The protective effects of PBN against MPTP toxicity are independent of hydroxyl radical trapping

To study the mechanism of the protective effect of the spin-trapping agent alpha-phenyl-N-tert-butyl nitrone (PBN) against MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) toxicity hydroxyl radicals and functional parameters of neuroprotection were determined. C57BL/6 mice received PBN (100 mg/kg IP) over a time period of 15 days and on day 8 MPTP (40 mg/kg SC). On day 15 striatal levels of dopamine, serotonin, and metabolites were analyzed. For radical determination mice received a single injection of salicylic acid (SA) (100 mg/kg IP) in the time period of 0.5 h before to 72 h after MPTP injection. In vivo maximum hydroxyl radical levels indicated by 2,3-dihydroxybenzoic acid/SA ratios were obtained 4 h after MPTP injection, and were not affected by PBN treatment. However, the MPTP-induced mortality, reduction of locomotor activity, continuous loss of body weight, and striatal dopamine depletion were significantly less pronounced in PBN-treated animals. These results elucidate the time course of hydroxyl free radical formation in MPTP toxicity. PBN improved the functional parameters of neuroprotection against MPTP toxicity, but there is no evidence for hydroxyl radical scavenging properties to this effect.

Salicylate protects against MPTP-induced impairments in dopaminergic neurotransmission at the striatal and nigral level in mice

The analgesic and anti-inflammatory drug sodium salicylate was studied for its potential protective effects in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. C 57BL/6 mice were treated with a single dose of sodium salicylate (50 mg/kg or 100 mg/kg i.p.) or saline immediately before injection of MPTP (30 mg/kg or 40 mg/kg s.c.) or saline. Analysis of striatal dopamine and metabolites as well as immunostaining for tyrosine hydroxylase of nigral sections was performed 7 days after MPTP treatment. MPTP (30 mg/kg) led to a strong decrease in striatal dopamine levels (1.87+/-0.27 ng/mg) compared to saline-treated controls (15.72+/-0.78 ng/mg), which was significantly attenuated by sodium salicylate 50 mg/kg and 100 mg/kg (5.59+/-0.56 ng/mg and 8.64+/-0.89 ng/mg, respectively). Remarkably, the MPTP-induced loss of tyrosine hydroxylase immunoreactivity in nigral cell bodies was nearly completely prevented by the higher dose of sodium salicylate. Furthermore, salicylate demonstrated radical scavenging effects in an in vitro Fenton system indicated by HPLC determination of the dihydroxylated reaction products of salicylate, namely, 2,3- and 2,5-dihydroxybenzoic acid. The protective effects of salicylate against reversible or irreversible impairments in dopaminergic neurotransmission after MPTP treatment may be related to its radical scavenging properties and other mechanisms which need to be clarified.

Pramipexole, a nonergot dopamine agonist, is effective against rest tremor in intermediate to advanced Parkinson's disease

We evaluated the efficacy of the nonergot dopamine receptor agonist pramipexole in 16 patients with advanced Parkinson's disease and marked rest tremor during an "on" period. The patients were drawn from a larger placebo-controlled, double-blind, randomized trial, which was not originally designed to investigate the effect of pramipexole on tremor. Eleven patients received pramipexole. The first effects were seen with a pramipexole dose of 0.75 mg/d with a reduction of the tremor item A of Unified Parkinson's Disease Rating Scale (UPDRS III, "on" state) by 25% and of rigidity and akinesia by 22%. Under the highest dose, 4.5 mg/d, the tremor score was improved by 61% over baseline (p < 0.0056, Wilcoxon signed rank) and the sum of rigidity and akinesia items by 66% (p < 0.0038, Wilcoxon signed rank). Five patients received placebo and did not improve. Based on this sample of patients, the nonergot dopamine receptor agonist pramipexole appears to have a potent anti-rest tremor action while being effective against akinesia and rigidity.

Tiagabine-induced absence status in idiopathic generalized epilepsy

Several medications such as baclofen, amitriptyline and even antiepileptic drugs such as carbamazepine or vigabatrin are known to induce absence status epilepticus in patients with generalized epilepsies. Tiagabine (TGB) is effective in patients with focal epilepsies. However, TGB has also been reported to induce non-convulsive status epilepticus in several patients with focal epilepsies and in one patient with juvenile myoclonic epilepsy. In animal models of generalized epilepsy, TGB induces absence status with 3-5 Hz spike-wave complexes. We describe a 32-year-old patient with absence epilepsy and primary generalized tonic-clonic seizures since 11 years of age, who developed her first absence status epilepticus while treated with 45 mg of TGB daily. Administration of lorazepam and immediate reduction in TGB dosage was followed by complete clinical and electroencephalographic remission. This case demonstrates that TGB can induce typical absence status epilepticus in a patient with primary generalized epilepsy.

Multiple system atrophy

Multiple system atrophy (MSA) is a degenerative central nervous system disease of unclear origin. Patients affected typically show symptoms attributable to the combined involvement of the extrapyramidal, pyramidal, cerebellar and autonomic nervous systems. At onset patients mostly see a doctor because of extrapyramidal or--more rarely--cerebellar symptoms. Evidence of autonomic nervous system involvement is often not apparent, at least to the neurologist, before the history is taken. In later stages, by contrast, involvement of all of the above systems is clinically detectable.

Temporo-spatial expression of bFGF and TGFbeta2 in embryonic dopaminergic grafts in a rat model of Parkinson's disease

In the present study we analyzed the temporo-spatial expression pattern of basic fibroblast growth factor (bFGF) and transforming growth factor beta 2 (TGFbeta2) in embryonic dopaminergic transplants in the 6-hydroxydopamine rat model of Parkinson's disease. The grafts differentiated for 1, 2, 4 and 8 weeks, respectively and were then analyzed using antibodies directed against tyrosine hydroxylase, bFGF and TGFbeta2. At all time points investigated, grafts contained tyrosine hydroxylase immunoreactive neurons. One week after transplantation the grafts displayed no immunoreactivity for bFGF and TGFbeta2. In more mature grafts (starting at 2 weeks post transplantation) bFGF and TGFbeta2 immunoreactivity became detectable within the graft and at the graft-host interface but was restricted only to astrocytes. In the striatum surrounding the graft, a transient increase of TGFbeta2 immunoreactive astrocytic processes was observed between 1 and 2 weeks after transplantation. This temporo-spatial expression pattern of TGFbeta2 immunoreactive astrocytes suggests that the upregulation of TGFbeta2 is more likely due to the trauma imposed by the transplantation procedure than to an intrinsic differentiation program. Lack of both bFGF and TGFbeta2 expression in grafted dopaminergic neurons compared to their normal expression in the adult rat substantia nigra indicates that these transplanted neurons do not develop their complete physiological phenotype. Together with the observed deficiency in astrocytic bFGF early after grafting this may be responsible for the poor survival of grafted embryonic dopaminergic cells.

Efficacy, safety, and tolerance of the non-ergoline dopamine agonist pramipexole in the treatment of advanced Parkinson's disease: a double blind, placebo controlled, randomised, multicentre study

OBJECTIVES

Pramipexole, a non-ergot dopamine D2/D3 receptor agonist, was investigated as an add on drug in advanced parkinsonian patients with motor fluctuations to assess efficacy, safety, and tolerance.

METHODS

Seventy eight patients of either sex with advanced Parkinson's disease and treatment complications such as motor fluctuations were enrolled into a double blind, placebo controlled, randomised, multicentre study (phase II) and assigned to add on treatment with pramipexole (n=34) versus placebo (n=44) to a previously stabilised antiparkinsonian medication (7 week dose titration interval, 4 week maintenance period). The primary end point of efficacy was the change from baseline in the total score of the unified Parkinson's disease rating scale (UPDRS) in the on "period" (2 hours after intake of study medication). Safety and tolerability were assessed on the basis of adverse events, vital signs, laboratory measurements, and ECG recordings.

RESULTS

There was a significant improvement of the pramipexole group in UPDRS total scores, subscores part II, III (activities of daily living and motor examination), and IV (complications of therapy). Mean UPDRS total score decreased by 37.3% under pramipexole compared with 12.2% under placebo (p<0.001). Patients under pramipexole reported an overall reduction in "off" periods of 12%--resulting in 1.7 more hours "on" time a day--compared with an increase in "off" periods of 2% under placebo. There were no unexpected safety results. The adverse event profile disclosed a high tolerability. The most important adverse events under pramipexole were fatigue, dyskinesia, and vivid dreams.

CONCLUSION

Pramipexole administration is an efficacious and well tolerated add on therapy in patients with advanced Parkinson's disease with an improvement in activities of daily living, motor function, and treatment associated complications.

A randomized controlled study of pergolide in patients with restless legs syndrome

BACKGROUND

Open clinical trials indicate that low doses of pergolide, a long-acting D1 and D2 dopamine agonist, lead to a reduction in the symptoms of restless legs syndrome (RLS) with subjective improvement in sleep quality.

OBJECTIVE

To assess the therapeutic efficacy of pergolide in improving sleep and subjective measures of well-being in patients with idiopathic RLS using polysomnography and clinical ratings.

METHODS

In a randomized, double-blind, placebo-controlled crossover design we enrolled 30 patients with idiopathic RLS according to the criteria of the International RLS Study Group. All patients were free of psychoactive drugs for at least 2 weeks before the study. Patients were monitored using polysomnography, clinical ratings, and sleep diaries at baseline and at the end of a 4-week pergolide or placebo treatment period. The initial dosage of 0.05 mg pergolide was increased to the best subjective improvement paralleled by 20 mg domperidone tid.

RESULTS

At a mean dosage of 0.51 mg pergolide as a single daily dose 2 hours before bedtime, there were fewer periodic leg movements per hour of time in bed (5.7 versus 54.9, p < 0.0001), and total sleep time was significantly longer (373 versus 261 minutes, p < 0.0001). Ratings of subjective sleep quality, quality of life, and severity of RLS were improved significantly without relevant adverse events.

CONCLUSION

Pergolide given as a single low-to-medium bedtime dose in combination with domperidone provides a well-tolerated and effective treatment of sensorimotor symptoms and sleep disturbances in patients with primary RLS.

The combination of hypointense and hyperintense signal changes on T2-weighted magnetic resonance imaging sequences: a specific marker of multiple system atrophy?

OBJECTIVE

To compare the frequency and specificity of hypointense magnetic resonance imaging (MRI) signal changes alone with the frequency and specificity of a pathological MRI pattern consisting of a hyperintense lateral rim and a dorsolateral signal attenuation on T2-weighted MRIs in patients with parkinsonism of various origins.

PATIENTS

Ninety patients with Parkinson disease (PD) (n = 65), progressive supranuclear palsy (PSP) (n = 10), and multiple system atrophy (MSA) of the striatonigral degeneration type (n = 15) underwent MRI.

SETTING

University medical center.

RESULTS

Nine of the 15 patients with MSA showed the pattern with hyperintense lateral rim and a dorsolateral hypointense signal attenuation on T2-weighted images within the putamen. This pattern was not found in the 65 patients with PD, nor in the 10 patients with PSP. Only hypointense changes in the putamen were found in 6 patients (9%) with PD, 4 patients (40%) with PSP, and 5 patients (36%) with MSA.

CONCLUSIONS

Our data suggest that the pattern consisting of hypointense and hyperintense T2 changes within the putamen is a highly specific MRI sign of MSA, while hypointensity alone remains a sensitive, but nonspecific MRI sign of MSA. In clinically doubtful cases, the appearance of a hypointense and hyperintense signal pattern on MRI makes the diagnosis of PD very unlikely, while hypointense signal changes alone do not exclude idiopathic PD.

[Early summer meningoencephalitis. Extension of the endemic area to mid-Hessia]

Tick-borne encephalitis (TBE) is the most severe arbovirus disease transmitted by ticks. The mortality of the central European form is 0.7-2%. Active immunisation is recommended for endemic regions. We report on 4 patients with TBE acquired in Middle-Hessen between 1994 and 1997 (2 in 1997). After repeated CSF and serum testing the TBE-specific antibodies were found in all 4 cases. In one case there was also evidence for a prior infection with borrelia burgdorferi. The results of the initial CSF-analysis were atypical in 2 cases (high cell count of 136 cells/mm3, total protein up to 1.5 g/l). The endemic region for TBE has expanded in northern direction into Middle-Hessen, a region in which Lyme borreliosis is also endemic. Thus, true double infections are possible. This and the initially frequently atypical CSF-findings make the differential diagnosis difficult. Therefore, repetitive CSF and blood examinations are recommended.

Relative quantification of signal on T2-weighted images in the basal ganglia: limited value in differential diagnosis of patients with parkinsonism

A reduction in signal in the basal ganglia on T2-weighted images is said to correlate with a poor response to L-DOPA and may help to identify patients with non-idiopathic parkinsonism. Our aim in this prospective study was to use the contrast-to-noise ratio of the MRI signal on T2-weighted images in various parts of the basal ganglia in 43 patients with de novo parkinsonism. Signal intensity measurements were compared to the response to the dopamine agonist apomorphine and dopamine-D2 receptor binding obtained by 3-iodo-6-methoxybenzamine single-photon emission computed tomography (IBZM-SPECT). A reduced contrast-to-noise ratio in the putamen correlated significantly with a negative response to apomorphine and reduced striatal IBZM binding. No additional signal intensity measurement correlated with response to apomorphine or specific IBZM binding. However, there was a considerable overlap of contrast-to-noise ratios between patients with a positive or negative response to apomorphine or normal and reduced IBZM binding. We suggest that semiquantitative assessment of signal intensity in the putamen shows a significant reduction in patients with probably nonidiopathic parkinsonism compared with patients with probably idiopathic parkinsonism. However, this method does not exclude idiopathic parkinsonism in a given patient.

A controlled study of additional sr-L-dopa in L-dopa-responsive restless legs syndrome with late-night symptoms

OBJECTIVE

To investigate whether a combination treatment of regular-release levodopa (rr-L-dopa) and sustained-release levodopa (sr-L-dopa) compared with monotherapy of rr-L-dopa improves sleep quality and reduces periodic limb movements (PLM) in patients with restless legs syndrome (RLS) and problems with maintaining sleep.

BACKGROUND

Reappearance of RLS symptoms during the second half of the night while being treated with rr-L-dopa is a common problem in the treatment of sleep disturbances caused by RLS.

METHODS

A randomized, controlled, double-blind crossover trial was undertaken. Eligible patients fulfilled the diagnostic criteria of the International RLS Study Group, and met an actigraphically confirmed higher number of PLM per hour time in bed (PLM index) during the second half compared with the first half of the night under treatment with rr-L-dopa. During the crossover periods the patients received 100 to 200 mg rr-L-dopa plus either placebo or 100 to 200 mg sr-L-dopa at bedtime for 4 weeks each period.

RESULTS

Thirty patients with RLS (11 men and 19 women) were assessed by actigraphy and subjective sleep quality, and showed a significant improvement in PLM index (p < 0.0001), in "time in bed without movements" (p < 0.0001), and in subjective sleep quality (p < 0.001). Eight of 30 patients reported an altered pattern of RLS symptoms, characterized by a time shift of RLS symptoms into the afternoon or evening, five of these during monotherapy with rr-L-dopa.

CONCLUSIONS

A combination therapy of rr-L-dopa and sr-L-dopa is better than monotherapy with rr-L-dopa in reducing the frequency of PLM and problems maintaining sleep, even in patients who are severely affected.

Rat fetal ventral mesencephalon grown as solid tissue cultures: influence of culture time and BDNF treatment on dopamine neuron survival and function

Free-floating roller tube (FFRT) cultures of fetal rat and human nigral tissue are a means for tissue storage prior to grafting in experimental Parkinson's disease. In the present study, FFRT cultures prepared from embryonic-day-14 rat ventral mesencephalon were maintained for 4, 8, 12, or 16 days in vitro (DIV) in the presence or absence (controls) of BDNF [100 ng/ml]. The dopamine content in the culture medium, analyzed by HPLC, was significantly higher (4-5 fold) in the BDNF group at DIV 8 and DIV 12 compared to the corresponding control levels (40 pg/ml). The number of tyrosine hydroxylase immunoreactive neurons was significantly higher for BDNF treated cultures (2729+/-300) at DIV 8, as compared to controls (1679+/-217). At DIV 12, the culture volume was significantly increased by BDNF (1.05+/-0.12 vs. 0.71+/-0.04 mm3). Similar results were obtained for total protein. Western blot analysis demonstrated increasing signals for GFAP with increasing time in culture, but levels for control and BDNF treated cultures did not differ at any time-point investigated. In conclusion, it is suggested that the time window for effective storage of dopaminergic tissue prior to grafting can be extended by using the FFRT culture technique and that the in vitro storage may be further prolonged by treatment with BDNF.

Pharmacological characterisation of dopamine overflow in the striatum of the normal and MPTP-treated common marmoset, studied in vivo using fast cyclic voltammetry, nomifensine and sulpiride

The in vivo measurement of electrically-evoked dopamine overflow was measured for the first time in the striatum of control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated common marmosets using fast cyclic voltammetry at untreated carbon-fibre microelectrodes, (7 microm, o.d.). The identity of dopamine was confirmed using electrochemical, pharmacological and histological criteria and complied with rat data from earlier studies. Dopamine overflow depended on the intensity, number of pulses, and frequency of the applied stimuli. Maximum dopamine overflow occurred using 1.0-2.0 mA, 200 micros pulse width, 150-200 pulses at 80-120 Hz stimulation of the medial forebrain bundle. Evoked dopamine overflow in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated marmosets showed a similar electrochemical and pharmacological profile compared to healthy controls, albeit the concentration detected was significantly reduced. The catecholamine uptake blocker, nomifensine, significantly increased the dopamine signal in control marmosets. However, in contrast, nomifensine had no significant effect on evoked dopamine overflow in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated marmosets. Apart from demonstrating that fast cyclic voltammetry with electrical stimulation can be reliably used to monitor dopamine overflow within the primate brain, our results describe for the first time the technical prerequisites for the fast cyclic voltammetric technique in the non-human primate brain.

Facial pain in a case of cranial dystonia: a case report

A 76-year-old man had shown sustained excruciating facial pain in the maxillary region for more than 30 years. Since he was suffering from blepharospasm, facial electromyography was performed and revealed a perioral dystonia. This possible cause of facial pain might have been overlooked had dystonia not been considered and electromyographical studies performed. Repeated intramuscular perioral injections of botulinum toxin brought about complete pain relief. This case shows that involuntary activity of facial muscles can cause a severe chronic pain syndrome. Possible mechanisms include irritation of ascending trigeminal fibers, muscle ischemia due to compression of blood -vessels, or release of pain-producing substances.

Neural transplantation in Parkinson's disease and its effects on rest tremor: a review of the literature

The transplantation of fetal mesencephalic dopaminergic tissue into the striatum of parkinsonian (PD) patients is an experimental therapeutic approach. The target population for this treatment are advanced, predominantly akinetic-rigid patients with therapy-associated complications, and not tremor-dominant PD patients. Based on a review of selected published data, no specific beneficial effect of fetal mesencephalic transplantation in PD patients was reported on the cardinal symptom rest tremor. On the one hand, this might be the result of a lack of efficacy of this treatment with respect to tremor; on the other hand, PD patients with predominant tremor may have a better prognosis with respect to motor function and therefore might not reach the advanced akinetic-rigid stage, which makes them eligible for neural transplantation. Rest-tremor dominant PD patients have not undergone fetal cell grafting; therefore its effect on rest tremor is unknown.

Effects of nicotine on hydroxyl free radical formation in vitro and on MPTP-induced neurotoxicity in vivo

Parkinson's disease (PD) is one of the most frequent disorders of the basal ganglia. From epidemiological studies there is a controversial discussion on the question whether tobacco smoking is correlated with a decreased incidence of PD. The present study aimed to elucidate the role of nicotine and its potential neuroprotective effects in a rodent model of PD. These effects may be related to an altered hydroxyl radical formation; this possibility was studied in vitro. Nicotine and alpha-phenyl-N-tert-butyl nitrone (PBN) were examined in a cell-free in vitro Fenton system (Fe3+/EDTA + H2O2) for their radical scavenging properties using the salicylate trapping method. Salicylic acid (0.5 mM) was incubated in the presence and absence of nicotine or PBN and the main products of the reaction of hydroxyl radicals with salicylic acid, namely 2,3- and 2,5-dihydroxybenzoic acid, were immediately determined using HPLC in combination with electrochemical detection. Nicotine and PBN were both able to significantly reduce hydroxyl radical levels at concentrations of 1, 2.5 and 5 mM. Interestingly, at 5 mM nicotine was able to reduce hydroxyl radical levels significantly more than the radical scavenger PBN (5 mM). To investigate the in vivo effects of nicotine, male C57BL/6 mice were used in the MPTP mouse model of PD. Nicotine (0.1 or 0.4 mg/kg s.c.) was administered twice daily for a period of 14 days. On day 8 a single injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg s.c.) was given as well as an enhanced protocol of nicotine treatment (0.1 or 0.4 mg/kg s.c., 30 min before MPTP and 30, 90, 210, 330, 450, 570 min after MPTP) for a total of seven injections of nicotine. High dosage nicotine treatment significantly increased the MPTP-induced loss of body weight and resulted in a significantly decreased striatal dopamine content and an increased dopamine turnover in comparison with the MPTP-treated controls at day 15. However, the lower dosage of nicotine did not significantly alleviate the MPTP-induced effects, although some parameters showed a slight tendency in this direction. These results demonstrate that in vitro nicotine has radical scavenging properties which might suggest neuroprotective effects. In vivo experiments with nicotine, however, showed that a low dosage of nicotine did not alleviate the MPTP-induced dopamine depletion, but a large dosage even enhanced it.

The economic impact of Parkinson's disease. An estimation based on a 3-month prospective analysis

OBJECTIVE

This study prospectively assesses the medical costs of Parkinson's disease (PD).

DESIGN

Over a period of 3 months (from July to September 1995), patients with PD documented all items of healthcare provision. These data were then used to calculate medical costs for an individual patient as well as the costs of PD.

PATIENTS AND SETTING

We included 20 outpatients with idiopathic PD from the neurological outpatient clinic, Klinikum Grosshadern, Munich, and 20 patients from two office-based neurologists in South-West Germany.

MAIN RESULTS

The mean 3-month medical cost of PD in 1995 deutschmarks (DM) was 5210 ($US3390, 2240 Pounds) consisting of DM1410 ($US920, 610 Pounds) for care and nursing, DM1580 ($US1030, 680 Pounds) for drug therapy, DM1320 ($US860, 570 Pounds) for inpatient hospital care, DM40 ($US26, 17 Pounds) for outpatient care and DM860 for other expenses ($US560, 370 Pounds). The expenditure was related to the disease evolution. Patients complaining of one-sided symptoms [Hoehn and Yahr stage I; (HY I)] were less expensive to treat (DM1930, $US1250, 830 Pounds) than patients who were severely incapacitated (HY V) [DM9740, $US6330, 4200 Pounds; HY V]. After 3 to 5 years of levodopa treatment approximately 50% of patients start to experience fluctuations in motor ability and dyskinesias [Unified Parkinson's disease rating scale, part IV (UPDRS IV)]. This onset of motor complications parallels an increase in costs. For patients who experienced motor fluctuations, annual costs were DM6550 ($US4260, 2820 Pounds) compared with DM3030 ($US1960, 1300 Pounds) for patients lacking this problem. Indirect non-medical costs were not calculated due to the limited number of patients. The impact of the disease on work, however, is clearly apparent from the patients' history: 19 out of 34 patients who had already stopped working attributed this to the disease, and only 6 patients were still working at the time of the survey.

CONCLUSION

PD poses a major financial impact to society which is expected to increase in future years as the age distribution shifts to older age groups. On the basis of a prevalence of PD of 183 per 100,000, we calculated an annual expenditure of DM3.0 billion for the direct medical costs of PD in Germany.

Polysomnographic sleep measures in patients with uremic and idiopathic restless legs syndrome

In the present study, the nocturnal electroencephalographic sleep pattern, the number of periodic leg movements (PLM) during sleep and wakefulness, and the subjective sleep parameters of patients with uremic (n = 10) and idiopathic (n = 17) restless legs syndrome (RLS) were compared. The main finding was that the total number of PLM (p = 0.019), the PLM index (p = 0.018), and the PLM index while awake (p = 0.003) were significantly higher in patients with uremic RLS compared with patients who had idiopathic RLS. Additionally, both groups showed a distinct time-of-night pattern of PLM activity. Polysomnographic measures of sleep continuity (total sleep time, sleep efficiency, sleep onset latency, time awake) and sleep architecture (amount of nonrapid eye movement sleep stages 1, 2, 3, and 4 and the amount of rapid eye movement sleep) did not differ between uremic and idiopathic RLS patients. With regard to subjective parameters, sleep quality was estimated to be worse in uremic RLS (p = 0.033), whereas other parameters (for example, severity of RLS, quality of life) did not differ between the two groups. It is suggested that uremia itself worsens the motor symptoms of RLS, probably as a result of increased excitability.

Secondary dystonias

Secondary or symptomatic dystonias are (1) often accompanied by other neurological deficits. (2) begin suddenly at rest and occur at rest from the onset, (3) are associated with different hereditary and environmental causes. From an aetiological point of view, secondary dystonias can be caused by focal brain lesions of various origin, neurodegenerative disorders, metabolic disorders of the central nervous system (CNS), and several drugs and chemicals that affect the basal ganglia, thalamus and brain stem. Furthermore, secondary (focal) dystonias can be caused by peripheral injury. In the following review, we will discuss epidemiology, genetics, pathogenesis, neuroimaging, neuropathology, clinical manifestation, clinical course and differential diagnosis of secondary dystonias. Therapeutic options are given depending on the aetiology and the topological type of dystonia.

BDNF and TrkB expression in intrastriatal ventral mesencephalic grafts in a rat model of Parkinson's disease

We investigated the expression of BDNF and its high affinity receptor trkB in fetal dopaminergic grafts in a rat model of Parkinson's disease. Grafts were allowed to differentiate for 7, 14, 28, or 56 days, respectively and were analyzed immunocytochemically thereafter with antibodies directed against tyrosine hydroxylase, BDNF and trkB. At all time points investigated, grafts contained tyrosine hydroxylase immunoreactive neurons. Immature grafts (7 days) displayed no immunoreactivity for BDNF which was restricted to glial cells at the graft-host interface. After longer differentiation periods BDNF-immunoreactivity was detectable in neurons and astrocytes within the grafts. No trkB immunoreactivity was found in immature grafts but a strong signal for trkB emerged in grafted neurons older than 14 days whereas glial cells remained unlabeled at all time points investigated. Expression of BDNF and trkB in grafted neurons and of BDNF in surrounding glial cells suggests an autocrine or paracrine action of BDNF on dopaminergic neurons possibly mediated by activated glia.