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.

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.

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.

Disturbances of dynamic balance in phasic cervical dystonia

OBJECTIVE

To quantitatively assess control of balance under static and dynamic conditions in patients with tonic and phasic cervical dystonia.

METHODS

Ten patients with purely tonic cervical dystonia with fixed postural deviation and 20 patients with cervical dystonia with phasic head movements were investigated at least 3 months after botulinum toxin injections. Seventeen age matched volunteers served as controls. Static posturography was performed on a force platform; dynamic equilibrium was studied on a stabilometer, which requires the subject to continuously adapt upright posture to an unstable tilting surface. Measurements of maximum amplitude and linear displacement of the pivot were taken with open and closed eyes.

RESULTS

Sway path values in static posturography were not significantly different between patients with cervical dystonia and controls. On dynamic posturography, patients with phasic cervical dystonia showed significantly higher platform measures (maximum amplitude and linear displacement of the pivot) with eyes open and closed By contrast, none of the dynamic platform measures differed significantly between patients with tonic cervical dystonia and controls.

CONCLUSIONS

Normal measures of dynamic equilibrium in tonic cervical dystonia argue against a primary abnormality of balance control in cervical dystonia. Impaired dynamic equilibrium in phasic cervical dystonia is likely to reflect a disruption of vestibular input due to repetitive, involuntary head oscillations.

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.

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.

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.

[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.

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.

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.

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.

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.

Unilateral painful legs and moving toes syndrome with moving fingers--evidence for distinct oscillators

This case report presents a patient with painful legs and moving toes on the right side followed by the development of involuntary movements in his right hand. The frequencies of the semirhythmic muscle activities in both extremities were different. This finding excludes one central pacemaker for both and supports the notion that separate oscillators in the segmental interneuron pool of different spinal areas may drive the individual movements in this case.

Quantitative assessment of botulinum toxin treatment in 43 patients with head tremor

We treated 43 patients who had head tremor as the major complaint with local botulinum toxin type A (Btx A) injections into neck muscles: 29 patients were classified as suffering from tremulous cervical dystonia (TCD), and 14 had head tremor without dystonia (HT). All patients were clinically assessed by means of the Tsui scale and a 4-point pain scale at baseline and follow-up visit. Quantitative recordings of head tremor with a bidirectional accelerometer system (horizontal and vertical planes) placed on the forehead were obtained before and 2-3 weeks after Btx A injections. Muscle selection for an injection was based on the visible and palpable tremor oscillation in the involved neck muscles and on analysis of standardized simultaneous electromyographic recordings of six cervical muscles. Patients with HT received mean total doses of 400 units (U) of Dysport (Btx A) (range, 160-560 U) distributed between the two splenius capitis muscles. Patients with TCD received a mean total dose of 500 U Dysport (range, 320-720 U) injected into a mean of 3 muscles (range, 2-4 muscles). The condition of all patients with HT and of 26 of the 29 patients with TCD improved subjectively. The total on the Tsui scale as well as pain scores decreased significantly (p < 0.05) following treatment. Latency of onset, duration of improvement, and side effects showed no significant difference in HT and TCD. Amplitude of HT decreased significantly for both groups following treatment. The mean dominant peak frequency in TCD and HT was slightly less than 5 Hz and did not change significantly after treatment.

Directional bias of initial visual exploration. A symptom of neglect in Parkinson's disease

In the present study, side preferences in spontaneous visual exploration were assessed systematically in 27 patients with idiopathic Parkinson's disease (IPD) and 17 age-matched controls. Assessment of initial visual exploration asymmetry (IVE) was based on the exploration of texture arrays requiring attentive oculomotor scanning. As shown in a previous study, most healthy subjects exhibit a marked asymmetry of IVE with a strong left-sided bias when assessed by this paradigm, while most neglect patients initiate exploration in the right half of the arrays. Standard assessments for symptoms of neglect (line bisection, line cancellation and double simultaneous stimulation) were performed as reference tests. In the IVE task 65% of normal controls and 69% of patients with predominantly right-sided IPD started exploration in the left half of the arrays. By contrast only 14% of patients with predominantly left-sided disease showed a leftward IVE. The majority shows an ambiguous (21%) or rightward (64%) directional bias for initial exploration and thus a behaviour that corresponds to the IVE abnormalities found in neglect patients. No abnormalities were found in the standard neglect tests in any of the groups. The atypical IVE in patients with predominantly left-sided Parkinson's disease should be interpreted in the context of recent concepts of attention postulating that a bias in early spontaneous orientation directed to the ipsilesional hemifield reflects a mild and residual manifestation of hemineglect. Since this subtle orientational bias is less subject to compensation than more conspicuous clinical signs of neglect, sensitivity is higher in IVE testing than in conventional neglect assessments in chronic disorders with subclinical neglect. The present findings contribute a new aspect to the complex picture of cognitive and visuospatial abnormalities in Parkinson's disease. Furthermore our results extend previous knowledge on the mechanisms of neglect and the role of dopamine in the mediation of attention.

Influence of concurrent tasks on gait: a dual-task approach

We studied the effect of concurrent tasks on motor control of gait with dual-task methodology. Ten healthy subjects were instructed to perform different cognitive and motor tasks during gait on a conductive walkway. Footswitch signals were recorded and stride time and double-support time were calculated. It was assumed that the former reflects gait-patterning mechanisms and the latter relates to balance control. Statistical analysis showed an increase in double-support time when a memory-retention task (digit-span) and a fine motor task (buttoning) were executed simultaneously during gait. During gait performance of the cognitive task declined compared to baseline conditions. Attentional demand of concurrent cognitive and motor tasks appeared to force subjects to modulate their gait strategy to ensure control of balance. Stride time was consistent across task conditions except when subjects performed fast finger-tapping during gait. Then all but one subject showed a decrease in stride time and an increase in stride-frequency that was repeatable on retest. Since different rhythmic movements are likely to share common neurobiological networks, we assumed that the modulation of stride-frequency was due to structural interference.

Hemimasticatory spasm in hemifacial atrophy: diagnostic and therapeutic aspects in two patients

We report two cases of hemimasticatory spasm in association with progressive hemifacial atrophy. On the basis of neurophysiological and magnetic resonance imaging assessments, a peripheral irritation of the trigeminal nerve--probably due to entrapment of the motor branches in the infratemporal fossa--is suggested as the cause of the involuntary movement. Local injections of botulinum toxin type A into the masticatory muscles proved to be a successful treatment in both patients.

Perseverative motor behaviour in Parkinson's disease

Difficulties in shifting of cognitive sets and perseverative behaviour have been shown to be part of the neuropsychology of Parkinson's disease, possibly due to frontal dysfunction. We have tested perseverative motor behaviour by assessing ability to generate random movement sequences in 15 patients with Parkinson's disease using the Breidt Perseveration Test Device (PTD). In this experiment subjects are instructed to press one of nine buttons arranged randomly on a metal board without use of systematic or repetitive strategies. The speed of this task that comprises 150 consecutive presses is determined by an acoustic go-signal appearing at 1 Hz frequency. Results were compared with 14 age-matched controls. Patients performance was impaired with intrusion of unwanted systematic strategies suggesting a decreased ability of Parkinson patients to generate random movement sequences.

Treating chronic hemiparesis with modified biofeedback

Eleven patients with chronic spastic hemiparesis were treated with biosignal processing (BSP), a modified biofeedback method in which the patient practices useful tasks, not isolated individual movements. A surface EMG measures sequential movements, and an acoustic signal monitors muscle exertion. The patient first learns how the signal develops by using the unaffected limb. Then the patient tries to reproduce the course of the signal in the paretic limb. Patients received 12 to 30 treatments for upper and/or lower extremities. We measured maximum strength as expressed through the EMG signal; ability to perform the trained action as measured by specific grading systems; and general increase in movement competence during a Bobath movement test. Ten patients showed improved strength; four made marked progress in the performance of specific tasks with the upper extremity, as did four with the lower extremity. Four patients in each group improved in general movement. We recommend the integration of useful tasks into movement exercises in EMG biofeedback therapy.