Clinical features, polysomnography and outcome in patients with hypnic headache.

Hypnic headache is rarely reported in Asians, and the proposed International Classification of Headache Disorders (ICHD)-2 criteria have never been field-tested. We studied 17 consecutive Taiwanese patients (M/F: 9/8, mean age at onset 69.6 years) with hypnic headache from a headache clinic. Fifteen patients (88%) reported >15 headache attack days per month. Polysomnography studies done on 11 patients recorded 12 attacks in seven patients: two during rapid eye movement (REM) sleep, three during non-REM sleep and two having both. Five of the seven patients reported their headache profile during polysomnography studies. The clinical course was mostly episodic without recurrence (n = 9, 53%), followed by relapsing/remitting (n = 5) and chronic (n = 3). The ICHD-2 criteria were not fulfilled in 35% (6/17) patients based on patient recall or 60% (3/5) patients based on direct questioning during polysomnography studies. The major reason was the presence of pulsatile rather than dull headache in our patients. Unlike previous studies, our study showed hypnic headache occurred equally in both REM and non-REM sleep, and most patients ran an episodic course.

Decay of a Resonance in 18Ne by the Simultaneous Emission of Two Protons.

Radioactive ion beams of 17F were used to study several resonance states in 18Ne. Clear evidence for simultaneous two-proton emission from the 6.15 MeV state (Jpi = 1(-)) in 18Ne has been observed with the reaction 17F+1H. Because of limited angular coverage, the data did not differentiate between the two possible mechanisms of simultaneous decay, diproton (2He) emission or direct three-body decay. The two-proton partial width was found to be 21+/-3 eV assuming 2He emission and 57+/-6 eV assuming three-body decay. The total width of the 1(-) state was measured to be 50+/-5 keV. Several additional resonances that decay by single proton emission were also studied.