New daily persistent headache (NDPH) starting as a single thunderclap headache is possibly a subform of reversible cerebral vasoconstriction syndrome (RCVS), according to a study published in Headache.
Researchers report a case series of 3 patients who were diagnosed with this unique subtype of NDPH at an academic clinic from 2016 through 2018. Diagnoses were performed by a headache neurologist and met the third edition of the International Classification of Headache Disorders criteria for NDPH. The initial headache met the criteria for thunderclap headache based on whether the first-ever headache peaked to a maximum intensity instantaneously and without latency. The neurologist inquired about other triggering events for NDPH, including infection, surgical procedure, and a stressful life event. Patients had extensive neuroimaging including magnetic resonance imaging of their brains without gadolinium, magnetic resonance angiography of the head and neck with dissection protocol, and a magnetic resonance venography of the brain.
The 3 patients were women with an average age of 46 years at headache onset. In the case report, the 42-year-old patient’s headaches began spontaneously without a triggering event. The initial headache, located in the left frontal, vertex, and temples, peaked to maximum intensity over several seconds and lasted for at least several minutes before partially declining in pain. Imaging studies were normal. The patient was started on 30 mg nimodipine twice-daily 4 months into her headache syndrome, at which point she became free of head pain and neurologic symptoms. Researchers found that neurologic/stroke like symptoms were noted in each of the 3 cases, possibly helping to distinguish single thunderclap headache from other subtypes of NDPH in which neurological deficits are typically not present. This subtype is presumed to be caused by cerebral artery vasospasm that is either persistent or intermittent, based on the syndrome’s response to nimodipine.
This research is limited by the small number of cases available on which to report and make any broad statements on true clinical characteristics, gender predominance, and potential risk factors.
The findings of this research prompted many questions and identified future research needs. First, if a single thunderclap headache is triggered by cerebral artery vasospasm, can it still be labeled by NDPH, which is recognized as a primary headache syndrome? Is this a neuroinflammatory issue, as it has been noted in the literature that there is a circadian variation to multiple cytokines including interleukin-6, interleukin-1β, interferon-γ, and tumor necrosis factor-α? Are there specific vasoactive compounds based in the central nervous system that are more readily released during this time period? What is the possible role of the hypothalamic-pituitary axis in this condition?
Jamali SA, Rozen TD. An RCVS spectrum disorder? New daily persistent headache starting as a single thunderclap headache (3 new cases) [published online March 4, 2019]. Headache. doi: 10.1111/head.13495