Stereotactic radiosurgery for intractable cluster headache: an initial report from the North American Gamma Knife Consortium.

Abstract Object The aim of this study was to evaluate the outcomes of Gamma Knife surgery (GKS) when used for patients with intractable cluster headache (CH). Methods Four participating centers of the North American Gamma Knife Consortium identified 17 patients who underwent GKS for intractable CH between 1996 and 2008. The median patient age was 47 years (range 26-83 years). The median duration of pain before GKS was 10 years (range 1.3-40 years). Seven patients underwent unsuccessful prior surgical procedures, including microvascular decompression (2 patients), microvascular decompression with glycerol rhizotomy (2 patients), deep brain stimulation (1 patient), trigeminal ganglion stimulation (1 patient), and prior GKS (1 patient). Fourteen patients had associated autonomic symptoms. The radiosurgical target was the trigeminal nerve (TN) root and the sphenopalatine ganglion (SPG) in 8 patients, only the TN in 8 patients, and only the SPG in 1 patient. The median maximum TN and SPG dose was 80 Gy. Results Favorable pain relief (Barrow Neurological Institute Grades I-IIIb) was achieved and maintained in 10 (59%) of 17 patients at a median follow-up of 34 months. Three patients required additional procedures (repeat GKS in 2 patients, hypothalamic deep brain stimulation in 1 patient). Eight (50%) of 16 patients who had their TN irradiated developed facial sensory dysfunction after GKS. Conclusions Gamma Knife surgery for intractable, medically refractory CH provided lasting pain reduction in approximately 60% of patients, but was associated with a significantly greater chance of facial sensory disturbances than GKS used for trigeminal neuralgia.

Climate change-linked range expansion of Nathusius' pipistrelle bat, Pipistrellus nathusii (Keyserling & Blasius, 1839)

Aim To examine the effect of climate change on the occurrence and distribution of Pipistrellus nathusii (Nathusius' pipistrelle) in the United Kingdom (UK).Location We modelled habitat and climatic associations of P. nathusii in the UK and applied this model to the species' historical range in continental Europe.Methods A binomial logistic regression model was constructed relating the occurrence of P. nathusii to climate and habitat characteristics using historical species occurrence records (1940-2006) and CORINE land cover data. This model was applied to historical and projected climate data to examine changes in suitable range (1940-2080) of this species. We tested the predictive ability of the model with known records in the UK after 2006 and applied the model to the species' known range in Europe.Results The distribution of P. nathusii was related positively to the area of water bodies, woodland and small areas of urbanization, and negatively related to the area of peat/heathland. Species records were associated with higher minimum temperatures, low seasonal variation in temperature and intermediate rainfall. We found that suitable areas have existed in the UK since the 1940s and that these have expanded. The model had high predictive power when applied to new records after 2006, with a correct classification rate of 70%, estimated by receiver operating characteristic analysis. Based on climate projections, our model suggests a potential twofold increase in the area suitable for P. nathusii in the UK by 2050. The single most influential climate variable contributing to range increase was the projected increase in minimum temperature. When applied to Europe, the model predictions had best predictive capability of known records in western areas of the species' range, where P. nathusii is present during the winter.Main conclusions We show that a mobile, migratory species has adapted its range in response to recent climate change on a continental scale. We believe this may be the first study to demonstrate a case of range change linked to contemporary climate change in a mammal species in Europe.

Summer habitat associations of bats between riparian landscapes and within riparian areas

The present study examines those features which promote bat feeding in agricultural riparian areas and the riparian habitat associations of individual species. Activity of Nathusius' pipistrelle (Pipistrellus nathusii), common pipistrelle (Pipistrellus pipistrellus), soprano pipistrelle (Pipistrellus pygmaeus), Leisler's bat (Nyctalus leisleri), and Myotis species (Myotis sp.) were recorded, and their habitat associations both "between" and "within" riparian areas were analyzed. General feeding activity was associated with reduced agricultural intensity, riparian hedgerow provision, and habitat diversity. Significant habitat associations for P. pipistrellus were observed only within riparian areas. Myotis species and P. pygmaeus were significantly related to indices of landscape structure and riparian hedgerow across spatial scales. Myotis species were also related to lower levels of riffle flow at both scales of analysis. The importance of these variables changed significantly, however, between analysis scales. The multi-scale investigation of species-habitat associations demonstrated the necessity to consider habitat and landscape characteristics across spatial scales to derive appropriate conservation plans.

When is the second local multiplier algebra of a C*-algebra equal to the first?

We discuss necessary as well as sufficient conditions for the second iterated local multiplier algebra of a separable C*-algebra to agree with the first.