[Headache as a warning symptom]

Chronic headache is an independent clinical picture. Headaches are to be interpreted as a warning sign from the body until this is excluded through differential diagnostics. The clarification and the initial treatment should be carried out by a neurologist to ensure sufficient diagnostic certainty.

Piracetam versus acetylsalicylic acid in secondary stroke prophylaxis. A double-blind, randomized, parallel group, 2 year follow-up study

Piracetam has been shown to inhibit platelet aggregation. Therefore, we performed a double-blind, randomized, parallel group study to compare the efficacy of daily 1600 mg piracetam t.i.d. vs. 200 mg acetylsalicylic acid (ASA) t.i.d. in secondary stroke prophylaxis. 563 patients after stroke as confirmed by computed tomography (CT) or magnetic resonance imaging (MRI) were enrolled and received either piracetam or ASA during a 2 year follow-up period. The primary endpoint was the rate of stroke, transient ischaemic attack (TIA), or death from vascular cause. The secondary endpoint was the rate of adverse events leading to a premature discontinuation of the study medication. Patients were visited at home every 3 months and were examined in hospital after 1 and 2 years. At every visit, the platelet function was evaluated. No significant difference and no significant equivalence could be shown for the primary endpoint between the piracetam and the ASA group both in the intention-to-treat and in the per-protocol analysis. However, there was a not significant trend in favor of ASA (11.7 vs. 15.2%). After excluding those patients who did not respond to antiplatelet medication in vitro, however, piracetam and ASA were equivalent in secondary stroke prophylaxis (stroke, TIA, or vascular death 10.1% in the piracetam group vs. 9.7% in the ASA group). Piracetam was significantly superior to ASA in the secondary endpoint (P=0.0039). The data suggest that the overall efficacy of piracetam in secondary stroke prophylaxis is not as good as that of ASA but that piracetam is better tolerated. However, our data furthermore show that nonresponders to pharmacological inhibition of platelet function are more frequent under piracetam therapy and that they may influence the results of large studies on secondary prophylaxis in vascular diseases.

Screening for HIV-associated distal-symmetric polyneuropathy in CDC-classification stages 1, 2, and 3

OBJECTIVES

A total of 670 patients were screened for distal symmetric HIV-associated polyneuropathy during CDC stages 1-3 and its correlation to immunological deterioration.

MATERIAL AND METHODS

Clinical examinations of 670 patients admitted to the neurological outpatient clinic at the Department of Neurology, University of Munster. Neurophysiological investigations were performed on the sural and peroneal nerve for detection of axonal and myelin lesion.

RESULTS

Clinical examination proved progressive clinical signs and symptoms indicating distal symmetric polyneuropathy from CDC 1 (32%) to CDC 3 (55%). At least one neurophysiological result was impaired in CDC 1 in 25% and in CDC 3 in 45%. Significant correlation between neurophysiological changes and CDC4(+)-cells and beta-microglobuline were detected for stage CDC 3 C.

CONCLUSION

Results show stage related prevalence of distal symmetric polyneuropathy already in early stages. In late stages of HIV-infection prevalence of distal symmetric polyneuropathy seems to be directly correlated to immunodeficiency syndrome. The pathogenesis of distal symmetric polyneuropathy during HIV-infection is up to now incompletely understood, but results indicate a clear dependency between progressive immunological dysfunction and neuropathy. High active antiretroviral therapy in patients suffering from distal symmetric polyneuropathy is a main topic of future studies.

The Contingent Magnetic Variation in Migraine

Abstract Migraine is characterized by an increased contingent negative variation. Separate comparisons of the early and late component showed that it was the former rather than the latter that was elevated. The function and localization of the early component are as yet poorly understood. The magneto-encephalogram was recorded in 16 patients with migraine and 17 healthy control subjects during a forewarned reaction time task. Neuromagnetic data were recorded with a 37-channel neuromagnetometer with the sensors being placed above the left hemisphere contralaterally to the side of the acoustic stimulation and the motor reaction. Subjects responded to the second of two low intensity sound stimuli that were administered with an interval of 4.5 s. Migraine patients exhibited a significantly higher amplitude of the early component of the contingent magnetic variation (CMV) than controls. Groups did not differ with regard to the amplitude of the late component. Modeling the sources with a single moving equivalent current dipole (ECD) provided a high goodness of fit for the M100 (magnetic N1) in both groups and for the early component of the CMV in migraineurs but not controls. The activity of the early component was centered medially with respect to the M100-ECDs and more laterally so in migraine patients than in controls.

A retrospective long-term analysis of the epidemiology and features of drug-induced headache

Drug-induced headache is well known to result from the abuse of compounds taken for the treatment of primary headache. The features of drug-induced headache depend on various features including the availability of drugs, the regional health system, and psychogenic factors of the patients. We performed a retrospective study on a series of 257 consecutive German patients presenting with drug-induced headache during the period 1983-1996. Our aim study was to evaluate the demographic features, the frequency of various drugs used, in particular of ergotamine derivates, and changes in these features during the study period. The frequency of drug-induced headache among all headache patients was 8%, with a female preponderance of 81%. Drug-induced headache occurred in all age groups, predominantly in migraine patients (35%). The mean number of substances used was 2.7, mainly, acetaminophen (47.9%), ergotamine tartrate (45%), and combined analgesics (56%). We did not find a significant difference between the associations with ergotamine tartrate and dihydroergotamine, although the latter was taken less frequently. Comparing the early and late years of our study period, there were no changes in the frequency of drug-induced headache (8% versus 7%), although changes in the frequency of some drugs changed (barbiturates, ergotamine tartrate, and codeine intake decreased whereas nonsteroidal anti-inflationary drugs, combined analgesics, and sumatriptan intake increased). Our data suggest that changes in drug availability and the introduction of classification criteria and treatment recommendations did not have a major impact on the frequency of drug-induced headache.

Inhibition of smoking-induced platelet aggregation by aspirin and pycnogenol

The effects of a bioflavonoid mixture, Pycnogenol, were assessed on platelet function in humans. Cigarette smoking increased heart rate and blood pressure. These increases were not influenced by oral consumption of Pycnogenol or Aspirin just before smoking. However, increased platelet reactivity yielding aggregation 2 hours after smoking was prevented by 500 mg Aspirin or 100 mg Pycnogenol in 22 German heavy smokers. In a group of 16 American smokers, blood pressure increased after smoking. It was unchanged after intake of 500 mg Aspirin or 125 mg Pycnogenol. In another group of 19 American smokers, increased platelet aggregation was more significantly reduced by 200 than either 150 mg or 100 mg Pycnogenol supplementation. This study showed that a single, high dose, 200 mg Pycnogenol, remained effective for over 6 days against smoking-induced platelet aggregation. Smoking increased platelet aggregation that was prevented after administration of 500 mg Aspirin and 125 mg Pycnogenol. Thus, smoking-induced enhanced platelet aggregation was inhibited by 500 mg Aspirin as well as by a lower range of 100-125 mg Pycnogenol. Aspirin significantly (p<0.001) increased bleeding time from 167 to 236 seconds while Pycnogenol did not. These observations suggest an advantageous risk-benefit ratio for Pycnogenol.

Dynamic changes of cognitive habituation and serotonin metabolism during the migraine interval

Migraine patients show a specific cognitive processing with a loss of habituation in the interval and a normal habituation in the attack as measured by event-related potentials (ERPs). It is unknown whether the loss of habituation changes during the migraine interval or is a stable state. Serotonin (5HT) metabolism is involved in the pathophysiology of migraine and also in the generation of ERPs. We enrolled 14 patients with regular migraine attacks in order to measure visually evoked ERPs repetitively during the migraine interval and in the migraine attack. Cognitive habituation was evaluated by analysis of P3 latency. Platelet serotonin content and free serotonin plasma level were measured at the same time points. The loss of habituation increased continuously during the migraine interval and abruptly normalized in the migraine attack (p < 0.05, time series analysis). The platelet 5HT content decreased significantly in the migraine attack (p < 0.03) and was at its maximum in the middle of the interval. The P3 latency was significantly increased in the attack (p < 0.01) and was significantly inversely correlated with the platelet 5HT content (r = -0.44, p < 0.001). Free 5HT plasma levels did not show any significant change. Our findings suggest that loss of cognitive habituation continuously increases during the migraine interval until its normalization in the migraine attack. This phenomenon cannot be attributed to serotonergic transmission. In patients with regular changes of cognitive habituation before the migraine attack, it might be possible to predict the attack by analysing ERPs.

Piracetam and platelets--a review of laboratory and clinical data

This paper reviews the effects of piracetam on platelet function and the evidence for its antiplatelet effect which is mediated mainly by inhibition of platelet aggregation. Piracetam also possesses antithrombotic activity in vivo. It has been shown to normalize platelet aggregation in patients with increased platelet aggregability in various disorders including acute stroke, transient cerebral ischemic attacks and diabetes mellitus. This, together with clinical improvement, has also been shown in patients with Raynaud's phenomenon. The results of recent studies are presented in which piracetam showed similar efficacy to aspirin in the secondary prophylaxis of ischemic stroke.

The impact of ergotamine-induced headache and ergotamine withdrawal on information processing

Ergotamine abuse and subsequent ergotamine-induced headache is a common problem in the pharmacological treatment of migraine and other headache types; often, withdrawal therapy is necessary. This study investigated whether ergotamine abuse affects information processing and whether withdrawal therapy can lead to an improvement of information processing. We designed a standardized neurophysiological retrospective (ergotamine abuse) and prospective (ergotamine withdrawal) study in a supraregional headache outpatient clinic. Seventy-one patients abusing ergotamine derivatives with subsequent daily headache were enrolled and compared to 36 migraine patients without ergotamine intake and 36 healthy subjects. Information processing was evaluated by latencies and amplitudes of visually evoked event-related potentials (ERP) before and after ergotamine withdrawal therapy. P3 latency of the ERP was significantly increased in ergotamine abuse (442 +/- 45 ms) versus migraine (415 +/- 40 ms) and healthy subjects (410 +/- 33 ms), there was no difference between ergotamine tartrate and dihydroergotamine abuse. The migraine specific loss of habituation in information processing as measured by P3 latency could not be observed in migraine patients with ergotamine abuse. After successful withdrawal therapy in 36 patients, the abnormally prolonged P3 latency was significantly shortened (452 +/- 47 ms versus 433 +/- 30 ms; P < 0.004). Our findings imply that information processing is impaired by ergotamine abuse and can be improved but not normalized after withdrawal therapy. Furthermore, our data provide strong evidence that ergotamine, besides its peripheral effects, has a central mode of action.

Drug-induced headache: long-term results of stationary versus ambulatory withdrawal therapy

Drug-induced headache is a well-known complication of the treatment of primary headache disorders, and its successful management is only possible by withdrawal therapy. However, it is unknown whether ambulatory or stationary withdrawal is the therapy preferred. We conducted a prospective study on the outcome of stationary versus ambulatory withdrawal therapy in patients with drug-induced headache according to the International Headache Society criteria. Out of 257 patients with the diagnosis of drug-induced headache during the study period, 101 patients (41 after ambulatory and 60 after stationary withdrawal therapy) could be followed up for 5.9 +/- 4.0 years. The total relapse rate after successful withdrawal therapy was 20.8% (14.6% after ambulatory and 25.0% after stationary withdrawal therapy, p < 0.2). The main risk factors for a relapse were male sex (OR = 3.9, CI = 1.3-11.6), intake of combined analgesic drugs (OR = 3.8, CI = 1.4-10.3), administration of naturopathy (OR = 6.0, CI = 1.2-29.3), and a trend to tension-type headache as the primary headache disorder (OR = 1.9, CI = 0.6-53.0). Our data suggest that neither the method of withdrawal therapy nor the kind of analgesic and other antimigraine drugs has a major impact on the long-term result after successful withdrawal therapy. Patients with risk factors according to our findings should be informed and monitored regularly, and combined drugs should be avoided. Furthermore, our data suggest that there is a need for research on individual psychological and behavioral risk factors for relapse after successful withdrawal therapy in drug-induced headache.

The influence of acetylsalicylic acid on cognitive processing: an event-related potentials study

The central effects of acetylsalicylic acid (ASA) are discussed controversially. In animal models, it has been shown that ASA can interact with the central serotonergic and catecholaminergic neuronal system. However, the relevance of this interaction for humans is still unknown. We performed a study on the influence of ASA on central cognitive processing. In 25 healthy subjects (age 21-56 years), visually evoked event-related potentials (ERP) and reaction time under IV ASA medication were recorded. ERP were evoked by an oddball paradigm. As compared to placebo, ASA decreased the latency of the P3 component significantly in a time interval of 20-40 min after administration. The latency of the N2 component was significantly decreased about 25 min after administration; the latency of the exogenous P2 component was not influenced by ASA. The mean choice reaction time was significantly decreased by ASA 35 min after administration. At this time point, there was a significant correlation between decrease in reaction time and increase in ASA plasma level. The data show that IV administration of ASA has an accelerating effect on the endogenous components of visual ERP and on reaction time. This finding suggests that ASA can influence central cognitive processing, possibly by ASA induced changes of neurotransmitters. Since serotonin can be released by ASA and serotonin release leads to a decrease of ERP latencies. we assume that ASA most likely influences cognitive processing via the central serotonergic transmitter system.

Progressive peripheral and central sensory tract lesion in HIV-infected patients evidenced by evoked potentials (a three-year follow-up study)

OBJECTIVE

To investigate progression of peripheral and central sensory tract lesion and its correlation to immunological deterioration.

METHODS

Clinical and neurophysiological investigation (evoked potentials of the median and tibial nerve) and immunological parameters (CD4-cells, beta 2-microglobuline) were followed up in 160 patients (24 females, 136 males, HIV infection for 2.7 +/- 2.3 years, mv +/- 1 sd) up to four times over approximately 3 years regardless of disease stage and evidence of neurological symptoms. Recordings were done using needle electrodes over the Th12 and C7 spinous process and from the scalp (10/20 system) in the conventional manner. Statistical analysis was performed intraindividually and in comparison to normal laboratory values (n = 96).

RESULTS

All parameters deteriorated during the follow-up period. Statistical analysis showed significant differences between probands and patients for evoked potentials, but also a significant deterioration for evoked potentials after three years at the end of the follow-up study. A significant correlation between progressive impairment of evoked potentials and laboratory data was found.

CONCLUSION

HIV infection induces a progressive lesion of the ascending sensory tracts. The results indicate a peripheral neuropathy as well as a progressive lesion of the ascending central sensory tracts. Pathogenesis of polyneuropathy and of central sensory tract lesion is up to now conjectural. Laboratory investigations indicate a clear-cut correlation between immunological alterations induced by HIV infection and its neurologic manifestation on ascending sensory tracts.

Event-related potentials (P300) in primary headache in childhood and adolescence

There is strong evidence for a loss of habituation during cognitive processing in migraine as measured by P300 and contingent negative variation in adults. Event-related potentials evoked by an oddball paradigm have not yet been studied in children and adolescents suffering from different primary headache types. We recorded visually evoked event-related potentials (two consecutive trials, 200 stimuli each) in 48 children and adolescents suffering from migraine without or with aura, from episodic tension-type headache, and from ergotamine-induced headache and analyzed the latencies, amplitudes, and reaction times. No statistically significant differences were noted between all headache types and healthy controls analyzing the averaged parameters for the whole measurement. However, a highly significant loss of cortical habituation as measured by P300 amplitude and latency could be observed in migraine without and with aura by analyzing the first and the second trial of measurement separately. This phenomenon increased with age and could not be seen in healthy controls, or patients with tension-type headache or ergotamine-induced headache. Our data suggest a specific cognitive processing in migraine even in children and adolescents. Measurement of the habituation effect in P300 latency and amplitude provides a specific method to differentiate between primary headache types in childhood and adolescence.

Impact of antiretroviral treatment on AIDS dementia: a longitudinal prospective event-related potential study

We investigated the impact of antiretroviral treatment on event-related potentials (ERP) as a possible marker of AIDS dementia. A total of 154 HIV-infected patients without central nervous system (CNS) neoplasm or opportunistic infection were examined and randomized to receive either zidovudine 500 mg/day or no antiretroviral treatment. The participants were prospectively examined by visually evoked ERP in a longitudinal design. Latencies and amplitudes of ERP were evaluated at the beginning of the study, after 1 year, and after 2 years. After 1 year, 98 patients could be analyzed, 47 of whom were taking zidovudine. In the treatment group, P3 latency was 419 +/- 55 msec at baseline and 424 +/- 52 msec at follow-up (not significant). In the patients without treatment, P3 latency was 437 +/- 42 msec at baseline and 462 +/- 53 msec at follow-up (p < .0001, Wilcoxon test). A significant inverse correlation existed between P3 latency and CD4 cell count in both groups. The increase of P3 latency in untreated patients and a stable P3 latency in treated patients could be confirmed in a subgroup analysis of 21 patients with a follow-up of three examinations in a 2-year period. Our data suggest that zidovudine has a positive impact on AIDS dementia as measured by ERP. This finding was observed in patients in different stages of HIV infection, thus suggesting that zidovudine is indicated in all stages of HIV infection to treat encephalopathy.

Influence of end-stage renal failure and hemodialysis on event-related potentials

Chronic renal failure frequently causes uremic encephalopathy with impairment of different cognitive functions, but the pathophysiology of uremic encephalopathy is still unknown. We measured visually evoked event-related potentials (ERPs) in 33 neurologically asymptomatic patients before and after they underwent hemodialysis and compared their data with those of a strictly age-matched healthy control group. Before hemodialysis, the patients' P3 latency was significantly increased and P3 amplitude was significantly decreased as compared with that of the healthy control group. After hemodialysis, P3 latency of the patients showed a significant decrease (457+/-56 before and 438+/-54 ms after hemodialysis) and the P3 latency habituation during the ERP measurement was also significantly decreased. Patients with higher levels of blood urea nitrogen (BUN), creatinine, and uric acid performed better in ERP measurement than did patients with lower levels. Hemoglobin did not influence ERP latencies and amplitudes. Our data suggest that impaired cognitive processing can be disclosed by ERP even in neurologically asymptomatic chronic renal disease. Removal of uremic toxins by hemodialysis leads to an improvement in cognitive processing.

Features, symptoms, and neurophysiological findings in stroke associated with hyperhomocysteinemia

BACKGROUND

Hyperhomocysteinemia has been shown to be a mild independent risk factor for premature atherosclerosis, and there is evidence of an increased rate of peripheral vascular occlusive disease, myocardial infarction, and stroke.

OBJECTIVE

To evaluate clinical, biochemical, and neurophysiological findings in patients with ischemic stroke with and without hyperhomocysteinemia.

SUBJECTS

One hundred twenty-five consecutive patients with a history of stroke and 60 healthy control subjects.

METHODS

Patients were divided into those with and those without hyperhomocysteinemia, which was defined as blood levels beyond the mean total plasma homocysteine level plus 2 SDs of the healthy control group. History, symptoms, cause, patterns of infarction, biochemical data, continuous and transcranial Doppler sonography, and event-related potentials were recorded in all patients.

RESULTS

Twenty-seven patients had hyperhomocysteinemia. Compared with the 98 patients without hyperhomocysteinemia, they had an increased rate of hypertension (odds ratio, 3.5; 95% confidence interval, 1.0-12.6), an increased level of uric acid (P < .007), an increased hematocrit (P < .02), a higher rate of microangiopathy (odds ratio, 2.8; 95% confidence interval, 1.1-7.2), and a trend to a higher rate of multiple infarction. Furthermore, the P3 latency of the event-related potential was significantly increased in hyperhomocysteinemia (P < .004).

CONCLUSIONS

Hyperhomocysteinemia is probably an independent risk factor for stroke, with a prevalence of about 20% in all patients with a history of stroke; however, additional factors (eg, hypertension, hyperuricemia) may have an enhancing effect. There are significant differences in stroke patterns between patients with and without hyperhomocysteinemia, with a higher rate of lesions typical of cerebral microangiopathy and a trend to multiple infarctions in the former. Impairment of cognitive processing as measured by visual event-related potential is more pronounced in hyperhomocysteinemia.

Reproducibility of different nerve conduction velocity measurements in healthy test subjects and patients suffering from diabetic polyneuropathy

According to literature, repeated nerve conduction velocity measurement may yield differences of up to 10 m/s in the same subject without any need to regard these differences as pathological. In order to get more details about the reproducibility of different nerve conduction velocity parameters, 59 healthy test subjects and 47 patients suffering from diabetic polyneuropathy were investigated. In the sural nerve latency prolongation after paired stimulation, conduction velocity and amplitude of nerve action potential were determined, in the peroneal nerve conduction velocity, distal latency, amplitude of nerve action potential after distal stimulation and F-wave. All investigations were performed using surface electrodes. Measurements were repeated within one day by the same investigator using exactly the same methods. No statistically significant differences between both investigations in test subjects and patients were found. Statistically, results for patients differed significantly from healthy test subjects. Six patients showed discrepancies between both measurements in the individual estimation normal/abnormal in comparison to laboratory norm values. In conclusion, these results demonstrate that strict adherence to technical and methodological parameters-including the same investigator-results in a higher improvement of reproducibility of nerve conduction velocity measurement. Multiple factors are operating in time but strict adherence to technical, methodological, physiological and biological parameters minimises changed results of neurophysiological measurements and improves reproducibility.

Cognitive processing in primary headache: a study on event-related potentials

BACKGROUND

There is experimental evidence for loss of cognitive habituation in migraine but not in other types of headache and not by visual event-related potentials (ERP).

OBJECTIVE

Determining the latencies (msec) and amplitudes (microV) of ERP components and the differences of these values in a two-trial analysis representing the amount of cognitive habituation.

PARTICIPANTS

Two hundred thirty-three patients with a headache diagnosis according to the criteria of the International Headache Society: migraine without aura (N = 77); migraine with aura (N = 31); cluster headache during period (N = 26); cluster headache during interval (N = 11); chronic paroxysmal hemicrania (N = 8); episodic tension-type headache (N = 33); ergotamine-induced headache (N = 47). Thirty age-matched healthy subjects served as a control group.

METHODS

ERPs were evoked by a visual oddball paradigm consisting of 2 x 200 flashes of light (85% white light; 15% red light). Evaluation of ERP components was done separately for the first 200 and the second 200 stimuli as well as for the entire series of stimuli.

RESULTS

We found an acceleration of the P3 latency during the second trial in migraine with and without aura, but not in the other headache types, and not in healthy controls. Ergotamine and sumatriptan abolished this loss of habituation in migraine patients. Increased ERP latencies as compared with healthy controls were present in patients with cluster headache, tension-type headache, ergotamine-induced headache, and migraine with aura, but not in migraine without aura.

CONCLUSION

There is a loss of cognitive habituation in migraine, which may serve as a specific but not sensitive diagnostic tool. The pathophysiologies of migraine and cluster headache have a specific modifying property on cognitive processing reflected by a loss of cognitive habituation or an increased cognitive processing time. These effects can, in part, be counterbalanced by antimigraine medication.

Progression of distal symmetric polyneuropathy during diabetes mellitus: clinical, neurophysiological, haemorheological changes and self-rating scales of patients

The complex interrelationships between progression of distal symmetric polyneuropathy (DSP) induced by diabetes mellitus and haemorheological alterations in correlation with the patients' self-rating scales about the progression of DSP were investigated. The study included 42 patients suffering from diabetes mellitus for 15 +/- 10 years. Clinical, neurophysiological and haemorheological follow-ups (platelet reactivity, erythrocyte aggregation, viscosity) were performed initially (A) and repeated 42 +/- 10 months later (B). At point B, clinical signs of DSP were found in 90.2% in the lower extremities, and 41.5% of the patients exhibited for the first time new symptoms and signs of DSP in the upper extremities. Besides conventional neurophysiological investigations (conduction velocity, amplitude) in the sural nerve, paired stimulation (LPSS) was applied. In peroneal nerve, conduction velocity, distal latency and F wave were estimated. These results confirmed the clinical progression of DSP (LPSS; p < 0.05). Platelet reactivity was statistically improved (p < 0.05) at point B predominantly as an effect of treatment (acetylsalicylic acid, Ginkgo biloba), whereas erythrocyte aggregation was increased at point B with and without treatment (p < 0.05). Blood glucose levels were abnormal at both points. Analogue self-rating scales showed that only 27% of the patients realized their progression of DSP. In conclusion, the results prove the clinical and neurophysiological progression of DSP and highlight that haemorheological changes may play a part in the conjectural pathogenesis of DSP. As patients to not realize the dramatic progression of DSP, information of the patients about the correlation between hyperglycaemia and progressive DSP should be reinforced.

Magnesium in the prophylaxis of migraine--a double-blind placebo-controlled study

The migraine prophylactic effect of 10 mmol magnesium twice-daily has been evaluated in a multicentre, prospective, randomized, double-blind, placebo-controlled study. Patients with two to six migraine attacks per month without aura, and history of migraine of at least 2 years, were included. A 4-week baseline period without medication was followed by 12 weeks of treatment with magnesium or placebo. The primary efficacy end-point was a reduction of at least 50% in intensity or duration of migraine attacks in hours at the end of the 12 weeks of treatment compared to baseline. With a calculated total sample size of 150 patients, an interim analysis was planned after completing treatment of at least 60 patients, which in fact was performed with 69 patients (64F, 5M), aged 18-64 years. Of these, 35 had received magnesium and 34 placebo. The number of responders was 10 in each group (28.6% under magnesium and 29.4% under placebo). As determined in the study protocol, this was a major reason to discontinue the trial. With regard to the number of migraine days or migraine attacks there was no benefit with magnesium compared to placebo. There were no centre-specific differences, and the final assessments of treatment efficacy by the doctor and patient were largely equivocal. With respect to tolerability and safety, 45.7% of patients in the magnesium group reported primarily mild adverse events like soft stool and diarrhoea in contrast to 23.5% in the placebo group.

Early detection of distal symmetrical polyneuropathy during HIV infection by paired stimulation of sural nerve

In 203 HIV infected patients in various clinical stages neurological examination, paired stimulation (LPSS), nerve conduction velocity (NCVS) and amplitude (AMPS) of the sural nerve, distal latency (DLP), nerve conduction velocity (NCVP), amplitude (AMPP) and F waves of the peroneal nerve were recorded. Neurological examination revealed symptoms and clinical signs of polyneuropathy in 67 (33%) (WR 1-6) of the patients. LPSS after paired stimulation was abnormal in 25.5%, NCVS in 14.2%, AMPS in 9.8%, NCVP in 11.8%, DLP in 11.2%, AMPP in 5.9% and FWP in 14.6%. Our findings indicate a high incidence of peripheral nerve system involvement during HIV infection. In 11.5% of all patients only LPSS proved polyneuropathy. Neurophysiological results from HIV infected patients with symptoms and clinical signs of polyneuropathy were statistically significantly different from HIV infected patients without symptoms and clinical signs of polyneuropathy. The delay of LPSS represents the most sensitive neurophysiological indicator of polyneuropathy during HIV infection and announces the onset of peripheral nerve disease even in early stages of infection, according to Walter Reed staging classification 1 and 2 (approx. 20%).

Two-year follow-up of aspirin responder and aspirin non responder. A pilot-study including 180 post-stroke patients

Aspirin is proposed to be effective in stroke-prophylaxis because it completely inhibits the platelet prostanoid-pathway. In about 90% of stroke victims, increased platelet reactivity (PR) can be reduced to the normal range by aspirin. Twelve hours later, about one third of them show an enhanced PR again. These patients are called secondary aspirin non responders (SANR). In this study the potential pathogenetic and prognostic impact of this biological feature on stroke recurrence was evaluated. Before discharge from the hospital, PR was determined 12 hours after an oral administration of 500 mg aspirin in 180 patients aged 58 +/- 15 years; 74 were female and 106 male. All had suffered a stroke in the internal carotid artery territory. Patients were treated with 3 x 500 mg aspirin/d and were followed up over a 24-month period. Major endpoints of this study were stroke, myocardial infarction or vascular death. On discharge from the hospital, 120 of the 180 patients showed a normal PR under aspirin treatment. High test values were found in 60 patients (SANR). Six patients were lost for follow-up. Because of side effects 36 (20%) of the 180 patients enrolled discontinued medication. Major endpoints occurred in 4 of these 36 patients (11%) and in 25 of the 138 remaining patients (18.1%); 19 patients died in consequence of a vascular event during the observation period. Major endpoints were seen in only 5 of 114 (4.4%) of the aspirin responders, but in 24 out of 60 SANR (40%, p < 0.0001). It may be assumed that early identification of SANR's is a clinically useful tool to classify patients at high risk for recurrence of vascular events.

Progression of distal-symmetric polyneuropathy in HIV infection: a prospective study

OBJECTIVE

To investigate progression of distal-symmetric sensory polyneuropathy and its correlation to immunological development.

METHODS

Clinical, neurophysiological and immunological parameters were followed in 42 HIV-infected patients for 13 +/- 6 months. Neurophysiological investigations were performed in the sural and peroneal nerve. Initially, 14 patients showed clinical signs of polyneuropathy (paresthesia, hypesthesia, diminution of vibration and deep ankle reflexes) compared with 28 patients at the end of the follow-up, 13 +/- 6 months later.

RESULTS

All neurophysiological parameters deteriorated during the observation period. In 20 patients changes of plasma immunoglobulin (Ig) G, IgM, IgA levels, T-helper-, T-suppressor-, natural killer cell counts and plasma beta 2-microglobulin were determined. There was a significant correlation between the development of IgG, IgM, IgA and paired stimulation and conduction velocity of the sural nerve (Spearman's rank-correlation coefficient, P < 0.05).

CONCLUSION

These results show that distal-symmetric polyneuropathy during HIV infection is rapidly progressive and related to immunological factors. It is assumed that immunological mechanisms play an important part in the pathogenesis of polyneuropathy during HIV infection.

Serotonin and amino acid content in platelets of autistic children

The platelet levels of serotonin and the amino acids aspartic acid, glutamine, glutamic acid and gamma-aminobutyric acid were measured in 18 drug-free autistic (DSM-III criteria) and 14 age-matched healthy children. Serotonin was significantly increased while the amino acids aspartic acid, glutamine, glutamic acid and gamma-aminobutyric acid were significantly decreased in comparison with the controls. It is suggested that the decline of the amino acids in platelets from autistic children represents a biochemical marker related to infantile autism.

The influence of acetazolamide on cerebral low-flow regions in migraine--an interictal 99mTc-HMPAO SPECT study

Acetazolamide, a carbonic anhydrase inhibitor, has proved to be useful in the assessment of "vasodilatory capacity" in cerebrovascular disease. To obtain further information on the nature of interictal low-flow regions in migraine, we reinvestigated 20 asymptomatic patients suffering from migraine with aura (n = 15) or without aura (n = 5) and who had either minor (n = 12) or marked (n = 8) regional hypoperfusion when examined in a previous 99mTc-HMPAO SPECT investigation. These patients received acetazolamide IV prior to tracer application. In 14/20 cases regional hypoperfusion resolved. Three patients with migraine with aura had less pronounced regional hypoperfusion compared to baseline. No change in baseline hypoperfusion was detectable in three older patients. No further decreases in flow were measured. In contrast to patients with cerebrovascular ischemia, in whom acetazolamide usually enhances low-flow regions, vasodilatory capacity appears intact in most migraine patients with interictal regional hypoperfusion. Thus, the "acetazolamide test" might be useful in the differential diagnosis of migraine with aura from transient cerebrovascular ischemia.

[Prevention of migraine using bisoprolol. Results of a double-blind study versus metoprolol]

AIMS

Comparison of bisoprolol, a beta-1 selective beta blocker with no intrinsic sympathomimetic activity (ISA) and metoprolol, which numerous studies have shown to be an effective migraine prophylactic.

STUDY DESIGN

Multicentric, cross-over study.

PATIENTS

125 patients suffering at least from 3 attacks of classic or common migraine a month for at least two years.

TREATMENT

Bisoprolol 5 mg given once a day, or metoprolol 50 mg given twice a day, for two periods of 12 weeks.

RESULTS

125 patients were admitted to the 4-week run-in phase. A comparison of the main target: frequency of migraine attacks was thus carried out in 78 patients (f. = 63, m. = 15). Both substances reduced the average frequency of migraine per 28-day period by about 50%. There was no statistically significant difference between the two beta-blockers (p greater than 0.05).

CONCLUSIONS

The results of the study show that 5 mg of bisoprolol and 100 mg of metoprolol a day have comparable efficacy for migraine prophylaxis, and show comparable tolerability.

Effect of physical stress on 5-hydroxytryptamine uptake kinetics (Km and Vmax) in human platelets

Platelet 5-HT uptake is possibly one mechanism by which plasma level of 5-HT is physiologically controlled. This mechanism may be of importance in the vascular 5-HT mediated tone and protect against thrombolysis and cardiovascular events. Physical stress is known to affect various platelet functions. The aim of this study was to investigate whether or not physical stress has any influence on platelet 5-HT uptake kinetics. In healthy adult persons (n = 13) the maximal rate (Vmax) and Michaelis-Menten constant (Km) of platelet 5-HT uptake (in vitro) were determined before (a), immediately after (b) and 1 hour after 50 min of squash playing (c). Immediately after squash Vmax and Km were elevates significantly as compared to the values before squash [Vmax(a): 77.0 +/- 31.0 (SD) pmol 5-HT/10(8) pl./min, Vmax(b): 109.9 +/- 48.4 (SD) pmol 5-HT/10(8) pl./min, p less than 0.01; Km(a): 5.16 +/- 1.73 (SD) x 10(-7) mol/1, Km(b): 7.59 +/- 2.37 (SD) x 10(-7) mol/1, p less than 0.05]. The percent elevations of Vmax (47%) and Km (42%) were of the same range. One hour after squash the values of Vmax(c) and Km(c) were found to be normalized. It is concluded that physical stress, like squash playing, does not affect net platelet 5-HT uptake in healthy persons at physiological plasma 5-HT concentrations. The significant increases of Vmax and Km of platelet 5-HT uptake are suggested to be adaptation reactions to keep the platelet net 5-HT uptake constant.

Determination of cerebral perfusion by means of planar brain scintigraphy and 99mTc-HMPAO in brain death, persistent vegetative state and severe coma

A total of 24 patients with clinical evidence of brain death (n = 17), severe coma (n = 2; GCS approximately 3) and apallic syndrome (n = 4) underwent a comparative investigation with 99mTc-HMPAO brain scintigraphy, EEG, auditory and somatosensory evoked potentials. Accompanied by EEG and evoked potentials, brain scintigraphy enabled confirmation of cerebral death in 15/17 patients. In one case clinical examination and evoked potentials suggest brain death, but cerebral perfusion and EEG were normal ("brain stem death"). One patient with evidence of cerebral death in clinical examination, brain scintigraphy and evoked potentials, showed questionable focal EEG activity; however, autopsy revealed intravital autolysis of the entire brain. All patients with apallic syndrome and deep coma showed a distinct cerebral perfusion, but gross EEG abnormalities; evoked potentials were delayed or absent. Planar scintigraphy with 99mTc-HMPAO appears to be superior to neurophysiological techniques discriminating patients with agonal cerebral dysfunction from those with brain death.

"Symptomatic migraine": intracranial lesions mimicking migrainous headache--a report of three cases

Case reports of three headache patients, two with intracerebral meningioma and one with hydrocephalus are presented, in whom the clinical picture fulfilled the criteria of the International Headache Society (IHS) for the diagnosis of migraine. The symptomatic (ie, lesional) nature of the headaches could be detected by neither clinical neurological examination nor routine investigations such as EEG and skull x-ray. On the other hand, brain imaging techniques (CT, MRI) were found to be of particular in value diagnosing the lesions. Our cases indicate that neuroimaging with CT or MRI in the assessment of headache patients should not be handled too restrictively. Compared to CT, however, the additional diagnostic value of MRI in headache seems to be limited.

Effects of acetylsalicylic acid in stroke patients. Evidence of nonresponders in a subpopulation of treated patients

Platelet reactivity (PR) was tested two and 12 hours after acetylsalicylic acid (ASA) intake in 82 stroke patients, aged 59 +/- 14 years (33 female and 49 male). 10% of these patients showed a pathologically enhanced PR at least two hours after intake of 500 mg ASA (= primary ASA-nonresponder (PNR)). Only 10 hours later, a further 26% of these ASA treated patients exhibited a pathological platelet reactivity (greater than 1.25) (= secondary ASA-nonresponder (SNR)). Single ASA dosages of 500 mg or 200 mg were of identical effectiveness. Additional administration of metoclopramide in combination with 100 mg ASA was more effective as compared to a single dosage of 1000 mg ASA. Those who were SNR at onset of ASA therapy remained SNR as well 28 days later. The change from a normal, ASA corrected PR, to pathological PR values before a period of 12 hours ended seemed a sudden and irreversible event that could only be corrected by the next ASA application.

[The effect of the lead electrodes on the conduction velocity of the sural nerve]

The result of nerve conduction velocity measuring depends upon all components of the measurement system. Earlier investigations showed that the nerve conduction velocity of the sural nerve depends also on technical attributes of recording electrodes. It was the objective of our study to investigate correlations between different recording electrodes and neurophysiological norm values as nerve conduction velocity and latency prolongation after paired stimulation of the sural nerve. Our investigations were carried out in twenty healthy volunteers aged 39 +/- 14 years. Stimulation of the sural nerve was performed at the lateral malleolus using always surface electrodes of the same type. Recording of nerve action potentials was done in each proband by four different types of electrodes. Surface electrodes consisted of tin, stainless steal and sintered silver/silver chloride, needle electrodes of stainless steel. The nerve conduction velocity using silver/silver chloride was 53.6 +/- 4.3 m/sec, using tin electrodes 53.1 +/- 3.9 m/s, using stainless steel 51.4 +/- 3.0 m/s and using needle electrodes 48,7 +/- 2.7 m/s. The Wilcoxon-test confirmed the differences of nerve conduction velocity between needle and silver/silver chloride and tin electrodes yielding p less than 0.05. Latency prolongation after paired stimulation of the sural nerve was independent from electrodes. In conclusion, our results indicate that electrodes take part in the system of standardization. Changing of recording or stimulation electrodes provoke the necessity of new standardization of norm values in clinical neurophysiology.

Event-related potentials in HIV-infected outpatients

Event-related potentials (ERP) were determined in 138 human immunodeficiency virus (HIV)-infected outpatients and 92 healthy controls of a corresponding age. Of the HIV-infected patients, 31.8% showed an abnormal latency of the P3-component of ERPs (P3-ERP), exceeding the mean value + 2 SD of P3-ERP latencies from age-matched healthy subjects. From the untreated patients in stage Walter Reed (WR) = 6, 71.4% had abnormal P3-ERP latencies, whereas in WR = 2, only 19.6% of P3-ERPs were abnormal. Fourteen patients were observed over a period of 3-16 months. P3-ERP latencies were shortened in 7 patients under treatment with zidovudine. A marked increase in P3-ERP latencies was observed in 7 untreated HIV-infected patients. It is assumed that ERPs are a useful neurophysiological method to detect early cerebral dysfunction in HIV-infected patients.

Circadian blood pressure rhythms in elderly hypertensive patients

Blood pressure was recorded for 24 h in 121 essential hypertensive patients aged between 20 and 90 years. To characterize the circadian blood pressure rhythm, the differences between the daytime blood pressures (recorded at 8-min intervals between 8 a.m. and 10 p.m.) and the night-time blood pressures (recorded at 30-min intervals between 10 p.m. and 8 a.m.) were calculated. The difference between daytime and night-time blood pressures was significantly (P less than 0.01) decreased in elderly hypertensive patients aged between 65 and 90 years compared with in those aged 20-39 years. In patients with heart insufficiency the circadian blood pressure rhythmicity was significantly (P less than 0.05) further reduced compared with in uncomplicated hypertensives. This may be explained by increased sympathetic tonus in patients with heart insufficiency and reduced vascular compliance may be the cause of the overall reduced circadian blood pressure rhythmicity in elderly hypertensive patients.

The platelet-reactivity-test--a useful "by-product" of the blood-sampling procedure?

Blood sampling demands the insertion of a needle into the blood-vessel thereby causing a destruction of the endothelial wall of the blood-vessel. The physiological reaction of platelets is the occlusion of endothelial lesions. Reaction of platelets induced by endothelial lesions lasts about 10 ms. Each blood sampling procedure should therefore activate platelets. A simple platelet test-system was designed following these considerations. Blood samples were collected twice, in EDTA-buffer and in EDTA-formalin-buffer. Activated (aggregated) platelets were fixed by formalin or dissolved in EDTA-buffer. Platelet-reactivity (PR) was calculated as quotient of the number of platelets remaining in the supernatant of both samples after centrifugation. The PR-index-values strongly depended on the blood-sampling procedure. Standardization of the blood sampling procedure led to normal distributed PR-index-values in 110 healthy controls (0.98 +/- 0.09). PR-index-values remained constant during a period of 260 days. PR-index-values in 49 patients suffering from encephalomyelitis disseminata were 1.04 +/- 0.15 and 1.64 +/- 0.6 in 72 patients suffering from transitoric ischemic attacks. Differences between healthy controls and patients suffering from TIA's were significant (p less than 0.001).