Contribution of intermittent photic stimulation to routine EEG.

OBJECTIVE: Intermittent photic stimulation (IPS) is an activation procedure performed during electroencephalography (EEG) to detect photosensitive patients. This procedure is recommended in routine EEGs but the benefit of IPS in the general population is not clearly ascertained. METHODS: We retrospectively analyzed 7683 EEGs of patients referred for a routine EEG to the Clinical Physiology Department of Lariboisière hospital, mainly from the emergency ward and the department of neurology, not specifically involved in epilepsy. All EEGs were performed with a standardized protocol. Photic driving response, photomyoclonic response and photoparoxysmal response (PPR) were specifically collected. A correlation analysis was performed between the response induced by IPS, demographical and clinical data, and current treatment or recreational drug use. RESULTS: Median age was 56.4 years (41.7-71.2); 3,042 (39.6%) of patients were female; 1,208 patients (15.7%) had a past medical history of epilepsy. Photic driving response occurred in 67 EEGs (0.9%), and PPR in 6 EEGs (0.1%), all with a known history of epilepsy. Thus 0.5% (6/1,208) of epilepsy patients had a PPR. Photomyoclonic responses were not observed. Juvenile myoclonic epilepsy was the only factor associated with the presence of PPR (RR=75.26 [11.82-479.21]). PPR was not associated with clinical symptoms or seizures. There was no correlation with the type of treatment or recreational drug use. CONCLUSIONS: Our results confirm that responses to IPS are rare in adult patients and especially PPR. Moreover, all patients with a PPR had a known previous history of epilepsy. These results question the benefit of IPS in adult patients with no history of epilepsy.

Chemical characteristics and cancer risk assessment of smokeless tobacco used in Tunisia (neffa).

INTRODUCTION: neffa, a form of air-dried smokeless tobacco used in North Africa, is spuriously perceived as a lower risk alternative to smoking. The objective of this study was to provide information on some harmful constituents of neffa and to use them for cancer risk assessment. METHODS: a high-performance liquid chromatography method coupled with fluorescence detector was used to determine polycyclic aromatic hydrocarbons (PAHs) in one sample of neffa. An atomic absorption spectrometry was performed to determine the concentrations of lead and cadmium in three samples of neffa. The levels of toxicants found in neffa were used to assess for lifetime cancer risk as advocated by the US Environment Protection Agency. RESULTS: the determination of PAHs in neffa allowed the identification of phenanthrene and anthracene. However, the higher molecular weight PAHs such as Benzo(a)Pyrene B(a)P were not detected. The concentrations of cadmium and lead varied between 1.3 to 2.8µg/g and 1.7 to 4.6µg/g respectively. Cancer risk for cadmium and lead varied between 4.2E-03 to 9.3E-03 and 2.5E-06 to 6.4E-06 respectively. Cancer risk for Cd exceeded the range of 10E-04 to 10E-06 of an acceptable risk. CONCLUSION: neffa is not a healthy alternative for overcoming smoking addiction. It contains mineral and organic pulmonary toxicants. This study could serve as a scientific basis to inform consumers about the products´ toxicity and help them to quit smokeless tobacco (SLT) use.

Stridor combined with other sleep breathing disorders in multiple system atrophy: a tailored treatment?

OBJECTIVES: To determine the frequency of sleep breathing disorders in multiple systemic atrophy (MSA, combining Parkinsonism, cerebellar syndrome, and dysautonomia) and evaluate the benefit/tolerance of various modes of ventilation. METHODS: We retrospectively analyzed 45 patients with MSA having undergone a videopolysomnography. Their sleep characteristics were compared to those of 45 patients with Parkinson's disease and 45 healthy controls, matched for age and sex. Patients with MSA received fixed continuous positive airway pressure (CPAP) when stridor was isolated, auto-adjusting CPAP when it was combined with obstructive sleep apnea, and adaptive servo-ventilation (ASV) when combined with central sleep apnea. RESULTS: Higher periodic leg movements index and more frequent REM sleep behavior disorder were observed in MSA patients, compared to patients with Parkinson's disease and healthy controls. In MSA, 28/45 (62.2%) patients had sleep breathing disorders, including (overlapping samples) stridor (n = 17, 38%), obstructive sleep apnea (n = 14, 31%), central sleep apnea (n = 4, 9%), and ataxic breathing (n = 1). Except for three initial refusals and two yet untreated patients, fixed CPAP (n = 9), auto-adjusting CPAP (n = 8) and ASV (n = 2) were well-tolerated (limited leaks and good compliance) and successfully controlled stridor plus sleep apnea. Treated patients had survival times similar to those of patients without any sleep breathing disorder. CONCLUSION: In this small group, tailored management of stridor in MSA as an independent issue or combined with obstructive and central sleep apnea, yields a survival similar to survival in patients without sleep breathing disorders.