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C Auer

Publications and source records attributed to C Auer.

At least 19 recordsLinked to original sources
PubMed2001

Is somatization a habituation disorder? Physiological reactivity in somatization syndrome.

The present study investigates whether physiological activity may play a part in maintaining the amplified perception of bodily processes typical for somatization. Eighty-one persons were classified into three groups by means of a structured clinical interview: 24 patients with somatization syndrome, 34 patients with somatization syndrome and comorbid major depression, and 23 healthy controls. Subjects completed four blocks of an attentional task, each of the blocks separated by resting periods. Physiological patterns demonstrated higher activity during mental tasks than during rest. The heart rate deceleration after changing from mental challenge to rest was less pronounced in the groups of patients with somatization syndrome than in controls. Moreover, patients with somatization syndrome reported feeling more and more tense during the investigation, while controls showed the tendency to habituate. The effects of heart rate and of feelings of tension partly replicated earlier findings, and demonstrated that physiological activity may interact with psychological processes in somatization.

Adult↗
PubMed2000

Repetitive transcranial magnetic stimulation causes a short-term increase in the duration of the cortical silent period in patients with Parkinson's disease.

In ten patients with Parkinson's disease (PD) and ten age-matched healthy controls, we applied 15 30-s trains of subthreshold 5-Hz repetitive transcranial magnetic stimulation (rTMS) over the primary motor hand area. Ten minutes after rTMS, PD patients showed a significant prolongation of the transcranially evoked silent period (SP) in the contralateral first dorsal interosseus muscle, whereas the SP remained unchanged in healthy subjects. Since the duration of the transcranially evoked SP is a well-established measure of intracortical inhibition, this finding demonstrates that rTMS is capable of inducing a short-term increase in intracortical inhibition in PD. The lack of a prolongation of the SP in healthy controls suggests that PD patients may be particularly susceptible to modulatory effects of rTMS on motocortical inhibition.

Adult↗
PubMed2000

Lasting cortical activation after repetitive TMS of the motor cortex: a glucose metabolic study.

OBJECTIVE: Cerebral [18F]fluorodeoxy-D-glucose PET ([18F]FDG-PET) was used to visualize the lasting neuronal activation after repetitive transcranial magnetic stimulation (rTMS) over the left hand area of the primary motor cortex (M1HAND). BACKGROUND: Applied over M1HAND, rTMS has been shown to produce a modulation of corticomotor excitability beyond the time of stimulation itself. METHODS: Eight right-handed subjects underwent nonquantitative [18F]FDG-PET measurements during two experimental conditions: at rest and after focal subthreshold 5-Hz rTMS over the left M1HAND. In the post-rTMS condition, [18F]FDG was injected immediately after the administration of 1,800 magnetic pulses over the left M1HAND. Relative differences in normalized regional cerebral metabolic rate of glucose (normalized rCMRglc) between conditions were determined using a voxel-by-voxel Student's t-test and volume-of-interest (VOI) analysis. Analysis was a priori restricted to the M1HAND, the supplementary motor area (SMA), and the primary auditory cortex of both hemispheres. RESULTS: A 5-Hz rTMS of the left M1HAND caused a lasting relative increase in normalized rCMRglc within the M1HAND bilaterally and the SMA. The magnitude and the topographic pattern of persisting relative rCMRglc increases within these motor cortical areas demonstrated considerable interindividual variations. CONCLUSIONS: Subthreshold 5-Hz repetitive transcranial magnetic stimulation (rTMS) over the hand area of the primary motor cortex is associated with a persisting neuronal activation in a distinct set of motor cortical areas beyond the time of stimulation. The current findings demonstrate that [18F]FDG-PET can localize and quantify regional net changes in synaptic cortical activity after rTMS and thus might elucidate the mechanisms underlying rTMS-associated therapeutic effects.

Adult↗
PubMed2000

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Journal Article↗
PubMed2000

Cortisol and somatization.

Somatization symptoms are frequently associated with depression, anxiety, and feelings of distress. These features interact with the activity of the HPA-axis. Therefore we investigated relationships between somatization symptoms and cortisol. Seventy-seven participants were classified into three groups: somatization syndrome (at least eight physical symptoms from the DSM-IV somatization disorder list), somatization syndrome combined with major depression, and healthy controls. The following data were collected: salivary cortisol at three time points (morning, afternoon, evening), nighttime urinary cortisol, serum cortisol after the dexamethasone suppression test (DST), and psychological variables such as depression, anxiety, somatization, and hypochondriasis. Salivary cortisol showed typical diurnal variations. However, the groups did not differ on any of the cortisol variables. A possible explanation may be counteracting effects of somatization and depression. Exploratory correlational analyses revealed that associations between cortisol and psychopathological variables were time-dependent. DST results correlated with psychological aspects of somatization, but not with the number of somatoform symptoms per se.

Adult↗
PubMed2000

Health seeking and perceived causes of tuberculosis among patients in Manila, Philippines.

Inefficient case finding is an important stumbling block to successful control of tuberculosis (TB). Multiple health seeking may account for delayed case finding. Health-seeking behaviour, health seeking delay, perceived causes, and perceived quality of care related to TB were studied in interviews with 319 sputum smear-positive TB patients. The patients were treated in 22 governmental health centres of Malabon, a municipality of Metro Manila, Philippines. Only 29% of the respondents had gone first to a health centre after onset of TB-related symptoms, and more than half (53%) had initially consulted a private doctor. A chest X-ray was obtained for nearly everyone (97%). Two thirds of the patients (66%) had received a prescription for drugs, and 29% had purchased and taken anti-TB drugs for at least three weeks before they came to a governmental health centre. Concerning community interactions, 36% said they knew at least one person who had been treated for TB without success. The health seeking delay after symptom onset was relatively short - 64% of the respondents said they went to a health facility within 1 month. Case studies illustrate the rationale for health seeking and explain delayed initiation of appropriate treatment for many patients. Findings underscore the need for and indicate approaches to health communication for improved control of TB. Our findings from interview narratives also suggest that improved interpersonal skills of health centre staff and co-ordination between the private doctors and the health centres may substantially improve services for TB patients.

Adult↗
PubMed2000

Sensitivity of indocyanine green angiography for the follow-up of active inflammatory choriocapillaropathies.

BACKGROUND: Inflammatory choriocapillaropathies (choriocapillaritis) correspond to the clinical spectrum of lesions of the fundus, including acute posterior multifocal placoid pigment epitheliopathy (APMPPE), multiple evanescent white dot syndrome (MEWDS), multifocal choroiditis (MC), and other rarer entities caused by inflammatory disturbances of choriocapillaris perfusion. The aim here was to study the sensitivity of indocyanine green (ICG) angiography in investigating and following inflammatory choriocapillaropathies. PATIENTS AND METHODS: Patients with inflammatory choriocapillaropthies were included who had had a dual fluorescein and ICG angiography as well as visual field testing (Goldman or computerized perimetry) at presentation and on follow-up visits. ICG angiography was performed according to a routine angiographic protocol used for inflammatory diseases and was correlated with fundus examination, fluorescein angiography, and visual field testing. RESULTS: Three patients with MEWDS, two with APMPPE, and two with MC were included. The visual field alterations in all seven patients were well correlated with the extent of the hypofluorescent areas seen on ICG angiography, whereas they were badly correlated with fluorescein angiographic signs and their evolution. The visual field in MEWDS was particularly well correlated with the importance of peripapillary hypofluorescence seen on ICG angiography. In MC, the evolution of new lesions was well demonstrated by ICG angiography and well correlated with visual symptoms and visual fields, but was barely detected on fundus examination and by fluorescein angiography. CONCLUSIONS: ICG angiographic signs were shown to be closely correlated with visual function (visual field testing). This was not the case for either fundus examination or fluorescein angiography. ICG angiography appears as a very sensitive follow-up parameter in inflammatory choriocapillaropathies, giving morphological information on the evolution of the disease and on the response to treatment when therapy is indicated.

Adult↗
PubMed1999

Imaging functional activation of the auditory cortex during focal repetitive transcranial magnetic stimulation of the primary motor cortex in normal subjects.

Positron emission tomography (PET) during focal repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising approach to study cortical connectivity in awake humans. However, the noise caused by the discharging magnetic coil might have confounding effects on the rTMS-related cortical activation pattern. In twelve healthy volunteers, 18-fluoro-2-deoxy-D-glucose (18FDG) PET was employed to visualize the functional activation of the primary auditory cortex (PAC) during 2 Hz rTMS of the left primary sensorimotor hand area. Magnetic stimuli (1800) were applied at an intensity of 140% of motor resting threshold during the uptake period of 18FDG. Though all subjects wore earplugs, rTMS-related noise induced a consistent bilateral increase of regional glucose utilization in the PAC (P < 0.05, corrected). Thus, rTMS-related acoustic input needs to be taken into account in combined rTMS/PET studies.

Adult↗
PubMed1999

Abnormal increase in the corticomotor output to the affected hand during repetitive transcranial magnetic stimulation of the primary motor cortex in patients with writer's cramp.

In fourteen right-handed patients with writer's cramp and 10 right-handed controls, 10 trains of suprathreshold 1 Hz repetitive transcranial magnetic stimulation (rTMS) were applied over the left primary motor hand area. Each rTMS train lasted for a minute with an intertrain interval of 10 s. The motor evoked potentials (MEPs) were recorded from the relaxed contralateral first dorsal interosseus muscle. The mean MEP area of each rTMS train was taken as a measure of the corticospinal motor output to the affected hand. While the mean MEP area decreased significantly in controls, patients showed a significant increase in mean MEP area during rTMS. The differential effect on MEP size was highly significant. The abnormal rTMS-associated facilitation of the corticomotor output to the affected hand demonstrates an increased excitability of the corticospinal motor system in writer's cramp.

Adult↗
PubMed1999

Repetitive transcranial magnetic stimulation has a beneficial effect on bradykinesia in Parkinson's disease.

The effect of focal 5 Hz repetitive transcranial magnetic stimulation (rTMS) of the motor hand area (M1) on bradykinesia was studied in 12 unmedicated patients with Parkinson's disease (PD). On 2 separate days, a real-rTMS was applied to M1 contralaterally to the more severely affected limb or a frontal sham-rTMS was applied 3 cm anteriorly to Fz in a random order. Stimulus intensity was 10% below resting motor threshold. Before and 20 min after rTMS, patients performed 15 consecutive pointing movements with the index finger contralaterally to the stimulated M1. Compared with sham-rTMS, real-rTMS over the contralateral M1 caused a significant decrease in total movement time without affecting end-point accuracy. Our data provide evidence that 5 Hz rTMS over M1 can improve bradykinesia in PD patients beyond the time of magnetic stimulation.

Adult↗
PubMed1999

Changes in handwriting resulting from bilateral high-frequency stimulation of the subthalamic nucleus in Parkinson's disease.

High-frequency stimulation of the subthalamic nucleus (STN) is a promising therapeutic approach in patients with severely disabling Parkinson's disease (PD). Whereas STN stimulation improves the cardinal signs of PD, little is known about the effects of STN stimulation on fine manual skills like handwriting. Therefore, the present study investigated the changes in handwriting during bilateral STN stimulation in 12 patients with advanced PD. Dopaminergic medication was discontinued at least 12 hours before the study. The patients were asked to write a standardized sentence repetitively. Five samples of the patient's script were recorded during effective bilateral STN stimulation and 1 hour after both stimulators had been switched off. The movements of the tip of the pencil were recorded using a digitizing tablet. Handwriting movements were segmented into subsequent up- and down-strokes, and a stroke-based kinematic analysis of handwriting was performed. During high-frequency STN stimulation, handwriting movements became faster and smoother indicating a partial restoration of an "open-loop" automatic performance. In addition, STN stimulation gave rise to a significant increase in the mean vertical stroke length demonstrating a stimulation-related reduction in micrographia. The present data underscores the importance of the STN in "open-loop" performance of highly skilled sequential hand movements.

Aged↗
PubMed1999

[The "heme"-sequence (T2*-weighted gradient echo magnetic resonance tomography). Value in differential spontaneous intracerebral hemorrhage diagnosis].

In four patients presenting with acute non-traumatic intracerebral or intraspinal hemorrhage, T2*-weighted gradient-echo MRI showed numerous residual hemosiderin deposits due to old intracerebral hemorrhages that were missed on initial CT and spin-echo MRI. The demonstration of additional chronic bleedings and their anatomical distribution provided important diagnostic information. In a hypertensive patient, the hemosiderin deposits were most pronounced within deep brain structures suggesting hypertensive cerebral microangiopathy. In a second patient, the cortico-subcortical distribution of the hemorrhages was typical of cerebral amyloid angiopathy. In a third patient, the diffuse distribution including spinal bleeding, the marked calcification, and the characteristic appearance on spin-echo MRI were consistent with multiple cavernomas. In another patient with cerebral and spinal hemorrhage, T2*-weighted gradient-echo MRI revealed new subclinical hemorrhages during follow-up. Based on these findings, we recommend that T2*-weighted gradient-echo MRI of the brain should be performed in all patients with acute intracranial and spinal bleedings.

Aged↗
PubMed1999

Trigeminal sensory input elicited by electric or magnetic stimulation interferes with the central motor drive to the intrinsic hand muscles.

In 6 normal subjects, unilateral supraorbital magnetic or electric stimulation resulted in a consistent symmetrical inhibition of the motor evoked potentials (MEPs) of the relaxed and preactivated first dorsal interosseus (FDI) muscle. A supraorbital stimulus caused a significant reduction in amplitude when the trigeminal CS was given 30 to 65 ms before transcranial magnetic stimulation (TMS). In addition, supraorbital magnetic stimulation induced a bilateral EMG suppression of the isometrically contracting FDI muscles, starting about 40 to 50 ms after the magnetic stimulus. In 4 subjects, MEPs evoked by transcranial electric stimulation or by TMS during slight muscle contraction showed a comparable trigeminomotor inhibition. These findings demonstrate that electromagnetic stimulation of trigeminal afferents interferes with the motor output to the intrinsic hand muscles inducing a bilateral inhibition which is probably mediated by a multisynaptic subcortical network. In all 6 subjects, TMS over the motor hand area or the cerebellum elicited a reproducible blink reflex. Since the blink reflex is a sensitive indicator of trigeminal excitation, one has to assume that TMS is associated with a significant excitation of trigeminal afferents. Therefore, trigeminomotor inhibition has to be considered in all TMS studies that use a conditioning-test design.

Adult↗
PubMed1999

Indocyanine green angiography features in toxoplasmic retinochoroiditis.

BACKGROUND: Indocyanine green (ICG) angiography detects the infrared fluorescence of ICG through the retinal pigment epithelium, providing visualization of the choroidal vascular network. The aim of this study was to analyze ICG angiographic features in toxoplasmic retinochoroiditis. METHODS: Indocyanine green angiography was performed according to a standard uveitis angiographic protocol in 28 consecutive patients diagnosed with acute toxoplasmic retinochoroiditis. Indocyanine green angiographic data were compared with fundus color photographs and fluorescein angiography (FA). Evolution of ICG angiographic signs after therapy (pyrimethamine and sulfadiazine with or without a tapering course of oral corticosteroids) was further analyzed. RESULTS: The main focus of retinochoroiditis was hypofluorescent at all phases of the ICG angiogram in 25/28 cases (89%), but late phase (35-45 minutes) ICG hyperfluorescence was seen in three cases, all of which had very superficial retinal involvement. The most striking features, however, were multiple hypofluorescent satellite dark dots (SDD), present in 21/28 cases (75%). In 17 of these 21 patients, hypofluorescent areas were silent on FA and fundus examination. After therapy, SDD disappeared from most of the cases. Furthermore, the hypofluorescence under the main lesion was markedly reduced or disappeared in some cases. CONCLUSIONS: Indocyanine green angiography showed that toxoplasmic retinochoroiditis is a more widespread process than is clinically suspected because it extends beyond the visible lesions. Indocyanine green angiography appears useful in assessing the extent of choroidal involvement and the evolution of lesions. It might become an important follow-up parameter and also may give new insights into the pathophysiology of this disease. Based on the findings gathered so far, ICG angiography appears indicated in the workup and management of toxoplasmic retinochoroiditis.

Acute Disease↗
PubMed1999

Low-frequency repetitive transcranial magnetic stimulation of the motor cortex in writer's cramp.

OBJECTIVE: To study the short-term effects of slow repetitive transcranial magnetic stimulation (rTMS) of the motor cortex on cortical excitability and handwriting in patients with writer's cramp. BACKGROUND: Cortical excitability of the primary motor cortex is abnormally enhanced in patients with writer's cramp. Therefore, reducing cortical excitability by low-frequency rTMS of the motor cortex might result in beneficial effects on handwriting in writer's cramp. DESIGN/METHODS: We studied the effects of subthreshold 1-Hz rTMS on motor threshold and cortico-cortical excitability using the paired-pulse technique in seven patients and seven controls. In another 16 patients and 11 age-matched controls we evaluated changes in cortical excitability by measuring the stimulus-response curve and the postexcitatory silent period before and after subthreshold 1-Hz rTMS. In addition, we analyzed the handwriting before and 20 minutes after 1-Hz rTMS. RESULTS: In the first experiment, low-frequency rTMS resulted in a normalization of the deficient cortico-cortical inhibition in the patients without affecting motor threshold. In the second experiment, 1-Hz rTMS resulted in a significant prolongation of the postexcitatory silent period without affecting the stimulus-response curve in the patient group. Moreover, the dystonic patients showed a significant reduction of mean writing pressure after subthreshold 1-Hz rTMS that was associated with clear but transient improvement in six patients. CONCLUSIONS: In some patients 1-Hz rTMS can reinforce deficient intracortical inhibition and may improve handwriting temporarily. Our data support the notion that reduced intracortical inhibition plays a part in the pathophysiology of focal dystonia.

Adult↗