Many neurological disorders precede pregnancy. Most affected women will have successful perinatal outcomes, although some disorders carry specific risks. Other women will have new-onset neurological symptoms during pregnancy, and these must be distinguished from pregnancy complications. Neurovascular disorders are an important cause of maternal mortality and accounted for more than 7 percent of maternal deaths in the United States from 2007 through 2016 (Petersen, 2019). Psychiatric disorders can manifest with cognitive and neuromuscular abnormalities and should be considered in the evaluation of neurological symptoms.
CENTRAL NERVOUS SYSTEM IMAGING
Computed tomography (CT) and magnetic resonance (MR) imaging assist in the diagnosis, classification, and management of many neurological disorders. As discussed in Chapter 49, (p. 873), these can be used safely during pregnancy (Chansakul, 2017; Lum, 2020). CT scanning is often used when rapid diagnosis is necessary and is excellent for detecting recent hemorrhage. That said, MR imaging is often preferred and is particularly helpful to diagnose demyelinating diseases, arteriovenous malformations (AVMs), congenital and developmental nervous system abnormalities, posterior fossa lesions, and spinal cord diseases (Jamieson, 2020). Whenever either modality is employed, a woman with advanced pregnancy should be positioned in a lateral tilt with a wedge under one hip to prevent hypotension and to diminish aortic pulsations, which may degrade the image.
Cerebral angiography with contrast injection, usually via the femoral artery, is a valuable adjunct to the diagnosis and treatment of some cerebrovascular diseases. Fluoroscopy delivers more radiation but can be performed with abdominal shielding. Positron emission tomography (PET) and functional MR imaging (fMRI) have not been evaluated in detail for use in gravidas (van den Heuvel, 2016).
In one national survey in the United States in 2012, 17 percent of persons aged 18 to 44 years reported a severe headache or migraine within the past 3 months (Blackwell, 2014). Burch and coworkers (2015) reported that 24 percent of nonpregnant women in this age group were similarly affected. Of pregnant women presenting with headache who received a neurological consultation, two thirds were due to primary disorders. The diagnosis was migraine in more than 90 percent. Of the other third due to secondary conditions, more than half stemmed from hypertensive disorders (Robbins, 2015). In one recent observational study at University of Texas Southwestern’s Clements University Hospital, 20 percent of emergency department postpartum visits were for headache (Rodriguez, 2021).
The classification by the International Headache Society (2018) is shown in Table 63-1. As discussed, in pregnant women, primary headaches are more common than those derived from secondary causes (Sperling, 2015). Migraine headaches are those most likely to be affected by the hormonal changes of pregnancy (Pavlovic, 2017). The incidences of different etiologies of severe headaches in pregnancy are shown in Figure 63-1 (Robbins, 2015...