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Biomedical subjects

G Ebersbach

Publications and source records attributed to G Ebersbach.

At least 19 recordsLinked to original sources
PubMed2006

Screening for cognitive impairment in Parkinson's disease--which marker relates to disease severity?

The frequency and pattern of cognitive deficits in Parkinson's disease (PD) is under discussion. We assessed 157 consecutive subjects with PD (66.4 +/- 8.9 years (mean +/- standard deviation); average duration of disease 3.5 +/- 1.3 years; average Hoehn and Yahr stage 2.4 +/- 0.9) diagnosed in centers specialized for the diagnosis and treatment of PD with brief tests for memory (Memory Impairment Screen), attention (Letter Sorting Test) and semantic fluency (category animals). Impaired memory was observed in about one half of the subjects regardless of severity of disease as assessed by staging according to Hoehn and Yahr. With greater severity, free recall was impaired and subjects required the cues to recall the items. Performance in the Letter Sorting Test and the semantic fluency task declined with increasing Hoehn and Yahr stage, also. We conclude that cognitive deficits are frequent in PD. Further analyses reveal that even in selected screening tests (e.g. semantic fluency) a significant impairment with increasing disease severity (Hoehn and Yahr stage) as opposed to disease duration alone can be demonstrated.

Aged↗
PubMed2006

[Vascular parkinsonian syndrome].

The present review shows that vascular parkinsonian syndrome (VPS) fulfilling stringent diagnostic criteria for parkinsonism is a rare disease that cannot always be distinguished from neurodegenerative parkinsonism on clinical grounds. Thus VPS needs to be differentiated from other disturbances, which have distinct phenomenological and therapeutical features including isolated gait disturbances associated with subcortical arteriosclerotic encephalopathy and neurodegenerative parkinsonism complicated by comorbid vascular encephalopathy. Acute or subacute VPS is usually caused by contralateral infarctions involving the external globus pallidus, ventrolateral thalamus, and, less often, the substantia nigra. Chronic VPS with insidious onset is related to bilateral subcortical infarctions affecting thalamocortical projections. Differentiation from degenerative parkinsonism is difficult in cases of VPS that display a progressive course and response to levodopa.

Cerebrovascular Disorders↗
PubMed2002

[Dysequilibrium in idiopathic Parkinson disease. The effect of cerebrovascular comorbidity].

Disturbance of balance in idiopathic Parkinson's disease (IPD) has a significant effect on disability. Yet the underlying mechanisms and the contribution of age-associated comorbidity to dysequilibrium are unclear. In this study, static posturography was performed in 30 healthy controls and 40 patients with IPD. Comparison of sway during quiet stance did not show significant differences between patients and controls. Multiple linear regression analysis was used to identify factors responsible for the considerable interindividual variance in patients. Results of the pull test, CT-verified cerebral microangiopathy, dementia, and age were assessed, but only cerebrovascular comorbidity contributed significantly to variance. Apart from increased sway, patients with coinciding cerebral microangiopathy (n = 20) more frequently had a history of falls or pathological responses in the pull test. The present results suggest that cerebrovascular comorbidity enhances dysequilibrium in IPD. Pathological sway in IPD can indicate comorbidity and may have implications for further diagnostics.

Aged↗
PubMed2001

The double par locus of virulence factor pB171: DNA segregation is correlated with oscillation of ParA.

Prokaryotic plasmids and chromosomes encode partitioning (par) loci that segregate DNA to daughter cells before cell division. Recent database analyses showed that almost all known par loci encode an ATPase and a DNA-binding protein, and one or more cis-acting regions where the proteins act. All par-encoded ATPases belong to one of two protein superfamilies, Walker-type and actin-like ATPases. This property was recently used to divide par loci into Types I and II loci. We show here that the Escherichia coli virulence factor pB171 encodes a double par locus that consists of one Type I and one Type II locus. Separately, each locus stabilized a test-plasmid efficiently. Together, the two loci mediated even more efficient plasmid stabilization. The par loci have a unique genetic organization in that they share a common central region at which the two different DNA-binding proteins probably act. Interestingly, a fusion protein consisting of the Walker-type ParA ATPase and Gfp was functional and oscillated in nucleoid regions on a time scale of minutes. ParA-green fluorescent protein (Gfp) oscillation depended on both ParB and parC but was independent of minCDE. Point mutations in the Walker A box motif simultaneously abolished plasmid stabilization and ParA-Gfp oscillation. These observations raise the possibility that ParA oscillation is prerequisite for active plasmid segregation.

Bacterial Proteins↗
PubMed2001

Sudden daytime sleep onset in Parkinson's disease: polysomnographic recordings.

Sleep attacks in Parkinson's disease are controversially discussed. This paper describes a patient with Parkinson's disease suffering from sudden, irresistible onset of sleep during daytime. Medication included levodopa, entacapone, budipine, and cabergoline. Introduction of entacapone was the last therapeutic action preceding onset of sleep events, suggesting increased bioavailabilty of levodopa to be provocative in this case. In contrast to previous cases, the sudden sleep events were witnessed by clinical staff members and documented by polysomnographic and video recordings. Polysomnography during these sleep events remarkably showed abrupt slowing of EEG-background activity and occurrence of slow eye movements and K-complexes within 10 seconds after stable wakefulness. Within 60 seconds, the polysomnographic pattern proceeded to stable sleep stage 2.

Electroencephalography↗
PubMed2001

Dynamic balance function in phasic cervical dystonia following Botulinum toxin therapy.

Previous research by our group revealed normal dynamic balance function in pure tonic cervical dystonia (CD) with impaired equilibrium in phasic CD patients investigated at least 3 months following Botulinum toxin (BtxA) treatment. The current study was performed to determine whether impaired dynamic equilibrium in phasic CD is influenced by symptomatic treatment with BtxA. Dynamic balance was tested in 20 patients with phasic CD on a dynamic platform with a cylindrical curved base (stabilometer) 4 weeks following BtxA treatment. Balance was assessed by the linear displacement of the platform and the maximum amplitude of platform displacement with open and closed eyes and compared with pre-BtxA data. Despite a clinically significant BtxA-induced reduction of phasic head movements, none of the platform measures improved significantly. In addition, there was no correlation between the BtxA-induced clinical improvement and changes in any of the dynamic balance measures pre- vs. post-BtxA. In conclusion, the persistent dynamic balance impairment after effective BtxA therapy may indicate that disequilibrium in phasic CD does not simply reflect disturbed vestibular input from repetitive head oscillations, but argues in favour of different sensorimotor processing in tonic and phasic CD.

Adult↗
PubMed2001

Rhythmic feet movements while falling asleep.

During the wake-sleep transition and sleep, diverse motor phenomena such as hypnagogic foot tremor may occur in the lower extremities. We investigated the relevance of this phenomenon in 375 consecutive subjects examined polysomnographically in a sleep disorders center. Rhythmic feet movements while falling asleep (RFM) were found in 28 subjects (7.5%). RFM occurred mostly as single, short series with a duration of between 10 and 15 seconds. They had a high night-to-night variability and were detected as rhythmic, oscillating movements of the whole foot or toes. Surface electromyographic (EMG) recordings displayed series of repetitive phasic bursts with a periodicity mostly between 1 and 2 per second. Single EMG burst duration varied between 300 and 700 msec. RFM at highest intensity occurred during presleep wakefulness, and usually persisted in sleep stages 1 and 2. RFM did not have a major sleep-disturbing effect in any of the affected subjects. Due to its high prevalence and the lack of a major sleep-disturbing effect, short series of RFM could be considered a quasiphysiological phenomenon. However, in more severe forms of RFM with evidence of a sleep-disturbing effect, RFM should be considered abnormal.

Adolescent↗
PubMed2001

Clinical characteristics of the geste antagoniste in cervical dystonia.

The geste antagoniste (moving an arm to the face or head) is a well-known clinical feature in cervical dystonia (CD) to alleviate the abnormal posture. The clinical phenomenology of these manoeuvres has not so far been assessed systematically. Fifty patients with idiopathic CD aware of at least one geste antagoniste (60% women, mean age at onset 44.1 years, mean disease duration 7.5 years) were subjected to a standardized investigation including a semiquantitative clinical rating scale and polymyographic recordings of six cervical muscles. Twenty-seven patients (54%) demonstrated more than one geste antagoniste (range 2-5). A clinically significant (> or = 30%) reduction of head deviation was observed in 41 patients (82 %). Dystonic head posture improved by a mean of 60 % along all planes by the geste manoeuvre with a complete cessation of head oscillations in nine of 33 patients (27 %) with phasic CD. No significant laterality of the "geste-arm" or the facial target area was found. The duration of geste-effects depended significantly on disease duration and determined the patient's self-rating of the benefit of the manoeuvre. EMG-polygraphy revealed two types of geste-induced polymyographic changes: a decrease in recruitment density and amplitude in at least one dystonic muscle (66%), and an increased tonic muscle activation in the remaining patients. The remarkable efficacy of the geste antagoniste and the considerable variety in performance, duration, and EMG-pattern of these manoeuvres warrant further investigation of the therapeutic use of sensorimotor stimulation, in particular for those CD patients who experience limited or no effect from botulinum toxin therapy.

Adolescent↗
PubMed2000

Sociocultural differences in gait.

Transcultural differences in routine motor behavior and movement disorders have rarely been assessed. In the present study gait was studied in 47 healthy inhabitants of Tyrol living in rural or semi-urban (Innsbruck, Austria) settings and 43 healthy subjects residing in Berlin, Germany. In addition, gait was assessed in 23 patients in early stages of idiopathic Parkinson's disease (11 in Berlin, 12 in Innsbruck). Healthy subjects in Berlin showed faster gait velocity than their counterparts in Tyrol, and patients with Parkinson's disease were slightly slower than their respective healthy peers in both environments. Surprisingly, patients with Parkinson's disease from Berlin had significantly faster walking speeds than both patients and healthy control subjects from Tyrol. High gait tempo in parkinsonian patients from Berlin was characterized by fast step-rates and short strides. Differences in normal gait in different sociocultural settings are thus reflected in parkinsonian slowing of gait.

Aged↗
PubMed1999

[Safety and tolerance of single-dose botulinum toxin Type A treatment in 204 patients with spasticity and localized associated symptoms. Austrian and German botulinum toxin A spasticity study group].

High dose oral anti-spastic medication is effective in the treatment of spasticity but has the disadvantage of frequent systemic side effects such as drowsiness and general weakness. Therefore, neurolytic and chemodenervation procedures are further therapeutic options, especially in cases of local spasticity. Apart from phenol blocks with the risk of persisting painful dysesthesia, botulinum toxin type A (BtxA) appears to be a safe and effective treatment. In 204 patients (mean age, 41.5 years [range 3-91 years]) with acute (n = 29, mean duration of disease 2.9 months [range, 1-6 months]) and chronic (n = 175, mean duration of disease 111 months [range, 7-500 months]) spasticity due to stroke, traumatic brain and spinal injury and other lesions of the upper motor neuron, the effects of single-dose BtxA treatment were studied. An overall dose of 181.2 units [range, 15-600 units] of BtxA (Botox) was injected in a mean of 3.3 [1-14] muscles per patient. Results were assessed using a modified Rating of Response to BtxA (RRB, Brin et al. 1995). The RRB includes a pre- and post BtxA assessment of the severity of spasticity-associated problems (patient's self-assessment), a rating of the current percentage of normal function in the region of the body selected for BtxA and a global rating of changes induced by BtxA. 191 (93.6%) patients demonstrated improvement over a mean of 7.7 weeks [1-36]; no deterioration was observed. Mean overall severity and function improved significantly (p < 0.001). No systemic or severe side effects were registered. Only in 5.9% of the patients were mild (n = 10) or moderate (n = 2) reversible adverse events reported. We conclude that BtxA injections are safe and effective in the treatment of local spasticity.

Administration, Oral↗
PubMed1999

Interference of rhythmic constraint on gait in healthy subjects and patients with early Parkinson's disease: evidence for impaired locomotor pattern generation in early Parkinson's disease.

Patients in the early stages of Parkinson's disease have been shown to walk slower with smaller steps, resembling the gait of normal elderly subjects, but specific disorders of dynamic equilibrium or rhythmic gait patterning have not yet been identified. In the present study, gait control in 22 healthy subjects and 22 patients with early Parkinson's disease was challenged by means of a paradigm requiring subjects to decrease their step rate (cadence) by 20% in response to a metronome signal (rhythmic constraint). Control subjects and patients were matched for age, sex, and body height. Eleven patients were receiving standard antiparkinsonian therapy and were assessed under their ongoing medication, whereas the remaining 11 patients had not yet been started on dopaminergic therapy ("de novo" Parkinson's disease). Gait parameters reflecting dynamic equilibrium (double-support time) and locomotor patterning (step length, stride duration) were recorded by means of a mechanical device (locometer). Sixteen patients and 16 control subjects were able to accomplish the task. Whereas regulation of step length became irregular during rhythmic constraint in both patients and control subjects, irregular timing of steps was only observed in patients suggesting disturbance of periodic locomotor activity generation.

Aged↗
PubMed1999

Worsening of motor performance in patients with Parkinson's disease following transdermal nicotine administration.

Nicotine has been reported to have positive effects on motor performance in patients with Parkinson's disease. In this study, motor performance was evaluated in 16 patients with idiopathic Parkinson's disease during a practical off-period using the motor part of the Unified Parkinson's Disease Rating Scale after 12 hours' exposure to a transdermal patch containing 35 mg nicotine or placebo. The study was performed using a double-blind crossover design. In contrast to previous reports, nicotine exposure was followed by a worsening of symptoms compared with placebo. A negative response to subthreshold dopaminergic stimulation, resulting from an inhibitory effect of low striatal dopamine concentrations acting on a subset of dopamine receptors, might possibly account for this finding.

Administration, Cutaneous↗
PubMed1999

Progression of falls in postmortem-confirmed parkinsonian disorders.

Although falls are known to occur in several parkinsonian disorders, such as Parkinson's disease (PD), multiple system atrophy (MSA), dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), differences in the evolution of this feature have not been studied systematically in pathologically confirmed cases. Seventy-seven cases with pathologically confirmed parkinsonian disorders (PD: n = 11, MSA: n = 15, DLB: n = 14, CBD: n = 13, PSP: n = 24), collected up to 1994, formed the basis for a multicenter clinicopathologic study organized by the National Institute of Neurological Disorders and Stroke to improve differential diagnosis of parkinsonian disorders. In the present study, we determined the time course, that is, the duration from first symptom to onset (latency) and duration from onset to death, of recurrent falls. Furthermore, we analyzed the diagnostic validity of a predefined latency to onset of recurrent falls within 1 year of symptom onset. Significant group differences for latency, but not duration, of recurrent falls were observed. Latencies to onset of falls were short in PSP patients, intermediate in MSA, DLB, and CBD, and long in PD. Recurrent falls occurring within the first year after disease onset predicted PSP in 68% of the patients. Our study demonstrates for the first time that latency to onset, but not duration, of recurrent falls differentiates PD from other parkinsonian disorders. Whereas early falls are important for the diagnosis of PSP, the addition of other features increases its diagnostic predictive value.

Accidental Falls↗
PubMed1999

Trick maneuvers in cervical dystonia: investigation of movement- and touch-related changes in polymyographic activity.

Antagonistic gestures or trick maneuvers are well-known clinical features to reduce or abolish dystonic posturing in cervical dystonia (CD). The maneuvers typically consist of a finger touch to the facial skin but their physiology remains unknown. To determine the temporal profile of geste maneuver performance, 25 patients with idiopathic CD were studied by means of polymyography of six cervical muscles prior to any botulinum toxin treatment. Two piezoelectric elements fixed to a fingertip of the hand involved in the trick maneuver and to the facial target region, respectively, were used to relate the essential points of the trick maneuver time course (start of geste-arm movement, facial contact, end of contact, end of movement) to changes in polymyographic activity. Thirteen patients (52%) showed marked reductions of electromyographic (EMG) activity (> or =50% in at least one muscle) during arm movement, definitely prior to contact between fingers and facial target area; in the remaining 12 patients (48%), geste-related EMG effects were confined to facial-finger contact. These results might indicate different physiological mechanisms in clinically indistinguishable antagonistic gestures.

Adult↗
PubMed1999

Dopamine D4 receptor polymorphism and idiopathic Parkinson's disease.

Patients with idiopathic Parkinson's disease (IPD) are described as having markedly decreased novelty seeking characteristics. Since recent publications suggest an association between the dopamine D4 receptor polymorphism and novelty seeking, we investigated this polymorphism in a group of 122 patients with IPD and 127 healthy control subjects. We found similar allele and genotype frequencies in both groups and no association with the age of onset of symptoms. Therefore, the dopamine D4 receptor polymorphism does not confer genetic susceptibility to IPD and cannot explain the decreased novelty seeking in IPD patients.

Aged↗
PubMed1999

Botulinum toxin A in the management of spastic gait disorders in children and young adults with cerebral palsy: a randomized, double-blind study of "high-dose" versus "low-dose" treatment.

The present study was performed to assess dose-response relationships of local botulinum toxin A (BtxA) treatment in children and teenagers with spastic gait due to cerebral palsy (CP) in a randomized, double-blind study employing a "high-dose" (200 units Botox per leg) and a "low-dose" (100 units Botox per leg) treatment arm in 33 patients with CP. Response parameters included changes in muscle tone assessed by the Ashworth scale at knee joint, range-of-motion (ROM) measurements at knee and ankle joint, objective analysis of longitudinal gait parameters as well as subjective assessments of improvement. Patients in the "high-dose" arm received 40-80 units Botox/muscle versus 20-40 units Botox/muscle in the "low-dose" group. Patients in both treatment arms showed significant improvement of Ashworth score (p<0.001) and ROM (p<0.01), while gait analysis revealed significant increase in gait velocity (p<0.01) and stride-length (p<0.001) over baseline. Subjects in the "high-dose" group showed significantly greater improvement on objective response measurements compared to "low-dose" patients. Also, children aged 7 years or less had greater functional benefit compared to the subgroup of patients older than 7 years. Incidence and severity of side-effects were similar in both treatment groups. The present study demonstrated dose-dependent functional improvement of dynamic deformities and spastic gait pattern in children and young adults with CP treated with local injections of botulinum toxin. A dose of 200 units Botox per leg distributed to 4 or 5 muscle bellies per leg is superior compared to 100 units Botox per leg without significantly affecting the risk of side-effects.

Adolescent↗
PubMed1999

Comparative analysis of gait in Parkinson's disease, cerebellar ataxia and subcortical arteriosclerotic encephalopathy.

Quantitative gait analysis has been used to elucidate characteristic features of neurological gait disturbances. Although a number of studies compared single patient groups with controls, there are only a few studies comparing gait parameters between patients with different neurological disorders affecting gait. In the present study, gait parameters were compared between control subjects, patients with parkinsonian gait due to idiopathic Parkinson's disease, subjects suffering from cerebellar ataxia and patients with gait disturbance due to subcortical arteriosclerotic encephalopathy. In addition to recording of baseline parameters during preferred walking velocity, subjects were required to vary velocity from very slow to very fast. Values of velocity and stride length from each subject were then used for linear regression analysis. Whereas all patient groups showed slower walking velocity and reduced step length compared with healthy controls when assessed during preferred walking, patients with ataxia and subcortical arteriosclerotic encephalopathy had, in addition, increased variability of amplitude and timing of steps. Regression analysis showed that with changing velocity, subjects with Parkinson's disease changed their stride length in the same proportion as that measured in controls. In contrast, patients with ataxia and subcortical arteriosclerotic encephalopathy had a disproportionate contribution of stride length when velocity was increased. Whereas the findings in patients with Parkinson's disease can be explained as a reduction of force gain, the observations for patients with ataxia and subcortical arteriosclerotic encephalopathy reflect an altered spatiotemporal gait strategy in order to compensate for instability. The similarity of gait disturbance in subcortical arteriosclerotic encephalopathy and cerebellar ataxia suggests common mechanisms.

Adult↗