwent side-to-side anastomosis of the intact median nerve to the adjacent distal musculocutaneous nerve via epineural windows. By 9 months after the second surgery, biceps muscle function had returned clinically and electrodiagnostically. Postoperative electromyographic and nerve conduction studies confirmed that the biceps muscle was being reinnervated partly by donor axons from the healthy median nerve and partly by the recovering musculocutaneous nerve. This case demonstrates that side-to-side anastomosis of an intact median to an injured musculocutaneous nerve can provide dual reinnervation of the biceps muscle while minimizing injury to both donor and recipient nerves.

Residency training: developing a program of quality and safety to train resident neurologists for the future.

Attention to quality and safety metrics is increasingly important for all physicians in practice due to mandates by governmental organizations, insurers, the public, and accreditation bodies. Neurology resident trainees need to acquire these skills, but little research in and outside of neurology provides guidance as to how to teach these important concepts. In the setting of new requirements mandating that training programs address these topics, we propose a number of strategies that can be implemented immediately in neurology residency training programs and call for increased investigation and sharing of best practices in order to adequately prepare neurology residents for the current and future environment of practice.

Magnetic resonance neurography for the evaluation of peripheral nerve, brachial plexus, and nerve root disorders.

OBJECT: Treatment of spinal and peripheral nerve lesions relies on localization of the pathology by the use of neurological examination, spinal MR imaging and electromyography (EMG)/nerve conduction studies (NCSs). Magnetic resonance neurography (MRN) is a novel imaging technique recently developed for direct imaging of spinal and peripheral nerves. In this study, the authors analyzed the role of MRN in the evaluation of spinal and peripheral nerve lesions. METHODS: Imaging studies, medical records, and EMG/NCS results were analyzed retrospectively in a consecutive series of 191 patients who underwent MRN for spinal and peripheral nerve disorders at the University of California, San Francisco between March 1999 and February 2005. Ninety-one (47.6%) of these patients also underwent EMG/NCS studies. RESULTS: In those who underwent both MRN and EMG/NCS, MRN provided the same or additional diagnostic information 32 and 45% of patients, respectively. Magnetic resonance neurograms were obtained at a median of 12 months after the onset of symptoms. The utility of MRN correlated with the interval between the onset of symptoms to MRN. Twelve patients underwent repeated MRN for serial evaluation. The decrease in abnormal signal detected on subsequent MRN correlated with time from onset of symptoms and the time interval between MRN, but not with resolution of symptoms. Twenty-one patients underwent MRN postoperatively to assess persistent, recurrent, or new symptoms; of these 3 (14.3%) required a subsequent surgery. CONCLUSIONS: Magnetic resonance neurography is a valuable adjunct to conventional MR imaging and EMG/NCS in the evaluation and localization of nerve root, brachial plexus, and peripheral nerve lesions. The authors found that MRN is indicated in patients: 1) in whom EMG and traditional MR imaging are inconclusive; 2) who present with brachial plexopathy who have previously received radiation therapy to the brachial plexus region; 3) who present with brachial plexopathy and have systemic tumors; and 4) in patients under consideration for surgery for peripheral nerve lesions or after trauma. Magnetic resonance neurography is limited by the size of the nerve trunk imaged and the timing of the study.

T-cell lymphoproliferative disorder following mycophenolate treatment for myasthenia gravis.

Immunosuppressive therapies are critical in the management of numerous conditions including myasthenia gravis. Mycophenolate mofetil is a widely used, oral immunosuppressive agent that is considered to have few adverse effects compared with similar drugs. We report the case of a patient who developed T-cell lymphoproliferative lesions following long-term treatment with mycophenolate mofetil and prednisone for myasthenia gravis. The lesions resolved following cessation of the treatment. This case highlights a serious complication of a commonly used drug.

Myasthenia gravis: diagnostic mimics.

The clinical hallmark of myasthenia gravis (MG) is fluctuating, painless weakness of muscles that most often affect extraocular, lower bulbar, or limb musculature. Predicting the probability of successful treatment for the patient assumes that the physician has made an accurate diagnosis. In this review, the practical differential diagnosis of MG is reviewed from the perspective of conditions (at presentation of symptoms and signs) that may mimic the disorder. The differential diagnosis includes disorders that limit eye movements (with or without associated diplopia), cause false-positive laboratory studies, and mimic MG but have normal eye movements. The differential diagnosis includes disorders that affect the upper brainstem, cranial nerves, neuromuscular junction, muscles, or local orbit anatomy. Nonneurological systemic diseases (i.e., encephalopathy, sepsis) can produce fluctuating ptosis or eye movements that can occasionally be confused with MG. Although MG is considered often in the differential diagnosis of weakness or fatigue symptoms that lack a correlate on neurological examination (subjective fatigue, breakaway weakness, chronic fatigue syndrome), MG is almost never found.