Field-testing the Criteria for ““ (Positive Persistent Visual Disturbance) Christoph J. Schankin, Farooq Maniyar, Peter J. Goadsby Headache Center, Department of Neurology, University of California, San Francisco, San Francisco CA

Background: Methods: Results (2):

1) Patients with so-called “visual snow“ (VS) have (1) Additional visual symptoms in patients with VS (identi cation): Prospective telephone interview with patients with “visual snow”. (Figure 1a, b): - Analysis of survey data collected by the self-help group On - Of 142 participants, 120 had “visual snow”. - Persistent (i.e. 24/7, with opened and closed), Vision Foundation. - “Visual snow” is dierently perceived in individual patients (Figure 2). - Dynamic (i.e. ickering, moving), - Asked for 12 items: (Figure 1c; afterimages, trailing), Conclusion: - Tiny dots in the entire visual eld. oaters, blue eld entoptic phenomenon (Figure 1d), photopsia Flashing (bright or dark), impaired night vision, colored clouds with eyes 17 (1) “Visual snow”... 2) Many (neuro-)ophthalmologists or neurologists have closed, photophobia, change, dim vision, astigmatism. 1 4 5 ...is almost always associated with additional visual symptoms. seen patients with VS, but it remains poorly studied. Colored Trans- ...represents a unique clinical syndrome. (2) Prospective telephone interviews (con rmation) 4 parent ...is distinct from typical visual in . 3) Only a few case series are available in the literature [1-5]. - Conrm these additional visual symptoms. Black & White 16 1 12 - Assess frequency of migraine and migraine with aura. 2 (2) Migraine and migraine with aura are common comorbidities. 4) Patients suer signicantly due to: - Beginning of VS: association with migraine, migraine aura, drug use. 1 - Persistent disabling symptoms - Collect information on ndings. (3) Intake of illicit drugs and ophthalmological pathologies might - Lack of knowledge in the medical community not be relevant. - Incorrect diagnoses: Migraine aura, post LSD-syndrome, psychogenic illness Figure 2: The dots perceived by patients with “visual snow” can have (4) Proposed clinical criteria for the syndrome “visual snow“: 5) Patients organize in self-help groups. Results (1): dierent “colors“. A Dynamic, continuous, tiny dots in the entire visual eld. B At least one additional visual symptom: - The additional visual symptoms derived from the identication sample Identication of additional visual symptoms in patients with VS: i Palinopsia are also highly prevalent when assessed in a prospective telephone - Of 140 data sets, 120 could be analyzed (symptoms entered). ii Enhanced entoptic phenomena interview (Table 1). - Table 1 shows the 8 most frequent additional visual symptoms iii Photophobia - Of patients, 98% (93%) have at least one (three) additional symptoms. Objectives: in bold. iv Impaired night vision C Symptoms are not consistent with typical migraine aura. Describe the clinical phenotype of patients with “visual snow“. These additional symptoms can be grouped into: D Symptoms are not attributed to another disorder - Identify additional visual symptoms in patient with VS. Palinopsia: trailing and afterimages (ophthalmological, drug abuse). - Generate preliminary criteria for VS. Enhanced entoptic phenomena: oaters, photopsia, blue eld - Conrm these criteria prospectively. phenomenon, self-light of the eye Photophobia Impaired night vision - Table 2 shows the association with headache, migraine aura, drug use.

(a) (b) Table 1: Additional visual symptoms in patients with “visual snow”. Results (1): identication Table 2: Association with headache, migraine aura, and illicit drug use sample. Results (2): conrmation sample (* only black & white “visual snow”). (black & white “visual snow“).

Headache/migraine aura within 7 days of onset Results (1) Results (2) 33%/10% Identication Conrmation (n = 40 with onset later in life) Intake of illicit drugs within 7 days of onset Number of patients 140 8% No symptoms entered 19 (n = 40 with onset later in life) No visual snow 1 Features of typical migraine aura (n = 57) 0% Patients analyzed = Patients with visual snow 120 100% 57* 100% Age (years) 26±10 N/A 31±12 N/A History of migraine/migraine with typical aura (n = 57) 54%/35% Female 37 31% 63 53% Signicant ophthalmology ndings Age of onset (years) 17±11 N/A 25±15 N/A 15% (n = 52 with dilated fundoscopy done) (c) (d) Duration (years) 9±10 N/A 9±12 N/A Palinopsia (trailing) 58 48% 32 56% Palinopsia (afterimages) 75 63% 47 83% Acknowledgements: Excessive oaters 88 73% 48 84% The study was supported by the Deutsche Forschungsgemeinschaft SCHA 1676/1-1. Photopsia (bright ashes) 53 44% 29 51% Photopsia (dark ashes) 32 27% References: Blue eld entoptic phenomenon 68 57% 44 77% [1] Belvis R, Ramos R, Villa C, et al. Brain apparent water diusion coecient magnetic Impaired night vision 69 58% 37 65% resonance image during a prolonged visual aura. Headache. 2010;50:1045-9. Colored clouds with eyes closed 49 41% 29 51% [2] Jager HR, Gin NJ, Goadsby PJ. Diusion- and perfusion-weighted MR imaging in Photophobia 65 54% 40 70% persistent migrainous visual disturbances. Cephalalgia. 2005;25:323-32. [3] Liu GT, Schatz NJ, Galetta SL, et al. Persistent positive visual phenomena in migraine. Color vision changes 15 13% Neurology. 1995;45:664-8. Dim vision 30 25% [4] Rothrock JF. Successful treatment of persistent migraine aura with divalproex Astigmatism 23 19% sodium. Neurology. 1997;48:261-2. Figure 1: Illustrations of visual symptoms drawn by a patient with “visual snow”. (a) Symptoms at [5] Wang YF, Fuh JL, Chen WT, et al. The visual aura rating scale as an outcome predictor night, (b) in daylight, (c) palinopsia (trailing), and (d) blue eld entoptic phenomenon. for persistent visual aura without infarction. Cephalalgia. 2008;28:1298-304.