Hallucinogenic Persisting Perception Disorder: A Case Series and Review of the Literature

Ford, Hannah; Fraser, Clare; Solly, Emma J; Clough, Meaghan; Fielding, Joanne; White, Owen; Walt, Anneke van der

doi:10.3389/fneur.2022.878609

Cited by 14 publications

(21 citation statements)

References 29 publications

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“…Recently, several studies have highlighted similarities in symptom profile between type 2 HPPD and VSS 18–20 . Type 2 HPPD is characterized by the chronic recurrence of perceptual abnormalities first experienced during exposure to hallucinogens 21 .…”

Section: Methodsmentioning

confidence: 99%

Perceived severity of Visual Snow Syndrome is associated with visual allodynia

2023

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Objective: To investigate whether sensory sensitivity is associated with the perceived severity of Visual Snow Syndrome (VSS) symptoms.Background: Visual Snow (VS) is a perceptual anomaly which manifests as flashing pinpricks of light throughout the visual field. VSS has an estimated population prevalence of 2.2% and is thought to be at least moderately debilitating for all who experience it. However, some people who meet the criteria for VSS have no awareness of it. This may be because they have lower sensory sensitivity, allowing them to ignore their visual phenomena. Method:Our study used a cross-sectional design. We recruited two distinct samples of people with VSS: a sample of people with confirmed VSS; and a sample of people who met the criteria for the condition but had no prior knowledge of it (latent VSS). The latter group was recruited and screened for symptoms via an online crowdsourcing platform. In total, 100 participants with VSS (49 with confirmed VSS, 51 with latent VSS) completed the Visual Snow Handicap Index and three measures of sensory hypersensitivity. Results:The 100 participants (52 female, 47 male, 1 non-binary) had a mean age of 35.1 years (SD = 12.2). Leiden Visual Sensitivity Scale scores were associated with both the perceived severity of VSS, β = 0.35, p = 0.003, and the number of VSS symptoms endorsed, β = 0.45, p < 0.001. On average, participants with VSS experienced elevated sensory hypersensitivity across all measures. Furthermore, longer duration of VSS was associated with lower perceived severity, F(1, 98) = 11.37, p = 0.001, R 2 = 0.103. Conclusions: Our results suggest that sensory hypersensitivity may be prevalent in people with VSS and indicate that visual allodynia is associated with increased severity of VSS. Additionally, our findings indicate that inclusion of cases of latent VSS in | 495 H EAD ACH E INTRODUC TI ON Visual Snow (VS) is a perceptual anomaly which manifests as flashing pinpricks of light (dynamic noise) throughout the visual field. 1 It is the key symptom of Visual Snow Syndrome (VSS); but VSS is also associated with other visual, auditory, and neurological phenomena, including palinopsia, enhanced entoptic phenomena, photophobia, and nyctalopia. 2 Figure 1 simulates the experience of VS, compared to normal vision.Between 5% and 50% of people with VSS have had the condition for as long as they can remember. 3,4 Many people who acquire VSS later in life can identify a specific preceding event, such as acquired brain injury, first-instance use of medication, or viral infection. 5,6 Research suggests that VSS impacts daily life, with challenges ranging from difficulty engaging with work due to struggles with computer screens, to inability to drive, especially at night. 7 However, anecdotal evidence from online VSS discussion groups, and recent quantitative evidence, suggests some people with VSS do not always find it debilitating. 7 Furthermore, people with lifelong VSS rate their perceptual phenomena as less debilitating and rate health-related quality of li...

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Section: Methodsmentioning

confidence: 99%

Perceived severity of Visual Snow Syndrome is associated with visual allodynia

2023

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“…This kind of dynamics would also explain why HPPD can be caused by SSRIs, given their potential in reopening the critical period for vision (Maya-Vetencourt et al, 2008). It would also explain the reports of subjects who recovered from HPPD after a second experience with a drug capable of inducing HPPD (Ford et al, 2022).…”

Section: Is Hppd Caused By a Reopening Of The Critical Period?mentioning

confidence: 95%

“…The onset of HPPD usually coincides with or follows the consumption of hallucinogens. The majority of cases reported in the literature have been induced by LSD, but HPPD can also be caused by psilocybin, cannabis, MDMA, and other recreational drugs (Ford et al, 2022;Martinotti et al, 2018). Unfortunately, the lack of population studies prevents us from knowing the incidence of HPPD.…”

Section: Is Hppd Caused By a Reopening Of The Critical Period?mentioning

confidence: 99%

“…A recent case report showed that an HPPD patient with increased delta activity over the occipital region was successfully treated using cathodal (inhibitory) transcranial direct current stimulation (tDCS; Haslacher et al, 2022). Moreover, the most common treatments for HPPD include benzodiazepines and antiepileptic drugs (Ford et al, 2022) The disinhibition hypothesis can explain some of the symptoms experienced by HPPD subjects. Visual snow could be caused by a decrease in the signal to noise ratio, which would make it difficult for the visual system to interpret visual inputs.…”

Section: Is Hppd Caused By a Reopening Of The Critical Period?mentioning

confidence: 99%

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The Relationship between Plasticity in the Primary Visual Cortex and the Hallucinatory Persisting Perception Disorder

Scarlatti¹

2023

Preprint

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The Hallucinatory Persisting Perception Disorder (HPPD) is a distressing condition associated with the consumption of hallucinatory drugs, especially psychedelics. Its symptoms include abnormal visual perceptions, hallucinations, and depersonalization/derealisation. They can appear after repetitive use of a psychoactive substance as well as after the first experience, and can last for a short period or for the entire life. It is currently not well understood how common HPPD is, or what are the mechanisms behind it. However, much research has been conducted on the processes behind plasticity in the primary visual cortex, both during development and in adulthood, and recent studies have provided some insights into how psychedelics work on the brain. It is then possible now to try and link the different pieces of information concerning plasticity in the visual cortex, psychedelics, and HPPD. With the recent increase in interest and attention surrounding psychedelics, the number of people experimenting with these substances has increased. As a result, it is important for research on HPPD and its potential relationship with psychedelics to continue, as well as for accurate information about the potential risks and effects of using psychedelics to be widely disseminated. The first part of this article describes the mechanisms behind the critical period for vision and plasticity of the visual system during development and adulthood. In the second part I show how this could be relevant for HPPD.

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“…36,37 The condition had previously appeared in the literature in association with recreational drug use and, independently, as a form of 'persistent migraine aura'. 38,39 Patients report continuous 'grainy', 'dotty' or 'pixelated' visual disturbance affecting the entire visual field of both eyes equally. Patients may also complain of persistent 'after images', which are unusual because they are positive (i.e.…”

Section: Visual Snowmentioning

confidence: 99%

Potential Uses for Precision Tinted Lenses in a Neurology Clinic

Wilkins¹,

Evans²,

Plant³

2022

US Neurology

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Photophobia is a complex disorder that can involve aversion not simply to bright light but to spatial patterns, colour and flicker. The use of tinted lenses to reduce photophobia in neurological diseases has a long history. Rarely has the possibility that different individuals might require lenses individually tailored to their needs been considered. Here we explore this possibility using the Intuitive Colorimeter system. The colorimeter illuminates text with coloured light and permits the colour, strength of colour and brightness to be manipulated separately. Many individuals find that a colour other than white is comfortable for viewing text. This colour is optimized in the colorimeter by a search strategy that allows for colour adaptation. Spectacle lenses are then individually tinted so that the chosen colour is experienced under conventional lighting. In this article, we review the use of the Intuitive Colorimeter in photosensitive epilepsy, autism, migraine, cluster headache, visual snow, stroke, multiple sclerosis and concussion; these are disorders in which individually coloured tints have featured in scientific and clinical reports. The evidence is preliminary rather than conclusive, but it suggests that precision tints can reduce photophobia. In patients with autism, the perception of emotion in facial expression is improved. Occasionally, the clinical benefit extends to the reduction of seizures and headaches and to an increase in reading speed.

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Hallucinogenic Persisting Perception Disorder: A Case Series and Review of the Literature

Cited by 14 publications

References 29 publications

Perceived severity of Visual Snow Syndrome is associated with visual allodynia

Perceived severity of Visual Snow Syndrome is associated with visual allodynia

The Relationship between Plasticity in the Primary Visual Cortex and the Hallucinatory Persisting Perception Disorder

Potential Uses for Precision Tinted Lenses in a Neurology Clinic

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