A 29-year-old Woman with Recurrent Pregnancy-induced Hypertension Based on Vascular Compression of the Medulla Oblongata

Abstract

We present a report of a 29-year-old woman with non-dipper type refractory hypertension due to the vascular compression of the medulla oblongata. The patient was diagnosed with hypertension at 17 years of age and underwent emergency Caesarean section at 26 weeks of gestation during 2 pregnancies due to severe high blood pressure. We suspected medullary compression by the curved posterior inferior cerebellar artery as the cause of her intractable hypertension, and she underwent Jannetta's decompression surgery. After the surgery, her blood pressure swiftly decreased to almost within the normal range, and her blood pressure pattern normalized to dipper type.

Keywords: Jannetta's decompression surgery; intractable hypertension; medullary compression; non-dipper type; pregnancy-induced hypertension.

Figure 1.

Clinical course of the present case with measured office blood pressure. The office blood pressure swiftly and significantly decreased after the decompression surgery. At present, the patient is being treated only with a minimum dose of amlodipine (2.5 mg/day), and her blood pressure is well controlled below 130/85 mmHg. The results of the blood test related to hypertension are listed at the bottom of this figure. Preg: pregnancy, wk: week, U-Pro/Cre: urinary protein/creatinine ratio, PRA: plasma renin activity, PAC: plasma aldosterone concentration

Figure 2.

Ambulatory blood pressure monitoring before and after the decompression surgery. The pattern of ambulatory blood pressure monitoring (ABPM) before the decompression surgery (A, B) showed a riser/non-dipper-type pattern with an elevated blood pressure at midnight. The ABPM pattern after the decompression surgery (C) showed a normal dipper-type pattern with a decreased blood pressure during sleep. The time zone (vertical, dark gray) depicts nighttime as between 10:00 PM and 06:00 AM The blood pressure zone (horizontal, dark gray) depicts the calculated average (av.) of the all-day blood pressure. The values of averaged day-time and night-time blood pressure are also written in each of the graphs.

Figure 3.

Brain MRI findings before and after the decompression surgery. The medulla oblongata was severely compressed by the curved left posterior inferior cerebellar artery (white arrow) before the decompression surgery [A: contrast-enhanced 3D T1-weighted image, B: three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequence with a slice thickness of 2 mm]. After the decompression surgery (C: 3D-FIESTA sequence with a slice thickness of 2 mm), the curved posterior inferior cerebellar artery was successfully separated from the ventrolateral side of the medulla oblongata, and cerebrospinal fluid could be seen between the structures (white arrow).

Figure 4.

Findings during the decompression surgery. Jannetta’s decompression surgery was performed, and the compressing artery was separated from the ventrolateral side of the medulla oblongata. PICA: posterior inferior cerebellar artery