A 21-year-old, 37-week pregnant woman, G1P0, with a PMH significant for diet-controlled gestational diabetes presented to the hospital with regular uterine contractions. She was admitted to the ob/gyn service for delivery. She didn’t use cigarettes, alcohol, or illicit substances, and her only medications were pre-natal vitamins and folate.
She had a normal CBC and glucose level, as well as unremarkable vital signs on admission. She had an uncomplicated, spontaneous vaginal delivery of a healthy infant. During delivery, she was briefly hypertensive to a systolic blood pressure of 160. Her elevated blood pressure resolved quickly with a dose of fentanyl. She didn’t have excessive bleeding. Forty minutes after delivery, she developed sudden onset bilateral blindness, described as a severe darkening of her vision.
Hospital medicine was consulted for further evaluation of her blindness. On visual exam, she was able to identify some movement but was unable to read or count fingers. Otherwise her neurologic exam was unremarkable.
A: Reversible cerebral vasoconstriction syndrome, cerebral venous sinus thrombosis, intracranial arterial dissection, and posterior reversible encephalopathy syndrome (PRES) are all conditions associated with pregnancy that can cause an acute neurological syndrome such as this. In addition, the differential diagnosis includes hypoglycemia, side effect from fentanyl, and conversion disorder or other psychiatric condition. CNS imaging should be pursued to rule in/out these diagnoses. When there is concern for a potential stroke, imaging generally starts with a non-contrast CT head and CT angiogram of the head and neck. If these are negative, MR imaging of the brain including venography can be pursued. In addition, basic labs should be checked, including CBC, BMP, LFTs, and urine protein level to evaluate for preeclampsia and significant metabolic derangements.
CT head and CT angiogram of the head and neck were unremarkable. Glucose was within normal limits. Lab testing was significant for a leukocytosis of 16, platelet count of 134, ALT 98, AST 94, and a protein-to-creatinine ratio of 1.8. MR angiography showed mild narrowing of the distal cavernous carotids bilaterally, and MRV was unremarkable. MRI brain showed areas of increased FLAIR signal involving posterior subcortical white matter suggestive of PRES.
