Pupillary response to topical naloxone in cluster headache.

Eye drops of naloxone were applied and pupillary diameters recorded at standard time intervals in 18 healthy controls and in 20 patients with episodic cluster headache during pain free intervals by means of a pupillometer. In the basal condition, the mean symptomatic side pupil in the cluster headache group was significantly smaller than the pupil of controls. Patients in the cluster period had a significantly smaller symptomatic-side pupil when compared to patients outside the bout. After naloxone, the pupils on the symptomatic as well as on the non-symptomatic side were significantly smaller than those in controls when expressed in mm. The difference between patients and controls persisted, and was, grossly speaking, of a not widely varying magnitude during the drug test. This study thus does not render any definite evidence for a role of opioids in the mechanism underlying the miosis of cluster headache.     

帕金森病非运动性症状之皮脂溢与多汗

帕金森病是一种常见的中枢神经系统变性疾病,临床表现以静止性震颤、运动迟缓、肌强直和姿势步态异常等运动性症状为特征。事实上,帕金森病的非运动性症状对患者的生活质量影响很大。皮脂溢和多汗是帕金森病患者两个常见的非运动性症状,然而在这一领域的研究相对较少,本文试图总结归纳现有的研究成果,就帕金森病皮脂溢和多汗的流行病学,两种症状与疾病的相关性及其发病机制等内容作简要综述。     

Cardiac autonomic function in patients suffering from primary focal hyperhidrosis

Cardiac autonomic function in patients (n = 63) with primary focal hyperhidrosis and healthy controls (n = 28) was investigated by short-term frequency domain power spectral analysis of heart rate variability. The power of the very-low-frequency band (0.01-0.05 Hz) was significantly lower in patients with axillary hyperhidrosis than in controls. No differences between groups could be observed at investigation of the low-frequency band (0.05-0.15 Hz), which was a surprising finding because this band represents also sympathetic cardiac innervation. At the high-frequency band (0.15-0.5 Hz), which represents parasympathetic cardiac innervation, an interaction of type and position influencing spectral power was detected. Our highly interesting findings indicate that primary focal hyperhidrosis is based on a much more complex autonomic dysfunction than generalised sympathetic overactivity and seems to involve the parasympathetic nervous system as well.     

Peripheral biomarkers and exposure to manganese.

Biochemical mechanisms underlying manganese (Mn) toxicity include dopamine (DA) auto-oxidation and free radical generation with subsequent neuronal damage. A neuroendocrine approach based on the measurement of serum prolactin (PRL) has been proposed to assess the tonic inhibition of pituitary lactotrope cells by the tubero-infundibular DA system. Low level exposure to Mn oxides in industrial settings is associated with a shift in the distribution of serum PRL towards higher levels as compared to matched controls. The follow-up of a small cohort of workers from a ferro-manganese plant showed that the increased prevalence of abnormally high PRL values is stable over time. Although the mechanistic basis for their application is less straightforward, other biochemical markers such as dopamine beta hydroxylase and monoamine oxidase Type B, have also been assessed. Contrary to PRL levels, these markers cannot be recommended to monitor early biochemical effects of manganese exposure at the workplace. Early biochemical events can be modified by genetically determined individual differences. Owing to the possible role of a reduced capacity of glutathione conjugation as a risk factor increasing the susceptibility to the action of free radicals generated in the presence of Mn, the class mu glutathione S transferase (GSTM1) genotype has also been assessed in workers occupationally exposed. However, the GSTM1 null genotype does not appear to play an important role in the susceptibility to biochemical effects of Mn. A logistic model of the dose-response relationship based on urinary Mn as marker of exposure indicates that the benchmark dose corresponds to Mn levels as low as 0.4 microgram/l. This would imply that environmental exposure to Mn may contribute to abnormally high serum PRL in the general population.     

Evaluation of objective methods to diagnose palmar hyperhidrosis and monitor effects of botulinum toxin treatment.

OBJECTIVE: To evaluate (1) if laboratory tests may be a useful complement in diagnosing palmar hyperhidrosis and (2) if such tests can be used in the follow up examination of treatment effects. METHODS: Repeated measurements of evaporation and conductance were made in glabrous skin on hands and compared with subjective estimates of the degree of sweating in 20 control subjects and 20 patients with a history of palmar hyperhidrosis. In addition, 17 patients were monitored for up to 6 months after treatment of the hands with botulinum toxin A. RESULTS: Before treatment, evaporation in the palms was higher in the patients than in the control subjects but skin conductance did not differ between the groups. After treatment both evaporation and skin conductance decreased markedly in the patients and then slowly returned towards pretreatment values. CONCLUSIONS: Measurements of evaporation, but not skin conductance, may be a useful objective adjunct when diagnosing palmar hyperhidrosis. Both methods can, however, be used to monitor intraindividual changes of sweating over time.     

Early exposure to lead and neuropsychological outcome in adolescence.

One hundred and ninety-five participants in the Cincinnati Lead Study were neuropsychologically evaluated in mid-adolescence. The neuropsychological measures yielded five factors labeled Memory, Learning/IQ, Attention, Visuoconstruction, and Fine-Motor. Prenatal, Average Childhood, and 78 month blood lead (PbB) levels were used in a series of multiple regression analyses. Following rigorous covariate pretesting and adjustment, a significant main effect of 78 month PbB on the Fine-Motor factor was found (p <.004). Significant interactions were also found between gender and lead exposure parameters for both Attention and Visuoconstruction indicating heightened risk in males. Finally, a trend toward significance was found for the PbB x SES interaction for Learning/IQ, consistent with previous evidence of increased educational and cognitive vulnerability for youth from more disadvantaged backgrounds. These results provide new evidence from the longest continuing prospective study of the remote effects of early lead exposure. They indicate the presence of selective neuropsychological effects in this population, and also that males and females are not uniformly affected. These results also underscore the complexity of models of neurobehavioral development, and the modest predictive power of any single determinant.     

Meningocele and ankyloblepharon following in utero exposure to olanzapine.

Although atypical antipsychotics are widely used during pregnancy, their safety is not well established. This case highlights the possible teratogenic effect of olanzapine, in which the baby was born with meningocele and ankyloblepharon. It is suggested that olanzapine may interfere with embryonic development at different stages of pregnancy.     

The use of botulinum toxins to treat hyperhidrosis and gustatory sweating syndrome

Hyperhidrosis is a chronic condition characterized by excessive sweating. Recent studies report that it affects approximately 2.8% of the population and typically begins during adolescence. Gustatory sweating usually occurs after parotid gland injury or surgery, and both disorders can be debilitating for those who are affected. Both diseases respond very well to botulinum toxin therapy and this article will review the use of botulinum toxins, including the serotypes used, dosing, and complications.     

Occupational exposure to electromagnetic fields and Alzheimer disease.

The association between occupational exposure to electromagnetic fields (EMF) and Alzheimer disease (AD) was examined. Subjects were identified from a large health maintenance organization in Seattle, Washington, and matched by age, sex, and proxy type. A complete occupational history was obtained from proxies and controls. Following the interview, two industrial hygienists (IHs) rated exposures to EMF for each job blinded to case-control status. Exposures to EMF were rated as probable intermittent exposure or probable exposure for extended periods to levels above threshold. Conditional logistic regression was used to calculate the risk of AD given EMF exposure stratified by IH. The odds ratios for ever having been exposed to EMF were 0.74 [95% confidence interval (CI) 0.29-1.92] and 0.95 (95% CI 0.27-2.43) for each IH, adjusting for age and education. No dose-response effect was noted. Agreement between the two IHs for ever having been exposed to EMF was good (kappa = 0.57, p < 0.0001). This study was unable to support an association between EMF and AD.     

Differences in accommodative properties of median and peroneal motor axons

OBJECTIVES: To investigate whether accommodation to depolarising and hyperpolarising currents differs for motor axons of human upper and lower limb nerves. METHODS: The threshold tracking technique was used to measure threshold electrotonus for median and peroneal motor axons. The threshold current that produced a compound muscle action potential 50% of maximum was measured, and membrane potential was altered using subthreshold polarising currents of 330 ms duration but of variable intensity, from +40% (depolarising) to -100% (hyperpolarising) of the unconditioned threshold. RESULTS: The maximal threshold changes (the peak of the S1 phase of threshold electrotonus) were significantly greater in median axons for both depolarising and hyperpolarising currents. The subsequent phases of accommodation to depolarising currents (S2) and to hyperpolarising currents (S3) were also significantly greater in median axons. These findings raised the possibility that greater accommodation (S2 and S3) in median axons resulted from greater changes in membrane potential. However, regression of S2 against S1 to depolarising currents disclosed significantly greater accommodation (27.8%) for median axons, suggesting that slow K(+) conductances may be more prominent on median than peroneal axons. By contrast, the relation between S3 and S1 to hyperpolarising currents was similar for the two nerves, suggesting that the difference in inward rectification was merely because the conductance varies with the extent of hyperpolarisation. CONCLUSIONS: Slow K(+) conductances are more prominent for median motor axons than for peroneal axons. It would therefore be expected that axons innervating the lower limbs have less protection from depolarising stress and could develop ectopic activity more readily.     

The outcome of ganglion clipping in hyperhidrosis and blushing

A total of 114 patients with various sympathetic disorders underwent endoscopic sympathetic block over different thoracic ganglions by the clipping method. The advantages of this method include the recognition of the clipped level, changeability, and reversibility. However, 4.4% of patients were unilaterally clipped at the wrong level.     

Gravimetry in sweating assessment in primary hyperhidrosis and healthy individuals

Objective

Though hyperhidrosis is generally considered a subjectively perceived disease, it seems more and more doubtful that merely subjective evaluation is sufficient to qualify the patient to surgery. The aim of this study was to develop further gravimetry as a method of evaluation of sweating intensity and determination of the applicability of it in post-operative follow-up of primary hyperhidrosis (PHH) patients.

Methods

Total of 1,485 gravimetry assays has been performed in 343 patients treated for hyperhidrosis and in 220 healthy volunteers. In all of the subjects the measurements were taken from four localizations (face, hands, armpits and trunk) and normalized by body surface of the participant. The measurements were taken twice for every participant to obtain test–retest correlations. Mean values and standard deviations (SD) have been evaluated and on that basis reference values were quantified. Thresholds for diagnosis of hyperhidrosis were quantified on the basis of normal distribution theory as healthy population mean +2 SD.

Results

In healthy volunteers, mean value of gravimetrically evaluated intensity of sweating were: facial: 19.15 ± 14.97 mg/min/m², palmar: 18.49 ± 14.06 mg/min/m², axillary: 42.39 ± 47.08 mg/min/m² and plantar: 15.77 ± 16.87 mg/min/m². Thresholds for diagnosis of hyperhidrosis were quantified, respectively as: 49, 46, 136 and 50 mg/min/m². The overall test–retest correlation was 0.71.

Interpretation

Gravimetry is easy, reproducible and fast method of evaluation of sweating. The reference values are stable and can serve as a qualifying and follow-up tool for evaluation of the patients with PHH in any localization.

     

Resistance to ischaemic conduction failure in chronic hypoxaemia and diabetes.

Median nerve function was studied in twelve diabetic subjects, six subjects with chronic hypoxaemia and ten control subjects. Resistance to ischaemic conduction failure (RICF), a characteristic electrophysiological feature of diabetic neuropathy, was assessed by measuring the decline in median nerve action potential amplitude at minute intervals for up to 20 minutes while the arm was rendered ischaemic. Initial nerve conduction velocity and action potential amplitude was similar in all three groups. Following the onset of ischaemia the time to a 50% reduction in action potential amplitude was prolonged in both diabetic subjects and hypoxaemic subjects compared with controls. After 20 minutes of ischaemia no control subject had persisting nerve function, while function remained in 5 (80%) of hypoxaemic subjects and 10 (83%) of diabetic subjects. The time to a 50% reduction in action potential amplitude during ischaemia correlated with the blood oxygen saturation among the hypoxic subjects and haemoglobin Alc among diabetic subjects. These results are consistent with the hypothesis that hypoxia has a role in the pathogenesis of resistance to ischaemic conduction failure in diabetes.     

Enhanced anxiety follows withdrawal from subchronic exposure to phencyclidine in rats

Anxiety was assessed in rats treated with 5mg/kg of PCP bid for 7 days. One week after withdrawal, measures were collected in the light/dark apparatus and during exposure to a cat odor. PCP decreased time spent in the lit area and number of contacts with a cat collar. PCP thus amplified rats' fear of unprotected environments and predatory threats, which seems compatible with the distorted emotional experience in human schizophrenia.