Published online by Cambridge University Press: 15 June 2018
Pixelated vision or visual snow has been associated with schizophrenia (Silverstein 2011). The impact of viewing a 3D motion picture on such a visualphenomenon has not heretofore been described.
Case Study: A 28 year old right handed single male three years prior to presentation noticed that all his vision was pixelated. The pixelated vision is panoramic, involving the entire visual field. The pixels are characterized by 10,000 flat white and gray dots measuring 1mm x 1mm. No changes in color, shape, or size were noted in high and low intensity light. White, dark, gray, or multicolored backgrounds had no effect on his vision. The visual distortions are not impacted by head movements, emotions, degree of tiredness, driving, or his hedonic perception of the object being visualized. The pixels were noted to disappear upon closure of both eyes but persisted during monocular vision with either eye. These visual hallucinations were sporadic during the first year and became continuous over the following two years. Two weeks after onset ofpixelated vision he developed auditory hallucinations and hyperacusis. These increased in intensity and frequency to 500-600 times per day. He denied palinopsia, migraines, tinnitus, and photophobia. These hallucinations persisted despite treatment with aripiprazole, paliperidone, lurasidone, olanzapine, clozapine, ziprasidone, benztropine, bupropion, lamotrigine, modafinil, trazodone, atomoxetine, and amphetamine.
Abnormalities in Examination: Hypoverbal, blunted affect, impaired concentration, preoccupied with racing thoughts. Admitted to actively having auditory and visualhallucinations, without suicidal or homicidal ideations. Memory testing: Able to recall 2 out of 4 objects in 3 minutes and 3 out of 4 with reinforcement. Similarities interpreted concretely. Visual Acuity: 20/20 OU. Retinal examination: Normal. Intraocular Pressure: 19 mm OD, 20 mm OS (normal). Automotive Perimetry Testing: Normal. Cover/Uncover: Normal. Near Convergence: 3 inches (normal). Lens or filtered prism have no effect on visual snow. MRI of his brain, EEG, BAER, liver function tests, CBC, vitamin B12, folate, and thyroid function tests were normal. MRA: mild hypoplasia of distal right vertebral artery.
Visual snow has been anecdotally described as static, continuous, and independent of the specific visual environment (McKendrick, 2017). However, thepersistence of visual snow in the presence of 3D movies has never been reported. The visual snow paralleled auditory hallucinations and hyperacusis in frequency and intensity, which suggests there may be generalized hyperexcitability of the brain inducing both auditory and visual hallucinations. Agents that reduce cortical hyperexcitability (i.e., anticonvulsants, anxiolytics) may have efficacy. Treatment with these agents has been described (Ghannam, 2017), warrants further investigation.
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