The necessity for sphenoidal electrodes in the presurgical evaluation of temporal lobe epilepsy: pro position.

Whether sphenoidal electrodes should be used in the presurgical evaluation of people with refractory epilepsy has remained controversial. Many studies have been published touting their advantages, or conversely, their lack of benefit. The present paper reviews the evidence supporting the utility of sphenoidal electrodes. In principle, sphenoidal electrodes have an advantage over laterally placed scalp electrodes in detecting inferiorly directed mesial temporal discharges. Published studies demonstrate that sphenoidal electrodes are more sensitive than scalp electrodes and sometimes detect interictal spikes and seizures not seen with scalp electrodes. While the net added yield is relatively low, perhaps 5 to 10%, those patients in whom sphenoidal electrodes provide unique localizing information have much to gain. Sphenoidal electrodes may spare some patients unnecessary intracranial electrode investigation and permit surgery for others.     

A Thalamic Contribution to Arousal-induced, Non-photic Entrainment of the Circadian Clock of the Syrian Hamster

It is well established that the circadian clock of the suprachiasmatic nuclei (SCN) is entrained by light. More recently, the potent effects of arousing, non-photic cues on the clock have been recognized. The neural mediators of non-photic entrainment are yet to be identified. To examine the contribution of the thalamic intergeniculate leaflet (IGL) and its NPY-immunopositive projection, the geniculo-hypothalamic tract to non-photic entrainment by arousal, male Syrian hamsters received lesions of the IGL (IGLX) which ablated NPY-immunoreactivity in the SCN. Their circadian responses to both photic and non-photic cues were then tested. Lesions resulted in a delay in the timing of activity onset following lights out, but had no effect on the behavioural or cellular circadian responses to phase-advancing light pulses presented at circadian time (CT) CT19 (where CT12 represents the time of activity onset). Injection with a benzodiazepine (chlordiazepoxide, 100 mg/kg) at CT6 suppressed wheel-running, increased general locomotion of intact controls and induced large phase advances of the circadian rhythm of wheel-running. Chlordiazepoxide also inhibited wheel-running in lesioned animals, but there was no significant increase in general locomotion and the lesioned animals did not phase advance. Serial arousal by injection of saline at intervals of 23.5 h for 6 days entrained the circadian rhythm of wheel-running of intact hamsters and was associated with an increase in general locomotor activity. Entrainment by serial arousal was abolished by IGLX. However, the lesioned animals did show a clear behavioural response to every presentation of the non-photic cue. These results show that the IGL is a necessary component of the neural pathways mediating both arousal- and benzodiazepine-induced non-photic entrainment.     

Protective effect of captopril on the blood-retina barrier in normotensive insulin-dependent diabetic patients with nephropathy and background retinopathy

The effect of 18 months' inhibition of angiotensin-converting enzyme by captopril on the leakage of fluorescein through the blood-retina barrier was examined in a prospective, randomized control study of 20 normotensive insulin-dependent diabetic patients with nephropathy and background retinopathy. After 18 months, 15 patients remained in the study. Fluorescein leakage remained nearly unchanged in the captopril-treated group, being 4.1 ± 4.1 (mean ± SD) × 10^–7 cm/s at baseline and 4.2±4.1 × 10^–7 cm/s after 18 months' treatment. The permeability increased significantly (P<0.01) from 3.3±2.2 × 10^–7 cm/s to 5.6±3.5 × 10^–7 cm/s at 18 months in the control group. Arterial blood pressure was nearly constant in both groups throughout the study. The results indicate that angiotensin-converting enzyme inhibition with captopril can arrest or delay a progressive breakdown of the blood-retina barrier in normotensive insulin-dependent diabetic patients with nephropathy and background retinopathy.The authors have no commercial or proprietory interest in the drugs or instruments used in this study     

Comparison of three immunoassays for diagnosing sensitization to latex in children with spina bifida

As natural rubber latex (latex) has become more widespread in our environment, physicians have become increasingly aware of the problem of possible allergic reactions. Many fatal and near-fatal incidents have been reported (mainly during surgery) (1—3) and data has been published on groups frequently exposed to latex, such as patients with spina bifida (4—9), healthcare professionals (10—12) and occupationally exposed persons (13). The incidence of latex allergy in children seems to be increasing (14). Tests are therefore needed which can reliably detect sensitization to latex. Our aim was to compare the diagnostic accuracy of three commercial immunoassays for measuring specific IgE in serum to latex.     

The influence of stigma on the sexual risk behavior of rural men who have sex with men.

Research investigating predictors of risky sexual behavior of rural MSM is sparse, even though the prevalence of HIV in rural areas has increased. This study explored two sets of predictors of 93 rural MSM's levels of risky sexual behavior: mental health variables and stigma emanating from men's family members, health care professionals, and people in the rural communities in which they live. Over 47% of the men were found to be at modified high to high risk. Logistic regression using a continuation logit model was used to test the relationship of the predictor variables and the four levels of risk. Findings indicate that self-esteem was predictive of the highest sexual risk behavior but not lower levels of risk. Stigma was predictive of modified high sexual risk when compared to low and no risk categories. No variables differentiated men at low risk from men at no risk.     

Geste antagonistes in idiopathic lower cranial dystonia.

Geste antagonistes, or sensory tricks, are well described in focal dystonia affecting the neck, hand, and face. Improvement in dystonic movements is typically maintained while the trick is performed, but disappears when the geste ends. We investigated the phenomenological features of geste antagoniste maneuvers in 19 patients with idiopathic lower cranial dystonia who were prospectively evaluated over a period of 6 years. Of the 19, 10 were men, mean age of onset was 49.8 years, and the most commonly involved lower cranial area was the jaw (10 patients). In most patients, dystonia was task-specific. Taking advantage of the improvement with a sensory geste, we manufactured oral appliances that mimicked the geste in 8 patients, and 3 continue to use it.