PubMed Health⌕ Search

Biomedical subjects

C Morgenstern

Publications and source records attributed to C Morgenstern.

At least 19 recordsLinked to original sources
PubMed2002

The efficacy of Ginkgo special extract EGb 761 in patients with tinnitus.

OBJECTIVE: The objective of the present study in 60 patients with chronic tinnitus aurium was to confirm the efficacy of oral treatment with 2 x 80 mg Ginkgo special extract EGb 761 per day subsequent to 10-day EGb 761 infusion treatment. METHODS: Patients with chronic tinnitus aurium underwent 10 days of in-patient infusion treatment with 200 mg/day EGb 761, after which they were randomized to double-blind, oral out-patient treatment with either 2 x 80 mg/day EGb 761 or placebo, given over a scheduled treatment period of 12 weeks. The primary outcome measure was the change in tinnitus volume in the more severely affected ear during randomized treatment. RESULTS: Fifty-two of 60 patients (89.7%) completed the infusion treatment; complete sets of data were available for 40 (66.7%), 30 (50.0%) and 22 (36.7%) patients after 4, 8 and 12 weeks of randomized treatment, respectively. For the primary outcome measure, significant superiority of EGb 761 over placebo was demonstrated in the intention-to-treat analysis data set after 4, 8 and 12 weeks of out-patient treatment (p < 0.05, 1-tailed), although the absolute treatment group difference was moderate. The results were supported by the secondary outcome measures for efficacy (e.g. decreased hearing loss, improved self-assessment of subjective impairment). During out-patient treatment, there were no attributable adverse events under EGb 761. CONCLUSIONS: A combination of infusion therapy followed by oral administration of Ginkgo special extract EGb 761 appears to be effective and safe in alleviating the symptoms associated with tinnitus aurium.

Administration, Oral↗
PubMed1997

Three-dimensional ultrasound angiography (power mode) for the quantification of carotid artery atherosclerosis.

Three-dimensional (3D) ultrasound angiography was performed to diagnose carotid artery atherosclerosis. Thirty-five patients (15 women, 20 men) with a history of cerebrovascular disease were examined using conventional color-coded Doppler ultrasound and 3D ultrasound angiography. Carotid stenosis was initially diagnosed using continuous-wave Doppler ultrasound. To determine intraobserver and interobserver reliabilities, 21 patients were evaluated using 3D ultrasound on three occasions. Sixty-five percent of patients were diagnosed with stenosis of more than 50%. Twenty-two percent of plaques had a smooth surface, 72.9% were ulcerated, and 5.1% were indeterminate. Data collection for 3D imaging required 5 minutes per patient, whereas image processing and plaque volume quantification required 30 minutes. Plaque volume ranged from 0.053 to 0.685 ml. The intraobserver and interobserver variabilities were 4.16 and 5.87%, respectively (r = 0.96, p < 0.0001; r = 0.89, p < 0.0001). 3D Color Doppler and 3D ultrasound angiography assessments of plaque volume differed by 8.5%. Plaques were more precisely differentiated using 3D ultrasound, and plaque volume quantification was less affected by echo shadowing after 3D reconstruction. In comparison to other techniques for the quantification of atherosclerotic lesions. 3D ultrasound angiography offers a more precise quantitative method for prospective, clinical studies of atherosclerosis.

Aged↗
PubMed1997

Transcranial power-mode duplex ultrasound in two patients with moyamoya syndrome.

Moyamoya syndrome is characterized by the reticulated collateralization of the intracranial vasculature distal to an occlusion of proximal intracranial vessels. In the present study this pathology was visualized in 2 patients, aged 29 and 32 years, using transcranial color Doppler imaging (TCDI). Digital subtraction angiography in both patients revealed stenosis of the intracranial portion of the internal carotid arteries, occlusion and stenosis of several cerebral arteries, and a bilateral reticulated collateral network particularly in the region of both basal ganglia, typical of moyamoya syndrome. TCDI with power-mode Doppler depicted parts of the intracranial collateral network, not possible using conventional color-flow Doppler. TCDI with power-mode Doppler permitted better visualization of intracranial vascular pathology in comparison to conventional color-flow Doppler, enabling a rapid and noninvasive diagnosis of rare cerebrovascular anomalies.

Adult↗
PubMed1996

Cerebrovascular disease assessed by color-flow and power Doppler ultrasonography. Comparison with digital subtraction angiography in internal carotid artery stenosis.

BACKGROUND AND PURPOSE: An understanding of carotid atherosclerosis is important to further our knowledge regarding the etiology of cerebral ischemia, and therefore it is necessary to accurately visualize carotid stenosis. The purpose of the present study was to compare different imaging techniques to determine their advantages and disadvantages in the diagnosis and quantification of middle- and high-grade internal carotid artery stenosis. In particular, we were interested in evaluating the effectiveness of the new ultrasound technique power Doppler. METHODS: Fifty-four patients with greater than 50% extracranial internal carotid artery stenosis, as determined by continuous-wave Doppler, were recruited prospectively to serve as subjects. All subjects were examined with color-flow Doppler, power Doppler, and digital subtraction angiography to enable visualization of carotid stenosis and plaque surface morphology. RESULTS: Thirty-four middle-grade stenoses (50% to 69%), 32 high-grade stenoses (70% to 99%), and 7 complete occlusions of the internal carotid artery were diagnosed with the use of digital subtraction angiography. Power Doppler visualized stenosis significantly more frequently and accurately than color-flow Doppler. Color-flow Doppler tended to overestimate and underestimate in patients with both middle- and high-grade stenosis. Power Doppler was superior to both color-flow Doppler and angiography with regard to differentiation of plaque surface morphology. CONCLUSIONS: This study demonstrates that power Doppler is an important, noninvasive imaging technique that has several advantages over color-flow Doppler in diagnosing carotid artery stenosis and visualizing plaque surface. Power Doppler, used in concert with other ultrasound techniques, should enable a more accurate detection and treatment of cerebrovascular disease.

Aged↗
PubMed1995

The efferent innervation of outer hair cells in humans: physiological investigations.

We report on a case of reversible pontine deafness caused by multiple sclerotic lesions in the pons, and describe six experiments in humans, in whom we recorded transient otoacoustic emissions and distortion products. Our findings indicate an inhibitory effect of efferent innervation on the motility of outer hair cells in humans. Otoacoustic emissions increased in patients with unilateral deafness after the central part of the efferent pathway was destroyed (pontine deafness). Otoacoustic emissions also increased in patients with myasthenia gravis after the administration of an acetylcholinesterase inhibitor. General myotonia (Batter-Curschmann-Steinert Syndrome) resulted in mild sensorineural hearing loss, and in the absence of contralateral inhibition of otoacoustic emissions. Otoacoustic emissions decreased gradually under general anesthesia with muscle relaxation. Contralateral acoustic stimulation was seen during anaesthesia with muscle relaxation.

Acoustic Stimulation↗
PubMed1992

Immunohistochemical findings of IgG recognized in the planum semilunatum of the guinea pig.

The planum semilunatum is located on the lateral side of the crista ampullaris of the semicircular canal. With regard to the functions of the planum semilunatum, some researchers assume the existence of secretory activity based on the microstructural features observed in isotopic experiments. In the present study, in order to confirm the existence of an immunological mechanism in the ampulla of the semicircular canal, the distribution of immunoglobulins in the semi-circular canal of guinea pigs was investigated immunohistochemically. Positivity of IgG was observed in the constituent cells of the planum semilunatum or beneath the basement membrane of the cells. It is concluded that ample IgG, which is an important constituent of the body fluids, is collected within this region. The planum semilunatum containing such ample amounts of IgG might be involved in the immunological mechanism operating in the ampullar of the semicircular canal.

Animals↗
PubMed1990

[Assessment of central disorders of the statoacusticus nerve using high resolution imaging procedures (PET and MRI)].

Disorders of the auditory and vestibular central nervous system can be diagnosed more precisely by high resolution magnetic resonance imaging (MRI) and positron emission tomography (PET). MRI is mostly used for small intrameatal acoustic neuromas up to 10 mm, intracranial cholesteatomas, and multiple sclerosis. Positron emission tomography has advantages after acoustic or electric stimulation in the auditory cortex. PET is not yet a routine procedure in clinical diagnosis.

Blood Glucose↗
PubMed1989

[Cytomegalovirus infection and inner ear deafness].

Bilateral sensorineural hearing loss of patients is correlated with elevated antibody titres against cytomegaly virus in serum in children as well as in adults. Unilateral deafness correlates with mumps infection. This is shown in a German population as well as in a Mediterranean group of patients. There is no evidence between antibody titer of Coxsackie virus, adenovirus and herpes virus or toxoplasma gondii interaction and sensorineural hearing loss neither unilaterally nor bilaterally.

Antibodies, Viral↗
PubMed1989

Immune response of the endolymphatic sac to horseradish peroxidase: immunologic route from the middle ear to the inner ear.

Twenty guinea pigs were immunized with horseradish peroxidase (HRP) intradermally and challenged with 5 mg of the same antigen in the tympanic bulla. The appearance of immunoglobulin-producing cells (plasma cells) in the inner ear structure was examined immunohistochemically in frozen sections. Four to 10 days following antigen challenge, 5 of the 20 animals showed significantly increased plasma cells in the subepithelial connective tissue of the endolymphatic sac (ES). Those cells showed positive reactions, mainly with IgG followed by IgM. The cells that reacted positively with IgA were few. Some of these plasma cells were considered to contain the specific antibody against HRP. The results indicate the role of the ES as a local immune response region for the inner ear complex, as well as the existence of an immunologic route from the middle ear cavity to the inner ear, particularly to the ES.

Animals↗
PubMed1988

[Pontine deafness--a new disease picture?].

The clinical features of pontine deafness are demonstrated in six patients with typical findings in pure-tone audiogram and speech audiometry, in stapedial reflex recordings, in brainstem-evoked potentials and cortical evoked potentials. The results of positron emission tomography (PET), magnetic response tomography (MRT), electrocochleography and the promontory test are presented. Results of cerebral spinal fluid and antibody titres in the serum are given. Pontine deafness is characterised by an interruption of the central auditory pathway cranial to the olive. This deafness should be differentiated from other forms of sensorineural hearing loss. The pathogenesis of pontine deafness is still unknown. However we should take it into consideration in the diagnosis of sudden unilateral deafness. No medical treatment method is known to date.

Adolescent↗
PubMed1987

Cation transport in the ampulla of the semicircular canal and in the endolymphatic sac.

We examined the effects of anoxia and ethacrynic acid on the endolymphatic potential and cation activity in the superior ampulla of the guinea pig, using double-barrelled ion-exchanger microelectrodes. In normal guinea pigs the ampullar endolymphatic potential was + 3.9 +/- 1.2 mV (n = 32), the Cl- activity 130 +/- 4.6 mM (n = 9), and the Na+ activity 18.4 +/- 4.4 mM (n = 20). After anoxia, the ampullar DC potential decreased rapidly and reversed its polarity within 5 min. It then decreased gradually for 60 min and increased afterwards to approximately zero. K+ activity decreased gradually after a latency of 10 min, whereas Na+ activity increased. During the gradual decrease of a negative ampullar endolymphatic potential, an increase in Na+ activity was observed. Thirty minutes after the intravenous injection of ethacrynic acid (100 mg/kg), the potential began to decrease, changed to a negative polarity, and approached a maximum negative level 100 min after the injection. The decrease in K+ activity corresponded to the reduction of potential whereas Na+ activity remained unchanged. The DC potential of the endolymphatic sac in normal guinea pigs was + 14.7 +/- 5.1 mV (n = 17). The Na+ concentration was 103.3 +/- 14.7 mM (n = 14) and the K+ concentration was 11.6 +/- 0.8 mM (n = 4). After anoxia, the DC potential decreased rapidly and approached 0 mV within 8 min. No negative potential could be observed. The Na+ concentration began to increase 2 min after anoxia and reached the extracellular Na+ concentration about 30 min later.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Endolymph formation in the inner ear of pigeons.

The endolymphatic space of pigeons was studied by using double-barrelled electrodes with a potassium liquid ion exchanger. The K+ activity of the endolymph was 155 mM in the cochlea and 133 mM in the ampulla, respectively. Positive DC potential in the cochlea (+14.5 mV) was much lower than in guinea pigs (+80 mV) whereas in the ampulla of pigeons the DC potential (+7.4 mV) was 2 times higher than that of guinea pigs (+3.9 mV). General application of ethacrynic acid in pigeons induced a weak change in DC potential and no typical intercellular edema in the cochlea and ampulla. Local application of ethacrynic acid and ouabain in the cochlea and ampulla of pigeons induced a negative DC potential of between -30 and -40 mV. This negative DC potential was higher than the anoxia-induced negative potential. Short hypoxia during a drug-induced DC potential resulted in a decrease in DC potential above the diffusion potential. Below the diffusion potential additional hypoxia increased the DC potential independent of the cause of intoxication.

Animals↗
PubMed1987

[Latency of the acoustic evoked stapedius reflex and its clinical significance].

We measured the mean latency of the stapedius reflex by normal listeners. We observed a prolongation of the latency by patients with operative and histological confirmed neurinoma of the VIII. nerve. Even if the measured stapedius reflex latency considerably varies, this method represents, any way, an important support to BERA to discover tumours of the cerebello-pontine angle.

Adolescent↗
PubMed1986

Calcium transport in the endolymphatic sac.

Ca++ activity and DC potential were measured in vivo in the endolymphatic sac (ES) of guinea pigs by means of double-barrelled ion-sensitive microelectrodes. We found a positive DC potential of 14 mV and a Ca++ activity of 4.7 X 10(-4) M. Anoxia induced a decrease in the DC potential and an increase in Ca++ activity; however, no negative DC potential was measured during permanent anoxia. The Ca++ activity measured was in agreement with the Ca++ value calculated with the Nernst equation, assuming a positive DC potential. On the basis of these data, it was suggested that the Ca++ in the ES is in electrochemical equilibrium with the surrounding fluid and no active Ca++ transport is necessary in the ES of guinea pigs.

Animals↗
PubMed1986

[Granular cell tumor of the orbits. Diagnosis and therapy].

Report on two cases of tumours in the retroorbital space. The histological examination showed them to be granular cell myoblastomas (Abrikossoff), which in one case was bilateral. Tumours within the orbital space are rare. It is necessary in every case to make a biopsy to clarify the type of tumour because some of them are malignant. Computed tomography cannot differentiate between benign and malignant tumours in the orbita.

Adult↗