Publications by authors named "M Chokroverty"

We describe a technique of percutaneous magnetic coil (MC) stimulation of the phrenic nerve trunk on one side of the neck and phrenic roots over the upper cervical vertebral column in 10 normal subjects and 2 patients. We were able to obtain compound muscle action potentials (CMAPs) from the diaphragm at two sites (xiphoid process and 7th intercostal space) after stimulation of the phrenic nerve trunk and roots. We noted that the onset latencies after phrenic root stimulation remained fixed despite increasing the stimulus intensity from 50% to 100% and on moving the MC vertically or laterally, suggesting that stimulation of the fastest conducting fibers was occurring at a fixed site, most likely at the intervertebral foramina.

View Article and Find Full Text PDF

We describe the technique of magnetic coil (MC) stimulation of the lumbosacral roots and the possible site of stimulation in 22 control subjects, and the clinical usefulness of MC stimulation in 5 patients with low back pain. We observed 2 components in the compound muscle action potential of the soleus muscle following MC stimulation over the lumbosacral region. The second component had the physiological properties of the H reflex.

View Article and Find Full Text PDF

In order to understand which neural elements are excited after percutaneous magnetic coil (MC) stimulation over the cervical vertebral column we have performed such study in 8 normal subjects and 4 patients. On moving the coil rostrocaudally up to 3 cm and horizontally up to 2 cm from the midline we found no change in the latencies of the compound muscle action potentials to biceps, deltoid, abductor pollicis brevis (APB) and abductor digiti minimi muscles indicating a fixed site of excitation of the spinal roots within the intervertebral foramina. F latencies to APB after stimulation of the median nerve at the wrist were always longer than the direct latencies obtained after cervical vertebral stimulation.

View Article and Find Full Text PDF

We report a case of advanced, unruptured tubal pregnancy proceeding beyond term. A 25-year-old woman was admitted at 42 weeks' gestation because of lower abdominal pain and inability to feel fetal movements. An ultrasound examination suggested fetal death.

View Article and Find Full Text PDF

The fine structure of quadriceps motor end-plates in hamsters was analyzed quantitatively one, two, four, seven, and thirty-two weeks following intraperitoneal injections of prednisolone. Except for transient increases in postsynaptic length and membrane profile concentration after prednisolone administration at dosages of 4 mgper kilogram of body weight for one week and 2 mg per kilogram for four weeks, mean values for various measurable profiles in the presynaptic and postsynaptic regions showed no significant differences between control and treated animals.

View Article and Find Full Text PDF