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(kăn″ă-lĭk″ū-lī′tĭs) A relatively rare infection of the tear duct of the eye. It is usually found in one eye rather than both, and in people over age 50. It may be caused by chronic infection with Actinomyces, Aspergillus, Candida, or Nocardia species.


(kăn″ă-lĭk′ū-lŭs) pl. canaliculi [L. canalicularis] A small channel or canal. In bone or cementum, such channels radiate out from lacunae and anastomose with canaliculi of neighboring lacunae.

lacrimal canaliculus In the eye, one of two short curved ducts, inferior and superior, beginning at the lacrimal punctum along the edge of each eyelid and carrying tears from the lacrimal lake into the lacrimal sac. canalicular (-lĭk′ū -lăr), adj.


(kă-nā′lĭs) pl. canales [L., channel] Canal.


Benign paroxysmal positional vertigo.

canalith repositioning maneuver

Use of the Hallpike maneuver to reposition a canalith in the semicircular canal(s) to relieve benign positional vertigo. SYN: Epley maneuver. SEE: Hallpike maneuver.


(kăn″ăl-ī-zā′shŭn) Formation of channels in tissue.


(kă-nal′ŏ-plas″tē) [canal + -plasty] 1. Surgery for glaucoma in which the drainage through the canal of Schlemm is improved by opening the ostia and stretching the trabecular meshwork. 2. Spinal surgery to alleviate lumbar spinal stenosis. 3. Canalplasty.


(kan′ăl-plas″tē) [canal + -plasty] Surgery to reopen a narrow, closed, or clogged external auditory canal, used to treat external otitis that has not responded to medical therapy. SYN: atresiaplasty; canaloplasty (3).

Canavan disease

(kan′ă-van″) [Myrtle May Moore Canavan, U.S. pathologist, 1879–1953] A rare inherited neurodegenerative disorder, one of the lysosomal storage diseases.

INCIDENCE: The disease most commonly occurs in Jewish families of Ashkenazi descent.

CAUSES: The disease is caused by a lack of an enzyme (aspartoacylase) needed to metabolize N-acetyl-aspartate (NAA). Excessive buildup of NAA in the white matter of the brain causes the symptoms of the disease.

SYMPTOMS AND SIGNS: Affected children have difficulties with posture, feeding, muscle tone, seizures, and mental retardation. Symptoms usually become apparent in the first year of life. Developmental delays and failure to meet psychomotor milestones in childhood are rapidly followed by brain atrophy and early mortality.

TREATMENT: Gene therapy holds promise for enhancing the activity of aspartoacylase and reducing the accumulation of NAA in the brain.

IMPACT ON HEALTH: The prognosis is poor: patients usually die before 4 years of age, but may survive into their 20s.


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