Ulnar neuropathy at the elbow.

Among the entrapment neuropathies, ulnar neuropathy at the elbow is second only to carpal tunnel syndrome in frequency; however, diagnosis and management are considerably more difficult in ulnar lesions than in carpal tunnel syndrome. Electrodiagnosis is the most important means of identifying and localizing ulnar neuropathies at the elbow, but even sophisticated techniques may sometimes fail to confirm diagnosis and localization preoperatively. Mild lesions are best managed conservatively. More severe lesions require surgical intervention. Simple decompression is now preferred over transposition in the majority of cases, but careful correlation of electrodiagnostic abnormalities and findings at surgery are necessary to ensure optimal outcome.

Pseudomeningoencephalitic presentation of pediatric Guillain-Barré syndrome.

Guillain-Barré syndrome is an acute, autoimmune polyradiculoneuropathy that improves with immune-modulating treatment if instituted early in the illness. Preliminary diagnosis relies on the clinician's recognition of the typical symptoms and signs as supporting evidence of the illness, such as nerve conduction studies, which may not be available emergently. We report eight children with Guillain-Barré syndrome in whom the initial presentation was atypical and suggested a primary central nervous system illness. In these patients, the predominant clinical symptoms included drowsiness, headache, irritability, and meningismus, although the classic features of Guillain-Barré syndrome (weakness, hyporeflexia) were also present. The atypical presentation caused delay in diagnosis in some cases. It is important to recognize this variant of pediatric Guillain-Barré syndrome to ensure expeditious diagnosis and treatment.

Guillain-Barré syndrome in children: clinical course, electrodiagnosis, and prognosis.

The electrodiagnostic features of acute childhood Guillain-Barré syndrome (GBS) have not been distinguished from those in the adult. We report nerve conduction and electromyographic data from 23 children. Sixty-one percent (14 of 23) fulfilled strict electrodiagnostic criteria for a demyelinating neuropathy, and the remainder demonstrated demyelination in at least one nerve. Reduced compound muscle action potential (CMAP) amplitude was the most common finding overall. Children less than 10 years old demonstrated significantly greater slowing of motor CV than children greater than 10 years old. Electrodiagnostic criteria associated with poor outcome (low mean CMAP and fibrillation potentials) in previous studies, primarily of adult patients, occurred in 39% (9 of 23 children). All patients on whom follow-up data were obtained recovered without residual disability. We conclude that electrodiagnostic prognostic indicators identified in general series of GBS may not apply to children.

Reducing intersubject variability in motor unit number estimation.

Motor unit number estimation (MUNE) attempts to directly assess the number of functioning motor units present in a muscle. It is an important addition to the electrodiagnostic evaluation; however, both intrasubject and intersubject reliability must be minimized for this technique to be clinically useful. A number of MUNE techniques have been developed. We propose a change in the way of calculating the MUNE, using the statistical technique described by Daube, and show that this modification reduces intersubject variability and improves test-retest reliability in normal subjects.