A 60-year-old woman with headache, confusion, and hallucinations.

A 60-year-old woman, healthy and highly functioning atbaseline, was in her usual state of health when she devel-oped new-onset headache in a bilateral temporoparietaldistribution. This was gradual in onset, associated withnausea and vomiting, and without photophobia or phono-phobia. She was noted to be disoriented to time, place, andperson by her family. She also rapidly developed auditoryhallucinations, which prompted admission to an outsidehospital. She was afebrile and hemodynamically stable.Kernig’s and Brudzinski’s signs were negative. Neurologicexamination was nonfocal. A noncontrast computed to-mography (CT) scan of the brain showed hypodensitieswith mild mass effect involving both posterior temporallobes and left frontal subcortical white matter. Magneticresonance imaging (MRI) of the brain (Figure 1) showedsignal changes in the same locations with smaller areas ofsignal abnormality and localized mass effect involving thesubcortical white matter of the frontal lobes and superiorcerebellar vermis. Gradient-echo imaging demonstratedmultiple tiny punctate areas of hemosiderin deposition inthe brain bilaterally without focal intracranial hemorrhageor ischemia. She was empirically treated with acyclovir,ceftriaxone, and vancomycin for suspected meningoen-cephalitis. Cerebrospinal ﬂuid (CSF) analysis showed 3white blood cells (WBCs)/high-power ﬁeld (hpf), 15 redblood cells (RBCs)/hpf, protein 16 mg/dl, and glucose 48mg/dl. Herpes simplex virus (HSV) polymerase chain re-action (PCR) was negative. Electroencephalogram (EEG)showed right temporal and parietal sharp waves but noepileptogenic activity. Blood, CSF, and urine cultures re-turned negative, after which antibiotics were discontin-ued. She was treated symptomatically and headaches im-proved, but did not resolve completely. She was dismissedhome and returned to work 2 weeks later.Four days later, she relapsed with severe headaches anddisorientation. She was hospitalized and a repeat MRI(Figure 1) showed areas of leptomeningeal enhancementand multiple white matter lesions with T2 hyperintensity,patchyenhancement,andrestricteddiffusion.Repeatlum-bar puncture showed 1 WBC/hpf, 8 RBCs/hpf, glucose 52mg/dl, and protein 65 mg/dl. CSF studies were negative ornormal for angiotensin-converting enzyme level, syphilis,Whipple’s disease, Lyme, HSV, West Nile virus, and en-terovirus PCR. Serologic studies for Western, Eastern, andCalifornia equine viral encephalitis were negative, as wereCSF bacterial, mycobacterial, and fungal cultures. Theerythrocyte sedimentation rate was 26 mm/hour and theC-reactive protein level was 1 mg/liter. Laboratory studieswere normal or negative, including a complete blood cellcount, liver and kidney functions, antinuclear antibody(ANA), extractable nuclear antigen (ENA) panel, antineu-trophil cytoplasmic antibodies, lupus anticoagulant, andantiphospholipid antibodies. Chest/abdomen/pelvis CTand mammogram were also normal. The patient subse-quently developed auditory hallucinations again and hadnew ﬁndings of peripheral vision loss on the left side andformedvisualhallucinations.Aneuroophthalmologyeval-uation conﬁrmed left homonymous hemianopia. EEGshowed periodic lateralized epileptiform discharges overthe right temporoparietal areas. Although hemodynami-cally stable, her confusion and disorientation continued toworsen. She underwent a right temporal lobe brain biopsythat was interpreted as being suggestive of vasculitis. Shewas treated with methylprednisolone intravenously 1 gmdaily for 3 days with a remarkable resolution of all of herclinical symptoms. She was also started on levetiracetamfor abnormalities on EEG and trimethoprim/sulfamethoxa-zole for