Inter-rater reliability determination for two tests of ulnar nerve conduction across the elbow.

INTRODUCTION: The inter-rater variability in determination of ulnar nerve conduction across the elbow compromises test accuracy. The extent of this variability is unknown. The objective of this study was to determine and compare inter-rater reliability of variables derived from 2 different ulnar nerve conduction studies (NCSs) across the elbow. METHODS: Two investigators performed a standard ulnar NCS and a 6-cm conduction time (Six-Centimeter Conduction Time test, SCCT) on 60 extremities of asymptomatic subjects. In the standard test, below-elbow (BE) and above-elbow (AE) stimulation points were ≥ 10 cm apart, measured along a curved path, to calculate across-elbow NCV. In SCCT, BE and AE were precisely 6 cm apart measured linearly to calculate CTE (conduction time elbow). Inter-rater reliability was assessed by means of intraclass correlation coefficients (ICC). RESULTS: ICC for across-elbow NCV and CTE were 0.726 and 0.801, respectively. CONCLUSIONS: Reliability of CTE and across-elbow NCV are similar. Shorter distances, if measured linearly, can be used to determine across-elbow ulnar nerve conduction. Muscle Nerve 55: 664-668, 2017.

High-resolution ultrasound in combat-related peripheral nerve injuries.

INTRODUCTION: Peripheral nerve injuries (PNI) sustained in combat are typically severe and are frequently associated with marked soft tissue damage, anatomic distortion, and retained metallic fragments. These features complicate clinical and electrodiagnostic assessment and may preclude MRI. METHODS: We describe 4 cases of military personnel who sustained high-velocity gunshot wounds or blasts with metal fragment injuries in which high resolution peripheral nerve ultrasound (US) proved beneficial. RESULTS: In these cases, the clinical and electrodiagnostic exams provided inadequate localization and severity data of the nerve injuries, and MRI was either precluded or provided no additional information. In each case, US disclosed focal nerve segment abnormalities, including regions of focal enlargement and nerve discontinuity with end-bulb neuroma, which guided surgical planning for nerve repair. The findings on US were subsequently confirmed intra-operatively. CONCLUSIONS: High resolution peripheral nerve US is a useful modality in assessment of combat-related PNI. Muscle Nerve, 2016 Muscle Nerve 54: 1139-1144, 2016.

Improving awareness of nonanesthesia-related malignant hyperthermia presentations: a tale of two brothers.

A 30-year-old man developed unexplained rhabdomyolysis, persistently increased creatine kinase and severe debilitating muscle cramps. After a nondiagnostic neurologic evaluation, he was referred for a muscle biopsy, to include histology/histochemistry, a myoglobinuria panel, and a caffeine halothane contracture test. Only the caffeine halothane contracture test was positive, and a subsequent ryanodine receptor type 1 gene evaluation revealed a mutation functionally causative for malignant hyperthermia. His identical twin brother, who was suffering from similar complaints, was found to share the same mutation. They each require oral dantrolene therapy to control symptoms, despite difficulty in identifying health care providers familiar with treating this disorder.

Myasthenia gravis--an unexpected cause of respiratory failure and reversible left ventricular dysfunction after cardiac surgery.

We report a case of postpericardiotomy myasthenia gravis. A 68-year-old male patient without prior history of neuromuscular or autoimmune disorders presented with respiratory failure and severe left ventricular dysfunction four weeks after mitral valve replacement. Markedly elevated acetylcholine receptor antibodies were noted, and the patient responded promptly to immunologic therapy. Awareness of this rare but potentially fatal consequence of cardiac surgery may allow the early institution of specific treatment.

Multiple cranial neuropathies.

Patients presenting with multiple cranial neuropathies are not uncommon in neurologic clinical practice. The evaluation of these patients can often be overwhelming due to the vast and complicated etiologies as well as the potential for devastating neurologic outcomes. Dysfunction of the cranial nerves can occur anywhere in their course from intrinsic brainstem dysfunction to their peripheral courses. The focus of this review will be on the extramedullary causes of multiple cranial neuropathies as discussion of the brainstem syndromes is more relevant when considering intrinsic disorders of the brainstem. The goals are to provide the reader with an overview of those extramedullary conditions that have a predilection for causing multiple cranial nerve palsies. In turn, this will serve to provide a practical and systematic approach to allow for a more targeted diagnostic evaluation of this, often cumbersome, presentation.

Post-traumatic shoulder dystonia in an active duty soldier.

Acquired focal dystonia is often precipitated by minor local traumatic injury, resulting in severe pain and disability. An active duty soldier with shoulder dystonia, after a fall, that responded partially to botulinum toxin A is described. Post-traumatic dystonia as a neurological illness is discussed, with emphasis on mechanisms, precipitating causes, differential diagnosis, and treatment implications for battlefield clinicians.