Reliability of clinical diagnosis of dystonia.

BACKGROUND: There is only one small single-center study on the reliability of the diagnosis of focal dystonia. The aim of this study was to assess the inter-rater reliability of dystonia diagnosis among neurologists with different professional experience. METHODS: Twenty-nine adults (18 with dystonia, 9 with other movement disorders, and 2 healthy controls) were videotaped while undergoing neurological examination and during the process of collecting information on the history of their condition. Each case was diagnosed by 35 blind raters (12 general neurologists, 21 neurology residents, and 2 experts in movement disorders) from different hospitals. Sensitivity and specificity were calculated confronting raters with the gold standard (the caring physician). Inter-rater agreement was measured by the Kappa statistic. RESULTS: Specificity and sensitivity were 95.2 and 66.7%, 76.3 and 75.2%, 84.6 and 71.6% for experts, general neurologists, and residents, respectively. Kappa values on dystonia diagnosis ranged from 0.30 to 0.46. The agreement was moderate for experts and residents (0.40-0.60) and fair for general neurologists (0.20-0.40). Kappas were the highest among experts for cranial and laryngeal dystonia (0.61-1), but not for cervical dystonia (0.37). CONCLUSIONS: The diagnosis of dystonia is difficult and only partially mirrors a physician's background.

Changes in lamotrigine pharmacokinetics during pregnancy and the puerperium.

To assess changes in the pharmacokinetics of the anti-epileptic drug lamotrigine (LTG) during pregnancy, plasma LTG concentrations at steady-state were determined at different intervals during 11 pregnancies in 10 women with epilepsy stabilized on long-term LTG therapy. In the five pregnancies that could be assessed both during gestation and after delivery, plasma LTG concentrations increased on average by 164% (range +75 to +351%) between the last observation during pregnancy and the puerperium (P < 0.05). When all pregnancies monitored during pregnancy were considered, plasma LTG concentrations declined by an average of 20% (range -64% to +13%) between the first and the last assessment before delivery. These findings confirm that plasma LTG concentrations decrease markedly during pregnancy and that, at least in some cases, this effect occurs as early as the first trimester. Because there is a large interindividual variability in the magnitude and time course of the pregnancy-associated pharmacokinetic changes, it is desirable to establish baseline plasma LTG concentrations in all women of childbearing potential and to monitor LTG levels at frequent intervals during pregnancy and the puerperium.