Common Complaint in Pregnancy
Headache is a common complaint in pregnancy.1 Patients who report having had the same problem for some time prior to pregnancy do not usually have a neurologic emergency. Chronic and recurrent headaches may be due to tension, migraine, sinusitis, pseudotumor cerebri, or in many cases be unexplained.
Migraine headaches are relatively common in reproductive age of women and often become less frequent and severe in pregnancy (75% of women). In a minority (5%) of migraine sufferers, however, they may present for the first time or become more severe in pregnancy and must be distinguished from other more immediately dangerous conditions. Many patients who think they have migraines do not have the classical pattern of aura, headache, and nausea. Headaches which, aside from frequency, are similar to those the patient has experienced in the past can generally be considered to not represent a neurologic emergency and can be managed symptomatically. Medications used for the treatment of migraine headache are listed in Table 16-1. If headaches appear to be becoming more frequent and severe or have accompanying neurologic manifestations, then they require further evaluation.
TABLE 16-1.Medications for Migraine ||Download (.pdf) TABLE 16-1. Medications for Migraine
|Medication ||Class ||Dosage ||Rout of administration ||Safety in pregnancy |
|Acetaminophen ||Pain reliever ||4 g/d max ||po or pr ||Yes |
|Codeine ||Narcotic ||30-90 mg q3-4h ||po ||Yes |
|Meperidine (Demerol) ||Narcotic ||25-100 mg q3-6h ||po, IM, or IV ||Yes |
|Ibuprofen ||Nonsteroidal ||3200 mg/d (divided doses) ||po ||Avoid in late pregnancy |
|Fioriceta ||Sedative, pain reliever, vasoconstrictor ||2 tabs q4h, 6/d max ||po ||Yes |
|Midrinb ||Vasoconstrictor, sedative, pain reliever ||2 caps, then 1 qh, no more than 5 in 12 h ||po ||Yes |
|Caffeine ||Vasoconstrictor ||500 mg in 50 mL IV, may repeat ||po or IV ||Yes |
|Imitrexc ||Vasoconstrictor ||po 300 mg/d SC 6 mg (max, 12 mg/d) ||po, SC, nasal spray ||Yes |
|Ergotamine and caffeine ||Vasoconstrictor ||2 mg + 200 mg, then 1 mg + 100 mg 2 caps; 30 min ||po or pr ||No |
|Nortriptyline ||TCA, (prophylaxis) ||25-100 mg qhs ||po ||Yes |
|Amitriptyline ||TCA, (prophylaxis) ||50-100 mg qhs ||po ||Yes |
|Sertraline ||SSRI, (prophylaxis) ||50-100 mg qhs ||po ||Probably |
|Fluoxetine ||SSRI (prophylaxis) ||20-40 mg qhs ||po ||Probably |
|Propranolol ||β-blocker (prophylaxis) ||80-120 mg qd ||po ||Low risk of IUGR |
|Nadolol ||β-blocker (prophylaxis) ||20-80 mg qd ||po ||Risk of IUGR |
|Atenolol ||β-blocker (prophylaxis) ||25-100 mg qd ||po ||Risk of IUGR |
|Carbamazepine ||Anticonvulsant (prophylaxis) ||Up to 1200 mg/d ||po ||Risk of malformations |
The new-onset headache (Table 16-2) or the occurrence of a headache with different location, quality, or accompanying neurologic symptoms demands further evaluation. Figure 16-1 outlines an approach to the evaluation of headache in pregnancy. The sudden onset of headache requires immediate evaluation and perhaps admission to the hospital. Headache is a common feature of preeclampsia which must be considered in any patient presenting in the second half of pregnancy. Since preeclampsia consists of a constellation of clinical and laboratory abnormalities, appropriate clinical and laboratory evaluation should be able to determine if it is a likely diagnosis in a specific patient (see Chap. 5).
TABLE 16-2.Workup for New Headaches
The differential diagnosis of sudden, severe headache in pregnancy is the same as for the nonpregnant patient with the addition of preeclampsia. It includes subarachnoid hemorrhage, intracerebral hemorrhage, cerebral venous thrombosis (CVT), meningitis, and mass lesions (tumors or abscess).
Subarachnoid hemorrhage can be due to ruptured cerebral aneurysms, arteriovenous malformations (AVM), or, rarely, preeclampsia or eclampsia.2 Cerebral aneurysms usually occur on the vessels of the circle of Willis or the proximal portions of the vessels arising from it. These saccular or berry aneurysms can be found in any patient but are more common in patients with Marfan syndrome or familial polycystic kidneys. Bleeds from aneurysms are more common in older patients (generally over age 30) and tend to occur in late pregnancy. In contrast, hemorrhage from an AVM tends to occur in younger patients (peak between 15 and 20 years) and are equally likely at all gestational ages. There is no way to clinically distinguish between bleeding from an AVM, a berry aneurysm, or preeclampsia. These patients all present with sudden onset of severe headache, nausea and vomiting, and meningeal signs. They may have focal neurologic deficits, altered state of consciousness, seizures, and hypertension. The condition of the patient at presentation is the most important prognostic feature (Table 16-3).
TABLE 16-3.CNS Hemorrhage Condition at Presentation (Hunt and Botterell Scale) ||Download (.pdf) TABLE 16-3. CNS Hemorrhage Condition at Presentation (Hunt and Botterell Scale)
|Grade I ||Alert, with/without nuchal rigidity |
|Grade II ||Drowsy/severe headache |
| ||No CNS deficit except cranial nerves |
|Grade III ||Focal CNS deficits (mild hemiparesis) |
|Grade IV ||Stupor with severe CNS deficit |
|Grade V ||Moribund |
The diagnosis of possible subarachnoid hemorrhage in pregnancy starts with a high index of suspicion raised by the presentation. Clinical and laboratory evaluation for possible preeclampsia/eclampsia must be accomplished since it is the more common diagnosis and if confirmed, requires specific therapy and possible delivery as the definitive treatment. If preeclampsia is ruled out, the cornerstone of evaluation is CNS imaging with CT, MRI, or MRA. Imaging contrast dyes may be used in pregnancy to help determine the nature of the hemorrhage and its source. Cerebral angiography may also be used to pinpoint the site of bleeding. Spinal tap will serve to confirm the presence of subarachnoid blood and rule out meningitis as the cause of the headache. Simultaneously with initiating the diagnostic workup, neurologic and neurosurgical consultation should be obtained.
Surgical management of both AVM and berry aneurysms can be accomplished in pregnancy but if the patient is near term, consideration of delivery prior to or simultaneously with the surgical repair should be considered. Surgery under hypotensive anesthesia or hypothermia can be well tolerated by the fetus. Continuous fetal heart rate monitoring is needed during and after surgery. Anesthetic medications generally suppress fetal heart rate variability and can make monitor interpretation more difficult. If fetal bradycardia occurs, it is desirable to raise the maternal blood pressure to improve utero-placental perfusion. Careful attention to maternal oxygenation will improve fetal condition. Almost all women known to have an AVM or berry aneurysm are delivered by cesarean section. If the lesion has been surgically treated by excision in the case of AVM or clipping in the case of aneurysm, then vaginal delivery can be safely conducted.
Cerebral Venous Thrombosis
Cerebral venous thrombosis (CVT) is uncommon. It is estimated to occur at a rate of 11.6/100,000 deliveries. Seventy-five percent of the cases occur in women. Pregnancy and oral contraceptives and the associated changes in the coagulation system are thought to be the explanation for this sex difference. Headache is the most frequent presenting symptom of CVT. The onset of headache may be gradual or acute and can even mimic subarachnoid hemorrhage. It can present similar to a migraine with an associated aura. It may be associated with signs of intracranial hypertension. It may be associated with focal neurologic signs, altered state of consciousness, or seizures. Sagittal sinus thrombosis often causes motor deficits, bilateral deficits, and seizures.
MRI imaging of the brain with MR venography is the most sensitive technique for demonstrating the lesion. Overall, these studies are 90% to 100% accurate. CT of the brain may be negative in up to 30% of documented cases of CVT. CT venography is a useful alternative to MR venography if MRI is not available. There is a relatively high false-positive rate with all modalities due to normal anatomic variations in the cerebral venous sinuses. Women who are diagnosed with CVT should be evaluated for acquired and inherited thrombophilias.
Meningitis commonly presents with headache plus other symptoms such as fever, malaise, meningismus, and perhaps focal neurologic signs. Whether bacterial, fungal, or viral, the diagnosis must be made by spinal tap before specific treatment can be provided. In the setting of severe, sudden onset of headache, an intracranial mass lesion must be ruled out with imaging studies before a lumbar tap is performed.
Intracranial mass lesions, tumor or abscesses, can lead to headache as well as focal neurologic signs and seizures. The cornerstone of the diagnosis of mass lesions is MRI or CT imaging of the brain. As noted above, MRI exposes the fetus to no-ionizing radiation and can be safely performed at any stage of pregnancy with no adverse fetal effects. A head or neck CT exposes the uterus to about 1 mrad of radiation. If an MRI is not readily available, a CT should be performed. Neurosurgical consultation should be obtained if a mass lesion is suspected.