This between-subjects cohort study (n=48) compared the prevalence of migraine in individuals with visual snow (continuously flickering dot hallucination) in a cohort diagnosed with Hallucinogen Persisting Perception Disorder (HPPD) versus visual snow cohort without prior use of illicit drugs. HPPD-related visual disturbances were primarily caused by ecstasy but weren’t accompanied by migraines, whereas visual snow disturbances were accompanied by migraines in over half of the control cohort.
“Background/objective: To investigate migraine prevalence in persons with Hallucinogen Persisting Perception Disorder (HPPD) presenting as visual snow syndrome (VSS)
Methods: Persons with visual snow as persisting symptom after illicit drug use (HPPD) were recruited via a Dutch consulting clinic for recreational drug use. A structured interview on (visual) perceptual symptomatology, details of drugs use, medical and headache history was taken. As a control group, persons with visual snow who had never used illicit drugs prior to onset were included. The primary outcome was lifetime prevalence of migraine. Symptom severity was evaluated by the Visual Snow Handicap Inventory (VHI), a 25‐item questionnaire.
Results: None of the 24 HPPD participants had migraine, whereas 20/37 (54.1%) of controls had migraine (p < 0.001). VHI scores did not differ significantly between the two groups; in both groups median score were 38 out of 100. In most HPPD cases (17/24; 70.9%), visual snow had started after intake of ecstasy; other psychedelic drugs reported included cannabis, psilocybin mushrooms, amphetamine, 4‐FMP, 3‐MMC, 2C‐B, and nitrous oxide.
Discussion: While none of the HPPD participants had migraine, over half of the visual snow controls without prior use of illicit drugs had migraine. This suggests that at least partly different pathophysiological factors play a role in both disorders. Users of ecstasy and other hallucinogens should be warned of the risk of visual snow. Further studies are needed to enhance understanding of the underlying neurobiology of HPPD and VSS to come to better management of these conditions.
Authors: Robin M. van Dongen, Gerard J. Alderliefste, Gerrit L.J. Onderwater, Michel D. Ferrari & Gisela M. Terwindt