Clinical experience of abrupt discontinuation of perampanel: a case series.

With an elimination half-life of 105 hours, perampanel (PER) allows a once-daily dosing regimen. In pivotal trials, when PER was tapered, it was therefore usually discontinued abruptly. Thus, in our hospital we have always practiced abrupt cessation. In this case series, we investigated how long PER serum concentrations still remain measurable after abrupt discontinuation of PER and whether withdrawal symptoms, such as an increase in seizures or status epilepticus, occur. PER serum levels and the clinical course of 15 adult in-patients were monitored for three weeks based on a retrospective study design following abrupt discontinuation of PER. After one week, PER was still detected in 13 of 15 patients, after two weeks in 10, and after three weeks in three. Neither a severe increase in seizure frequency nor status epilepticus occurred. However, modifications of the concomitant antiseizure drugs were necessary. The abrupt discontinuation of PER leads to a slow decrease in plasma concentration, thus resembling self-evident gradual discontinuation of PER. In some cases, PER may still be measurable and thus clinically active even weeks after its discontinuation. Efficacy and safety of other antiseizure drugs can be estimated appropriately only thereafter.

Is brivaracetam-induced elevation of carbamazepine-epoxide levels common and clinically relevant? - A case series.

Brivaracetam (BRV) was recently introduced for the treatment of patients with focal epilepsy. BRV undergoes relatively few interactions, but one of them leads to the elevation of carbamazepine (CBZ)-10,11-CBZ-epoxide (CBZ-E) if BRV is co-administered with CBZ. This interaction has been considered to be clinically negligible. We present a case series of nine patients. In eight of them, levetiracetam (LEV) was switched to BRV. In the remaining case, oxcarbazepine was replaced by CBZ and added to a stable BRV dose. A marked increase of CBZ-E occurred in every case and was associated with clinically relevant symptoms including blurred vision, diplopia, dizziness, or fatigue in three of them. However, in the remaining six, the elevated CBZ-E levels were not associated with any tolerability problems. The importance of CBZ-E for adverse events under CBZ may have been overemphasized in the past and is not clinically impairing in most cases treated with the combination of BRV and CBZ.

Artists portray human faces with the Fourier statistics of complex natural scenes.

When artists portray human faces, they generally endow their portraits with properties that render the faces esthetically more pleasing. To obtain insight into the changes introduced by artists, we compared Fourier power spectra in photographs of faces and in portraits by artists. Our analysis was restricted to a large set of monochrome or lightly colored portraits from various Western cultures and revealed a paradoxical result. Although face photographs are not scale-invariant, artists draw human faces with statistical properties that deviate from the face photographs and approximate the scale-invariant, fractal-like properties of complex natural scenes. This result cannot be explained by systematic differences in the complexity of patterns surrounding the faces or by reproduction artifacts. In particular, a moderate change in gamma gradation has little influence on the results. Moreover, the scale-invariant rendering of faces in artists' portraits was found to be independent of cultural variables, such as century of origin or artistic techniques. We suggest that artists have implicit knowledge of image statistics and prefer natural scene statistics (or some other rules associated with them) in their creations. Fractal-like statistics have been demonstrated previously in other forms of visual art and may be a general attribute of esthetic visual stimuli.