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Biomedical subjects

W Trojaborg

Publications and source records attributed to W Trojaborg.

At least 91 records · Page 5Linked to original sources
PubMed1987

Electrophysiological study of the peripheral and central neurotoxic effect of cis-platin.

We describe clinical and electrophysiological findings in 8 patients with tumors of germ cell origin before and after treatment with high-dose cisplatin (800-1400 mg) combined with etoposide and bleomycin. All patients developed clinical or electrophysiological signs, or both, of a peripheral sensory neuropathy. One had in addition clinical and electrophysiological signs of CNS involvement, and 2 had a central conduction defect revealed by auditory stimulation.

Adolescent↗
PubMed1987

Cerebral blood flow, PaCO2 changes, and visual evoked potentials in mechanically ventilated, preterm infants.

Two estimations of global cerebral blood flow (CBF) using 133-Xenon clearance were done with an interval of about one hour in 16 mechanically ventilated, newborn infants, of less than 33 weeks gestational age. In eight infants CBF was estimated just before a change in ventilator settings, and again when the PaCO2 was stable. In the remaining eight infants small spontaneous changes in PaCO2 occurred. The CBF-CO2 reactivity was similar in the two groups (+67%/kPa (95% confidence interval 13-146) and 52%/kPa (24-86)) and considerably higher than the CBF-CO2 reactivity estimated from the interindividual variation of flow and PaCO2 (+19%/kPa (4-36)). There were no significant relations between CBF and arterial blood pressure. Flash evoked potentials (VEP) were recorded during the 133-Xenon clearances in 8 of the infants. VEP showed no relation to changes in CBF, even when the blood flow rose from the lowest levels. CBF and VEP were obtained once in 9 other infants. Among the 17 infants, the latency of the first negative wave of the VEP was not related to the CBF level. Mean CBF in the 25 infants was 12.3 ml/100 g/min (range 4.3 to 18.9), mean PaCO2 was 4.2 kPa (range 2.3 to 6.4). Thus, CBF-CO2 reactivity appeared to be normal in these clinically stable, mechanically ventilated, preterm infants, suggesting that their low cerebral blood flow was well regulated. The absence of a relation of CBF with VEP suggested that cerebral blood flow was not critically decreased.

Blood Gas Monitoring, Transcutaneous↗
PubMed1987

Ocular ethambutol toxicity. A case report with electrophysiological considerations and a review of Danish cases 1972-81.

A 76-year-old female with ocular ethambutol toxicity prompted two investigations. Firstly, she was followed electrophysiologically, with multichannel recorded pattern reversal visual evoked potential techniques using full-field, half-field, central-field and peripheral field stimulation, plus flash VEP and ERG. The examinations performed 2, 5 and 7 months after ethambutol withdrawal indicated damage to the papillomacular bundle, while a late follow-up after recovery showed potentials of near normal configuration. Secondly an epidemiological survey was attempted based on the 37 ethambutol toxicity cases registered to the Danish Board on Adverse Reactions 1972-81, making up 1% of those receiving antituberculous therapy. They showed a significant preponderance of elderly (24/37 greater than 65 years) and of females (29/37). There was only one foreigner in the series. A detailed analysis of visual function in a subsample of 22 cases (those registered 1977-81) showed that visual impairment lasted several months, and that usually recovery was not complete. Using the visual demands for driver's license as criterium, 20 fulfilled the demands prior to therapy, but only 12 after recovery.

Aged↗
PubMed1987

Subclinical optic neuropathy in multiple sclerosis. A neuro-ophthalmological investigation by means of visually evoked response, Farnworth-Munsell 100 Hue test and Ishihara test and their diagnostic value.

Affection of the optic nerves play a central role in multiple sclerosis (MS) symptomatology. In reported autopsy series the prevalence of optic neuropathy has approached 100%. In the present study subclinical affection of the optic nerves was investigated by visual evoked response (VER), Farnworth-Munsell 100 Hue test (FM 100 Hue test) and Ishihara plates in 17 patients with normal visual acuity and without a history of acute optic neuritis. Optic neuropathy was demonstrated in 72% of the eyes. The occurrence of optic neuropathy was also investigated by the same methods in 16 patients with previous acute optic neuritis, which was bilateral in 5 patients. Affection of the optic nerves was demonstrated in 95% in this group. The affection of also the fellow eye in patients with previous monolateral optic neuritis is unexplained. It may be an analogue to the symmetry of plaques found in the brain and the spinal cord. The cause of this peculiar distribution of lesions is, like the ethiology of MS, unexplained at present. In comparing the different methods of demonstrating optic neuropathy, VER is recommended as the method of choice.

Adult↗
PubMed1987

Immunoglobulin deposits in peripheral nerve endings detected by skin biopsy in patients with IgM M proteins and neuropathy.

Immunofluorescence studies of sural nerve and skin biopsies from three patients with IgM M proteins and clinical neuropathy showed that IgM M protein was bound to the nerve myelin in two patients and by the peri- and endoneurium in one. It is suggested that immunohistochemical studies of skin biopsies provide a simple effective method of detecting immunoglobulin binding to peripheral nerves in patients suspected of having an autoimmune neuropathy. In contrast to sural nerve biopsy, skin biopsy does not cause sensory loss or pain in a denervated area and can easily be repeated.

Aged↗
PubMed1986

Quantitative analysis of individual motor unit potentials: a proposition for standardized terminology and criteria for measurement.

The physiology of the motor unit potential (MUP) is reviewed. The aim is to identify the electrophysiological events in the motor unit that generate the individual parts of the MUP. This is based on insight gained from new experimental techniques, such as single-fiber electromyography (EMG), scanning EMG, and simulation studies of the MUP. A terminology for the different parts of the MUP is also suggested, and nine parameters used to describe different features of the MUP are delineated: duration, spike duration, amplitude, area, spike area, phases, turns, satellites, and variability. Technical aspects, such as electrode type, filtering, and sampling rate of the computers, are discussed as well. In Appendix A, different manual and computer-aided methods for quantitative MUP analysis are described. Despite minor systematic differences between the methods, MUP durations measured by different methods correlate highly with each other (Appendix B). The manual and computer-aided methods have comparable variability between repeated measurements.

Action Potentials↗
PubMed1986

Pharmacokinetics and pharmacodynamics of guanidine hydrochloride in an hereditary myasthenia gravis-like disorder in dogs.

The pharmacokinetic parameters of guanidine hydrochloride were analysed in dogs with an hereditary neuromuscular transmission disorder by the use of 14C-guanidine hydrochloride. The content of intravenously administrated 14C-guanidine hydrochloride in plasma, urine and faeces was determined by liquid scintillation counting. The drug was rapidly distributed in the organism with a plasma half-life of 7-8 h and most was eliminated in the urine. The clinical and electrophysiological effects of guanidine hydrochloride on the muscular weakness and fatigue induced by exercise were determined after oral and intravenous administration. Guanidine hydrochloride improved muscle-function, but had no apparent effect when administered during an attack of weakness. An effective level of guanidine in plasma (2-10 micrograms/ml) changed the muscle response evoked by trains of repetitive stimulation. The myasthenic decrement during short stimulation trains was unchanged.

Animals↗
PubMed1986

Clinical and electrophysiological recovery from peroneal palsy.

Clinical examination, electromyography and conduction studies in motor and sensory fibres were performed in 14 patients with peroneal palsy of compressive or spontaneous origin. After a period of from 5 months - 3 years, the clinical and electrophysiological examinations were repeated. The rate of recovery was not uniformly good, as only 6 of 14 patients had a complete clinical recovery. Most patients had an incomplete electrophysiological recovery which only partly corresponded to the clinical findings. Electromyography and conduction studies in sensory and motor fibres were found to be of value in predicting the outcome of the peroneal palsy.

Adult↗
PubMed1986

Motor neuron disease and plasma cell dyscrasia.

In the years 1977 to 1984, 10 of 206 patients (4.8%) with motor neuron disease (MND) had M proteins; 4 had IgM and 6 had IgG. Among 100 control patients with other neurologic diseases, only 1 had an M protein. We later added six cases of MND and M proteins, as well as three with polyclonal IgM elevations and two with Bence-Jones proteins. Including other reports, there are now 37 known cases of MND with monoclonal and 5 with polyclonal gammopathy. There is evidence that plasma cell dyscrasia is often undetected; the actual incidence of serum immunoglobulin abnormality in patients with MND may be greater than our figure.

Adolescent↗
PubMed1985

Visual evoked potentials in pseudotumor cerebri.

Pattern reversal visual evoked potentials in 13 patients with pseudotumor cerebri were significantly delayed (99 +/- 7.3 ms [mean +/- SD]) compared with the findings in 20 normal subjects (94 +/- 2.7 ms), although only four patients had latencies outside the normal range. There was, however, a significant correlation between the intracranial pressure and the latency of visual evoked potentials. After medical treatment of the intracranial hypertension, visual evoked potential latencies decreased in patients who recovered and in whom the papilledema disappeared. In one patient with progressive visual failure, the visual evoked potentials were abnormal before disturbances of visual fields and visual acuity were evident. Repeated examinations of visual evoked potentials might be of value in patients with pseudotumor cerebri to ensure neurosurgical intervention in due time to prevent visual loss in patients with impending optic nerve atrophy.

Adolescent↗
PubMed1985

Ophthalmologic prognosis in benign intracranial hypertension.

In a prospective study twenty patients with benign intracranial hypertension, 15 females and five males with mean age 34 years (range 12-61 years), were followed up from 12 to 61 months (mean 22 months). Initially all patients showed marked papilledema, normal visual acuity, considerable enlargement of the blind spot area, and significantly delayed pattern reversal visual evoked potentials. During medical treatment eleven patients showed within 3-6 months a rapidly regression and normalization of papilledema, blind spot area, and visual evoked potentials. Eight patients continued in showing papilledema including disc gliosis, enlargement of blind spot area, and pathological visual evoked potentials. One patient developed optic nerve atrophy. The results indicated that repeated examinations of visual evoked potentials, when suspect of threatening visual loss has come up (papilledema, increased blind spot area, and field defects), might increase the change of diagnose of an optic nerve atrophy as early as possible.

Adolescent↗
PubMed1985

Adult metachromatic leukodystrophy: neurophysiologic findings.

The visual and somatosensory evoked potentials were delayed in two cases of the adult form of metachromatic leukodystrophy. Brainstem auditory evoked potentials were normal. The conduction velocity along peripheral nerves was 50% slowed in one case and near normal in the other. The findings are compatible with demyelination in the central and peripheral nervous systems. The diagnosis of metachromatic leukodystrophy should be considered in cases of early dementia, with or without psychosis or other neurologic deficits, in which evoked potentials are delayed and peripheral nerve conduction is slowed.

Adult↗
PubMed1984

Flash visual evoked potential as a prognostic factor for vitreous operations in diabetic eyes.

In 116 diabetic eyes scheduled for vitreous surgery, the visual evoked potential (VEP) after flash stimulation was recorded prior to surgery. Latencies of the flash evoked potentials show a distribution suggestive of a Gaussian curve with an abnormal extension. Dividing the material into two groups based on a latency shorter or longer than 100 milliseconds revealed a highly significant difference in the visual improvement following surgery between patients with a short and patients with a long latency (P less than 0.001). With a latency longer than 100 millisec. most patients showed no visual change after operation, and among the few who did the change, consisted more often in visual reduction than improvement. Additional investigations in the study reveal that it is likely that the prolonged latency of the flash VEP is due to pathology of the retina or visual pathways.

Diabetic Retinopathy↗
PubMed1984

Conduction studies along the accessory nerve and follow-up of patients with trapezius palsy.

The accessory nerve was stimulated at the posterior triangle of the neck and responses were evoked simultaneously from the upper, middle and lower part of the trapezius muscle. Sixteen patients were investigated, 10 with trapezius palsy following surgical procedures at the posterior cervical triangle, three with a history suggestive of neuralgic amyotrophy and three of unknown origin. On the unaffected side the latency increases 0.16 ms per 10 mm increase in conduction distance corresponding to a conduction velocity of 63 m/s. Evidence is presented that the upper, middle and lower part of the trapezius muscle receive innervation from the accessory nerve. Follow-up of patients showed spontaneous nerve regeneration after complete axonal degeneration. These findings suggest that surgical intervention should be delayed to allow for spontaneous reinnervation. Clinical recovery was incomplete in cases of iatrogenic origin.

Accessory Nerve↗
PubMed1984

Conduction studies of the long thoracic nerve in serratus anterior palsy of different etiology.

We studied nerve conduction in 24 patients with serratus anterior palsy of different etiology. On the unaffected control side, the latency of the evoked motor responses after stimulation of the long thoracic nerve in the supraclavicular fossa increased 0.2 msec per 10-mm increase in conduction distance, corresponding to a velocity of 67m-s. The method was valuable in determining whether the lesion was partial or complete and in revealing regeneration after wallerian degeneration.

Adolescent↗
PubMed1984

Misonidazole neuropathy.

Neurotoxic side effects of misonidazole with peripheral neuropathy was investigated in two series of patients. The first series consisted of eight patients with carcinoma of the pharynx, larynx or lung who, during treatment with misonidazole, developed peripheral neuropathy dominated by severe sensory symptoms and signs localized mainly to the lower extremities. Misonidazole was given for three to seven weeks in a total dose of 9.6 - 12.6 g/m2 (11 g/m2 or more in four of the patients). The symptoms subsided partially within a few months after cessation of the therapy. Electrophysiological and histological findings indicated axonal neuropathy with loss of large fibres and secondary demyelination. The second series consisted of 70 patients with carcinoma of the pharynx or larynx who, in addition to radiotherapy, were given either placebo or misonidazole over four weeks in a total dose of 11 g/m2. Fourteen patients out of 36 receiving misonidazole (38%) developed peripheral polyneuropathy, mostly in the feet, while this occurred in only two of the 34 patient placebo group.

Aged↗
PubMed1983

Visual evoked potential as a prognostic factor for vitrectomy in diabetic eyes.

To determine whether or not the electrophysiological status of the eye can give information as to the result of vitreous surgery, the visual evoked potential to flash stimulation was measured prior to vitreous surgery. Seventy-four eyes were submitted to surgery. Latencies of flash evoked potentials showed a distribution suggestive of a Gaussian curve with an abnormal extension. Dividing the material into 2 groups based on a latency longer or shorter than 100 millisec revealed a highly significant difference in visual improvement after surgery between patients with long latency and patients with short latency (P less than 0.001). With a latency longer than 100 millisec the patient has an almost equal chance of visual improvement or visual reduction by surgery. The frequency of operative complications was twice as high in patients with latency longer than 100 millisec compared to patients with a latency shorter than 100 millisec.

Diabetic Retinopathy↗