2. a sudden, transitory constriction of a passage, canal, or orifice; spasms usually occur when the nerves supplying muscles are irritated, and are often accompanied by pain. A
vasospasm is a rare type that occurs in a blood vessel. Spasms vary from mild twitches to severe
convulsions and may be the symptoms of any number of disorders. Usually, they will cease when the cause is corrected, but sometimes the only treatment is to suppress the symptoms, as in
epilepsy.
Clonic Spasms. These are spasms in which contraction and relaxation of the muscle alternate; this is the most common type of spasm and usually is not severe. A typical clonic spasm is the
hiccup. Hiccups usually occur when the diaphragm is irritated, as by indigestion, although occasionally they may result from a serious condition such as a brain tumor; they generally disappear by themselves or after a drink of water.
Spasms may be repetitive twitching motions, some of which are called
tics. Tics often accompany other types of spasm, as in such diseases as
cerebral palsy and
sydenham's chorea, and may also be seen in neuralgia. In
tic douloureux the nerves of the face are involved.
Habit spasms are a type of repetitive twitching movements that seem purposeless or without a cause; they include twitching of the face, blinking of the eyes, and grimacing. The movements are rapid and always repeated in the same way, unlike the spasms associated with chorea. The motions are carried out automatically in response to a stimulus that once may have existed but no longer does.
In a
convulsive spasm the entire body is jerked by sudden violent movements that may involve almost all the muscles. These spasms may last from a fraction of a second to several seconds, or even minutes. (See also
convulsion.)
Tonic Spasms. If the contraction of a spasm is sustained or continuing, it is called a
tonic or
tetanic spasm. These are generally severe because they are caused by diseases that affect the central nervous system or brain, such as
tetanus,
rabies, and
cerebral palsy. Severe tonic spasms can be fatal if not treated promptly; continued spasms can bring on exhaustion or asphyxiation. The treatment varies with the cause; if the disease is caused by a microorganism in the system, as in tetanus, antiserum must be administered immediately. Antibiotics are also used to help curb infection. In many cases tranquilizers, sedatives, and narcotics must be administered to help ease the spasms.
infantile s's (
infantile massive s's) (
jackknife s's) a syndrome of severe
myoclonus appearing in the first 18 months of life, and associated with general cerebral deterioration; it is marked by severe flexion spasms of the head, neck, and trunk and extension of the arms and legs. Called also
jackknife seizures.