We are pleased to share recent contributions to Visual Snow Syndrome (VSS) research by Dr. Evgeniy Sokolov of Sechenov University, one of Russia’s leading medical institutions.
At the 22nd International Headache Congress (IHC 2025) in São Paulo, Brazil, Dr. Sokolov presented an abstract on the differential diagnosis of VSS, HPPD, and VSS with migraine aura.
Dmitriy Vladimirovich Romanov, Alexey Vladimirovich Sergeev, Azaliya Rustamovna Nurmeeva, Anastasiya Anatolyevna Kononirova, Artem Alexandrovich Pyatkov, and Dr. Evgeniy Sokolov co-wrote the abstract “Differential Diagnosis in Patients with Symptoms of Visual Snow (VSS, HPPD-II, Migraine with Aura): Clinical Features.”
You can view the posters and certificates that were given out in recognition of this accomplishment below.
Additionally, Dr. Sokolov won second place in the scientific competition for his abstract on the psychiatric comorbidity of VSS and HPPD at the International Congress “Comorbid Neurology 2025.” Below is a translation of the paper from Russian to English.
Introduction
Visual Snow Syndrome (VSS) is a neuro-ophthalmological disorder characterized by persistent visual disturbances, including noise/static resembling the picture of an old unplugged television, prolonged afterimages (palinopsia), impaired night vision (nyctalopia), enhanced vitreous floaters, the Scheerer phenomenon (blue-field entoptic phenomenon), and photophobia. More than 20 additional visual and non-visual symptoms have also been described, including tinnitus, depersonalization-derealization syndrome, “brain fog,” and others.
Hallucinogen-persisting perception disorder type 2 (HPPD-II) presents with similar symptoms and likely shares common pathogenetic mechanisms with VSS, although HPPD-II is triggered by the use of psychoactive substances. Literature indicates a high prevalence of affective disorders among patients with VSS and HPPD-II; however, the role of personality traits in this context remains unclear.
Materials and Methods
An online survey was conducted among a community of patients with VSS and HPPD-II symptoms (n = 315). Telephone interviews were performed to clarify clinical presentations and verify diagnoses. To objectify visual symptomatology, a specially developed questionnaire for functional visual disturbances was used. Mental status was assessed using:
- Generalized Anxiety Disorder questionnaire (GAD-7)
- Patient Health Questionnaire (PHQ-9)
- Hamilton Anxiety and Depression Scales (HAM-A, HAM-D)
- Personality Inventory for DSM-5—Brief Form (PID-5-BF)
- ICD-11 Personality Disorder Severity scale (PDS-ICD-11)
Results and Discussion
Two groups were identified: VSS (n = 153) and HPPD-II (n = 83), while 79 respondents were excluded due to insufficient diagnostic criteria or refusal to participate. The groups were comparable in age and gender.
- Overall anxiety (GAD-7) averaged 10.6 points and 12.1 points on HAM-A, indicating mild but clinically significant anxiety.
- Depression severity (PHQ-9, HAM-D) averaged 14.48 and 8.92 points, consistent with moderate depression.
- No statistically significant differences in anxiety levels between the groups were observed (p > 0.1).
Personality trait analysis revealed a predominance of negative affectivity (25%), detachment (22.91%), and psychoticism (20.83%). Maladaptive personality trait severity differed significantly between groups (PDS-ICD-11):
- VSS: 9.48 points—mildly expressed
- HPPD-II: 14.67 points — moderate expression
(t.emp = 2.2, p < 0.05)
Conclusion
Patients with VSS and HPPD-II demonstrate mild anxiety, moderate depression, and a wide prevalence of maladaptive personality traits. Psychiatric consultation is recommended after diagnosis to determine the need for appropriate psychotherapy, such as CBT, ACT, or mindfulness-based interventions.
Dr. Evgeniy Sokolov
Fellow, N.V. Sklifosovsky Institute of Clinical Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
e-mail: [email protected]
Together, the Visual Snow Initiative and Sechenov University aim to advance the scientific understanding, clinical management, and global advocacy for patients living with VSS. Through continued innovation, collaboration, and advocacy, we strive to improve outcomes for those affected by VSS.
For more information about VSI’s research initiatives and collaborations, visit the Visual Snow Initiative.