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(dis-tō′sh(ē-)ă) [dys- + toco- + -ia] Difficult labor. It may be produced by either the size of the fetus or the small size of the pelvic outlet.

FETAL CAUSES: Large fetal size (macrosomia) usually causes this condition. Other factors are malpositions of the fetus (transverse, face, brow, breech, or compound presentation), abnormalities of the fetus (hydrocephalus, tumors of the neck or abdomen, hydrops), and multiple pregnancy (interlocked twins).

MATERNAL CAUSES: Uterus: Causes include uterine inertia, congenital anomalies (bicornuate uterus), tumors (fibroids, carcinoma of the cervix), and abnormal fixation of the uterus by previous operation. Bony pelvis: Causes include flat or generally contracted pelvis, funnel pelvis, exostoses of the pelvic bones, and tumors of the pelvic bones. Cervix uteri: Causes include Bandl ring, a rigid cervix that will not dilate, and stenosis and stricture preventing dilatation. Ovary: Ovarian cysts may block the pelvis. Vagina and vulva: Causes include cysts, tumors, atresias, and stenoses. Pelvic soft tissues: A distended bladder or colon may interfere.

DIAGNOSIS: Dystocia generally can be detected by vaginal examination, ultrasound, and external pelvimetry before the patient goes into labor.

TREATMENT: Treatment varies according to the condition that causes the dystocia. The goal is correction of the abnormality in order to allow the fetus to pass. If this is not possible, operative delivery is necessary. SEE: cesarean section.


(dĭs-tō′nē-ă) [dys- + tono- + -ia] Prolonged involuntary muscular contractions that may cause twisting (torsion) of body parts, repetitive movements, and increased muscular tone. These movements may be in the form of rhythmic jerks. The condition may progress in childhood, but progression is rare in adults. In children the legs are usually affected first. dystonic (dĭs-ton′ik), adj.

ETIOLOGY: Many childhood dystonias are genetically inherited. Drugs used to treat psychosis, Parkinson disease, strokes, brain tumors, toxic levels of manganese or carbon dioxide, and viral encephalitis may produce dystonia.

TREATMENT: Offending drugs are withdrawn, and the patient may be treated with diphenhydramine, or, in the case of dystonias caused by neuroleptic drugs, benztropine. Focal dystonias, such as blepharospasm or torticollis, may be treated with injected botulinum toxin, which paralyzes hypertonic muscle groups. Other treatments include physical therapy, deep brain stimulation, and pallidotomy.

cervical d. Spasmodic torticollis.

focal d. Prolonged contraction affecting a single body part or a group of muscles, e.g., in the neck or hand. The most common focal dystonias are blepharospasm, torticollis, and writer's (musician's) cramp.

idiopathic torsion d. A relatively uncommon, progressive neurological syndrome beginning in childhood and marked by twisting postures of the neck, limbs, and/or pelvis. The condition is an autosomal dominant trait. SYN: dystonia musculorum deformans.


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