Global hemispheric CT hypoperfusion may differentiate headache with associated neurological deficits and lymphocytosis from acute stroke.

Headache with associated neurological deficits and lymphocytosis (HaNDL) is characterized by temporary recurrent neurological deficits, moderate–severe headache, cerebrospinal fluid lymphocytosis, elevated protein, and increased opening pressure.1 Although CT and MRI should be normal, single photon emission CT may indicate focal hypoperfusion and electroencephalogram may reveal slowing or even epileptiform activity2 resolving once the patient is symptom-free (3 months). Catheter angiography also yields normal results but may trigger an acute neurological episode.3,4 Because HaNDL is a benign, self-limited syndrome, it is important to differentiate it from cerebrovascular disease to avoid unnecessary interventions such as catheter angiography and thrombolysis. We present a case initially thought to be acute stroke in which the patient was considered for thrombolysis. CT perfusion changes atypical for stroke made stroke diagnosis questionable and thrombolysis was withheld.