Biomedical subjects

S Chokroverty

Publications and source records attributed to S Chokroverty.

112 records · Page 7Linked to original sources

PubMedDate not supplied

Diaphragmatic denervation in intensive care unit patients.

The causes of prolonged requirement for mechanical ventilation in the intensive care unit (ICU) are currently a subject of investigation. Critical illness polyneuropathy (CIP), an axonal polyneuropathy that frequently occurs with prolonged sepsis and multi-organ failure, has been cited as a frequent cause of difficulty with weaning from a ventilator. The relative contribution of diaphragmatic denervation in ICU patients with and without CIP has not been definitively determined. We reviewed 102 ventilator dependent intensive care unit (ICU) patients. Critical illness polyneuropathy (CIP) was diagnosed based upon electrodiagnostic criteria. Electrodiagnostic studies included diaphragmatic needle electromyography (EMG) to evaluate for diaphragmatic denervation. The medical charts of the patients with diaphragmatic denervation were reviewed for etiologies other than CIP for the diaphragmatic denervation. Our results suggest: 1) Respiratory impairment in ICU patients may often be unrelated to either CIP or diaphragmatic denervation; 2) Only about half of ventilator dependent CIP patients have diaphragmatic denervation; 3) Diaphragmatic denervation in ICU patients frequently may be attributable to causes other than CIP.

Action Potentials↗

PubMedDate not supplied

Trapezius CMAP amplitude asymmetry in accessory neuropathy.

In accessory neuropathy electrodiagnosis, upper trapezius compound muscle action potential (CMAP) latencies and amplitudes are commonly measured. The few prior reports describing middle and lower trapezius recording have traditionally emphasized latency value determination. The utility of amplitude measurement with middle and lower trapezius recording has not, to our knowledge, been previously described in individual patients with accessory neuropathy. We report three patients (A-C) who developed unilateral accessory neuropathy following surgical procedures. Accessory nerve conduction studies were performed with surface recording over the upper, middle, and lower trapezius muscles. Latency values were normal except for a prolonged lower trapezius latency value in patient B. Side-side trapezius amplitude comparisons revealed striking asymmetries from all three recording sites in patients A and B (71-95% CMAP amplitude decrements) and in the lower trapezius recording of patient C. Middle and lower trapezius side-side CMAP amplitude comparisons may increase the sensitivity of accessory neuropathy electrodiagnosis.

Accessory Nerve Diseases↗

PubMedDate not supplied

Magnetic stimulation of the human peripheral nerves.

In this report some preliminary data after magnetic stimulation of the peripheral nerves in 8 normal individuals are presented. Compound muscle action potentials were recorded by surface electrodes after magnetic and conventional electrical stimulation of the median, ulnar, peroneal, tibial, femoral and sciatic nerves, and the lumbosacral roots. The data clearly show the ability of the magnetic coil to stimulate the roots in sites relatively inaccessible to electrical stimulation and obtain consistent muscle response suggesting important clinical application of magnetic stimulation in lumbosacral root disorders. However, before the magnetic coil can be recommended for general use, a very careful study comparing the responses after conventional electrical stimulation with those obtained after magnetic stimulation of each nerve in the upper and lower limbs must be evaluated.

Action Potentials↗

PubMedDate not supplied

Propriospinal myoclonus.

The concept of propriospinal myoclonus is briefly reviewed in this report. Myoclonus can be classified according to the site of the generator into cortical, subcortical but supraspinal, and spinal myoclonus. Propriospinal myoclonus is a special type of spinal myoclonus characterized by rhythmic or arrhythmic, spontaneous or sometimes stimulus-sensitive flexion or extension movements of the axial muscles of the body with or without spread to the limbs excluding the cranially innervated muscles. Neurophysiologic study shows a characteristic pattern of order of recruitment of electromyographic bursts which are initially noted in the midthoracic segments (myoclonic generator) followed by propagation up and down the spinal cord via slowly conducting (3-11 M/s) pathways, such as the propriospinal systems. The role of spinal cord in functioning as a stepping generator and in locomotion has been strengthened by this new concept of propriospinal myoclonus.

Animals↗