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.     

"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.     

The nutritional response to home enteral nutrition in childhood

The nutritional response to home enteral nutrition (HEN) was evaluated in a prospective study of 44 consecutive children (median age 48 months) who received HEN for more than 1 month (median duration 6 months). Three groups were studied: 17 children were stunted, 14 were wasted and 13 were adequately nourished but unlikely to maintain oral intake during anticipated nutritional stress. In the stunted group (median duration of HEN 15 months) there was a significant correlation between improvements in height–for–age z scores and duration of feeds ( r = 0.63; p = 0.006). In the wasted group (median duration of HEN 4 months) all anthropometric indices improved significantly ( p < 0.05). HEN was also successful in maintaining nutritional status in the third group. Thus, supplementary HEN is an effective method of nutritional support for a variety of indications, provided concurrent advice from a nutritional care team is available.     

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.     

Diagnosis and clinical associations of zinc depletion following bone marrow transplantation

Following the emergence of biochemical zinc deficiency after bone marrow transplantation, the clinical value of plasma alkaline phosphatase activity as an early indicator of biochemical zinc depletion was investigated in this group of patients. Serial measurements of plasma zinc and alkaline phosphatase activities in 28 consecutive children (median age 8.7 years; 16 males) undergoing bone marrow transplantation were carried out and clinical associations recorded. A significant fall in plasma zinc occurred after the bone marrow transplant, and 19 children developed biochemical zinc deficiency (Zn < 11 mumol/l) at a median of 7 days following the transplant. Zinc depletion was more common in younger patients and in children with diarrhoea. A positive correlation was found between plasma zinc and alkaline phosphatase activities. Zinc depleted patients had more febrile episodes of longer duration and were more likely to have a positive blood culture. Haemopoetic recovery was not affected by zinc deficiency. Following zinc supplementation, alkaline phosphatase showed a significant increase. The sensitivity of a low alkaline phosphatase as a screening test for biochemical zinc deficiency was 83%, with a specificity of 86%. Low alkaline phosphatase activity following bone marrow transplant is an indication for zinc supplements.     

OCCUPATIONAL ASTHMA IN A CHEESE PACKER

Occupational asthma is an increasingly common clinical problem.¹ A worker who develops asthma for the first time when starting work in a new environment may be straightforward to diagnose. However, when asthma occurs after a latent period following initial exposure, or when a pre-existing asthmatic develops work-related symptoms, the occupational link may be less easy to appreciate. This case report concerns a cheese factory worker with pre-existing asthma who experienced severe symptoms when a new process was introduced for drying grated cheese and was able to return to work only after the process was modified. The drying agent responsible has not been previously reported as a cause of asthma.     

FIRST-LINE TREATMENT IN ACUTE NON-DYSENTERIC DIARRHOEA: CLINICAL COMPARISON OF LOPERAMIDE OXIDE,LOPERAMIDE AND PLACEBO

SUMMARY The use of antimicrobial agents for the treatment of acute diarrhoea has become more common with the introduction of quinolone compounds, which are active against most types of bacterial pathogens. Despite the fact that such drugs have been used for empirical therapy or even for prophylaxis, current opinion would restrict their use to specific groups of patients who are likely to show particular benefit from them. Non-specific therapy seems a more appropriate initial treatment for cases of acute, non-dysenteric diarrhoea. Clinical trial data are presented here comparing the effects of loperamide oxide 1 and 2 mg to those of placebo and loperamide 2 mg in this condition. All the drug preparations were significantly superior to placebo, in particular reducing the time to complete relief of symptoms to about 24 hours, as opposed to 45 hours on placebo treatment. Of these preparations, loperamide oxide 1 mg is to be preferred, as it produces fewer constipation-like episodes after treatment. The introduction of loperamide oxide 1 mg represents a useful advance in the non-specific treatment of acute, non-dysenteric diarrhoea.     

On the mechanism of the effects of potassium restriction on blood pressure and renal sodium retention

Dietary potassium restriction increases sodium and chloride retention, whereas potassium administration promotes both diuresis and natriuresis. In epidemiologic and clinical studies, potassium intake is inversely related to blood pressure and is lower in blacks than in whites. The present studies examined the mechanism by which potassium restriction fosters sodium conservation and the impact of race on this response. Twenty-one healthy black and white men and women ingested an isocaloric, potassium-restricted diet (20 mmol/d) containing 180 mmol/d of sodium with and without a potassium supplement (80 mmol/d) for 9 days on two occasions. Additionally, eight of these subjects ingested the same diets for 3 days followed by a water load to determine free water clearance before and during the early phase of dietary potassium restriction. During potassium restriction, mean arterial pressure (MAP) derived from 24-hour blood pressure measurements was higher (85.7 +/- 1.6 mm Hg v 82.0 +/- 1.3 mm Hg; P < 0.001), cumulative sodium excretion lower (984 +/- 59 mmol/d v 1,256 +/- 58 mmol/d; P < 0.001), and weight greater (71.1 +/- 2.1 kg v 69.3 +/- 2.2 kg; P < 0.001). Blacks displayed no greater increase in MAP, although they excreted less sodium overall and less potassium on the potassium-supplemented diet. After a water load, minimum urine osmolality (Uosm) was lower (53.0 +/- 3.0 mOsm/L v 65.6 +/- 3.5 mOsm/L; P = 0.01) and free water clearance greater (4.44 +/- 0.59 mL/min v3.72 +/- 0.58 mL/min; P = 0.009) during potassium restriction. In conclusion, in healthy, normotensive subjects, potassium restriction was associated with an increase in blood pressure and volume expansion effected by increased renal sodium and chloride retention. Potassium restriction was also associated with increased free water clearance and enhanced diluting capacity consistent with augmentation of Na+, K+:2Cl- cotransporter activity in the thick ascending limb of Henle. This mechanism may play an important role in the renal adaptation required for potassium conservation, but at the expense of sodium chloride retention and an elevation in blood pressure.     

Botulinum toxin A in the prophylactic treatment of migraine--a randomized, double-blind, placebo-controlled study

Botulinum toxin A has been suggested to be effective in the prophylactic treatment of migraine. However, only very few randomized, double-blind, placebo-controlled studies are available. We designed such a study with a specific focus on different injection sites. Sixty patients with a migraine according to the criteria of the International Headache Society were randomly assigned to receive either placebo in the frontal and neck muscles, or to receive 16 U botulinum toxin A in the frontal muscles and placebo in the neck muscles, or to receive in total 100 U botulinum toxin A in the frontal and neck muscles. The observation period was 3 months. In both treatment groups, 30% of patients showed a reduction of migraine frequency in month 3 by at least 50% compared with baseline, in the placebo group 25% of the patients showed such a reduction (P = 0.921). There were no significant differences between the three study groups with respect to reduction of migraine frequency, number of days with migraine, and the number of total single doses to treat a migraine attack. In the post hoc analysis, the reduction of all accompanying symptoms was significantly higher in the 16 U treatment group compared with the placebo group. In the 100 U treatment group significantly more adverse events occurred compared with the placebo group. All adverse events were mild and transient. Our study did not show any efficacy of botulinum toxin A in the prophylactic treatment of migraine. Only accompanying symptoms were significantly reduced in the 16 U but not in the 100 U treatment group. Future studies should focus on the efficacy of botulinum toxin A in specific subgroups of patients, on the efficacy of repetitive injections, and on other injection sites.