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Biomedical subjects

A Schrag

Publications and source records attributed to A Schrag.

At least 37 records · Page 2Linked to original sources
PubMed2001

Arm tremor in cervical dystonia differs from essential tremor and can be classified by onset age and spread of symptoms.

The pathophysiology of arm tremor in patients with cervical dystonia (CD) and its relationship to other types of tremor is unclear. In the present study, we have compared the tremor in these patients with that seen in patients with essential tremor (ET) using two neurophysiological techniques: the triphasic EMG pattern accompanying ballistic wrist flexion movements; and reciprocal inhibition between forearm muscles. During ballistic wrist flexion movements, the latency of the second agonist EMG burst was later in ET than CD patients. This suggests that the mechanism of the arm tremor in CD may differ from that in ET. There was no group difference between reciprocal inhibition in patients with ET or CD. However, there was much more variability in the data from patients with CD. Because of this, we subdivided the CD patients into two groups, group A with normal levels of presynaptic inhibition and group B with reduced or absent presynaptic inhibition. A posteriori, it turned out that the patients in these two subgroups had similar clinical symptoms, but different clinical histories. The arm tremor of patients in group A started simultaneously with torticollis (mean onset age of arm tremor 40 years +/- 20.7 SD, interval between onset of arm tremor and torticollis 0 +/- 2.9 years) whereas it began much earlier (mean onset age 14 years +/- 6 SD) and preceded onset of torticollis by a longer interval (21.6 +/- 17.5 years) in patients of group B. Patients in group A also had less co-contraction in their ballistic wrist movements between the first agonist and the antagonist burst than those patients in group B. We conclude that arm tremor in patients with CD may have a mechanism different from that seen in patients with ET. Moreover, the data imply that there are two subgroups of CD patients with arm tremor, one with a late and simultaneous onset of arm tremor and torticollis (group A), and another with an early onset of arm tremor and later development of torticollis (group B). These groups do not correspond to the currently proposed clinical subdivision of 'dystonic tremor' and 'tremor associated with dystonia'.

Adult↗
PubMed2000

Multiple system atrophy/progressive supranuclear palsy: alpha-Synuclein, synphilin, tau, and APOE.

Article abstract-Alpha synuclein, tau, synphilin, and APOE genotypes were analyzed in patients with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) and controls. The predisposing effect of the tau insertion polymorphism to the development of PSP is confirmed. However, no effect of alpha-synuclein, synphilin, or APOE variability on the development of PSP, or of tau, alpha-synuclein, APOE, or synphilin gene variability on the development of MSA, are demonstrated.

Apolipoproteins E↗
PubMed2000

Firing patterns of pallidal cells in parkinsonian patients correlate with their pre-pallidotomy clinical scores.

It is unclear how the disordered activity of cells in the basal ganglia contributes to the symptoms of Parkinson's disease (PD). We recorded from single neurons extracellularly in 3 regions of the globus pallidus (GPe, GPie and GPii) in patients undergoing pallidotomy for PD. Movement-related cell firing patterns, analysed using hidden Markov models, were significantly correlated with patients' preoperative clinical scores (off drugs). Responses of cells in GPii correlated best with the scores for specific motor tasks, rather than general ones related to activities of daily living, but the reverse was true for responses from GPe. In both GPii and GPe, a higher score (i.e. greater parkinsonian severity) was associated with greater variability in cell firing rather than an increase in firing rate itself.

Activities of Daily Living↗
PubMed2000

Low-dose olanzapine for levodopa induced dyskinesias.

OBJECTIVE: To assess the usefulness of low-dose olanzapine (2.5 to 7. 5 mg/day) for Levodopa-induced-dyskinesias (LID) in patients with PD. METHODS: Ten patients with PD and LID took part in this randomized, placebo-controlled, double blind, crossover trial. Patients received a 2-week course of olanzapine or placebo in each treatment phase with 1-week washout in between. Dyskinesias were assessed at baseline and after each treatment period with an acute dopaminergic challenge and unified PD rating scale (UPDRS) questionnaires. Patients also kept on/off and dyskinesia diaries for the last 3 days prior to each assessment. RESULTS: There was a 41% difference in dyskinesia reduction on olanzapine compared to placebo, as measured by objective dyskinesia rating scales (mean percentage reduction abnormal involuntary movement score: 30% versus -11.2%, p < 0.02). Similar differences were demonstrated by patient diaries (mean reduction: 46% versus -2%, p < 0.02) and UPDRS items 32 and 33. Compared with placebo, treatment with olanzapine resulted in significant increases in 'off' time as measured by patient diaries (30% versus 2%) and reported adverse events (1.7 versus 0.1) including increased parkinsonism (1.1 versus 0.1) and a nonsignificant reported increase in drowsiness. CONCLUSIONS: Low-dose olanzapine is effective in reducing dyskinesias in PD, but even at very low doses can result in unacceptable increases in parkinsonism and 'off' time.

Aged↗
PubMed2000

Differentiation of atypical parkinsonian syndromes with routine MRI.

OBJECTIVE: To evaluate the use of routine MRI in differentiating between patients with progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal degeneration (CBD) and control subjects. METHODS: Two neuroradiologists rated blindly and independently axial T2-weighted and proton density MR images of 54 patients with MSA, 35 patients with PSP, 5 patients with CBD, and 44 control subjects. RESULTS: More than 70% of patients with PSP and more than 80% of patients with cerebellar predominant MSA could be classified correctly with 0.5-T or 1.5-T scans, and no patient in these groups was misclassified. In the remaining patients an unequivocal differentiation could not be made. However, only approximately 50% of patients with parkinsonism-predominant MSA could be classified correctly, and 19% of them (all of whom had had 0.5-T scans) were misclassified. CONCLUSIONS: Characteristic findings on routine MRI, either 1.5 T or 0.5 T, can contribute to the identification of MSA and PSP. However, in a minority of patients no unequivocal diagnosis can be made using MRI findings alone.

Adult↗
PubMed2000

Health-related quality of life following bilateral intrastriatal transplantation in Parkinson's disease.

Intrastriatal transplantation of embryonic dopaminergic tissue is a new, experimental approach for the treatment of Parkinson's disease (PD). Clinical trials have shown longterm graft survival and therapeutically valuable improvements with decreased L-dopa dose and time spent in the "off"-phase, and reduced rigidity and hypokinesia. We have measured health-related quality of life (HRQoL) using the Nottingham Health Profile (NHP) in five patients subjected to bilateral transplantation in the caudate and putamen to explore the influence of intrastriatal grafts on HRQoL and the value of such measures in trials of restorative therapies. The results demonstrate improved HRQoL following transplantation, with individual patients showing striking improvements within different dimensions of the NHP as well as the NHP distress index (NHPD). The most pronounced improvements after grafting were observed for physical mobility along with emotional reactions and energy. These results indicate that intrastriatal transplantation of embryonic dopaminergic tissue can give rise to improvements within most areas of HRQoL, and that HRQoL measurements provide important information additional to that obtained by traditional, symptom-oriented assessment protocols. However, the optimal approach to HRQoL measurement in PD remains to be determined.

Activities of Daily Living↗
PubMed2000

Benign hereditary chorea--entity or syndrome?

The existence of "benign hereditary chorea" (BHC), a rare disorder of childhood-onset familial chorea without other neurologic features or progression, has increasingly been questioned, because many patients with this disorder were subsequently diagnosed with different conditions. We therefore analyzed all published reports of families with BHC and contacted their authors to obtain follow-up information. In addition, we reviewed all patients in whom at least one of the authors had at some stage considered a possible diagnosis of BHC. Of 42 families reported to have BHC in the literature, we obtained follow-up information on 11 families, three of which had been seen by us. An additional seven new, unreported families and four sporadic cases, in which this diagnosis was suspected by at least one of us at one point, were reviewed and videotaped. On reviewing the videotapes of the 11 families in the literature, the diagnosis of BHC was changed in nine. In the remaining two families, atypical features suggesting different diagnoses were present in the original reports. In none of our own previously unreported patients (seven familial and four sporadic) was BHC diagnosed unequivocally by all evaluators after review of their video recordings. In three of these families and all four sporadic patients the diagnosis was changed; in one family multifocal myoclonus could not be differentiated from chorea by any author, and in the remaining three families no consensus between the raters was found. Apart from the 11 families in whom we obtained follow-up information, analysis of the remaining 31 reports on families with BHC also revealed atypical features in the majority. We conclude that BHC is not a diagnosis, but a syndrome that requires further investigation. Whether there is a distinct entity "BHC" with a single gene abnormality remains to be proven.

Adolescent↗
PubMed2000

How does Parkinson's disease affect quality of life? A comparison with quality of life in the general population.

BACKGROUND: Adequate provision of appropriate healthcare resources for patients with chronic neurologic disorders such as Parkinson's disease (PD) requires knowledge of the impact of the illness on their life. Quality of life (QoL) instruments measure the impact of the disease on general well-being that cannot be fully appreciated by clinical rating scales and allow comparisons with other patient groups and the general population. OBJECTIVES: To assess QoL in a population-based sample of patients with PD in different disease stages in comparison with the general population. METHODS: All 124 patients with PD seen in a population-based study on the prevalence of parkinsonism in the London area were asked to complete a QoL battery including the EuroQoL 5D (EQ-5D), the Medical Outcome Study Short Form (SF 36), and the 39-item Parkinson's Disease questionnaire (PDQ-39). An interview and complete neurologic examination, including the Hoehn and Yahr scale, were performed on the same day. The patients' QoL scores were compared with published QoL norms from the United Kingdom population. RESULTS: Quality of life, as measured by the PDQ-39, the EQ-5D, and the physical summary of the SF 36, deteriorated significantly with increasing disease severity. The greatest impairment was seen in the areas related to physical and social functioning, whereas reports of pain and poor emotional adjustment had similar prevalence in patients with PD and the general population. The impairment of QoL was seen in all age groups and was similar for men and women, but the differences between patients with PD and the general population were most marked in the younger patient groups. CONCLUSIONS: Parkinson's disease interferes with various aspects of QoL, particularly those related to physical and social functioning. This information should be taken into account in the clinical management and planning and allocation of healthcare resources to this population.

Adult↗
PubMed2000

Essential tremor: an overdiagnosed condition?

The diagnosis of essential tremor (ET) and its differentiation from other types of tremor is often difficult. In 1994 Bain et al. defined a classical phenotype by studying 20 patients with pure essential tremor and similarly affected family members in at least three generations. We assessed how many of the patients diagnosed by different neurologists at our institution as having ET conformed to this defined phenotype. We randomly selected 50 patients who were diagnosed with ET by any neurologist at the National Hospital for Neurology and Neurosurgery since the publication of the Bain et al. report, and determined the number of patients who had clinical features compatible with the phenotype that it had defined. Only 25 (50%) of these patients had ET so defined. Ten patients clearly had alternative diagnoses: four had clear additional dystonia, two neuropathic tremor, two had unilateral leg tremor, one drug-induced tremor, and one sudden onset after head trauma. The remaining 15 patients also had atypical features including myoclonus (one), onset in a body part other than the arms (six), sudden onset (two), rest tremor (seven), onset after the age of 65 years (four), a family member with an isolated head tremor (one), or reduced armswing (two). The diagnosis of ET is overused even among experienced neurologists, and other types of tremor should be considered in atypical patients before making this diagnosis.

Adolescent↗
PubMed2000

Dyskinesias and motor fluctuations in Parkinson's disease. A community-based study.

We investigated the prevalence of dyskinesias and motor fluctuations, and the factors determining their occurrence, in a community-based population of patients with Parkinson's disease. Among 124 patients with Parkinson's disease, 87 (70%) had received a levodopa preparation. Among these 87 patients, 28% were experiencing treatment-induced dyskinesias and 40% response fluctuations. The prevalence of motor fluctuations was best predicted by disease duration and dose of levodopa, whereas dyskinesias could be best predicted by duration of treatment. Patients with a shorter time from symptom onset to initiation of levodopa and younger patients had developed motor complications earlier, and patients who had started treatment with a dopamine agonist had developed these treatment complications later. Although a satisfactory response to medication was associated with higher rates of motor complications, poor or moderate response was associated with lower quality of life in patients with a disease duration of </=5 years or >/=10 years. We conclude that motor fluctuations are most strongly related to disease duration and dose of levodopa, and dyskinesias to duration of levodopa treatment. However, poorer quality of life associated with inadequate dosage of levodopa may be the price for a low rate of motor complications in patients with Parkinson's disease.

Age of Onset↗
PubMed2000

Bilateral caudate and putamen grafts of embryonic mesencephalic tissue treated with lazaroids in Parkinson's disease.

Five parkinsonian patients were transplanted bilaterally into the putamen and caudate nucleus with human embryonic mesencephalic tissue from between seven and nine donors. To increase graft survival, the lipid peroxidation inhibitor tirilazad mesylate was administered to the tissue before implantation and intravenously to the patients for 3 days thereafter. During the second postoperative year, the mean daily L-dopa dose was reduced by 54% and the UPDRS (Unified Parkinson's Disease Rating Scale) motor score in 'off' phase was reduced by a mean of 40%. At 10-23 months after grafting, PET showed a mean 61% increase of 6-L-[(18)F]fluorodopa uptake in the putamen, and 24% increase in the caudate nucleus, compared with preoperative values. No obvious differences in the pattern of motor recovery were observed between these and other previously studied cases with putamen grafts alone. The amount of mesencephalic tissue implanted in each putamen and caudate nucleus was 42 and 50% lower, respectively, compared with previously transplanted patients from our centre. Despite this reduction in grafted tissue, the magnitudes of symptomatic relief and graft survival were very similar. These findings suggest that tirilazad mesylate may improve survival of grafted dopamine neurons in patients, which is in agreement with observations in experimental animals.

Adult↗
PubMed2000

The EQ-5D--a generic quality of life measure-is a useful instrument to measure quality of life in patients with Parkinson's disease.

OBJECTIVE: To test the feasibility and validity of the EQ-5D (a widely used generic (disease non-specific) quality of life (QoL) instrument which allows comparisons between different patient groups and the general population) to assess QoL in patients with Parkinson's disease. METHODS: All 124 patients with Parkinson's disease seen in a community based study on the prevalence of parkinsonism were asked to complete a QoL battery comprising the EQ-5D, the medical outcome study short form (SF-36), the PDQ-39, a disease specific instrument to assess QoL in PD, and the Beck depression inventory. A structured questionnaire interview and a complete neurological examination including the Hoehn and Yahr stage of illness scale, the Schwab and England disability scale, the motor section of the unified Parkinson's disease rating scale (UPDRS), and the mini mental state examination (MMSE) were performed on the same day. RESULTS: The response rate was 78% and the completion rate of the EQ-5D among responders was 96%. The EQ-5D summary index correlated strongly with the PDQ-39 (r=-0.75, p<0.0001) as well as the physical score of the SF-36 (r=0.61, p<0.0001). There was a significant correlation of the EQ-5D summary index with disease severity, as measured by the Hoehn and Yahr stage of illness, the Schwab and England disability scale, the motor section of the UPDRS, and the depression score. The EQ-5D summary index also distinguished between patients with and without depression, falls, postural instability, cognitive impairment hallucinations, and those with deterioration of health over the previous year. CONCLUSION: The EQ-5D is a feasible and valid instrument to measure QoL in Parkinson's disease and reflects the severity and complications of the disease.

Activities of Daily Living↗
PubMed2000

What contributes to quality of life in patients with Parkinson's disease?

OBJECTIVE: To identify the factors that determine quality of life (QoL) in patients with idiopathic Parkinson's disease in a population based sample. Quality of life (QoL) is increasingly recognised as a critical measure in health care as it incorporates the patients' own perspective of their health. METHODS: All patients with Parkinson's disease seen in a population based study on the prevalence of parkinsonism were asked to complete a disease-specific QoL questionnaire (PDQ-39) and the Beck depression inventory. A structured questionnaire interview and a complete neurological examination, including the Hoehn and Yahr scale, the Schwab and England disability scale, the motor part of the unified Parkinson's disease rating scale (UPDRS part III), and the mini mental state examination were performed by a neurologist on the same day. RESULTS: The response rate was 78%. The factor most closely associated with QoL was the presence of depression, but disability, as measured by the Schwab and England scale, postural instability, and cognitive impairment additionally contributed to poor QoL. Although the UPDRS part III correlated significantly with QoL scores, it did not contribute substantially to predicting their variance once depression, disability, and postural instability had been taken into account. In addition, patients with akinetic rigid Parkinson's disease had worse QoL scores than those with tremor dominant disease, mainly due to impairment of axial features. CONCLUSION: Depression, disability, postural instability, and cognitive impairment have the greatest influence on QoL in Parkinson's disease. The improvement of these features should therefore become an important target in the treatment of the disease.

Aged↗
PubMed1999

Prevalence of progressive supranuclear palsy and multiple system atrophy: a cross-sectional study.

BACKGROUND: The prevalence of progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) in the general population is unknown. Clinicopathological studies of patients diagnosed as having Parkinson's disease suggest that the two disorders may be underdiagnosed. We investigated the population prevalence of these disorders. METHODS: We screened computerised records of 15 general practices in London, UK, for patients with specific diagnostic labels suggestive of Parkinson's disease or parkinsonism and all patients who had ever received antiparkinsonian medication. We assessed eligible patients by review of records, interview, physical examination, and video recordings of neurological signs for independent diagnostic confirmation. We diagnosed parkinsonian disorders according to published criteria and further reviewed patients with atypical features after 1 year. FINDINGS: The participation rate was 84%. The age-adjusted prevalence for PSP was 6.4 per 100,000 (five probable and one possible case [95% CI 2.3-10.6]) and for MSA 4.4 per 100,000 (two probable and two possible cases [1.2-7.6]). An additional four atypical patients were identified at 1 year but did not fulfil criteria for PSP or MSA. INTERPRETATION: Our results suggest that the true prevalence of PSP and MSA has been underestimated, since many patients in the community remain undiagnosed or misdiagnosed.

Aged↗
PubMed1999

Reduction of Parkinsonian signs in patients with Parkinson's disease by dopaminergic versus anticholinergic single-dose challenges.

We investigated the effect of an anticholinergic (biperiden) and a dopamine agonist (apomorphine) on tremor, rigidity, and akinesia in patients with idiopathic Parkinson's disease. In a standardized, crossover study design 17 patients received single-dose challenges of 5 mg biperiden intravenously and a previously determined dose of apomorphine subcutaneously on 2 consecutive days. Resting (RT), postural (PT), and action tremor (AT) were assessed using spectral analysis of accelerometer data, and Unified Parkinson's Disease Rating Scale (UPDRS) scores for rigidity and akinesia were determined before and after administration of the study drug. Both single-dose challenges significantly reduced the amplitude of RT, PT, and AT, but only apomorphine significantly reduced UPDRS scores for rigidity and akinesia. In only one patient was tremor reduced by the dopamine agonist but not by the anticholinergic. We found that anticholinergic and dopaminergic agents are both effective in reducing tremor in IPD, and there was no evidence for a selective anticholinergic responsiveness of parkinsonian tremor. Akinesia and rigidity, on the other hand, were not improved by biperiden. We therefore conclude that dopaminergic substances are as effective as anticholinergics in patients with parkinsonian tremor and additionally improve other parkinsonian signs.

Adult↗
PubMed1999

Atypical and typical cranial dystonia following dental procedures.

It is generally recognized that focal dystonia of the limbs or cervical region and blepharospasm sometimes follow, and in these cases may be caused or triggered by, peripheral injury. However, the association between peripheral injury and lower cranial dystonia is rare. We report eight cases who developed cranial dystonia within hours to months following a dental procedure. One group of five cases, all women, developed atypical dystonia associated with painful paresthesias at the site of dystonia. Two of these five cases had fixed jaw-deviating dystonia, whereas the remaining three had additional tremor and spread of their dystonia to involve the tongue in all three, and the lips and neck in two cases. These five patients are reminiscent of cases of limb causalgia-dystonia syndrome, which occurs after minor peripheral trauma and can spread. The remaining three cases developed more typical cranial dystonia following the dental procedure. There was no family history of dystonia or prior use of neuroleptics in any of the patients. The close association in time and location of the procedure and onset of symptoms suggests that the onset of the dystonia may have been caused by the dental intervention, but whether there is a causal relationship between the dental intervention and the development of the dyskinesias requires further epidemiologic studies.

Adult↗