Biomedical subjects
K Wessel
Publications and source records attributed to K Wessel.
Effective cabergoline treatment in idiopathic restless legs syndrome.
OBJECTIVE: To assess the efficacy and safety of the dopamine agonist cabergoline (CAB) in patients with restless legs syndrome (RLS). METHODS: Patients with moderate to severe RLS were randomized into four groups receiving placebo, 0.5 mg, 1 mg, or 2 mg CAB once daily in a double-blind, placebo-controlled, multicenter dose-finding trial followed by an open long-term extension trial of 47 weeks. Efficacy was assessed with the RLS-6 scales and International RLS Study Group severity scale (IRLS). RESULTS: A total of 85 patients (age 56 +/- 10 years, 71% females) were treated. Severity of RLS-6 scale symptoms during the night (the primary endpoint) was markedly improved by all CAB doses compared to placebo (placebo: -1.4 +/- 3.1, 0.5 mg CAB: -4.2 +/- 3.0 [p = 0.0082], 1.0 mg CAB: -4.0 +/- 2.9 [p = 0.0040], 2.0 mg CAB: -4.8 +/- 3.7 [p = 0.0026]). Similar results were found for the RLS severity at bedtime and during the day, IRLS, and satisfaction with sleep. A stable, clinically relevant improvement was achieved in all efficacy measures (severity during the night: change between last assessment and baseline: -5.6 +/- 2.5, rate of remission: 71.2%) throughout 1 year with a mean CAB dose of 2.2 mg per day. During long-term treatment, 6 of 66 treated patients were affected (n = 2) or possibly affected (n = 4) by mild augmentation. Under CAB therapy up to 1 year, 11 of 85 patients discontinued treatment due to a drug-related adverse event. CONCLUSIONS: Cabergoline is an efficacious and well-tolerated option for the treatment of restless legs symptoms during the night and the day.
[Therapy of back pain: what is evidence-based?].
Back pain has to be classified by localisation, duration, and existence or absence of neurological deficits. Therapy mainly depends on the severity of neurological symptoms. The time period between the onset of symptoms and efficient therapy should be short in order to prevent the development of chronic pain. Therefore a sufficient, consistent and evidence-based conservative treatment should be initiated early on, with the only exception of special emergency situations as described further down in this article. Patients should not be immobilized, a better outcome is proven in patients who immediately continued practising their daily activities. First line medication consists of non-steroidal-anti-inflammatory-drugs (NSAID). If necessary, opioids and muscle-relaxants may be applied additionally. Surgical procedures are only indicated in a small number of patients. A sufficient data base with regard to the benefit of acupuncture, orthesis, and chiropractic medicine is lacking. Local injections should only be done in very special cases. Concerning chronic back pain a multimodal, multi-disciplinary pain treatment concept with physical training and behavioural therapy should be applied in order to teach the patient to avoid a passive and maladjusted attitude. Antidepressant drugs may also be indicated in chronic back pain.
Transcranial magnetic brain stimulation and the cerebellum.
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Positive neuropathic sensory symptoms as endpoints in diabetic neuropathy trials.
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Voluntary palatal tremor is associated with hyperactivation of the inferior olive: a functional magnetic resonance imaging study.
Voluntary palatal tremor in a patient with essential palatal tremor induced activation predominantly within regions corresponding to the inferior olive, adjacent brainstem, and dentate nuclei. Finger movements elicited only ipsilateral lobular cerebellar activation, suggesting a dysfunctional nuclear activation by palatal tremor.
Collet-Sicard's syndrome as a result of jugular vein thrombosis.
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[Electromyography of the infrahyoid muscles - part 1: normal findings].
BACKGROUND: The infrahyoid muscles (IHM) are very useful as a neurovascular myofascial flap in plastic reconstructive surgery of the upper aerodigestive tract, especially for restoration of the muscular component in larger tongue defects. As a base for further postoperative investigations on the function of transferred IHM this first part of the study describes the physiological function and the electromyographical features of the IHM. METHODS: In 17 patients with cancer of the upper aerodigestive tract the sternohyoid and sternothyroid muscles and in additionally eight patients the upper part of the omohyoid muscle were studied electromyographically. Muscular activity was recorded at various movements and maximal voluntary innervation. In ten healthy volunteers the motor unit potentials (MUP) during light voluntary innervation of these muscles were studied. RESULTS: In both muscles we found the steadist and strongest muscular activity at isometric head bending and yaw opening, in the omohyoid muscle also at head rotation. At swallowing and breathing in (2/3) of the cases muscular activity could be recorded. Amplitudes and electromyographic charge pattern in comparison were diminished. Phonation und tongue movements showed no noticable muscular activity. Analysis of the MUP in 10 healthy volunteers showed a mean amplitude of 274 +/- 59 microV and a mean duration of 8.5 +/- 0.6 ms. CONCLUSIONS: The presented study demonstrates that EMG of the IHM are recorded best while head bending, yaw opening and head rotation. Since there is no interchange of nerve fibres between the hypoglossal nerve and the cervical ansa it should be possible to differentiate between original tongue muscles and transferred muscles in electromyographic studies of myofascial flaps after tongue reconstruction.
[Electromyography of the infrahyoid muscles - part 2: pathological findings].
BACKGROUND: The infrahyoid muscles (IHM) can easily be used as a neurovascular myofascial flap for reconstructive surgery in the oral cavity and pharynx and especially for functional tongue reconstruction following tumor ablation. METHODS: In order to detect neurogenic lesions caused by neck pathologies, in particular lymph node metastasis, we studied ten patients (nine patients suffering from tongue carcinoma and one patient after traumatic tongue ablation) by preoperative electromyography of the IHM. These results were compared to ten healthy controls. RESULTS: We found no pathological spontaneous activity with the EMG at rest in any patient. During light voluntary innervation, the motor unit potentials (MUP) were normal in controls and in patients with normal ultrasound, CT scans and histologic examination after neck surgery. When pathologic lymph nodes were found in the neck, the number of polyphasic MUP in the ipsilateral IHM was increased in some cases (n = 6), and normal in others (n = 5). Traumatic or radiogenic lesions clearly resulted in pathological EMG findings (n = 6). Maximal innervation of the IHM was obtained during head bending and jaw opening. We found no difference in the discharge pattern of both groups. CONCLUSIONS: Due to their extent lymph node metastasis can lead to neurogenic lesions of the cervical ansa of the IHM. Neurogenic damages are most clearly present after traumatic lesions of the neck (prior operations, radiotherapy). EMG at maximal voluntary contraction instead revealed no lesions. The clinical impact of these demonstrated neurogenic lesions need to be studied by measuring the muscle strength of the IHM.
[Electromyography of the infrahyoid muscles - part 3: findings after transposition as a myofascial flap in tongue reconstruction].
BACKGROUND: Due to the preservation of its nerval supply the neurovascular infrahyoid muscle flap in tongue reconstruction enables to prevent atrophy of the musculature. In this study the integrity of the infrahyoid muscles (IHM) after transposition into the oral cavity was examined by means of electromyography. METHODS: 17 patients after partial or complete reconstruction of the tongue with IHM were studied at varied times after surgery. The IHM in the oral cavity was inserted by a concentric needle electrode and activity at rest as well as the discharge pattern at maximal voluntary innervation was evaluated. During light voluntary activity a motor unit potential (MUP) analysis were performed. RESULTS: 13 of 17 patients (76,5 %) in total revealed electromyographic activity in the transfered IHM flaps. Within the first 6 months after surgery 71,5 % of the patients or 77,8 % of the IHM flaps showed activity. After 6 months in 61,5 % of the patients or 64,7 % of the IHM flaps muscular activity was demonstrated. In 84,6 % of the patients or 88,2 % of the flaps we could detect neurogenic lesions at least once. Maximal voluntary contraction showed a discrete activity pattern in 63 %. In 26 % of all cases we found a discrete to reduced interference pattern and in 10 % a reduced interference pattern. CONCLUSIONS: Functioning muscle tissue could be demonstrated in the most IHM flaps, but almost all of the studied muscles showed neurogenic lesions with a loss of motor units due to the traumatic surgery. Maybe bioelectrical stimulation of the Ansa cervicalis with implantable amplifiers will lead to better flap contractility in the future.
New metabolic pathways of alpha-lipoic acid.
The excretion and biotransformation of rac-alpha-lipoic acid (LA), which is used for the symptomatic treatment of diabetic polyneuropathy, were investigated following single oral dosing of [(14)C]LA to mice (30 mg/kg), rats (30 mg/kg), dogs (10 mg/kg), and unlabeled LA to humans (600 mg). More than 80% of the radioactivity given was renally excreted. Metabolite profiles obtained by radiometric high-performance liquid chromatography revealed that LA was extensively metabolized irrespective of the species. Based on a new on-line liquid chromatography/tandem mass spectroscopy assay developed for negative ions, LA and a total of 12 metabolites were identified. Mitochondrial beta-oxidation played the paramount role in the metabolism of LA. Simultaneously, the circulating metabolites were subjected to reduction of the 1,2-dithiolane ring and subsequent S-methylation. In addition, evidence is given for the first time that the methyl sulfides formed were partly oxidized to give sulfoxides, predominantly in dogs. The disulfoxide of 2,4-bismethylmercapto-butanoic acid, the most polar metabolite identified, was the major metabolite in dogs. Furthermore, new data are presented that suggest conjugation with glycine occurred as a separate metabolic pathway in competition with beta-oxidation, predominantly in mice.
Association between clinical disease activity and Epstein-Barr virus reactivation in MS.
OBJECTIVE: To assess the potential significance of Epstein-Barr virus (EBV) reactivation in disease activity in MS patients. METHODS: The prevalence of antibodies against herpes simplex virus type 1 (HSV-1), HSV-2, EBV, and cytomegalovirus was determined in a group of 108 MS patients and in 163 healthy control subjects. Sera were analyzed using combinations of novel assay systems employing highly purified viral and recombinant antigens. In addition, PCR for the detection of EBV DNA was performed in serial samples. RESULTS: In contrast to the control populations, antibodies against EBV were present in 100% of MS patients. Among the tested human herpesviruses, this high extent of seropositivity was only found for EBV. Primary infection was found exclusively in the control group (3.7%), whereas serologic evidence of EBV reactivation was seen in MS patients (13. 9%) as well as control subjects (17.2%). There was no temporal coincidence between EBV reactivation and disease activity in MS patients. However, in 19 patients followed monthly for 1 year, active viral replication as measured by increased immunoglobulin (Ig) M and IgA responses to EBV early antigens (p54 + p138) and positive serum DNA was seen in 72.7% of patients with exacerbations during the study period and in none of the patients with clinically stable disease. CONCLUSIONS: The results demonstrate an association between EBV reactivation and disease activity in MS patients over time, and suggest that EBV might play an indirect role in MS as an activator of the underlying disease process.
CNV and temporal uncertainty with 'ageing' and 'non-ageing' S1-S2 intervals.
OBJECTIVES: Uncertainty about the timing of a known external event is an everyday phenomenon but has been rarely investigated with electrophysiological methods. We studied how the amplitude of the contingent negative variation (CNV) is affected by temporal variation of S2 presentation. Competing hypotheses about the development of CNV during the foreperiod until S2 presentation were that CNV either would follow a monotonic trend, be it increasing or decreasing, or alternatively that the time-course of CNV would be affected by the probability with which S2 was presented at each time-point in a given task. METHODS: The interval between cueing stimulus and imperative stimulus was randomly chosen from 3 different values between 1.3 and 2.6 s, using 3 different probability distributions in separate blocks: an 'ageing', a 'non-ageing' and a 'Gaussian' distribution. RESULTS: As previously shown, reaction times were determined by the probability of the imperative stimulus at the given length of the foreperiod. The same was found for CNV amplitude: the effects of temporal uncertainty on CNV mainly depended on the particular distribution of temporal probabilities used in a block. The relevant parameter was the a posteriori probability of event occurrence, very similar to the effects of this parameter on response times. In fact, the major part of the effect of a posteriori probability on CNV was common variation of CNV and response times. CONCLUSIONS: Thus, under temporal uncertainty the amplitude of CNV reflects the subjective expectancies for the occurrence of a given event, with this variation being related to variations in response times.
Altered prevalence and reactivity of anti-Epstein-Barr virus antibodies in patients with multiple sclerosis.
In this study, the prevalence and reactivity of anti-Epstein-Barr virus (EBV) antibodies were investigated in 107 patients with multiple sclerosis (MS) in comparison to age- and gender-matched healthy controls from a north German state. We found a significant 100% EBV-seropositivity and a significant lack of primary EBV infections in the MS group, indicating that all MS patients are infected with EBV before the development of MS. Although there were no differences in reactivities of EBV-specific anti-early antigen (EA)-immunoglobulin G (IgG), -IgM, and -IgA antibodies between each group, MS patients had significant lower anti-Epstein-Barr nuclear antigen (EBNA)1-IgG antibody titers as a possible serological sign for a defective control of the persistent latent EBV carrier state and EBV reactivations. Longitudinal studies of MS patients are necessary to further determine the implications of EBV reactivations on the course and disease activity of MS.
Integrating effective home care aide recruitment & retention strategies.
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Consequences of altered cerebellar input for the cortical regulation of motor coordination, as reflected in EEG potentials.
The cerebellum is certainly involved in fine coordination of movements, but has no efferences of its own to the muscles. Thus, it can exert its influence only via other cerebral areas that have those efferences. This study investigated in patients with cerebellar atrophy how cortical motor areas are affected by dysfunction of the cerebellum. The main question was whether the patients' slow cortical electroencephalogram (EEG) potentials during key-press preparation and execution would be generally altered or would be specifically altered when fine coordination was needed. In the coordination task, right- and left-hand keys had to be pressed simultaneously with different forces, under visual feedback. Control tasks were to press with both hands equally or with one hand only. The patients indeed had a performance deficit in the coordination task. Their cortical EEG potentials were already drastically reduced in the simple tasks, but were enhanced by the same amount as in healthy subjects when more coordination was needed. These results suggest that the cerebellum is not exclusively active in fine coordination, but is generally involved in any kind of preparatory and executive activity, whereas the motor cortex becomes more active with fine coordination. The role of the cerebellum might be to provide the motor cortex with information needed for coordinating movements. In cerebellar atrophy, this altered input may be sufficient for the motor cortex in controlling simple tasks, but not for complex ones.
Clinical and molecular findings in multiple sclerosis patients with type 1 diabetes mellitus.
The clinical and molecular findings in three patients with multiple sclerosis (MS) and additional type 1 diabetes mellitus are described. These patients all presented with a severe and progressive disease course of MS. Molecular testing for HLA class II genes demonstrated the presence of the haplotype DRB1*0401, DQB1*0302 in all patients. This haplotype is closely linked to type 1 diabetes mellitus and is increased among patients with the primary progressive subtype of MS. We conclude that the immunogenetic background in patients with diabetes mellitus may determine the severity and clinical course of MS in these individuals. Copyright 1999 Harcourt Publishers Ltd.
Changed intracortical facilitation and silent period in the motor cortex of patients with cerebellar degeneration.
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