Precompensation of 3D field distortions in remote focus two-photon microscopy

Remote focusing is widely used in 3D two-photon microscopy and 3D photostimulation because it enables fast axial scanning without moving the objective lens or specimen. However, due to the design constraints of microscope optics, remote focus units are often located in non-telecentric positions in the optical path, leading to significant depth-dependent 3D field distortions in the imaging volume. To address this limitation, we characterized 3D field distortions arising from non-telecentric remote focusing and present a method for distortion precompensation. We demonstrate its applicability for a 3D two-photon microscope that uses an acousto-optic lens (AOL) for remote focusing and scanning. We show that the distortion precompensation method improves the pointing precision of the AOL microscope to < 0.5 µm throughout the 400 × 400 × 400 µm imaging volume

Alexithymia in juvenile primary headache sufferers: a pilot study

Starting in the 1990s, there has been accumulating evidence of alexithymic characteristics in adult patients with primary headache. Little research has been conducted, however, on the relationship between alexithymia and primary headache in developmental age. In their research on alexithymia in the formative years, the authors identified one of the most promising prospects for research, as discussed here. The aim of this study was to verify whether there is: (a) a link between tension-type headache and alexithymia in childhood and early adolescence; and (b) a correlation between alexithymia in children/preadolescents and their mothers. This study was based on an experimental group of 32 patients (26 females and 6 males, aged from 8 to 15 years, mean 11.2 ± 2.0) suffering from tension-type headache and 32 control subjects (26 females and 6 males, aged from 8 to 15 years, mean 11.8 ± 1.6). Tension-type headache was diagnosed by applying the International Headache Classification (ICHD-II, 2004). The alexithymic construct was measured using an Italian version of the Alexithymia Questionnaire for Children in the case of the juvenile patients and the Toronto Alexithymia Scale (TAS-20) for their mothers. Higher rates of alexithymia were observed in the children/preadolescents in the experimental group (EG) than in the control group; in the EG there was no significant correlation between the alexithymia rates in the children/preadolescents and in their mothers

Sintomas da síndrome de apnéia-hipopnéia obstrutiva do sono em crianças Symptoms of obstructive sleep apnea-hypopnea syndrome in children

OBJETIVOS: Investigar os sintomas mais freqüentes encontrados em crianças com diagnóstico polissonográfico de síndrome da apnéia-hipopnéia obstrutiva do sono (SAHOS). MÉTODOS: Foram avaliadas 38 crianças consecutivamente encaminhadas ao laboratório do sono com suspeita de SAHOS no período de junho de 2003 a dezembro de 2004. Os pacientes foram submetidos a um questionário pré-sono e a polissonografia. RESULTADOS: A idade média foi de 7,8 ± 4 anos (variação, 2-15 anos), sendo 50% das crianças do sexo masculino. Não apnéicos corresponderam a 7,9% dos pesquisados, distúrbio leve obstrutivo do sono ocorreu em 42,1%, moderado em 28,9% e severo em 22,1%. Observou-se maior freqüência de casos severos de apnéia entre crianças menores de seis anos (idade pré-escolar). Dentre as crianças com SAHOS, os sintomas mais citados foram ronco e obstrução nasal, presentes em 74,3 e 72,7% das crianças, respectivamente. Sonolência excessiva e bruxismo ocorreram em, respectivamente, 29,4 e 34,3% dos casos e doença do refluxo em apenas 3,1%. Agitação das pernas e dificuldade para iniciar o sono foram encontradas em, respectivamente, 65 e 33% dos avaliados. Todas as crianças que apresentaram SAHOS de grau severo tinham queixa de ronco e bruxismo. CONCLUSÕES: Nossos resultados mostraram que os sintomas mais freqüentes em crianças e adolescentes com SAHOS são ronco e obstrução nasal. Além disso, quadros mais graves da SAHOS estão associados à menor faixa etária.<br>OBJECTIVE: To investigate the symptoms most frequently found in children with a polysomnographic diagnosis of obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: We evaluated 38 children consecutively referred to the sleep laboratory with suspicion of OSAHS between June of 2003 and December of 2004. The patients were submitted to a pre-sleep questionnaire and to polysomnography. RESULTS: The mean age was 7.8 ± 4 years (range, 2-15 years), and 50% of the children were male. Children without apnea accounted for 7.9% of the sample. The obstructive sleep apnea observed in the remainder was mild in 42.1%, moderate in 28.9% and severe in 22.1%. Severe cases of apnea were most common among children under the age of six (pre-school age). In children with OSAHS, the most common symptoms were snoring and nasal obstruction, which were observed in 74.3 and 72.7% of the children, respectively. Excessive sleepiness and bruxism were seen in 29.4 and 34.3%, respectively, and reflux disease was seen in only 3.1%. Restless legs and difficulty in falling asleep were identified in 65 and 33%, respectively. All of the children diagnosed with severe OSAHS also presented snoring and bruxism. CONCLUSIONS: Snoring and nasal obstruction were the most common symptoms found in our sample of children and adolescents with OSAHS. In addition, OSAHS severity was associated with being in the lower age bracket