ABSTRACT
Using principles derived from electric field measurements and studies of phrenic nerve in vitro, neuromagnetic stimuli in humans were predicted to excite selective low threshold sites in proximal and distal cauda equina. Physical models, in which induced electric fields were recorded in a segment of human lumbosacral spine immersed in a saline filled tank, supported this prediction. Conclusions from the model were tested and confirmed in normal human subjects. Ipsilateral motor evoked potentials were elicited in lower limb muscles and striated sphincters by magnetic coil (MC) stimulation of both proximal and distal cauda equina. Over proximal cauda equina a vertically oriented MC junction and cranially directed induced current elicited a newly identified compound muscle action potential (CMAP). The F response latency and lack of attenuation when the target muscle was vibrated suggest that the proximal response is a directly elicited M response arising near or at the rootlet exit zone of the conus medullaris. Over distal cauda equina, lumbar roots were optimally excited by a horizontally oriented MC junction, and sacral roots by an approximately vertically oriented MC junction, eliciting CMAPs with similar appearance but shorter latency consistent with the known intrathecal lengths of the lower lumbar and sacral nerve roots. The induced current was usually most effective when directed towards the spinal fluid filled thecal sac. Normal subjects showed stable CMAP onset latencies elicited at proximal and distal cauda equina despite wide variation in amplitude. Thus, cauda equina conduction time can be directly calculated. This new method may improve the detection and classification of peripheral neuropathies affecting lower limbs and striated sphincters.
Subject(s)
Cauda Equina/physiology , Electromyography/methods , Magnetics , Neural Conduction/physiology , Adult , Electric Stimulation , Female , Humans , Lumbosacral Region/innervation , Lumbosacral Region/physiology , Male , Muscle, Skeletal/innervation , Muscle, Skeletal/physiology , Peripheral Nerves/physiology , Sacrum/innervation , Sacrum/physiology , Spinal Canal/physiology , Spinal Nerve Roots/physiology , Thigh/innervation , Thigh/physiology , Time FactorsABSTRACT
We report a juvenile patient who developed vertebrobasilar occlusion following nonpenetrating head and neck trauma, with complete recovery. The patient presented with transient signs of brain-stem dysfunction that were secondary to embolization and/or extension of a thrombus. He was treated with anticoagulants. We have found no other reports of such treatment in juvenile vertebrobasilar occlusion that complicated nonpenetrating head and neck trauma.
Subject(s)
Brain Concussion/complications , Brain Stem/blood supply , Intracranial Embolism and Thrombosis/etiology , Vertebrobasilar Insufficiency/etiology , Administration, Oral , Cerebral Angiography , Child , Dicumarol/administration & dosage , Heparin/administration & dosage , Humans , Infusions, Intravenous , Intracranial Embolism and Thrombosis/drug therapy , Male , Vertebrobasilar Insufficiency/drug therapyABSTRACT
The injury pattern in the child who falls from a height is markedly different from that in the adult, so a different imaging protocol is needed. To help establish such a protocol, the authors reviewed the charts and imaging records of 45 children and infants 12 years of age and younger who had fallen one to six stories. Extremity fractures were the most common injury, occurring in 20 patients. Head injuries (including skull fractures) occurred in 19 patients. Abdominal injuries were present in only one patient. Pneumothoraces were seen in four patients and lung contusions in two patients. Fractures of the pelvis, spine, and os calcis were uncommon. The height of the fall did not enable prediction of either the severity or type of injury. The authors recommend radiography of the cervical spine and chest alone in the initial evaluation of the injured child and greater willingness to obtain computed tomographic (CT) scans of the head in children than in adults. Radiographs of the pelvis, thoracolumbar spine, and lower extremities, as well as CT scans of the head and abdomen, should be obtained on a case-by-case basis, and not according to protocol, as is often the situation in adults.
Subject(s)
Accidental Falls , Accidents , Wounds and Injuries/diagnostic imaging , Abdominal Injuries/diagnostic imaging , Child , Child, Preschool , Craniocerebral Trauma/diagnostic imaging , Fractures, Bone/diagnostic imaging , Humans , Infant , Pelvis/diagnostic imaging , Pelvis/injuries , Spinal Injuries/diagnostic imaging , Thoracic Injuries/diagnostic imaging , Tomography, X-Ray ComputedABSTRACT
Development of pontine calcifications following radiation therapy for suprasellar tumors is described in two patients, 5 and 9 years old. Post-radiotherapy brain calcifications are rare in the brain stem.
Subject(s)
Brain Diseases/diagnostic imaging , Calcinosis/diagnostic imaging , Pons/radiation effects , Radiotherapy/adverse effects , Tomography, X-Ray Computed , Brain Diseases/etiology , Brain Neoplasms/radiotherapy , Calcinosis/etiology , Child , Child, Preschool , Female , Humans , MaleABSTRACT
A group of 23 pediatric patients seropositive for HIV antibody were studied by computed tomography and evaluated neurodevelopmentally. Significant neurodevelopmental delays were found in over 95% of the patients studied. CT findings in six patients were normal and thirteen of 23 (57%) had prominence of the CSF spaces. Less frequent findings included calcifications in the basal ganglia and white matter. Cerebral mass lesions included one case of lymphoma and one case of hemorrhage. The CT findings in the pediatric age group differs from the adult population in that contrast enhancing inflammatory mass lesions are uncommon.