Characteristic changes in brain electrical activity due to chronic hypoxia in patients with obstructive sleep apnea syndrome (OSAS): a combined EEG study using LORETA and omega complexity.

EEG background activity of patients with obstructive sleep apnea syndrome (OSAS, N = 25) was compared to that of normal controls (N = 14) to reflect alterations of brain electrical activity caused by chronic intermittent hypoxia in OSAS. Global and regional (left vs. right, anterior vs. posterior) measures of spatial complexity (Omega) were used to characterize the degree of spatial synchrony of EEG. Low resolution electromagnetic tomography (LORETA) was used to localize generators of EEG activity in separate frequency bands. Comparing patients to controls, lower Omega complexity was found globally and in the right hemisphere. Using LORETA, an increased medium frequency activity was seen bilaterally in the precuneus, paracentral and posterior cingulate cortex. These findings indicate that alterations caused by chronic hypoxia in brain electrical activity in regions associated with influencing emotional regulation, long-term memory and the default mode network. Global synchronization (lower Omega complexity) may indicate a significantly reduced number of relatively independent, parallel neural processes due to chronic global hypoxic state in apneic patients as well as over the right hemisphere.

Distal myopathy with rimmed vacuoles and cerebellar atrophy.

Distal myopathies constitute a clinically and pathologically heterogeneous group of genetically determined neuromuscular disorders, where the distal muscles of the upper or lower limbs are affected. The disease of a 41-year-old male patient started with gait disturbances, when he was 25. The progression was slow, but after 16 years he became seriously disabled. Neurological examination showed moderate to severe weakness in distal muscles of all extremities, marked cerebellar sign and steppage gait. Muscle biopsy resulted in myopathic changes with rimmed vacuoles. Brain MRI scan showed cerebellar atrophy. This case demonstrates a rare association of distal myopathy and cerebellar atrophy.

Uniform qualitative electrophysiological changes in postoperative rest tremor.

Ablation and deep brain stimulation (DBS) can treat pharmacologically uncontrollable tremor. Here, we compared the postoperative electrophysiological changes in resting hand tremor after 32 ablations and 12 DBS implantations in patients with severe tremor-dominant idiopathic Parkinson's disease (PD) and essential tremor (ET). Short- and long-term accelerometric data were acquired after surgery and were compared to the preoperative tremor. After effective surgical treatments, significant rest tremor reduction and increase in both frequency and approximate entropy (ApEn) were detected in all PD cases, irrespective of the type and target of intervention. However, the long-term effect of DBS implantation on tremor reduction was significantly better compared to that after ablative treatments. In cases of thalamotomy, the postoperative increase in frequency and ApEn was significantly larger in essential tremor compared to PD, suggesting that the etiology of tremor may influence the size of the similar changes. However, cases where clinical tremor re-emerged 6 to 12 months after the surgery, no change in frequency and ApEn was detected on the second postoperative day, despite an initial tremor reduction and clinical improvement similar to the effective operations. Our results suggest that uniform postoperative changes in rest tremor and the increase in frequency and ApEn could be due to attenuation of pathological oscillators and might be immediate indicators of the effectiveness of neurosurgical treatments relieving tremor.

Distribution of spatial complexity of EEG in idiopathic generalized epilepsy and its change after chronic valproate therapy.

The objective of this study was to investigate the global and regional spatial synchrony of the EEG background activity, and to assess the effect of chronic valproate therapy on spatial synchrony. 15 idiopathic generalized epilepsy (IGE) patients were examined and compared to 16 normal controls. Resting EEG with 19 channels was investigated before and during chronic administration of valproate (VPA). Omega, a single-valued measure of spatial covariance complexity, was calculated to assess the degree of spatial synchrony of EEG. Furthermore, a new parameter was defined to characterize the distribution of spatial synchrony (Antero-Posterior Complexity Ratio, APCR). Global Omega complexity was significantly lower in IGE compared to controls, while regional complexity showed significant differences only in the anterior region: the IGE group showed lower complexity. APCR was significantly lower in IGE. VPA therapy (1) lowered the global complexity, (2) increased regional complexity in the anterior region, but decreased it in the posterior region, and (3) increased APCR. In IGE lower complexity, i.e. enhanced spatial synchrony, was found, especially in the anterior cortical area. VPA modified the distribution of spatial synchrony in IGE patients towards that of normal controls, although the effect is not identical with full normalization of cortical bioelectric activity. Whether the observed change of spatial synchrony distribution may reflect the normalizing effect of valproate on the brain state is worth further investigation.

Suicide in Hungarian Huntington's disease patients.

We studied 96 families with Huntington's disease (HD). There were 396 deaths reported in 195 males and 201 females. Family history and clinical information about the deceased were collected and 40 suicides were found. Suicide occurred most frequently in the early or late stages of the disease; age at onset was slightly lower among those who committed suicide. Of the 40 subjects who committed suicide, 34 were male and 6 were female; this was not significantly different to the expected ratio based on suicide in the general population. Those who committed suicide had a smaller number of children than other HD patients. No significant relationship was shown between the sex of the affected parent and suicide. Four suicides occurred in hospital. Suicide among patients with HD is more common than in the general population. Knowledge about the high suicide risk in this disease is important for genetic counseling.

Short-term effect of low-dose atorvastatin on haemorrheological parameters, platelet aggregation and endothelial function in patients with cerebrovascular disease and hyperlipidaemia.

INTRODUCTION AND OBJECTIVE: Haemorrheological parameters and endothelial function are known to be altered in vascular diseases, including stroke. Treatment with HMG-CoA reductase inhibitors ('statins') improves cerebrovascular (and cardiovascular) morbidity and mortality in patients with atherosclerosis; the beneficial effects may involve lipid-independent mechanisms. The aim of this study was to assess the short-term effect of low-dose atorvastatin on haemorrheological parameters, platelet aggregation and endothelial dysfunction in patients with chronic cerebrovascular disease and hyperlipidaemia. PATIENTS AND METHODS: Twenty-seven patients (mean age 61 +/- 8 years) with chronic cerebrovascular disease and hyperlipidaemia were included in the study. Serum lipid levels, haemorrheological parameters (haematocrit, plasma fibrinogen levels, plasma and whole blood viscosity [WBV] and red blood cell [RBC] aggregation and deformability) and platelet aggregation were assessed at baseline and after 1 and 3 months of treatment with atorvastatin (Sortis) 10 mg/day. von Willebrand factor (vWF) activity (a measure of endothelial function) was measured at baseline and after 1 month of treatment. Adverse events were recorded at each visit. Physical examinations, haematological assessments and serum and urine chemistry assays were performed during the study. RESULTS: Plasma total cholesterol levels were reduced by a mean of 27% compared with baseline after both 1 and 3 months of treatment (p < 0.001). Low density lipoprotein-cholesterol levels were reduced by a mean of 40% and 38% (p < 0.001), respectively, after 1 and 3 months of treatment, compared with baseline values. Triglyceride levels decreased by 20% at 1 month and by 10% after 3 months (p < 0.001). Atorvastatin significantly improved WBV after 3 months of treatment and RBC deformability after 1 month and 3 months of treatment (p < 0.05). Collagen-induced platelet aggregation was significantly decreased at 1 (p < 0.05) and 3 months (p < 0.001) compared with baseline values, despite unaltered antiplatelet therapy. vWF activity was also improved significantly (p < 0.05) after 1 month of treatment. CONCLUSIONS: Our findings show that the beneficial effects of atorvastatin are complex. Besides lipid lowering, atorvastatin can improve haemorrheological parameters, platelet aggregation and endothelial dysfunction after short-term and low-dose therapy. Whether such early laboratory changes translate into clinical utility for secondary stroke prevention awaits the results of endpoint trials.

[Effect of vinpocetin on the hemorheologic parameters in patients with chronic cerebrovascular disease]. / Vinpocetin hatása krónikus agyérbetegségben szenvedók hemoreológiai viszonyaira.

INTRODUCTION: Data collected from large number of multicenter, randomized trials in acute and chronic stroke patients provide evidence, that incidence and high mortality of cerebrovascular disorders can be decreased mainly by prevention and that the effectiveness of acute stroke treatment is limited. The terminology of "chronic cerebrovascular diseases" involves many pathologic entities and often atypical clinical symptoms refer to the focal or global hypoperfusion of the brain. However, hemorheological disturbances seem to be important factors of the complex pathomechanism. Vinpocetine has successfully been used in the treatment of cerebrovascular diseases, the part of the mechanism of action are the favourable rheological effects demonstrated after oral administration in more previous studies. AIMS AND METHODS: In this study the hemorheological changes after administration of small (30 mg/day) and high dose (increased to 70 mg/day) intravenous vinpocetine for 7 days in 30 patients in chronic phase of ischemic cerebrovascular disease were investigated. RESULTS: High dose parenteral vinpocetine treatment significantly (p < 0.05-0.005) decreased the hematocrit, the whole blood and plasma viscosity and red blood cell aggregation compared to the values before the treatment. Only red blood cell aggregation was improved significantly (p < 0.05) by small dose treatment. CONCLUSION: This study and other hemorheological studies in cerebrovascular patients demonstrated persistent rheological abnormalities despite the preventive therapy. The beneficial rheological effect of high dose parenteral vinpocetine indicates the use of this drug in the treatment of chronic cerebrovascular diseases.

Oral magnesium load test in patients with migraine.

OBJECTIVE: To determine whether migraineurs may have a systemic deficiency of magnesium. BACKGROUND: Magnesium deficiency has been shown to play a potential role in the pathogenesis of migraine, but there are no data on total body magnesium status in migraineurs. METHODS: An oral magnesium load test was performed by giving 3000 mg of magnesium lactate during a 24-hour interictal period to 20 patients with migraine (15 women and 5 men; mean age, 37.9 years) and 20 healthy volunteers (16 women and 4 men; mean age, 39.6 years). Baseline and postload magnesium concentrations were determined from serum and 24-hour urine specimens. RESULTS: There was no significant difference between the groups in the baseline serum and urine magnesium concentrations, although the latter tended to be lower (P = .064) in the migraine group. The postload magnesium concentrations were significantly higher within both the migraine (P < .0001 and P < .0001) and the control (P = .0009 and P < .0001) groups compared to the baseline values. After loading, the 24-hour urinary magnesium excretions were significantly lower (P = .0007) in the patients with migraine than in the controls, but serum values did not differ. CONCLUSIONS: Magnesium retention occurs in patients with migraine after oral loading, suggesting a systemic magnesium deficiency.