“…However, given her thrombocytopenia, use of enoxaparin, APS, immunodeficient status, and viral-type prodrome and rash, she was at risk of several secondary causes of headache, including intracranial hemorrhage, cerebral venous sinus thrombosis (CVST), sinusitis, aseptic meningitis, and both common and opportunistic CNS infections such as tuberculosis, intracerebral abscess formation, cryptococcus, toxoplasmosis, and neoplastic disease. 1 With this differential diagnosis in mind, the ideal initial diagnostic battery for this patient includes an emergent noncontrast head CT to rule out an intraparenchymal hemorrhage, MRI with and without gadolinium to evaluate for mass lesions and meningeal enhancement, magnetic resonance venography (MRV) to rule out CVST, and a lumbar puncture to evaluate for opportunistic infections. 1,2 Noncontrast head CT performed the day of the patient's recurrent headache showed no acute abnormality.…”