Hematological, biochemical and metabolic investigations on blood and urine between attacks are normal, as are karyotyping and EKG recordings. EKG recordings during attacks show sinus tachycardia. CT, MRI, EMG and nerve conduction studies produce normal results. EEG recordings are normal between attacks but show early-onset tachycardia during attacks. On the Neuropathic<unk>  Questionnaire patients indicated that<unk>  during attacks is<unk> ly unpleasant and typically felt deep, though also superficial on occasion. Aside from presentation of typical symptoms (see Signs and symptoms above) mutation of the gene SCN9A aids in appropriate diagnosis as this gene is mutated in 8 of 14 studied families.
Paroxysmal extreme pain disorder
Nociplastic pain
Functional somatic syndrome
Psychogenic pain
Mass psychogenic illness
Syndrome of subjective doubles
Cephalalgiaphobia
Postorgasmic illness syndrome