The management of seizures during pregnancy requires a multidisciplinary approach. Antiepileptic drugs have been associated with neural tube defects, fetal facial dysmorphism, cleft lip and palate, heart defects, and digital defects. Despite the potentially teratogenic effects of anticonvulsants, the risks of uncontrolled seizures to the mother and fetus warrant continuation of seizure medications in the known epileptic during pregnancy. Ideally, counseling of the mother regarding risks and benefits should begin prior to conception.
Efforts can be made to reduce the risk to the fetus. For example, single-drug regimens are preferred to multidrug regimens, dosing can be split to avoid high peak levels of drugs, and supplementation of folic acid and vitamin K may be given to reduce the risk of neural tube defects and neonatal hemorrhage. Compliance can be a problem during pregnancy, often due to the mother's concern for drug toxicity.
Initial evaluation of a pregnant woman with a seizure is generally as discussed above, with some important distinctions. An obstetrical evaluation is needed to determine gestational age and fetal well-being. Since pregnancy is a hypercoagulable state, stroke as an etiology for the seizure should be considered. Head CT scan may be performed with lead shielding of the abdomen. MRI is also considered safe in pregnancy, although this has not been well studied.
When a woman beyond 20 weeks of gestation develops seizures in the setting of hypertension, edema, and proteinuria, her condition is referred to as eclampsia. Attention should be paid to signs and symptoms associated with eclampsia such as headache, blurry vision, confusion, hyperreflexia, and epigastric pain. Rarely, eclampsia may occur up to eight weeks postpartum.
The decision to initiate treatment for a first-time seizure in a pregnant female is complex and should involve the obstetrician and neurologist. The emergency physician should not make definitive treatment decisions alone. There are many factors involved, including cause and type of seizure, risk of recurrence, and gestational age of the fetus.
Although a healthy fetus should tolerate a single generalized seizure, there are two situations, eclampsia and status epilepticus, which can be life-threatening to both the mother and the fetus. Although not an anticonvulsant per se, magnesium sulfate (4 to 6 g IV followed by 1 to 2 g/h IV drip) has been used to treat eclampsia with good results since 1925. An international multicenter, randomized, clinical trial involving 1687 eclamptic women compared magnesium sulfate to diazepam and phenytoin. The study demonstrated a 52 percent lower risk of recurrence of seizures in women allocated magnesium sulfate rather than diazepam. Furthermore, the women allocated magnesium sulfate had a 67 percent lower risk of recurrence than those given phenytoin. The women administered magnesium sulfate also had a lower incidence of pneumonia, ICU admission, and assisted ventilation than those administered phenytoin. 12 A review of randomized, controlled trials of eclamptic women derived a seizure recurrence rate following phenytoin of 23.1 percent, whereas the recurrence rate following magnesium sulfate was 9.4 percent. 13 The definitive treatment of eclampsia is delivery of the fetus. This topic is discussed in greater detail in Chap 101.
Status epilepticus may occur in both epileptics and nonepileptics. Treatment should proceed as for any nonpregnant patient, but should include fetal monitoring as well as assistance from an obstetrician and neonatologist if delivery is a possibility. Lorazepam and diazepam are the two benzodiazepines of choice; phenytoin or phenobarbital may be used as second-line choices (see Fig.; 224-1 for doses). EEG should be used to confirm seizure cessation. Because both the seizure and the treatments can cause respiratory depression or hypotension, close monitoring is necessary.
FIG. 224-1. Guidelines for management of status epilepticus. (Adapted from Lowenstein and Alldredge.14)
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