Review of the Diagnostic Challenges of Lambert-Eaton Syndrome Revealed Through Three Case Reports.

Lambert-Eaton syndrome (LES) is a rare immune-mediated disorder characterized by proximal leg weakness, autonomic symptoms and hypoactive tendon reflexes. The paraneoplastic form is associated with small-cell lung cancer in 50-60% of cases, whereas the remaining cases are found in younger adults with a higher likelihood of coexisting autoimmune disease. The early recognition of LES is crucial for improving clinical outcomes but remains a major challenge.

Proficiency of nerve conduction using standard methods and reference values (Cl. NPhys Trial 4).

Introduction: The Cl. NPhys Trial 3 showed that attributes of nerve conduction (NC) were without significant intraobserver differences, although there were significant interobserver differences.

Methods: Trial 4 tested whether use of written instructions and pretrial agreement on techniques and use of standard reference values, diagnostic percentile values, or broader categorization of abnormality could reduce significant interobserver disagreement and improve agreement among clinical neurophysiologists.

A trial of proficiency of nerve conduction: greater standardization still needed.

Introduction: The aim of this study was to test the proficiency (accuracy among evaluators) of measured attributes of nerve conduction (NC).

Methods: Expert clinical neurophysiologists, without instruction or consensus development, from 4 different medical centers, independently assessed 8 attributes of NC in 24 patients with diabetes mellitus (DM) on consecutive days.

Results: No significant intraobserver differences between days 1 and 2 were found, but significant interobserver differences were seen.

"Unequivocally Abnormal" vs "Usual" Signs and Symptoms for Proficient Diagnosis of Diabetic Polyneuropathy: Cl vs N Phys Trial.

OBJECTIVE To repeat the Clinical vs Neurophysiology (Cl vs N Phys) trial using "unequivocally abnormal" signs and symptoms (Trial 2) compared with the earlier trial (Trial 1), which used "usual" signs and symptoms. DESIGN Standard and referenced nerve conduction abnormalities were used in both Trials 1 and 2 as the standard criterion indicative of diabetic sensorimotor polyneuropathy. Physician proficiency (accuracy among evaluators) was compared between Trials 1 and 2.

Critical illness polyneuropathy and myopathy: a major cause of muscle weakness and paralysis.

Critical illness polyneuropathy (CIP) and myopathy (CIM) are complications of critical illness that present with muscle weakness and failure to wean from the ventilator. In addition to prolonging mechanical ventilation and hospitalisation, CIP and CIM increase hospital mortality in patients who are critically ill and cause chronic disability in survivors of critical illness. Structural changes associated with CIP and CIM include axonal nerve degeneration, muscle myosin loss, and muscle necrosis.

Guillain-Barre syndrome following cardiac surgery. Difficult diagnosis in the intensive care unit.

Weakness of limb and respiratory muscles developing in the course of treatment in the intensive care unit (ICU) is commonly due to critical illness polyneuropathy, a complication of sepsis, or critical illness myopathy, a complication of the use of neuromuscular blocking agents and steroids. Guillain-Barre syndrome may rarely occur in this setting. We report 2 patients identified in our ICU in the last 20 years.

Signs and symptoms versus nerve conduction studies to diagnose diabetic sensorimotor polyneuropathy: Cl vs. NPhys trial.

The purpose was to test whether physicians can validly and reproducibly diagnose diabetic sensorimotor polyneuropathy (DSPN). Twelve physicians assessed 24 patients with diabetes mellitus (DM) on consecutive days (576 examinations) with physical features and voice disguised. Results were compared to gold standard 75% group diagnosis (dx) and a nerve conduction score (Sigma5 NC nds).

Brief review: Nondepolarizing neuromuscular blocking drugs and critical illness myopathy.

Purpose: Critically-ill patients who receive nondepolarizing neuromuscular blocking drugs (NMBDs) may be at risk of developing profound muscle weakness that may last for months after the NMBD is discontinued, especially when large cumulative doses of NMBDs and corticosteroids are co-administered to septic, mechanically ventilated patients. This review focuses on the etiology and clinical features of critical illness myopathy (CIM), summarizes specific risk factors for its development, and discusses strategies that might be used to attenuate or even prevent the development of this potentially devastating syndrome.

Clinical Features: The etiology of CIM is unknown.

Neuromuscular manifestations of critical illness.

Critical illness, more precisely defined as the systemic inflammatory response syndrome (SIRS), occurs in 20%-50% of patients who have been on mechanical ventilation for more than 1 week in an intensive care unit. Critical illness polyneuropathy (CIP) and myopathy (CIM), singly or in combination, occur commonly in these patients and present as limb weakness and difficulty in weaning from the ventilator. Critical illness myopathy can be subdivided into thick-filament (myosin) loss, cachectic myopathy, acute rhabdomyolysis, and acute necrotizing myopathy of intensive care.

Dyspnea as the predominant manifestation of bilateral phrenic neuropathy.

Phrenic neuropathy associated with brachial neuritis has been well described; however, bilateral phrenic neuropathy with minimal or no involvement of the brachial plexus has not. We review the clinical features, as well as the results of radiographic studies, pulmonary function tests, and electrodiagnostic studies, of 3 patients in whom dyspnea was the presenting manifestation of bilateral phrenic neuropathy. All 3 patients had acute-onset dyspnea, which led to consideration of a pulmonary or cardiac etiology.

Cajal's contribution to the neurology of breathing.

Cajal, through his pioneering investigations, was able to characterize the location and connections of several brainstem nuclei. This, coupled with previous investigations by others, allowed him to formulate a concept of the microscopic anatomy of automatic respiration.

Genotype/Phenotype Correlations in X-Linked Dominant Charcot-Marie-Tooth Disease.

We have studied the relationship between genotype, clinical phenotype, and pathology in 13 families with dominant X-linked Charcot-Marie-Tooth (CMT) neuropathy. Connexin32 (Cx32) gene mutations were spread throughout the coding region and included eight missense mutations, one 8-bp deletion/4-bp insertion frame shifting mutation, two nonsense mutations, and one deletion of the entire coding sequence. One hundred sixteen affected CMTX patients (53 males and 63 females) and 63 unaffected, at-risk individuals were compared by neurological and electrophysiological examinations and analyzed by gender; nerve biopsies were available from seven index cases.