ABSTRACT

Thromboembolic phenomena are the serious consequences of assisted reproductive technology. We present a case of cerebral sinus vein thrombosis (CVST) following ovarian hyper stimulation syndrome (OHSS). Ten days after recovering from OHSS, the patient presented in the emergency department with thunderclap headache. Her Magnetic Resonance Venography (MRV) showed occluded left transverse sinus and left sigmoid sinus. The patient was treated with low molecular weight heparin. She made a good recovery and was independent in activities of daily living in follow up after six months. Disturbances of the coagulation system may occur in moderate OHSS and also persist even after the clinical symptoms of OHSS have resolved.

Keywords: Ovarian Hyperstimulation Syndrome; Cerebral Veins; Thrombosis

Ovarian hyperstimulation syndrome (OHSS) occurs in 1% to 10% of IVF cycles  among women undergoing ovarian hyperstimulation with exogenous gonadotrophin administration and is known as a potentially life-threatening complication of OHSS (1). Complications are thought to be secondary to hypovolaemia and the hypercoagulability state induced by increased vascular permeability. High levels of estrogen and relative venous stasis in the lower limb secondary to ovarian enlargement are also

contributory (2-4). In this report, we are going to present a case of cerebral sinus thrombosis following OHSS.

Case Presentation

A 22-year-old woman with severe headache was referred by neurologist as an acute admission to the neurology department. She presented with a two-day history of thunderclap headache. Examination showed bilateral papilledema. The patient had a two-year history of infertility secondary to Polycystic Ovary Syndrome (PCOS) and had only recently commenced ovarian stimulation and intracytoplasmic sperm injection (ICSI) treatment for that, with subsequent embryo transfer. Two weeks prior to admission she had been admitted under the care of gynecologists with abdominal pain and nausea. Blood analysis showed a normal hematocrit of 35%, platelets 307000, sodium 140 (normal 135–145 mEq/l), potassium 4.1 (normal 3.5–5.5 mEq/l), creatinine 0.9 (normal <1.2mg/dl) and blood urea nitrogen (BUN) 18 (normal <25 mg/dl). Abdominal ultrasound showed moderate volume ascites, multi-cystic ovaries. Her clinical and laboratory finding were consistent with moderate ovarian hyperstimulation syndrome, and she was started on conservative treatment, including intravenous hydration. She was discharged on the fifth day of conservative treatment. However, ten days later the patient presented to urgent care with the complaint of severe headache. During the second admission laboratory findings were: hematocrit 33.9%; hemoglobin 11.8 g/dl; white blood cell count 10000/ml; platelet count 307000/ml; and both prothrombin time and electrolyte levels within normal limits. At six    hours    after    admission,    the    patient condition suffered deterioration. Confessional state was noted, in addition to Wernicke aphasia. Brain CT scan and magnetic resonance imaging (MRI) showed hemorrhagic infarction in left temporo-parietal region associated with massive edema and somewhat midline shift and also right thalamic infarction (Figure 1).

Figure 1: Axial fluid attenuated inversion recovery (FLAIR) images demonstrate two areas of infarction; in left temporo-parietal region and right thalamus. Associated brain CT scan (not represented here) revealed non-homogenous hemorrhage in the temporo-parietal infarcted region.  

Brain MRI illustrated thrombosis formation in left transverse sinus (Figure 2).

Figure 2: Coronal T1 weighted MRI images show thrombosis formation in left transverse sinus.

Magnetic resonance venography (MRV) revealed non-visualized or occluded left transvers sinus and sigmoid sinus (Figure 3). Deep venous thrombosis which is in charge of right thalamic infarction cannot be proved by conventional MRI and MRV, but it has been logically considered due to deep venous thrombosis based on the patient's history and superficial vein thrombosis.

Figure 3: Magnetic resonance venography (MRV) illustrates occluded left transvers sinus and left sigmoid sinus

Conclusion

Ovarian hyper stimulation syndrome can cause significant morbidity; early recognition may help to avoid complications of this syndrome. Obstetricians should be aware that patients may present with symptoms of thrombotic complications even several weeks after OHSS symptoms have resolved.

Conflict of Interest

The authors have no conflict of interest.

References

1. Brinsden PR, Wada I, Tan SL, Balen A, Jacobs HS. Diagnosis, Prevention and Management of Ovarian Hyper Stimulation Syndrome. Br J Obstet Gynecol 1995; 102(10):767-72.
2. Stewart J, Hamilton P, Murdoch A. Upper Limb Thrombosis Associated with Assisted Conception Treatment. Hum Reprod 1997; 12(10):2174-5.
3. Practice Committee of the American Society for Reproductive Medicine. Ovarian Hyperstimulation Syndrome. Fertil Steril 2003; 80:1309-14.
4. Ou Y, Kao YL, Lai SL, Kung FT, Huang FJ, Chang SY, et al. Thromboembolism after Ovarian Stimulation: Successful Management of a Women with Superior Sagittal Thrombosis after IVF and Embryo Transfer: Case Report. Hum Reprod 2003; 18(11):2375-81.
5. Arya  R, Shehata HA, Patel RK, Sahu S, Rajasingam D, Harrington KF, et al. Internal jugular vein thrombosis after assisted conception therapy. Br J Haematol 2001; 115(1):153-5.
6. Aboulghar M, Mansour R. Ovarian Hyperstimulation Syndrome: Classifications and Critical Analysis of Preventative Measures. Hum Reprod Update 2003; 9(3):275-89.
7. Rao AK, Chitkara U, Milki AA. Subclavian Vein Thrombosis Following IVF and Ovarian Hyperstimulation: A Case Report. Human Reproduction 2005; 20(12): 3307-12.
8. Kodama H, Fakuda J, Karube H, Matsui T, Shimizu Y; Tanaka T. Status of the Coagulation and Fibrinolytic Systems in Ovarian Hyperstimulation Syndrome. Fertil Steril 1996; 66(3):417-24.