A repeated, uncontrolled, purposeless contraction of a muscle or group of muscles, most commonly in the face, shoulders, or arms. Typical tics include blinking, mouth twitching, and shrugging. Tics usually develop in childhood and are often a sign of a minor psychological disturbance. They usually stop within a year of onset but in some cases persist into adult life. (See also Gilles de la Tourette’s syndrome.)
A repetitive, usually involuntary SPASM that varies from being the simple twitch of a muscle – for example, affecting an eyelid – to complex coordinated actions. About 20 per cent of children suffer from tic which normally lasts several months. Emotional stress is a common cause (see GILLES DE LA TOURETTE’S SYNDROME).
n. a repeated and largely involuntary movement (motor tic) or utterance (vocal tic) varying in complexity from a muscle twitch or a grunt to elaborate well-coordinated actions and repeated words or phrases. Simple tics occur in about a quarter of all children and usually disappear within a year. Tics most often become prominent when the individual is exposed to emotional stress. See also Tourette’s syndrome.
Ticks are blood-sucking arthropods which are responsible for transmitting a wide range of diseases to humans, including ROCKY MOUNTAIN SPOTTED FEVER, African tick typhus, LYME DISEASE and ?èvre boutonneuse (see TYPHUS FEVER). Apart from being transmitters of disease, they cause intense itching and may cause quite severe lesions of the skin. The best repellents are dimethyl phthalate and diethyltoluamide. Once bitten, relief from the itching is obtained from the application of calamine lotion. Tick-bites are an occupational hazard of shepherds and gamekeepers. (See also BITES AND STINGS.)... ticks
A recently introduced antiplatelet drug, which decreases clumping of blood PLATELETS and thus inhibits the formation of clots (see BLOOD CLOT; THROMBUS). It is used to prevent episodes in patients with a history of symptomatic ischaemic disease such as STROKE and INTERMITTENT CLAUDICATION. The drug should be started under hospital supervision.... ticlopidine
n. a bloodsucking parasite belonging to the order of arthropods (the Acarina) that also includes the *mites. Tick bites can cause serious skin lesions and occasionally paralysis (see Ixodes; Amblyomma), and certain tick species transmit *typhus, *Lyme disease, and *relapsing fever. Diethyltoluamide (DEET) is used as a tick repellent. There are two families: Argasidae (soft ticks), which includes Ornithodoros, with mouthparts invisible from above and no hard shield (scutum) on the dorsal surface; and Ixodidae (hard ticks), including Dermacentor, Haemaphysalis, and Rhipicephalus, with clearly visible mouthparts and a definite scutum.... tick
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