Multiple etiologies of secondary headaches associated with arachnoid cyst, cerebrospinal fluid hypovolemia, and nontraumatic chronic subdural hematoma in an adolescent: A case report.

Background: Diagnosing the cause of headaches can be challenging. Even if intracranial lesions are found in a patient, careful assessment is essential for diagnosis, and treatment strategies will differ for each etiology. Case Description: A 16-year-old boy presented with sudden-onset headache which had lasted for 2 days. His headache was aggravated in the orthostatic position. The patient denied recent head trauma. He had been diagnosed with an arachnoid cyst (AC) in his right middle cranial fossa. Computed tomography (CT) revealed bilateral subdural effusions and slit-like lateral ventricles with no significant changes to the AC. After intravenous hydration followed by 2 days bed rest, his symptoms abated. He was diagnosed as having suffered spontaneous cerebrospinal fluid (CSF) hypovolemia. One month later, the patient experienced recurrent gradual onset headache and vomiting. CT revealed chronic right side subdural hematoma (SDH) with intracystic hemorrhage, which resulted in the elevation of intracranial pressure. An urgent hematoma evacuation was performed. He became symptom-free immediately after surgery. Postoperative follow-up CT showed no change in the AC and no recurrence of SDH. The lateral ventricles and subdural space were normal in size. Conclusion: We report a case presenting multiple types of secondary headaches, which were caused by intracranial hypotension or hypertension, with different etiologies. These were spontaneous CSF hypovolemia, nontraumatic intracystic hemorrhage form of AC, and nontraumatic chronic SDH. Although lesions seen at the time of initial diagnosis did not need surgical treatment, careful observation and repetitive imaging assessments might be useful for discovering unsuspected additional etiologies requiring surgical intervention.