The development of episodic future thinking in middle childhood.

The ability to imagine future events (episodic future thinking-EFT) emerges in preschoolers and further improves during middle childhood and adolescence. In the present study, we focused on the possible cognitive factors that affect EFT and its development. We assessed the ability to mentally project forward in time of a large cohort of 135 6- to 11-year-old children through a task with minimal narrative demands (the Picture Book Trip task adapted from Atance and Meltzoff in Cogn Dev 20(3):341-361. doi:10.1016/j.cogdev.2005.05.001, 2005) in order to avoid potential linguistic effects on children's performance. The results showed that this task can be used to assess the development of EFT at least until the age of 8. Furthermore, EFT scores correlated with measures of phonological short-term and verbal working memory. These results support the possibility that cognitive factors such as working memory play a key role in EFT.

Brief Report: Self-Based and Mechanical-Based Future Thinking in Children with Autism Spectrum Disorder.

This brief report is a partial replication of the study by Jackson and Atance (J Dev Disabil 14:40-45, 2008) assessing nonverbal Self-based and Mechanical-based future thinking (FT) in children with Autism Spectrum Disorder (ASD). In a first step, these tasks were administered to 30 children with ASD. The two Self-based tasks were then modified as a verbal component could not be completely ruled out. Consequently, 77 children with ASD and 77 children with typical development received the modified Self-based FT tasks and the Mechanical-based FT tasks. We partially replicated the previous findings. Participants with ASD had impaired FT in both kinds of tasks and both groups performed better on tasks assessing Mechanical-based FT than Self-based FT. These results suggest that impairments of FT in ASD are not limited to Self-Projection.

Higher mitochondrial DNA content in human IUGR placenta.

IUGR has been associated to a specific placental phenotype with reduced uptake of specific nutrients. Recently, it has been hypothesized that IUGR may be determined during early gestation. This period is characterized by decidual trophoblast invasion and by intense cellular growth, replication and differentiation. Since a huge energetic availability is required during gestation, we hypothesize that mitochondria may play a crucial role in this process being the main energetic producer in the cell. The aim of this study was to investigate the role of mitochondria in IUGR pathogenesis, evaluating the number of mitochondrial DNA copies (mtDNA) in IUGR placentae compared to controls. Placental samples were collected from 50 singleton pregnancies at the time of elective caesarean section. Twenty-six pregnancies were controls with normal intrauterine growth (AGA) and 24 were studied after the in utero diagnosis of IUGR. All samples were analyzed by real-time quantitative PCR and statistical analysis was performed by non-parametric tests. The median value of mitochondrial DNA content (IQR) in AGA and IUGR placentae was significantly different (455 and 698, respectively, p=0.004). The cell types responsible for the difference observed is unknown and it is possible that changes observed in the proportion of cell types may influence this measurement. Moreover, a significant negative relationship was observed between mtDNA and umbilical venous pO(2), with the highest levels detected in the most severe IUGR cases according to Doppler findings and to the presence of preeclampsia. These data suggest a relationship between the pathogenesis of IUGR and increased placental mtDNA copies. From our results we can speculate that increased mtDNA represents an adaptation of the metabolic placental mechanism to the calorie restriction of the fetus. Furthermore, we found that this rise was inversely related to oxygen tension in the umbilical vein. Although no specific pathogenetic role can be implied, mtDNA increases with hypoxia in placentas of IUGR.

Electro-oculographic abnormality in eyes with uveal melanoma.

PURPOSE: To seek out correlations between preoperative electro-oculogram (EOG) recordings with different types of uveal melanomas, after surgery. METHODS: We analysed the EOG recordings of 120 patients with uveal melanomas, histologically verified, 100 in the choroid and 20 in the iris and ciliary body. The EOG data were correlated with the site, size and histological type of the tumor. RESULTS: In 100 eyes with choroidal melanoma the Arden Index (AI) was less than in fellow eyes (mean 126.6, SD +/- 23.8 and 202.9, SD +/- 47.0; p=0.01). The EOG values were not different with respect to the histological type, site and size of tumor. In cases with iris and ciliary body melanomas the AI were not significantly different from the fellow eyes (mean 180.6, SD +/- 23.6 and 203.2, SD +/- 38.7; p=0.07). CONCLUSIONS: Since the EOG is abnormal in eyes with choroidal melanoma, it can be considered a powerful auxiliary for diagnosing these tumors.

Unilateral retinitis pigmentosa: clinical and electrophysiological report of four cases.

Unilateral retinitis pigmentosa (URP) is a rare tapetoretinal dystrophy affecting only one eye. The François and Verriest criteria are necessary to make a correct diagnosis of URP: exclude all infective etiologies, check that the clinical signs of retinitis are present in the affected eye and ensure the total absence of any signs or symptoms of retinitis pigmentosa in the fellow eye. The standard electroretinogram and standard electro-oculogram are very useful for the correct diagnosis. Other pigmentary retinopathies simulating retinitis pigmentosa have to be excluded, such as previous retinal inflammatory diseases like syphilis, rubeola, other viral diseases and onchocerciasis. In this paper, 4 cases of URP are reported.

Electronystagmographic investigation in X-linked ocular albinism.

Albinism represents the most frequent cause of nystagmus induced by visual sensory disorders. We studied five patients aged between three and five years with ocular albinism with the aim of identifying the characteristics of nystagmic oscillations. The patients underwent complete ophthalmological examination and electronystagmography (ENG). ENG revealed either pendular or jerk waveforms (or both) with the same complex effects of fixation seen in those with idiopathic congenital nystagmus. Three children presented face turn due to reduced severity of nystagmus in lateroversion. Latent nystagmus was not observed.

Effect of myopic excimer laser photorefractive keratectomy on the electrophysiologic function of the retina and optic nerve.

PURPOSE: To assess by electrophysiologic testing the effect of photorefractive keratectomy (PRK) on the retina and optic nerve. SETTING: Eye Clinic, S. Salvatore Hospital, L'Aquila University, Italy. METHODS: Standard pattern electroretinograms (P-ERGs) and standard pattern visual evoked potentials (P-VEPs) were done in 25 eyes of 25 patients who had myopic PRK for an attempted correction between 5.00 and 15.00 diopters (D) (mean 8.00 D). Testing was done preoperatively and 3, 6, 12, and 18 months postoperatively. The contralateral eyes served as controls. During the follow-up, 3 patients (12%) developed steroid-induced elevated intraocular pressure (IOP) that resolved after corticosteroid therapy was discontinued. RESULTS: No statistically significant differences were seen between treated and control eyes nor between treated eyes preoperatively and postoperatively. CONCLUSION: Myopic excimer laser PRK did not seem to affect the posterior segment. The transient steroid-induced IOP rise did not seem to cause functional impairment.

Homonymous bilateral hemianopsia: electrophysiological study of a case.

Described is a case of bilateral homonymous hemianopsia with macular sparing, resulting from head trauma. The case presented lesions of the occipital visual areas which involved entirely the left hemisphere and only partially the right hemisphere. VEP were obtainable only from electrodes placed on the right hemisphere with both right eye and left eye stimulation. VEP mapping showed that each eye projects macular fibres towards functional areas of the right occipital hemisphere. Electrophysiological examination confirmed objectively and for the first time in man the theory of "double cortical macular representation". Clinical implications of this finding are discussed.

Assessment of visual contrast sensitivity in hyperbaric oxygen.

Hyperbaric oxygen therapy is used in ophthalmology in ischemic pathologies of the anterior and posterior segments. Our experiment was done on a healthy group of volunteers aged between 10 and 50 yr. We examined the subject's vision before and after acute HBO exposure (60 min at 2.5 atm abs with pure oxygen) to verify whether vasoconstriction induced by hyperoxemia can influence eyesight. We measured the psychophysical determination of the threshold contrast according to Maione-Maffei's zebra test. The results demonstrated that contrast sensitivity is significantly improved for almost all the studied frequencies in normal subjects after acute HBO exposure. We hypothesize that the visual system has a reserve which is activated by an improvement of retinal oxygenation.

Electroretinographic findings in congenital oculomotor apraxia (Cogan's syndrome).

We performed visual evoked potential testing and electroretinography in five patients with Cogan's oculomotor apraxia. The visual evoked potentials were normal, confirming previously reported data. Electroretinograms were abnormal in two of the five patients examined. A previous study showed normal electroretinogram responses bilaterally in one patient. Our findings suggest the existence of two variants of the syndrome; the one with electroretinogram anomalies has a worse visual prognosis.

Single-sweep analysis using an autoregressive with exogenous input (ARX) model.

Single-sweep visual evoked potential analysis would be useful in clinical electrophysiology practice because it would make possible the evaluation of transient phenomena, but recording single-sweep visual evoked potentials is difficult because of the low signal-noise ratio. To increase this ratio we used a filter based on an autoregressive with exogenous input model. We studied a group of 12 diabetic patients matched with a control group of 14 normal subjects. The model, in most cases, allowed us to extrapolate the P100 component from each single sweep of visual evoked potential. The visual evoked potential values obtained by means of averaging were not significantly different in the groups studied, but single-sweep analysis showed different distribution of the P100 component amplitude. The preliminary results of our study evidenced differences in the amplitude and latency distribution of normal and diabetic subjects, thus confirming the power of this new technique and its ability to obtain some information that is masked by the averaging method.

Best's multiple vitelliform degeneration.

Best's disease with multifocal lesions is rare. The authors describe four cases of multifocal vitelliform disease. The fluorescein angiographic features of macular and extramacular lesions are considered. Different stages of evolution may be present between central and extramacular lesions.

Corneal endothelial anomalies in the fetal alcohol syndrome.

The fetal alcohol syndrome involves various neural crest-derived structures thus causing systemic and ocular malformations. This study investigated anomalies of the corneal endothelium, a neural crest-derived tissue, in eight children affected by fetal alcohol syndrome without known anterior segment anomalies. We performed specular biomicroscopy on the central corneal endothelium. The data were then compared with those from 80 age-matched healthy children, applying the same methods. Significant differences were found between patients with fetal alcohol syndrome and healthy subjects for mean cell density (P = .032), polymegethism (P = .000), and percentage of hexagonal cells (P = .000). We also found a close correlation between endothelial anomalies and auditory dysfunction in the patients with fetal alcohol syndrome. These alterations may be a consequence of alcohol-induced toxic effects on neural crest cells destined to form both the corneal endothelium and the organ of Corti in the same embryogenic period.

Microphthalmos with colobomatous orbital cyst in trisomy 13.

The authors describe a case of trisomy 13 with microphthalmos and colobomatous cyst of the optic nerve and of the chorioretina with orbital extension, in a six-month-old female patient. The colobomatous cyst has been studied by means of computerized axial tomography and ultrasonography in order to follow its evolution. The orbital cyst has not increased in size.

Carotid occlusive disease: an electrophysiological macular investigation.

Thirteen patients with carotid stenosis were studied by the authors by the measuring the Visual Evoked Potentials (VEPs) before and after thromboendarterectomy. This test of retinal function measures the recovery time of the amplitude of the major positive peak (P100) after photostress. When compared to that we observed in controls, we found, a significant increase of the P100 recovery time in patients suffering from carotid disease with severe stenosis. The method proved suitable for the functional evaluation of the vascular reconstruction of the carotid area, since four weeks after surgery a physiological recovery of the amplitude of VEP was observed. This method is proposed by the authors for the long-term functional evaluation of patients subjected to carotid thromboendarterectomy for tight stenosis of the carotid bifurcation.

VEP pattern after photostress: an index of macular function.

Eighty-seven subjects were examined by means of visual evoked potentials (VEPs) to evaluate the recovery time of the amplitude of the pattern VEP after photostress. Twenty-eight subjects were normal and 59 patients were affected by carotid occlusive disease, vascular retinopathies with and without macular involvement, and connective tissue diseases treated with antimalarial drugs. This examination method emphasizes visual dysfunction in a stage where ophthalmological changes are absent or minimal and therefore may be a useful test for the investigation of macular function.

An electrophysiological study on panretinal photocoagulation in diabetic retinopathy.

Twelve patients with proliferative diabetic retinopathy were treated with panretinal photocoagulation. EOG, ERG, and OPs were recorded before and after photocoagulation. It was found that EOG and ERG were reduced after photocoagulation. This may be explained by the fact that laser radiation is absorbed mainly in the pigment epithelium. As OPs amplitude improved after treatment, OP/ERG quotient may be said to reflect the new retinal situation and to represent a means of evaluating the course of retinopathy.