Temporal Crescent Research Articles

Identification of a Novel Frameshift Variant of ARR3 Related to X-Linked Female-Limited Early-Onset High Myopia and Study on the Effect of X Chromosome Inactivation on the Myopia Severity.

X-linked myopia 26 (Myopia 26, MIM #301010), which is caused by the variants of ARR3 (MIM *301770), is characterized by female-limited early-onset high myopia (eo-HM). Clinical characteristics include a tigroid appearance in the fundus and a temporal crescent of the optic nerve head. At present, the limited literature on eo-HM caused by ARR3 mutations shows that its inheritance mode is complex, which brings certain difficulties to pre-pregnancy genetic counseling, pre-implantation genetic diagnosis, and prenatal diagnosis. Here, we investigated the genetic underpinning of a Chinese family with eo-HM. Whole exome sequencing of the proband revealed a novel frameshift mutation in ARR3 (NM_004312, exon10, c.666delC, p. Asn222LysfsTer22). Although the mode of inheritance of the eo-HM family fits the X-linked pattern of ARR3, the phenotypes of three patients deviate from the typical early-onset high myopia. Through X-chromosome inactivation experiments, the patient's different phenotypes can be precisely explained. In addition, this study not only enhanced the correlation between ARR3 and early-onset high myopia but also provided explanations for different phenotypes, which may inspire follow-up studies. Our results enrich the knowledge of the variant spectrum in ARR3 and provide critical information for preimplantation and prenatal genetic testing, diagnosis, and counseling.

The Pseudo-Hypoplastic Myopic Optic Disc

A 7-year-old girl had 20/25 vision in the right eye (OD) (with correction) and 20/20 vision in the left eye (OS), with no afferent pupillary defect. Retinoscopy showed –4.75 OD and plano OS. Retinal examination showed a small tilted right optic disc, with a temporal crescent of retinal pigment epithelium (RPE) and choroid pierced inferotemporally by a retinal vein (Fig A). OCT showed a smaller right disc with a smaller neuroretinal rim and cup volume (Fig B), but equal retinal nerve fiber layer (RNFL) (Fig B) and ganglion cell thickness (bottom left).

Size and position of the optic disc crescent in a white European population with myopia.

SignificanceOne of the first clinically observed changes in the retina with progressing myopia is in the form of optic disc crescents. If such a change is predictive of myopia progression, it could aid in myopia management interventions to target those at greatest risk of progression and subsequent ocular morbidity.PurposeTo investigate the type, dimension and appearance of optic disc crescents and how they relate to the level of myopia.MethodsRetrospective data collection analysing retinal photographs of healthy children and adults with a refractive error of ≤−0.50 D sphere and astigmatism ≤2.00 D. Crescent location, maximum crescent width and vertical disc diameter were measured from retinal images of right eyes only.ResultsFour‐hundred eyes with a mean spherical error (SER) of −0.50 to −14.00 D (aged 7–81 years) were included (83.5% exhibited a discernible crescent). Mean (SD) maximum crescent width was 0.24 (0.24) mm. Univariate analysis showed a significant correlation between crescent width and age (r = 0.26, p < 0.001). SER was correlated with crescent width when controlling for age (r = −0.45, p < 0.001) and to the ratio of crescent width to vertical disc diameter (r = −0.43, p < 0.001). Temporal crescents were the most frequently observed (74%), followed by inferior temporal crescents (17%). One‐way between‐groups analysis of variance showed a significant difference between crescent locations (F = 5.2, p < 0.001). Post‐hoc analysis revealed significant differences in SER between those with no crescent versus an inferior‐temporal crescent, as well as differences between those with temporal versus inferior‐temporal crescents. Other crescent locations did not differ significantly in the level of myopia. Participants not exhibiting a crescent had the lowest level of myopia (mean [SD] −3.03 [1.97)] D), while those with inferior temporal crescents had a mean (SD) SER of −5.01 (2.37) D.ConclusionIn this white European population, higher levels of SER were associated with increasing crescent size. Eyes with inferior temporally located crescents were more myopic.

Fundus changes in high myopic Kashmiri population

Background: High myopia (defined as myopia of -6D or more) is one of the main causes of visual impairment worldwide. High myopia is always accompanied by pathological structural changes such as axial elongation, posterior staphyloma, lacquer crack formation, thinning of the retina and choroid, and choroidal neovascularization.&#x0D; Aims and Objectives: The purpose of this study was to examine the fundus changes in eyes with high myopia.&#x0D; Materials and Methods: All study participants underwent dilated fundus examination and fundus photography. Myopia-related macular (posterior staphyloma, lacquer cracks, Fuchs spot, myopic chorioretinal atrophy, and myopic choroidal neovascularization)and optic disc (optic nerve head tilt,optic disc dimensions, and peripapillary atrophy) changes were evaluated.&#x0D; Results: Statistical analysis was performed to evaluate fundus changes in eyes with high myopia. Data analysis included 107 eyes of 57 patients.Mean ± SE was 12.07 ± 3.184D in eyes with high myopia. Mean ± AL was 26.68± 1.577mm in eyes with high myopia. The mean age was 28.54 ± 9.44 years(14-50 years). Fundus changes were: Temporal crescent in 56 (52.33%) eyes, tessellated fundus appearance in 52(48.59%) eyes, lacquer cracks in 40 (37.38%) eyes, tilted disc in 30 (28%) eyes, lattice degeneration in 20(18.69%) eyes, posterior staphyloma in 20(18.69%) eyes, focal chorioretinal atrophy in 3 (2.8%) eyes. CNV in 2 (1.86%)eyes and retinal hole in 1(1%) eye.&#x0D; Conclusions: Tessellated fundus and temporal crescent were the most common fundus findings among Kashmiri population with high myopia. In this population, lacquer cracks and tilted disc were also common, while CNV and retinal holes were rare.

Field Expansion with Multiplexing Prism Glasses Improves Pedestrian Detection for Acquired Monocular Vision.

PurposePatients with acquired monocular vision (AMV) lose vision in the temporal crescent on the side of the blind eye. This visual field loss affects patients’ ability to detect potential hazards in the blind field. Mounting a base-in multiplexing prism (MxP) on the nasal side of the seeing eye can provide true field expansion and enable detection of potential collision hazards. We evaluated the efficacy of the MxP glasses in a virtual reality walking environment.MethodsA three-dimensional printed clip-on MxP holder that can be adjusted for an individual user's facial parameters was developed. Virtual reality walking scenarios were designed to evaluate the effect of MxP field expansion on the detection of a pedestrian approaching from different initial bearing angles and courses. The pedestrian detection rates and response times of 10 participants with simulated AMV (normally sighted participants with one eye patched) and three patients with AMV were measured.ResultsThe MxP provided true field expansion of about 25°. Participants performed significantly better with the MxP than without the MxP in the pedestrian detection task on their blind field, while their seeing field performance was not significantly different.ConclusionsThe MxP glasses for patients with AMV improved the detection of potential collision hazards in the blind field.Translational RelevanceThe MxP with an adjustable clip-on holder may help patients with AMV to decrease the risk of collision with other pedestrians.

In vivo functional localization of the temporal monocular crescent representation in human primary visual cortex

The temporal monocular crescent (TMC) is the most peripheral portion of the visual field whose perception relies solely on input from the ipsilateral eye. According to a handful of post-mortem histological studies in humans and non-human primates, the TMC is represented visuotopically within the most anterior portion of the primary visual cortical area (V1). However, functional evidence of the TMC visuotopic representation in human visual cortex is rare, mostly due to the small size of the TMC representation (~6% of V1) and due to the technical challenges of stimulating the most peripheral portion of the visual field inside the MRI scanner. In this study, by taking advantage of custom-built MRI-compatible visual stimulation goggles with curved displays, we successfully stimulated the TMC region of the visual field in eight human subjects, half of them right-eye dominant, inside a 3 ​T MRI scanner. This enabled us to localize the representation of TMC, along with the blind spot representation (another visuotopic landmark in V1), in all volunteers, which match the expected spatial pattern based on prior anatomical studies. In all hemispheres, the TMC visuotopic representation was localized along the peripheral border of V1, within the most anterior portion of the calcarine sulcus, without any apparent extension into the second visual area (V2). We further demonstrate the reliability of this localization within/across experimental sessions, and consistency in the spatial location of TMC across individuals after accounting for inter-subject structural differences.

Three Dimensional Evaluation of Posterior Pole and Optic Nerve Head in Tilted Disc

For over a century, tilted disc syndrome (TDS) has been defined vaguely. The lack of consensus of the terminology arises from the lack of understanding of the pathogenesis of this condition. Also, myopic discs with temporal crescents or peripapillary atrophy (PPA) are histologically indistinguishable from TDS. Therefore, we examined the morphological background of the extreme ONH appearances such as the myopic tilted disc and the TDS by analyzing the posterior segment of the eye from a three-dimensional (3D) perspective. 107 eyes of 107 subjects were classified into 3 groups with respect to the optic disc torsion degrees: (1) mild torsion (0–30 degrees; 35 eyes) and (2) moderate torsion (30–60 degrees; 35 eyes) and (3) severe torsion (60–90 degrees; 37 eyes). SSOCT images were analyzed in coronal view, which supplements anterior-posterior depth (z axis in Cartesian coordinates). The amount of optic disc torsion was significantly correlated with Disc-DPE angle and Fovea-Disc depth (r = 0.548, P < 0.001 and r = 0.544, P < 0.001). In conclusion, we describe specific types of posterior sclera configuration that corresponds to the increasing degree of optic disc torsion, even in the extreme ONH appearances such as the myopic tilted disc and the TDS. These findings suggest that the optic disc appearance is determined by the configuration of the posterior sclera.

Does the World Health Organization criterion adequately define glaucoma blindness?

PurposeBlindness in glaucoma is difficult to assess with merely the use of the current World Health Organization (WHO) definition (a visual field restricted to 10° in a radius around central fixation), as this criterion does not cover other types of visual field loss that are encountered in clinical practice and also depict blindness. In this study, a 5-point ordinal scale was developed for the assessment of common visual field defect patterns, with the purpose of comparing blindness as outcome to the findings with the WHO criterion when applied to the same visual fields. The scores with the two methods were compared between two ophthalmologists. In addition, the variability between these assessors in assessing the different visual field types was determined.MethodsTwo glaucoma specialists randomly assessed a sample of 423 visual fields from 77 glaucoma patients, stripped of all indices and masked for all patient variables. They applied the WHO criterion and a 5-point ordinal scale to all visual fields for the probability of blindness.ResultsThe WHO criterion was mostly found applicable and in good agreement for both assessors to visual fields depicting central island of vision or a temporal crescent. The percentage of blindness scores was higher when using the ordinal scale, 21.7% and 19.6% for assessors A and B, respectively, versus 14.4% and 11.3% for the WHO criterion. However, Kappa was lower, 0.71 versus 0.78 for WHO.ConclusionsThe WHO criterion is strictly applied and shows good agreement between assessors; however, blindness does not always fit this criterion. More visual fields are labeled as blind when a less stringent criterion is used, but this leads to more interobserver variability. A new criterion that describes the extent, location, and depth of visual field defects together with their consequence for the patient’s quality of life is needed for the classification of glaucoma blindness.

Patching for Diplopia Contraindicated in Patients with Brain Injury?

Patching for double vision is a common palliative treatment for head-trauma patients with acquired strabismus when prisms are not feasible. We review literature on spatial neglect and discuss possible effects of monocular occlusion on spatial attention. Patching the left eye has been shown to worsen spatial judgments in some brain-injured patients with left neglect by inhibiting the right superior colliculus further impairing contralateral leftward orienting (the Sprague Effect). Because more peripheral parts of the visual field increasingly project to the contralateral superior colliculus with the temporal crescent being entirely contralateral, avoiding patching of the temporal crescent was advised, and in most cases can be achieved by taping off the spectacle lens and avoiding an elastic eye patch.

Increased Plasma cGMP in a Family With Autosomal Recessive Retinitis Pigmentosa Due to Homozygous Mutations in the PDE6A Gene.

To describe genotype and phenotype in a family with autosomal recessive retinitis pigmentosa (arRP) carrying homozygous mutations in the gene for the α-subunit of cyclic guanosine monophosphate (cGMP)-hydrolyzing phosphodiesterase 6 (PDE6A). Moreover, to compare their plasma cGMP levels to controls, exploring the possible role for cGMP in RP diagnostics. Seven siblings and their parents were recruited. Microarray, verified by Sanger sequencing, was used for genotyping. Investigations included slit lamp and fundus examination, Goldmann perimetry, full-field and multifocal electroretinography (ERG), and optical coherence tomography (OCT). Cyclic GMP was measured with an immunoassay kit. All siblings and their father were homozygous, and the mother heterozygous, for IVS6+1G>A in PDE6A. Seven family members also carried c1532G>A in ABCA4. Visual fields were constricted with mere central remnants in older subjects and additional temporal crescents in younger subjects. Visual acuity ranged from 0.8 to amaurosis. Full-field ERGs showed extinguished rod responses and minimal cone responses. Multifocal ERGs were severely reduced. Optical coherence tomography revealed either general attenuation or central macular edema. Mean plasma cGMP in patients was approximately twice that in controls. To our knowledge, this is the first phenotypic description of arRP due to homozygous IVS6+1G>A mutations in PDE6A and these seem here to be associated with severe RP leading to early extinction of rod responses as well as reduced macular function. Additionally, patients showed increased plasma levels of cGMP, indicating a possible role for cGMP measurements as part of the clinical tests for this and, after further investigations, maybe other forms of RP.

The temporal crescent syndrome

Retro-chiasmal lesions almost always give rise to homonymous field defects with only one exception. The nasal visual field extends to 60% of the horizon, whereas the temporal field extends to...

Localization of protein kinase C isoforms in the optic pathway of mouse embryos and their role in axon routing at the optic chiasm

Protein kinase C (PKC) plays a key role in many receptor-mediated signaling pathways that regulate cell growth and development. However, its roles in guiding axon growth and guidance in developing neural pathways are largely unknown. To investigate possible functions of PKC in the growth and guidance of axons in the optic chiasm, we first determined the localization of major PKC isoforms in the retinofugal pathway of mouse embryos, at the stage when axons navigate through the midline. Results showed that PKC was expressed in isoform specific patterns in the pathway. PKC-α immunoreactivity was detected in the chiasm and the optic tract. PKC-βΙΙ was strong in the optic stalk but was attenuated on axons in the diencephalon. Immunostaining for PKC-ε showed a colocalization in the chiasmatic neurons that express a surface antigen stage specific embryonic antigen-1 (SSEA-1). These chiasmatic neurons straddled the midline of the optic chiasm, and have been shown in earlier studies a role in regulation of axon growth and guidance. Expression levels of PKC-βΙ, -δ and -γ were barely detectable in the pathway. Blocking of PKC signaling with Ro-32-0432, an inhibitor specific for PKC-α and -β at nanomolar concentration, produced a dramatic reduction of ipsilateral axons from both nasal retina and temporal crescent. We conclude from these studies that PKC-α and -βΙΙ are the predominant forms in the developing optic pathway, whereas PKC-ε is the major form in the chiasmatic neurons. Furthermore, PKC-α and -βΙΙ are likely involved in signaling pathways triggered by inhibitory molecules at the midline that guide optic axons to the uncrossed pathway.

See-Saw Nystagmus in a Patient with Septo-Optic Dysplasia

Septo-optic dysplasia, also called de Morsier syndrome, is characterized by optic nerve hypoplasia, absence of the septum pellucidum, and thinning of the corpus callosum. Only once before has this rare form of nystagmus been reported in a patient with septo-optic dysplasia (1). We present such a case and document the findings with videography. A 37-year-old woman was referred because of bitemporal visual field defects detected on a routine examination. The patient had no pertinent past medical history. Physical examination revealed a woman of normal stature and weight. Best-corrected visual acuity was 20/20 in the right eye and 20/40 in the left eye. The anterior ocular segment was unremarkable. Pupils constricted normally to direct light without an afferent pupillary defect. See-saw nystagmus was present, manifesting intorsion of the elevating eye and extorsion of the depressing eye. (Video, Supplemental Digital Content 1, https://links.lww.com/WNO/A2). Ophthalmoscopy showed bilateral small tilted hypoplastic optic discs with a temporal crescent in the right eye. There was no double-ring sign (Fig. 1).FIG. 1: Fundus photography shows bilateral hypoplastic optic discs.Humphrey visual fields (30-2 protocol) showed bitemporal defects that had partial respect for the vertical meridian in both eyes with a central island of retained field in the right eye temporally (Fig. 2). Stratus III optical coherence tomography (OCT) showed decreased thickness of the retinal nerve fiber layer superiorly and inferiorly (Fig. 3).FIG. 2: Humphrey visual fields (protocol 30-2, gray scale) show bitemporal hemianopic defects consistent with optic chiasmal dysfunction.FIG. 3: Optical coherence tomography shows bilateral thinning of the retinal nerve fiber layer in both eyes, which is more marked nasally.Brain MRI showed absence of the septum pellucidum and reduced optic nerve and chiasmal thickness, findings consistent with de Morsier syndrome (Fig. 4).FIG. 4: Precontrast coronal brain MRI shows absence of the septum pellucidum (asterisk) and moderate thinning of the optic chiasm (arrow).Our patient with septo-optic dysplasia presented with see-saw nystagmus, which is characterized by elevation and intorsion of one eye with depression and extorsion of the other eye in one-half cycle, followed by reversal of those movements in the next half cycle. This type of nystagmus is believed to result from a defect that prevents the eyes from compensating for head rotations. Apart from this case of de Morsier syndrome, see-saw nystagmus is associated with isolated congenital absence or a decrease in the number of retinal ganglion cell axons crossing in the chiasm, parasellar masses, trauma to the optic chiasm, retinitis pigmentosa, rod cone dystrophy, midbrain lesions, and brain irradiation (3). Danielle S. Rudich, MD Mount Sinai School of Medicine Department of Ophthalmology New York, New York Robert L. Lesser, MD Departments of Ophthalmology and Visual Science and Neurology Yale University School of Medicine New Haven, Connecticut [email protected] Acknowledgment We thank Michael C. Brodsky, MD (Mayo Clinic Department of Ophthalmology, Rochester, MN) for his comments.

Structural Sequelae and Refractive Outcome After Successful Laser Treatment for Threshold Retinopathy of Prematurity

To study the structural sequelae and refractive outcome in eyes with a favorable structural outcome following laser treatment for threshold retinopathy of prematurity (ROP). Premature infants with threshold ROP had laser treatment with a minimum follow-up of 1 year. Complete ocular examination and refraction was done. Analysis and correlation of structural sequelae and refractive outcome was done. One hundred eighty-four eyes of 93 preterm infants were followed up. Structural changes such as vascular tortuosity, narrowing of arcades, temporal crescent, disc drag, and macular heterotopia were seen. Mean refractive error observed was -4.71 D spherical equivalent. Myopia was seen in 80.43% of eyes. The study revealed various structural sequelae and their correlation with refractive outcome.

A distinct anatomical network of cortical areas for analysis of motion in far peripheral vision

We defined cortical areas involved in the analysis of motion in the far peripheral visual field, a poorly understood aspect of visual processing in primates. This was accomplished by small tracer injections within and around the representations of the monocular field of vision ('temporal crescents') in the middle temporal area (MT) of marmoset monkeys. Quantitative analyses demonstrate that the representation of the far periphery receives specific connections from the retrosplenial cortex (areas 23v and prostriata), as well as comparatively stronger inputs from the primary visual area (V1) and from areas surrounding MT (in particular, the medial superior temporal area, MST). In contrast, the far peripheral representation receives little or no input from most other extrastriate areas, including the second visual area (V2), the densely myelinated areas of the dorsomedial cortex, and ventral stream areas; these areas are shown to have robust projections to other parts of MT. Our results demonstrate that the responses of cells in different parts of a same visual area can be determined by different combinations of synaptic inputs, in terms of areas of origin. They also suggest that the interconnections responsible for motion processing in the far periphery of the visual field convey information that is crucial for rapid-response aspects of visual function such as orienting, postural and defensive reactions.

Homonymous hemianopias: clinical-anatomic correlations in 904 cases

Homonymous hemianopia (HH) impairs visual function and frequently precludes driving. Most knowledge of HH is based on relatively few cases with clinical-anatomic correlations. The objective of this study was to describe the clinical characteristics and clinical-anatomic correlations of HH. The authors reviewed medical records of all patients with HH seen in their service between 1989 and 2004. Demographic characteristics, characteristics of visual field defects, causes of visual field defects, neuroradiologic definition of lesion location, and associated neurologic deficits were recorded. A total of 904 HH were found in 852 patients. A total of 340 HH (37.6%) were complete and 564 HH (62.4%) were incomplete. Homonymous quadrantanopia (264 HH, 29%) was the most common type of incomplete HH, followed by homonymous scotomatous defects (116 HH, 13.5%), partial HH (114 HH, 13%), and HH with macular sparing (66 HH, 7%). A total of 407 HH (45.0%) were isolated. Causes of HH included stroke (629 HH, 69.6%), trauma (123, 13.6%), tumor (102, 11.3%), brain surgery (22, 2.4%), demyelination (13, 1.4%), other rare causes (13, 1.4%), and unknown etiology (2, 0.2%). The lesions were most commonly located in the occipital lobes (45%) and the optic radiations (32.2%). Every type of HH, except for unilateral loss of temporal crescent and homonymous sectoranopia, was found in all lesion locations along the retrochiasmal visual pathways. This study shows that HH is usually secondary to stroke, head trauma, and tumors. The authors conclude that although the characteristics of visual field defects can be helpful in lesion location, specific visual field defects do not always indicate specific brain locations.—Author’s abstract

Avaliação das alterações fundoscópicas na miopia degenerativa

To evaluate the presence of fundus changes in degenerative myopia. Forty patients with refractive error of at least -6.00 diopters were selected for ophthalmologic examination followed by posterior pole photograph and echobiometry. We studied 57 eyes of 37 patients with refractive error ranging from -6.25 to -28.50 diopters, with mean -14.05, and axial length ranging from 26.06 to 32.86 mm, with mean 28.01. We found a temporal crescent in 36.5% and a peripapillary one in 20% of the eyes. Choroidal vessels were seen in 35% of the eyes. Posterior pole changes were as follow: posterior staphyloma in 10.5%, Fuchs' spots in 3.5% and lacquer cracks in 1.5%. Peripheral retinal examination revealed paving stone chorioretinal atrophy in 17.5%, white without pressure in 10.5%, lattice degeneration in 5%, retinal tears in 3.5% and retinoschisis in 1.5% of the examined eyes. Fundus changes that lead to decreased vision are common in patients with degenerative myopia. Peripheral retinal examination is very important in these patients due to the increased risk of retinal detachment.

Homonymous hemianopias

To describe the clinical characteristics and clinical-anatomic correlations of homonymous hemianopia (HH). Homonymous hemianopia impairs visual function and frequently precludes driving. Most knowledge of HH is based on relatively few cases with clinical-anatomic correlations. The authors reviewed medical records of all patients with HH seen in their service between 1989 and 2004. Demographic characteristics, characteristics of visual field defects, causes of visual field defects, neuroradiologic definition of lesion location, and associated neurologic deficits were recorded. A total of 904 HH were found in 852 patients. A total of 340 HH (37.6%) were complete and 564 HH (62.4%) were incomplete. Homonymous quadrantanopia (264 HH, 29%) was the most common type of incomplete HH, followed by homonymous scotomatous defects (116 HH, 13.5%), partial HH (114 HH, 13%), and HH with macular sparing (66 HH, 7%). A total of 407 HH (45.0%) were isolated. Causes of HH included stroke (629 HH, 69.6%), trauma (123, 13.6%), tumor (102, 11.3%), brain surgery (22, 2.4%), demyelination (13, 1.4%), other rare causes (13, 1.4%), and unknown etiology (2, 0.2%). The lesions were most commonly located in the occipital lobes (45%) and the optic radiations (32.2%). Every type of HH, except for unilateral loss of temporal crescent and homonymous sectoranopia, was found in all lesion locations along the retrochiasmal visual pathways. Homonymous hemianopia is usually secondary to stroke, head trauma, and tumors. Although the characteristics of visual field defects can be helpful in lesion location, specific visual field defects do not always indicate specific brain locations.

Heteromodal connections supporting multisensory integration at low levels of cortical processing in the monkey

While multisensory integration is thought to occur in higher hierarchical cortical areas, recent studies in man and monkey have revealed plurisensory modulations of activity in areas previously thought to be unimodal. To determine the cortical network involved in multisensory interactions, we performed multiple injections of different retrograde tracers in unimodal auditory (core), somatosensory (1/3b) and visual (V2 and MT) cortical areas of the marmoset. We found three types of heteromodal connections linking unimodal sensory areas. Visuo-somatosensory projections were observed originating from visual areas [probably the ventral and dorsal fundus of the superior temporal area (FSTv and FSTd), and middle temporal crescent (MTc)] toward areas 1/3b. Somatosensory projections to the auditory cortex were present from S2 and the anterior bank of the lateral sulcus. Finally, a visuo-auditory projection arises from an area anterior to the superior temporal sulcus (STS) toward the auditory core. Injections in different sensory regions allow us to define the frontal convexity and the temporal opercular caudal cortex as putative polysensory areas. A quantitative analysis of the laminar distribution of projecting neurons showed that heteromodal connections could be either feedback or feedforward. Taken together, our results provide the anatomical pathway for multisensory integration at low levels of information processing in the primate and argue against a strict hierarchical model.

Recurrent Migraine Aura Triggered by Coronary Angiography

Fifteen minutes after having a coronary angiogram, as a preoperative test before replacement of my ascending aorta in 1998, at 41 years of age (Hankey 1999), I was lying on...