- 1. SYN: induration (2). 2. In neuropathy, induration of nervous and other structures by a hyperplasia of the interstitial fibrous or glial connective tissue. [G. sklerosis, hardness]- amyotrophic lateral s. (ALS) a fatal degenerative disease involving the corticobulbar, corticospinal, and spinal motor neurons, manifested by progressive weakness and wasting of muscles innervated by the affected neurons; fasciculations and cramps commonly occur. The disorder is 90–95% sporadic in nature (although a number of cases are inherited as an autosomal dominant trait [MIM*105400]), affects adults (typically, older adults), and usually is fatal within 2–5 years of onset. It is the most common subgroup of motor neuron disease, and the only one manifested by a combination of upper and lower abnormalities. Variants include: 1) progressive bulbar palsy, in which isolated or predominant lower brainstem motor involvement occurs; 2) primary lateral s., in which only upper motor neuron abnormalities are seen; and 3) progressive spinal muscle atrophy, in which only lower motor neuron dysfunction is noted. SYN: Aran-Duchenne disease, Charcot disease, Duchenne-Aran disease, Lou Gehrig disease, progressive muscular atrophy, progressive spinal amyotrophy.- endocardial s. SYN: endocardial fibrosis.- hippocampal s. a loss of cortical neurons and a reactive astrocytosis in the hippocampal regions of some persons with epilepsy.- mantle s. a common cerebral lesion in the palsied states of early life characterized by nodular cortical atrophy.- Mönckeberg s. SYN: Mönckeberg arteriosclerosis.- multiple s. (MS) common demyelinating disorder of the central nervous system, causing patches of s. (plaques) in the brain and spinal cord; occurs primarily in young adults, and has protean clinical manifestations, depending upon the location and size of the plaque; typical symptoms include visual loss, diplopia, nystagmus, dysarthria, weakness, paresthesias, bladder abnormalities, and mood alterations; characteristically, the plaques are “separated in time and space” and clinically the symptoms show exacerbations and remissions. SYN: disseminated s., insular s..- nodular s. SYN: atherosclerosis.- nuclear s. increased refractivity of the central portion of the lens of the eye. See nuclear cataract.- ovulational s. SYN: physiologic s..- physiologic s. a slowly progressive s. in the walls of the ovarian arteries that commences after puberty. SYN: menstrual s., ovulational s..- primary lateral s. considered by many to be a subgroup of motor neuron disease; a slowly progressive degenerative disorder of the motor neurons of the cerebral cortex, resulting in widespread weakness on an upper motor neuron basis; spasticity, hyperreflexia, and Babinski signs are present, but not fasciculation potentials, nor any electrodiagnostic evidence of a lower motor neuron lesion. SYN: lateral spinal s..- systemic s. 1. a systemic disease characterized by formation of hyalinized and thickened collagenous fibrous tissue, with thickening of the skin and adhesion to underlying tissues (especially of the hands and face), dysphagia due to loss of peristalsis and submucosal fibrosis of the esophagus, dyspnea due to pulmonary fibrosis, myocardial fibrosis, and renal vascular changes resembling those of malignant hypertension; Raynaud phenomenon, atrophy of the soft tissues, and osteoporosis of the distal phalanges (acrosclerosis), sometimes with gangrene at the ends of the digits, are common findings. The term progressive systemic s. is commonly used and is appropriate for cases with initially widespread skin involvement including the trunk. However, when skin involvement is limited to the distal extremities and face, there is often prolonged delay in appearance of visceral manifestations. SEE ALSO: CREST syndrome. 2. SYN: scleroderma.- tuberous s. [MIM*191100] phacomatosis characterized by the formation of multisystem hamartomas producing seizures, mental retardation, and angiofibromas of the face; the cerebral and retinal lesions are glial nodules; other skin lesions are hypopigmented macules, shagreen patches, and periungual fibromas; autosomal dominant inheritance with variable expression, caused by mutation in either the tuberous s. gene (TSC1) on chromosome 9q or TSC2 on 16p. SYN: Bourneville disease, epiloia.- valvular s. fibrosis, often with calcification of valves, considered to be an aging change and not due to primary valvular disease.
* * *1) a pathological condition in which a tissue has become hard and which is produced by overgrowth of fibrous tissue and other changes (as in arteriosclerosis) or by increase in interstitial tissue and other changes (as in multiple sclerosis) called also hardening2) any of various diseases characterized by sclerosis usu. used in combination see ARTERIOSCLEROSIS, MULTIPLE SCLEROSIS, MYELOSCLEROSIS
* * *n.hardening of tissue, usually due to scarring (fibrosis) after inflammation or to ageing. It can affect the lateral columns of the spinal cord and the medulla of the brain (amyotrophic lateral sclerosis or Lou Gehrig's disease), causing progressive muscular paralysis (see motor neurone disease). It can also occur in scattered patches throughout the brain and spinal cord (see multiple sclerosis) or in the walls of the arteries (see arteriosclerosis, atherosclerosis). See also tuberous sclerosis.
* * *scle·ro·sis (sklə-roґsis) [Gr. sklērōsis hardness] an induration or hardening, such as hardening of a part from inflammation, increased formation of connective tissue, or disease of the interstitial substance.
Medical dictionary. 2011.