| OOA | outer optic anlage |
|---|---|
| OR | a logical binary relation that is true if any argument is true, and false otherwise; [o]estrogen rec... |
| OT | objective test; oblique talus; occlusion time; occupational therapist, occupational therapy; ocular ... |
| OX | optic chiasma; oxacillin; oxalate; oxide; orthopedic examination; oxytocin |
| PION | posterior ischemic optic neuropathy |
| central areolar choroidal atrophy | A slowly progressive pigmentary degeneration in young persons; characterised by black foci closely set together and coalescent at the posterior pole and macular region. Synonym: central areolar choroidal atrophy, central areolar choroidal sclerosis. (05 Mar 2000) |
|---|---|
| Vulpian's atrophy | Progressive spinal muscular atrophy beginning in the shoulder. Synonym: scapulohumeral atrophy. (05 Mar 2000) |
| cerebellar atrophy | A degeneration of the cerebellum, particularly the Purkinje cells, as the result of abiotrophy or of toxic agents, as in alcoholism. (05 Mar 2000) |
| periodontal atrophy | Decrease in size and/or cellular elements of the periodontium after it has reached normal maturity. (05 Mar 2000) |
| peroneal muscular atrophy | A group of three familial peripheral neuromuscular disorders, sharing the common feature of marked wasting of the more distal extremities, particularly the peroneal muscle groups, resulting in "stork legs." Two of the three subtypes are hereditary sensorimotor polyneuropathies, one demyelinating in type and the other axon loss in type, while the third subgroup is an anterior horn cell disorder. It usually involves the legs before the arms; pes cavus is often the first sign; autosomal dominant, autosomal recessive, and X-linked recessive types, with severity related to genetic type. Synonym: Charcot-Marie-Tooth disease. (05 Mar 2000) |
| choroidal vascular atrophy | Atrophy affecting either all choroidal vessels or only the choriocapillaris, occurring either diffusely or confined to the posterior pole of the eye. (05 Mar 2000) |
| gyrate atrophy | Progressive, autosomal recessive, diffuse atrophy of the choroid, pigment epithelium, and sensory retina that begins in childhood. (12 Dec 1998) |
| gyrate atrophy of choroid and retina | A slowly progressive atrophy of the choriocapillaris, pigmentary epithelium, and sensory retina, with irregular confluent atrophic areas and an associated ornithinuria; autosomal recessive inheritance; due to a deficiency of ornithine d-aminotransferase. (05 Mar 2000) |
| Pick's atrophy | Circumscribed atrophy of the cerebral cortex. Synonym: lobar sclerosis, progressive circumscribed cerebral atrophy. (05 Mar 2000) |
| Werdnig-Hoffmann muscular atrophy | Transmitted as autosomal recessive on chromosome 5q. Progressive dysfunction of the anterior horn cells in the spinal cord and brainstem cranial nerves with profound weakness and bulbar dysfunction occurring in the first two years of life. Three groups, based on age of clinical onset, are recognised. Synonym: familial spinal muscular atrophy, Hoffmann's muscular atrophy, infantile muscular atrophy, infantile progressive spinal muscular atrophy, progressive infantile spinal muscular atrophy, Werdnig-Hoffmann disease, Werdnig-Hoffmann muscular atrophy. (05 Mar 2000) |
| compensatory atrophy | Atrophy especially of an endocrine organ as a result of its function being assumed by a new source of hormone. (05 Mar 2000) |
| congenital cerebellar atrophy | Familial disorder that causes degeneration of various cells in the cerebellum. Two types are recognised, one in which the granular layer cells degenerate, the other in which the Purkinje cells degenerate. (05 Mar 2000) |
| multiple system atrophy | A name grouping together the four cerebral degenerative diseases of olivopontocerebellar atrophy, shy-drager syndrome, striatonigral degeneration, and one form of parkinson disease, considering them different forms of the same disease process. (12 Dec 1998) |
| muscular atrophy | Derangement in size and number of muscle fibres occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation. (12 Dec 1998) |
| muscular atrophy, spinal | Progressive degenerative disorder of motor neurons in the spinal cord, brainstem, and motor cortex, manifested clinically by muscular weakness, atrophy, and corticospinal tract signs in varying combinations. (12 Dec 1998) |