A transient syndrome of migrainous headache with neurologic deficits and CSF lymphocytic pleocytosis is described in 7 young adult patients examined at the Strong Memorial Hospital, University of Rochester Medical Center, Rochester, NY. The clinical characteristics of 33 similar cases, 13 in children and adolescents, previously reported in the literature are also analysed. The diagnostic criteria for this syndrome include severe headache, temporary (<4 days) neurologic deficit, CSF lymphocytosis (16-350 WBC/mm3), and self-limited course (range 1-84 days, mean 21 days). The neurologic signs and symptoms were usually transient hemiparesis or sensory changes, confusional episodes, and aphasia. CSF protein was increased in 91% of cases, CSF pressure increased in 73%, focal, nonepileptiform EEG irregularities were recorded in 72%, and a viral illness or fever preceded the headaches in 50%. Apart from 2 patients showing unidentified bright objects on MRI, neuroimaging studies were negative. The headaches had characteristics of migraine with aura, unilateral location, pulsating quality, nausea, and photophobia, but unlike typical migraine, the headache syndrome was not chronic. The syndrome resolved within 3 months. The cause is undetermined. 
COMMENT. The differential diagnoses listed by the authors for this syndrome include Lyme neuroborreliosis, neurosyphilis, neurobrucellosis, mycoplasma infection, granulomatous meningitis, neoplastic meningitis, autoimmune disease, HIV meningitis, and a side effect of cerebral angiography. Other illnesses with similar features are hemiplegic migraine, seizure disorder, and recurrent aseptic meningitis (Mollaret’s meningitis). The syndrome is self limited, and a viral etiology seems likely.