d g p ( PRESENTATION A sample of cerebrospinal fluid from a 52-year-old-woman told an interesting tale. The patient reported a 1-week history of worsening headache, shortness of breath, and fatigue but denied any fever, chest pain, orthopnea, paroxysmal nocturnal dyspnea, nausea, vomiting, abdominal pain, or diarrhea. She had experienced a subarachnoid hemorrhage 7 months earlier, and at that time, she had required several ventricular shunts for persistent hydrocephalus. When she was admitted to the Rush University Medical Center, she had a functioning ventriculopleural shunt. The original device was inserted 4 months before her current illness but replaced 2 months later at the same site after it malfunctioned.