CSF hypocretin-1 levels in restless legs syndrome

CSF hypocretin-1 levels at 6 pm did not significantly differ between patients with restless legs syndrome (RLS) and control subjects as measured by direct radioimmunoassay and after acid extraction. The authors did not observe significant differences between early onset and late onset RLS. Hypocretin-1 levels did not correlate with RLS severity or polysomnographic measures. These results contrast with previous findings reporting significantly increased CSF hypocretin-1 in the late evening and mostly in early onset RLS.

Candidate gene studies in focal dystonia

BACKGROUND

Genetic susceptibility factors for focal idiopathic torsion dystonia (F-ITD) are not established. Mutations in the DYT1 gene can cause focal dystonia, and an association with a polymorphism in the D5 receptor gene (DRD5) has been reported but not confirmed.

OBJECTIVE

To investigate a possible role of DYT1 polymorphisms, a CA repeat in the D5 receptor gene (DRD5), the human leukocyte antigen (HLA)-DRB locus, and four polymorphisms in the homocysteine metabolism in the pathogenesis of F-ITD.

METHODS

Initially, 100 German patients and 100 matched control subjects were investigated. A second French population with 121 F-ITD patients and matched control subjects was also studied.

RESULTS

Two polymorphisms of the beta-cystathionine synthase gene were associated with F-ITD in the German population, but this finding was not replicated in a second independent F-ITD patient and control group of French origin. None of the other investigated polymorphisms was associated with F-ITD. The authors failed to confirm a previously reported association with a polymorphism in DRD5.

CONCLUSION

No evidence for an involvement of DYT1, DRD5, HLA-DRB, or polymorphisms in the homocysteine pathway in the pathogenesis of F-ITD was found.

Electrophysiology of focal clonic seizures in humans: a study using subdural and depth electrodes

Focal clonic seizures are a frequent epileptic phenomenon. However, there are few data about their pathogenesis. Eleven patients with focal epilepsy who experienced focal clonic seizures during prolonged video-EEG monitoring were included in this study. Nine patients had subdural electrodes on the precentral gyrus and one patient had additional bilateral subthalamic nucleus (STN) depth electrodes. In five patients, the EEG was co-registered with the EMG of muscles which were involved in the clonic seizures. The frequency, pattern and evolution of the ictal EEG were analysed and their relationship to STN and EMG activity was studied. Focal clonic seizures were always associated with a polyspike-wave pattern in the EEG of the primary motor area (frequency range 1.6-3.4 Hz), while neighbouring electrodes not overlying the precentral gyrus showed different EEG patterns. At seizure onset, the ictal EEG derived from the precentral gyrus consisted of repetitive spiking for 8-28 s (median 19.5 s), accompanied by a continuous increase in muscle tone. This evolved to a pattern of polyspike-wave complexes which were associated with clinical clonus and lasted for 14-202 s (median 30.5 s). The clonic muscle contractions consisted of bursts of compound muscle action potentials (CMAPs) which occurred synchronously in agonistic and antagonistic muscles and were separated by periods of complete muscle relaxation. Each series of CMAPs followed the polyspikes in the EEG with a latency of 17-50 ms. The periods of muscle relaxation occurred during the EEG slow waves. Only some of the cortical spikes were followed by ipsilateral STN spikes. CMAPs followed the cortical polyspikes independently of whether or not STN spikes were seen. The study suggests that focal clonic seizures are focal tonic-clonic seizures. The epileptic clonus consisted of simultaneous contractions of agonistic and antagonistic muscles at regular intervals and was generated by localized polyspike-wave activity in cortical primary motor areas. Activation of the STN did not appear to be an essential component of clonic seizures.

CD45 isoform expression in autoimmune myasthenia gravis

In myasthenia gravis (MG), humoral and cellular immune mechanisms are involved in the autoimmune pathogenesis. In this study, we investigated the role of the CD45 molecule in MG, having recently reported an association in multiple sclerosis. CD45, a protein-tyrosine phophatase receptor type C (PTPRC), is essential for both thymic selection and peripheral activation of T and B cells. Our aims were to determine (a) the prevalence of a functional mutation in the CD45 gene (exon 4 77C --> G; prevalence analysis), and (b) the distribution of memory (CD45RO+) and naive (CD45RA+) T cells in the peripheral blood (subset analysis). T cells from 78 patients with generalised MG were stained with monoclonal antibodies against CD45RO, CD45RA, CD4 and CD8 and quantified by four-colour flow cytometry. The control panel for the prevalence analysis (a) consisted of 303 healthy individuals. (b) From those, 67 age- and sex-matched probands were randomly selected as controls for the subset analysis. Patients were stratified according to their MG onset age, thymic pathology and immunosuppressive treatment. Statistical analysis was performed by Fisher's exact test, asymptotic chi2 test, the two-sided Mann-Whitney test and Spearman's correlation coefficient. As a result, the 77C --> G mutation in exon 4 of the CD45 gene was found in 1 of 78 patients versus none of the 303 controls. Thus, no association was detected with this single nucleotide polymorphism in MG patients overall. Surprisingly, however, ratios of CD45RO+ to CD45RA+ T cells were lower among CD8+ T cells from patients with late-onset MG (P = 0.023). Thymoma patients also showed a similar trend among CD4+ and CD8+ T-cells, as expected. These differences were not related to immunosuppressive drug treatment or thymectomy (in the 67 informative patients). Since there is no other evidence for increased thymopoiesis in late-onset MG, we propose an altered subset balance in the circulation.

Pramipexole in patients with Parkinson's disease and marked drug resistant tremor: a randomised, double blind, placebo controlled multicentre study

OBJECTIVE

To compare the tremorlytic properties of pramipexole, a non-ergoline dopamine agonist to those of placebo as add on medication in patients with Parkinson's disease.

METHODS

Eighty four patients with early or advanced Parkinson's disease and marked, drug resistant tremor under a stable and optimised antiparkinsonian medication were included in a double blind, randomised, placebo controlled, multicentre study and assigned to add on treatment (7 week dose titration interval, 4 week maintenance period) with either pramipexole (n=44) or placebo (n=40) as adjunct. The primary end point was the absolute change in tremor score, defined as the sum of tremor related items (16, 20, 21) of the unified Parkinson's disease rating scale (UPDRS) in "on" periods. Secondary end points included the percentage change in tremor score, the absolute and percentage changes in long term EMG tremor registration, and the change in tremor self rating scales. Safety and tolerability were assessed on the basis of adverse events, laboratory tests, ECG, and vital signs.

RESULTS

Pramipexole was significantly superior to placebo with a difference between treatment groups in the mean absolute change in tremor score of -4.4 (95% confidence interval (95% CI) -6.2 to -2.5) (p<0.0001), corresponding to a difference in the mean percentage change of -34.7% in favour of pramipexole. The secondary end points were consistent with the significant change in tremor score and provided further evidence for the benefit of pramipexole compared with placebo. Long term EMG registration as an objective measure showed a difference in mean absolute change in tremor occurrence of -15.2% (95%CI -21.4 to -9.0) (p<0.0001), and a difference in the mean percentage change of -45.7% in favour of pramipexole. The treatment effects increased during dose titration and remained stable during the 4 week maintenance dose period until the end of the study. The average daily pramipexole dose during maintenance was 4.1 (SD 0.9) mg. Safety analysis showed an increased rate of fatigue, insomnia, nausea, abdominal pain, and headache under pramipexole, comparable with previous studies.

CONCLUSION

Pramipexole proved to be an effective agent for patients with Parkinson's disease and drug resistant tremor.

Evaluation of healthcare utilization and health status of patients with Parkinson's disease treated with deep brain stimulation of the subthalamic nucleus

OBJECTIVE

To assess the effects on motor functioning, health status and direct medical costs of high-frequency stimulation of the subthalamic nucleus (DBS-STN) in patients with idiopathic Parkinson's disease (PD). In addition, the cost-effectiveness of DBS-STN vs. drug treatment was investigated.

METHODS

16 consecutive patients with PD from two centers (Düsseldorf/Cologne; Kiel) treated by DBS-STN were prospectively evaluated. Clinical evaluations were done at baseline and 1, 3, 6, 12 months following surgery by means of the Unified Parkinson's disease Rating Scale (UPDRS). Health status of PD patients was assessed using the Sickness Impact Profile (SIP) at baseline and 6 months following surgery. Relevant economic data were taken from the medical records and costs (1999) were derived from different German medical economic resources. Costs were determined from the perspective of the health care provider.

RESULTS

Following DBS-STN UPDRS scores (subscores and sum score) as well as health status improved considerably in PD patients. The overall SIP score and the physical dimension score (p < 0.009) were significantly different (p < 0.01) six month after surgery compared with baseline values. Mean costs of DM 40,020 (US dollars 20,810, EURO 20,410, GB pounds 12,810) per patient were spent during the 12 month observation period for in-patient and out-patient care. These expenses included already the costs for the electronic device for bilateral stimulation. Following DBS-STN medication was considerably reduced. Mean daily drug costs at baseline were DM 46.7+/-21.8 (US dollars 24, EURO 24, GB pounds 15) and DM 18.3+/-17.7 (US dollars 10, EURO 9, GB pounds 6) at 12 months following DBS-STN. Accounting for the decreased drug consumption, total annual costs amounted to DM 31,400 (US dollars 16,330, EURO 16,010, GB pounds 10,050). Further, we estimated the incremental cost effectiveness as DBS-STN had higher costs but was more effective than baseline treatment. The incremental total cost-effectiveness ratio for DBS-STN was DM 1.800 (US dollars 940, EURO 920, GB pounds 580) for one point decrease of the UPDRS.

CONCLUSION

DBS-STN is an effective treatment that considerably alleviates the severity of signs and symptoms and improves the health status of patients with PD. Compared with drug treatment, however, the expenditures associated with DBS-STN are increased when only direct medical costs are considered in a one year horizon. However, on a long-term basis costs will decrease considerably because of the reduction of the drug expenditure and improved functioning in all activities of daily living. To adequately evaluate the cost-effectiveness of DBS-STN compared with standard drug regimen for PD it is necessary to include direct, indirect and intangible costs on a long-term basis and under standardized circumstances.

Monoamine oxidase-inhibition and MPTP-induced neurotoxicity in the non-human primate: comparison of rasagiline (TVP 1012) with selegiline

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to induce parkinsonism in man and non-human primates. Monoamine-oxidase B (MAO-B) has been reported to be implicated in both MPTP-induced parkinsonism and Parkinson's disease, since selegiline (L-deprenyl), an irreversible MAO-B inhibitor, prevents MPTP-induced neurotoxicity in numerous species including mice, goldfish and drosophyla. However, one disadvantage of this substance relates to its metabolism to (-)-methamphetamine and (-)-amphetamine. Rasagiline (R-(+)-N-propyl-1-aminoindane) is a novel irrevesible MAO-B-inhibitor, which is not metabolized to metamphetamine and/or amphetamine. The present study compared the effects of high doses of selegiline and rasagiline (10 mg/kg body weight s.c.) on MPTP-induced dopaminergic neurotoxicity in a non-human primate (Callithrix jacchus) model of PD. Groups of four monkeys were assigned to the following six experimental groups: Group I: Saline, Group II: Selegiline/Saline, Group III: Rasagiline/Saline, Group IV: MPTP/Saline, Group V: Rasagiline/MPTP, Group VI: Selegiline/MPTP. Daily treatment with MAO-B-inhibitors (either rasagiline or selegiline, 10 mg/kg body weight s.c.) was initiated four days prior to MPTP-exposure (MPTP-HCl, 2 mg/kg body weight subcutaneously, separated by an interval of 24 hours for a total of four days) and was continued until the end of the experiment, i.e. 7 days after the cessation of the MPTP-injections, when animals were sacrificed. MPTP-treatment caused distinct behavioural, histological, and biochemical alterations: 1. significant reduction of motor activity assessed by clinical rating and by computerized locomotor activity measurements; 2. substantial loss (approx. 40%) of dopaminergic (tyrosine-hydroxylase-positive) cells in the substantia nigra, pars compacta; and 3. putaminal dopamine depletion of 98% and its metabolites DOPAC (88%) and HVA (96%). Treatment with either rasagiline or selegiline markedly attenuated the neurotoxic effects of MPTP at the behavioural, histological, and at the biochemical levels. There were no significant differences between rasagiline/MPTP and selegiline/MPTP-treated animals in respect to signs of motor impairment, the number of dopaminergic cells in the substantia nigra, and striatal dopamine levels. As expected, both inhibitors decreased the metabolism of dopamine, leading to reduced levels of HVA and DOPAC (by >95% and 45% respectively). In conclusion, rasagiline and selegiline at the dosages employed equally protect against MPTP-toxicity in the common marmoset, suggesting that selegiline-derived metabolites are not important for the neuroprotective effects of high dose selegiline in the non-human MPTP-primate model in the experimental design employed. However, unexpectedly, high dose treatment with both MAO-inhibitors caused a decrease of the cell sizes of nigral tyrosine hydroxylase positive neurons. It remains to be determined, if this histological observation represents potential adverse effects of high dose treatment with monoamine oxidase inhibitors.

Late-onset myoclonic epilepsy in Down's syndrome (LOMEDS)

The aim of this paper is to report a patient with late-onset myoclonic epilepsy in Down's syndrome (LOMEDS) as a differential diagnosis of adult-onset progressive myoclonic epilepsies. A 55-year-old male with Down's syndrome (DS) is described who developed progressively frequent myoclonus and generalized myoclonic-tonic seizures (GMTSs) at the age of 52. EEG recordings demonstrated background slowing and generalized polyspike-wave discharges occasionally associated with myoclonic jerks, leading to the classification of the primary generalized epileptic myoclonus. Descriptions of late-onset epilepsy in DS patients are rare. However, a review of the pertinent literature revealed at least two other cases of elderly DS patients developing progressive myoclonic epilepsy after the onset of dementia. We suggest that late-onset myoclonic epilepsy in Down's syndrome as characterized here should be considered in the differential diagnosis of adult-onset myoclonic epilepsies. LOMEDS apparently shares features with myoclonic epilepsy in Alzheimer's disease (AD) and Unverricht-Lundborg disease (ULD) caused by a mutation on chromosome 21. Since life expectation of DS patients has markedly increased, LOMEDS may be more frequent than currently acknowledged.

Steele-Richardson-Olszewski-syndrome: the relation of dopamine D2 receptor binding and subcortical lesions in MRI

We compared (123)I-iodobenzamide single photon emission computed tomography (IBZM-SPECT) for imaging of striatal dopamine D(2) receptors in vivo, and MRI in 32 patients with the clinical diagnosis of progressive supranuclear palsy (PSP). We found a significant inter-dependence of reduction of specific striatal IBZM binding indicative of striatal degeneration and of the absence of multiple signal hyperintensities in MRI; age had no influence neither on IBZM binding nor on signal hyperintensities. We conclude that the presence of multiple signal hyperintensities should raise doubt on the correct clinical diagnosis.

Patterns of cerebrospinal fluid pathology correlate with disease progression in multiple sclerosis

Multiple sclerosis is a chronic inflammatory and demyelinating disease of the CNS with, as yet, an unknown aetiology. Temporal profile, intensity and treatment responses are highly variable in multiple sclerosis suggesting pathogenetic heterogeneity. This hypothesis has been supported by histopathological studies disclosing at least four different subtypes of acute demyelinating lesions. Although stratification of multiple sclerosis patients into these categories would be extremely helpful for clinical studies, this approach is impractical as it requires brain biopsy. In this study we investigated CSF cytology from 60 multiple sclerosis patients by flow cytometry. We identified different patterns of CSF cytology, which were independent of immunological parameters in the peripheral blood. The most variable CSF parameter was the B cell to monocyte ratio, which remained stable during different phases of disease in selected patients. The ratio correlated with disease progression but not with disability or disease duration in a retrospective, consecutive analysis. A high ratio (predominance of B cells) was associated with more rapid disease progression, whereas a low ratio (predominance of monocytes) was found in patients with slower progression. Our study demonstrates the existence and potential clinical relevance of different CSF cytology patterns. We hypothesize that CSF cytology patterns may reflect the heterogeneity in the pathogenesis of multiple sclerosis.

Macrogol 3350/electrolyte improves constipation in Parkinson's disease and multiple system atrophy

We describe an open study of macrogol 3350 in 10 cases of constipated patients with Parkinson's disease or multiple system atrophy. The agent produced a marked improvement in symptoms in all cases.

[Lateralizing and localizing signs and symptoms of epileptic seizures: significance and application in clinical practice]

This report reviews the lateralising and localising signs of epileptic seizures in respect to the differential diagnosis of epilepsy. The lateralising value of epileptic signs and symptoms can frequently be derived from the neuroanatomy. Focal clonic, focal tonic, and versive seizures as well as ictal unilateral dystonia are associated with a seizure onset zone in the contralateral hemisphere. Postictal nose wiping is performed with the hand ipsilateral to the epileptogenic zone. Similarly, unilateral blinking points to an ipsilateral seizure onset. Automatisms with preserved consciousness, ictal speech, and vomiting correlate to an epileptogenic zone in the non-dominant hemisphere, while postictal dysphasia is produced by seizures arising from the dominant hemisphere. Lateralising and localising signs and symptoms of epileptic seizures are of great help in the differential diagnosis of epilepsy from the first diagnosis of epileptic events to presurgical video-EEG monitoring.

Immunosuppressive treatment of ocular myasthenia gravis

Myasthenia gravis (MG) is caused by autoantibodies against proteins at the neuromuscular junction. This autoimmune process leads to abnormal fatiguability and weakness of striated muscle. Ptosis and diplopia are among the most common manifestations of MG. The term "ocular MG" (OMG) as opposed to "generalised MG" (GMG) is used to define the clinical subtype of MG with isolated eye muscle weakness. Although OMG may appear to cause only moderate disability, it can significantly impair the patient's activities of daily living and progress to generalised myasthenia. Therefore, a clear management plan should be installed early in these patients. Since prospective treatment trials have not been performed, basic management strategies for OMG have to be deduced from retrospective studies, trials in GMG, and generally accepted clinical experience. Cholinesterase inhibitors are used in all types of MG, but are often less helpful in OMG. In the absence of thymoma, thymectomy is usually not considered in OMG, although a few studies have described histological abnormalities in thymuses from patients with OMG. Corticosteroids are of great short term benefit in most patients with OMG but potential adverse effects limit their long term use. Azathioprine is needed to reduce long term corticosteroid adverse effects, but this agent requires about 6 months to be effective. In summary, OMG has a good prognosis in most patients, with corticosteroids and azathioprine being the major treatment options. The challenges for the clinician are to recognise the condition despite the large number of differential diagnoses, to minimise the patient's symptoms using the therapies available and to carefully limit potentially hazardous therapeutic efforts, especially in mild or even uncertain cases.

No association of three polymorphisms in the alpha-2-macroglobulin and lipoprotein related receptor genes with multiple sclerosis

Alpha-2-macroglobulin (A2M) is a proteinase inhibitor involved in deactivation of cytokines and modulation of antigen-mediated immune responses. Based on its role in inflammatory and neurodegenerative disorders, we investigated the role of A2M and its receptor low-density lipoprotein receptor-related protein (LRP) for the development of multiple sclerosis (MS). We analyzed the frequency of two polymorphisms in the A2M (Val 1000 Ile, Exon 18 del), and one polymorphism in the LRP (A216V) gene in a case control study involving 326 MS patients, and 290 controls, all defined for the expression of HLA-DR15. No association was found for any of the three polymorphism with MS. Furthermore, no differences in serum A2M levels were detected between MS patients and controls. The results do not suggest a contribution of A2M and LRP to the development of MS.