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Introduction: The aim of the study was to describe patterns of neuromuscular weakness using a combination of electromyography and histology, and to evaluate functional outcome in patients following complicated cardiovascular surgery., Methods: Fifteen adults requiring long-term mechanical ventilation (>15 days) following cardiovascular surgery associated with postoperative complications were prospectively included. Electrophysiological and histological analyses (muscle and nerve) were performed when failure to wean from mechanical ventilation associated with peripheral neuromuscular weakness was noticed. Functional disability was evaluated 12 months after surgery., Results: Six patients had a predominantly axonal neuropathy, six presented with myopathy, and three patients had a combination of axonal neuropathy and myopathy. All of them presented with acute tetraparesis and failure to wean from mechanical ventilation. All of the study patients who received corticosteroids exhibited a myopathic pattern (with or without axonopathic changes) but never an axonopathic pattern only. Only two of the eight survivors at 12 months were not ambulatory. These two patients had no detectable compound muscle action potential on electrophysiological examination., Conclusion: The combination of electromyographic evaluation and neuromuscular histological abnormalities could help to identify the type and severity of neuromuscular weakness, in turn helping to evaluate the patient's potential functional prognosis.

Several neurological manifestations of Lyme disease, both central and peripheral, have been described. Reported here is a case of acute transverse myelitis related to a Lyme neuroborreliosis that presented with isolated acute urinary retention and no lower-extremity impairment. This case, documented by urodynamic and electrophysiological investigations, partially resolved after 6 weeks of intravenous ceftriaxone, affording the removal of the indwelling catheter. Alpha blocker therapy was needed for 3 months, until the complete normalisation of urodynamic and electrophysiological records. This case study indicates that whenever urinary retention is encountered associated with acute transverse myelitis or alone, the patient should be investigated for Lyme disease.

In a systematic study we attempted to activate the respiratory neurons antidromically by stimulating the spinal cord and the vagus. This has led to an anatomical and functional classification of the neurons: bulb-spinal neurons whose axons enter the spinal cord, vagal motoneurons, propriobulbar neurons which cannot be activated antidromically. We used simultaneously other tests (localization, response to Hering-Breuer reflexes or to cortical stimulation) which gave positive results. Two groups of respiratory neurons were apparent: a dorsal respiratory nucleus with only inspiratory bulbo-spinal neurons and a ventral respiratory nucleus with inspiratory and expiratory bulbo-spinal neurons, vagal motoneurons and propriobulbar neurons. The bulbo-spinal neurons and some propriobulbar neurons are normally related to Hering-Breuer reflexes evoked by lung inflation or deflation, but the recurrent laryngeal motoneurons or fibres and some propriobulbar neurons can give a paradoxical response to lung inflation. By cortical stimulation the propriobulbar neurons show only an arrest of their discharge, whereas the bulbo-spinal neurons give a burst of spikes followed by an inhibition. These results led to the following conclusions: (i) the propriobulbar neurons do exist; (ii) some neurons classified as medullary respiratory neurons have not really a ventilatory function: they belong to the laryngeal system; (iii) it is fundamental to use systematically the antidromic test and some other ones to know exactly the hodological situation of the neurons in the respiratory complex.