PubMed Health⌕ Search

PubMed · 10874778

Clinical assessment of complex visual dysfunction.

Abstract

The study of patients with lesions of the central visual system has shown that certain complex visual disturbances are generally associated with lesions in the ventral occipital lobe and adjoining temporal lobe, while other disturbances are more commonly associated with lesions of the dorsal occipital cortices and adjoining parietal lobe. Cerebrovascular lesions in the distribution of the posterior cerebral artery, tumor, trauma, and neurodegenerative processes such as Alzheimer's disease are common etiologies of these disturbances and can be assessed using modern neuroimaging techniques. The corresponding visual function deficits can be separated out by a systematic clinical approach incorporating visual sensory and cognitive testing procedures, as outlined below.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Rizzo. 2000. Clinical assessment of complex visual dysfunction.. https://doi.org/10.1055/s-2000-6834

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Histone H3K9 methyltransferases regulate cortical growth by coordinating heterochromatin formation and neural progenitor dynamics.

DNA packaging into heterochromatin is a fundamental mechanism of transcriptional silencing, yet its role in regulating neural progenitor behavior during brain development remains poorly understood. Trimethylation of histone H3 lysine 9 (H3K9me3), catalyzed by the methyltransferases SETDB1, SUV39H1, and SUV39H2, is a defining feature of heterochromatin, but functional redundancy among these enzymes has obscured their developmental roles. Here, we generated a cortex-specific triple knockout mouse model lacking Setdb1, Suv39h1, and Suv39h2 to directly interrogate H3K9me3 function during corticogenesis. Combined loss of H3K9 methyltransferases caused genome-wide depletion of H3K9me3, disruption of neural progenitor cell-cycle progression, and impaired cortical neurogenesis, resulting in microcephaly. H3K9 methyltransferases preserve neural progenitor identity and function by silencing clustered protocadherins, meiosis-associated genes, and a cell-cycle restraint program through H3K9me3 deposition. Loss of H3K9me3 promoted local chromatin opening and increased transcription factor occupancy, enabling transposable elements to acquire cryptic enhancer activity and modulate proximal gene expression. Together, these findings establish H3K9me3 heterochromatin as an active regulator of neural progenitor dynamics and lineage fidelity, revealing a central epigenetic mechanism that restricts aberrant transcriptional programs to ensure cortical growth.

Cerebral Cortex↗

Prosopagnosia.

Explore the source record for details and available documents.

Cerebral Cortex↗

Prenatal diagnosis of malformations of cortical development by dedicated neurosonography.

OBJECTIVE: Malformations of cortical development (MCD) are rarely diagnosed in utero. We describe and compare the ultrasonographic and pathology findings in a cohort of fetuses with MCD. METHODS: Fetuses with MCD were identified among all fetuses evaluated for suspected brain anomalies at the Fetal Neurology Clinic, and the ultrasonographic findings were compared with the results of the pathology examination. RESULTS: We suspected the presence of MCD by ultrasonography in 23 fetuses. The mean gestational age at the time of ultrasound diagnosis was 26.2 (range, 18-40) weeks. The ultrasonographic findings leading to the diagnosis of MCD were abnormally overdeveloped gyri and sulci for gestational age (n = 7), delay in sulcation (n = 5), abnormally thin cortex (n = 5) abnormally wide and broad sulci (n = 3), bulging into the lateral ventricle (n = 1), cortical cleft (n = 1), and multiple intraparenchymal echogenic nodules (n = 1). All fetuses had associated central nervous system (CNS) and/or non-CNS anomalies. Pathology examination (performed in 17 fetuses) confirmed MCD in 16. CONCLUSIONS: Cortical malformations can be diagnosed in utero by ultrasonography based on the presence of specific deviations from the normal pattern of development. The identified cases may represent the more severe forms in the MCD spectrum. The pathology findings do not always conform to the current classification systems of MCD but help in differentiating between possible genetic and acquired etiologies and in some cases provide a definitive syndromic diagnosis.

Cerebral Cortex↗