Secondary normal pressure hydrocephalus following pituitary apoplexy: A case report.

Background: Although secondary normal pressure hydrocephalus (sNPH) can occur in various central nervous system diseases, there are no reports of sNPH caused by pituitary lesions. Herein, we present a unique case of sNPH caused by pituitary apoplexy.

Case Description: A 70-year-old man was transferred to our hospital because of a sudden onset of headache and loss of consciousness. The cerebrospinal fluid (CSF) test showed slightly elevated cell counts and protein levels but a negative CSF culture test. Magnetic resonance imaging showed a dumbbell-like cystic lesion with hemorrhagic change at the sella turcica. From the above, the patient was diagnosed with aseptic meningitis caused by pituitary apoplexy. Pituitary hormone replacement therapy was undertaken, and his symptoms fully improved. However, two months later, he complained of a gait disturbance and incontinence that had gradually appeared. Brain imaging with computed tomography showed no ventricular enlargement compared with initial images, although the lateral ventricles were slightly enlarged. As a CSF drainage test improved his symptoms temporarily, sNPH with possible longstanding overt ventriculomegaly in adults (LOVA) background was suspected. We performed a lumboperitoneal shunt (LPS) placement, which improved his symptoms.

Conclusion: This case suggests that sNPH can develop even after a small subarachnoid hemorrhage caused by a pituitary apoplexy in LOVA patients. If the aqueduct of Sylvius is open, sNPH with a LOVA background can be successfully treated with LPS placement.