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Biomedical subjects

E D Means

Publications and source records attributed to E D Means.

48 records · Page 3Linked to original sources
PubMed1978

Effects of laminectomy on spinal cord blood flow.

The effect of a one-segment (L-2) laminectomy on spinal cord blood flow (SCBF) was determined by the reference sample method using isotope-labeled microspheres. The SCBF was measured before laminectomy (control) and at 15 minutes postlaminectomy with the dura exposed (Series 1), 1 hour postlaminectomy with the laminectomy site closed (Series 2), 24 hours postlaminectomy with the laminectomy site closed (Series 3), and 24 hours postlaminectomy with the dura exposed (Series 4). With the laminectomy site open, SCBF was significantly depressed (22% to 45%) along the entire length of the spinal cord at 15 minutes postlaminectomy. At 1 hour postlaminectomy (with the laminectomy site closed), SCBF approached control values, although areas with significantly lowered flow were still observed in all portions of the spinal cord. By 24 hours postlaminectomy, SCBF had returned to prelaminectomy levels. However, if within 1 hour preceding the 24-hour SCBF measurement, the laminectomy site was reopened, SCBF tended to fall at and caudad to the laminectomy site. These data indicate that laminectomy can cause a significant decline in SCBF. At the present time, the mechanism(s) for this laminectomy-induced depression of SCBF are unknown, although a temperature-induced vasoconstriction is suspected.

Animals↗
PubMed1978

Microvascular perfusion experimental spinal cord injury.

Microperfusion of the spinal cords in cats was studied using a colloidal carbon perfusion technique following compression injury at 1/2 hour, 2 hours, 4 hours, 8 hours, 24 hours, and 51 days. Quantitative estimates of vascular filling were determined at these post-compression intervals. Microperfusion diminished in both the gray and white matter at 1/2 hour following injury and severe lack of perfusion was evident at 8 and 24 hours. Diminished filling of the vessels of gray and white matter seemed to parallel the degree of hemorrhagic necrosis of the gray matter. An increased number of vessels were evident in the spinal cords of long term survivals. The observation that microperfusion in the white matter of the spinal cord was diminished at 24 hours is at variance with some previous investigations. The hypoperfusion of the white matter found in this study suggests that ischemia plays a role in paraplegia resulting from experimental compression injury of the spinal cord.

Animals↗
PubMed1976

Cerebrospinal fluid lactate and electrolyte levels following experimental spinal cord injury.

Cerebrospinal fluid (CSF) lactate, sodium (Na+), potassium (K+), calcium (Ca++), magnesium (Mg++), and chloride (C1-) levels were determined for 17 to 21 days following experimental spinal cord compression in cats. Laminectomies were performed at L-2 under general anesthesia with aseptic techniques. Paraplegia was produced by applying a 170-gm weight transdurally for 5 minutes. Significant increases in CSF lactate levels were observed on the first through ninth days post injury with peak levels (50% above normal) occurring at Day 5. The only significant postinjury CSF electrolyte changes were elevation in Ca++ concentration on Days 3, 9, 11, 13, and 15, elevation in K+ concentration on Days 9 and 11 and decline in C1- levels on the first day. The CSF K+ increase probably reflected cellular loss of K+ from damaged tissue whereas the Ca++ rise may have resulted from increased CSF protein levels. The prolonged elevation of CSF lactate indicates that tissue hypoxia plays a role in spinal cord compression paralysis, and that there is a continuing hypoxia of metabolically active spinal cord tissue for several days post injury.

Animals↗
PubMed1973

The numb chin in breast cancer.

Numbness of the chin, an uncommon neurological symptom, was observed in 15 patients with cancer. Thirteen had breast cancer. This symptom usually heralded progressive involvement of the cranial nerves or cerebrum and denoted a poor prognosis in patients with a short `tumourfree interval'. The pathogenesis is commonly related to dural involvement of the Vth cranial nerve at the base of the brain, although metastasis to the mandible might sometimes be implicated. The reason for the peculiar predilection for the mandibular branch of the trigeminal nerve to be affected by breast cancer is not known.

Adult↗
PubMedDate not supplied

Pathology of lacquer thinner induced neuropathy.

Seven men aged 17 to 22 years developed severe distal symmetrical predominately motor polyneuropathy after repeated inhalation of a commercially available brand of lacquer thinner. Motor nerve conduction velocities were markedly slowed. Fascicular biopsy specimens of sural nerve showed a striking loss of myelinated nerve fibers. Prominent neurofilamentous masses resulted insegmental paranodal distention of axons with secondary thinning and retraction of myelin from the node of Ranvier. Autopsy material from one case revealed central chromatolysis of anterior horn cells in the lumbosacral enlargement and axonal swellings in the fasciculus gracilis. One or more volatile hydrocarbons contained in the lacquer thinner involved may be neurotoxic if inhaled to excess any many cause a neuropathy with characteristic pathological features.

Adolescent↗
PubMedDate not supplied

Efficacy of a monothermal warm water caloric screening test.

The validity of using monothermal caloric screening tests to shorten bithermal caloric test time has been disputed by several investigators. The purpose of this study was to reexamine the efficacy of a monothermal warm caloric screening test. Two retrospective investigations (n = 130) served to generate normative data and provide an estimate of the false-negative rate of the warm monothermal caloric screening test. A prospective investigation (n = 30) was also conducted. Predictions were made regarding bithermal caloric test normality from warm monothermal data, and the bithermal test was completed. The results of this prospective investigation suggested that a warm monothermal screening test can predict normal bithermal caloric responses with greater than 97% accuracy. Criteria for normality include less than 29.54% warm caloric maximum slow phase eye velocity (SPEV) interaural difference, maximum SPEVs that are greater than 11 degrees/s for each ear, absence of significant positional or spontaneous nystagmus, and normal ocular motility.

Caloric Tests↗