Imaging intracranial plasma extravasation in a migraine patient: a case report.

Despite recent research advances, the origin of nociception in migraine headaches remains unclear and continues to be a topic of intense examination. Experiments using animal models of dural neurogenic plasma extravasation (DNPE) as an index of meningeal inflammation provided the basis for the meningeal inflammation hypothesis of migraine pain. Objective. We explore the possibility that DNPE can be detected in humans during a migraine attack. Methods. DNPE single photon emission computerized tomography (SPECT) with an intravenous injection of technetium-99m (Tc-99m) human serum albumin (HSA) has been used in a 46-year-old migraine symptomatic patient who met the International Headache Society criteria for episodic migraine. The patient was injected with 10 mCi HSA and imaged by SPECT. A second (delayed) SPECT was done 3 hours later. After 3 days, following complete resolution of her migraine headache, the patient returned for the control SPECT. Results. All SPECT images were compared with the patient's self-recorded pictorial description of her migraine head pain epicenter. Tc-99m HSA extravasation appeared on the same side and approximately in the same region as the epicenter of the patient's head pain. Conclusion. This observation suggests the occurrence of intracranial plasma extravasation during migraine attacks. Activity on SPECT scans suggests that tracer extravasation and not hyperemia is responsible for the positive finding.