| juvenile spinal muscular atrophy | Slowly progressive proximal muscular weakness and wasting, beginning in childhood, caused by degeneration of motor neurons in the anterior horns of the spinal cord; onset usually between 2 and 17 years of age; usually autosomal recessive inheritance. Synonym: juvenile muscular atrophy, Kugelberg-Welander disease, Wohlfart-Kugelberg-Welander disease. (05 Mar 2000) |
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| familial spinal 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) |
| filum of spinal dura mater | The thread-like termination of the spinal dura mater, surrounding and fused to the filum terminale of the cord, and attached to the deep dorsal sacrococcygeal ligament; extends from S2-3 to Co2 vertebral levels. Synonym: filum durae matris spinalis. (05 Mar 2000) |
| lateral column of spinal cord | A slight protrusion of the gray matter of the spinal cord into the lateral funiculus of either side, especially marked in the thoracic region where it encloses preganglionic motor neurons of the sympathetic division of the autonomic nervous system; it corresponds to the lateral horn appearing in transverse sections of the spinal cord. See: gray columns. Synonym: columna lateralis, lateral column of spinal cord. (05 Mar 2000) |
| lateral cutaneous branches of ventral primary ramus of thoracic spinal nerves | Branches arising in approximately the anterior axillary line at the level of the second through sixth intercostal spaces. Synonym: rami mammarii laterales nervorum intercostalium, lateral cutaneous branches of intercostal nerves. (05 Mar 2000) |
| lateral funiculus of spinal cord | The lateral white column of the spinal cord between the lines of exit and entrance of the anterior and posterior nerve roots. Synonym: funiculus lateralis, anterolateral column of spinal cord, lateral funiculus of spinal cord. (05 Mar 2000) |
| lateral mammary branches of lateral cutaneous branches of thoracic spinal nerves | Branches arising from the lateral cutaneous branches of the ventral primary rami of spinal nerves (intercostal nerves) T-3 to T-6 which run anteriorly to supply the lateral aspect of the breast. Synonym: rami mammarii laterales rami cutanei lateralis nervorum thoracicorum, rami mammarii laterales rami cutanei lateralis nervorum intercostalium, lateral mammary branches of lateral cutaneous branches of intercostal nerves. (05 Mar 2000) |
| lateral spinal sclerosis | 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. Synonym: lateral spinal sclerosis. (05 Mar 2000) |
| fractional spinal anaesthesia | Insertion of a catheter into the spinal subarachnoid space and leaving it in situ to permit serial intermittent injection of local anaesthetic solution for prolonged spinal anaesthesia. Synonym: fractional spinal anaesthesia. (05 Mar 2000) |
| loops of spinal nerves | Loops of the spinal nerves, connecting ventral primary rami of the spinal nerves. Synonym: ansae nervorum spinalium. (05 Mar 2000) |
| low spinal anaesthesia | Spinal anaesthesia in which the level of sensory denervation extends to the tenth or eleventh thoracic dermatome. (05 Mar 2000) |
| lumbar enlargement of spinal cord | A spindle-shaped swelling of the spinal cord beginning at the level of the tenth thoracic vertebra and tapering into the medullary cone, with maximum thickness opposite the last thoracic vertebra, consequential to the innervation of the lower limb. Synonym: intumescentia lumbalis, lumbar enlargement of spinal cord. (05 Mar 2000) |
| lumbar part of spinal cord | Portion of spinal cord which consists of the five lumbar segments (L1-L5) and from which five pairs of lumbar spinal nerves originate; in the adult it is located in the T10-L1 portion of the vertebral canal, and is enlarged relative to other parts of the cord due to its involvement in innervation of the lower limb. (05 Mar 2000) |
| lumbar segments of spinal cord | The five lumbar segments of the spinal cord which give rise to the five pairs of lumbar spinal nerves and constitute the lumbar part of the spinal cord. Synonym: segmenta medullae spinalis lumbaria. (05 Mar 2000) |
| abducens nerve | <anatomy, nerve> The 6th cranial nerve. The abducens nerve originates in the abducens nucleus of the pons and sends motor fibres to the lateral rectus muscles of the eye. Damage to the nerve or its nucleus disrupts horizontal eye movement control. (12 Dec 1998) |