| melanotic neuroectodermal tumour of infancy | A benign neoplasm of neuroectodermal origin that most often involves the anterior maxilla of infants in the first year of life. It presents clinically as a rapidly growing blue-black lesion producing a destructive radiolucency; histologically, it is characterised by small round undifferentiated tumour cells interspersed with larger polyhedral melanin-producing cells arranged in an alveolar configuration. Synonym: melanoameloblastoma, pigmented ameloblastoma, pigmented epulis, progonoma of jaw, retinal anlage tumour. (05 Mar 2000) |
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| spongy degeneration of infancy | Autosomal recessive degenerative disease of infancy; mostly in Jewish infants; onset typically within first 3-4 months of birth, consisting of blindness, psychomotor regression, enlarged head, optic atrophy, hypotonia, spasticity, increased N-acetylaspartic acid urinary excretion. MRI shows enlarged brain, decreased attenuation of cerebral and cerebellar white matter, and normal ventricles. Pathologically, there is increased brain volume and weight, and spongy degeneration in the subcortical white matter. See: leukodystrophy. Synonym: Canavan's sclerosis, Canavan-van Bogaert-Bertrand disease, spongy degeneration of infancy. (05 Mar 2000) |
| diencephalic syndrome of infancy | <paediatrics> Profound emaciation after initial normal growth, locomotor hyperactivity and euphoria, usually with skin pallor, hypotension and hypoglycaemia. It is usually due to neoplasm involving the anterior hypothalamus. (05 Mar 2000) |
| infancy | Babyhood; the earliest period of extrauterine life; roughly, the first year of life. (05 Mar 2000) |
| transient hypogammaglobulinaemia of infancy | A type of primary immunodeficiency that occurs in infants of both sexes, usually before the sixth month of life, probably resulting from immaturity of lymphoid tissue. Synonym: transient agammaglobulinaemia. (05 Mar 2000) |
| fibrous hamartoma of infancy | A tumour appearing usually in the upper arm or shoulder in the first two years of life and consisting of cellular fibrous tissue infiltrating the subcutis. (05 Mar 2000) |
| accessory visual apparatus | The eyelids, with lashes and eyebrows, lacrimal apparatus, conjunctival sac, and extrinsic muscles of the eyeball. Synonym: organa oculi accessoria, accessory organs, accessory visual apparatus, adnexa oculi, appendages of eye. (05 Mar 2000) |
| Bender Visual Motor Gestalt test | <psychology> A psychological test used by neurologists and clinical psychologists to measure a person's ability to visually copy a set of geometric designs. It consists of nine geometric designs on cards. The subject is asked to redraw them from memory after each one is presented individually. It is useful for measuring visuospatial and visuomotor coordination to detect brain damage. Synonym: Bender Visual Motor Gestalt test. (14 Aug 2000) |
| Broca's visual plane | A plane drawn through the visual axes of each eye. (05 Mar 2000) |
| receptor, visual | The layer of rods and cones, the visual cells, of the retina. (12 Dec 1998) |
| pattern recognition, visual | Visually perceived characters, shapes, displays, or designs. (12 Dec 1998) |
| visual | Pertaining to vision or sight. Origin: L. Visualis, from videre = to see (18 Nov 1997) |
| visual acuity | <microscopy> The ability to detect fine details or small distances with the eye. Visual acuity can vary substantially depending on the definition used and method of measurement chosen. Under favourable conditions, the resolution of the human eye or ability to distinguish the twoness of adjoining lines, is about I minute of arc while the threshold delectability, or the detection of misaligned steps in a line (which is also a form of visual acuity), can be as low as a fraction of a second of arc. (05 Aug 1998) |
| visual agnosia | The inability to recognise objects by sight; usually caused by bilateral parieto-occipital lesions. Synonym: optic agnosia. (05 Mar 2000) |
| visual angle | The angle formed at the retina by the meeting of lines drawn from the periphery of the object seen. (05 Mar 2000) |