Palinopsia Following Acute Unilateral Partial Vestibular Deafferentation: A Case Report

Abstract

Palinopsia is defined as the persistence or reappearance of images after cessation of the visual stimulus. One patient presented episodes of palinopsia after the functional loss of the 3 semicircular canals of the right ear while the otolithic function was preserved. None of classical causes was identified in this patient, intoxications, brain tumors, migraines, psychiatric disorders, etc. For a movement to be perceived as a single event, central processes of temporal integration are necessary to correct the shift between the rapid vestibular information, and the slow visual information. However, it has been shown on animal models that vestibular inputs are slower than normal in case of peripheral deafferentation limited to the canalar function with preservation of the otolithic function, which is the case in this patient. Therefore, we hypothesize that episodes of palinopsia he presents result from the fact that temporal integration processes do not take into account the slower than normal vestibular information due to the peripheral disorder and continue to slow it down. Thus, the patient keeps the visual image in memory until the late arrival of the vestibular information.

Palinopsia as a Rare Presenting Symptom of Occipital Stroke “Case Report”

“…There was no cognitive decline or ataxia as seen in palinopsia in ceroid lipofuscinosis [11]. Palinopsia usually results from a lesion in the dominant hemisphere in 25% of cases [9], as seen in our patient. Authors have reported a case of a glioblastoma tumor in the non-dominant occipito-temporal region, wherein the pattern of palinopsias was a complex scene of the family members and room contents [12].…”

“…Palinopsia in our patient was also not associated with visual snow which is characterized by the perception of TV static-like "snow" in the entire visual field [16]. The absence of vestibular symptoms and normal hearing function of this patient makes it unlikely to be associated with vestibular dysfunction which may provoke palinopsia in few cases [9]. Selective intra cerebral stimulation of the right lateral fusiform gyrus may result in partial or superimposed palinopsia on other images (facial palinopsia) [17].…”

“…Stafuzza et al reported a patient with episodes of palinopsia after the functional loss of the 3 semicircular canals of the right ear with preservation of the otolithic function [9]. The abnormal temporal integration of the visual and vestibular inputs may result in palinopsia if there is a delay in the vestibular inputs [9]. The absence of vestibular symptoms and normal hearing function in our patient makes it unlikely to be a causal factor.…”

“…Episodes of palinopsia may also occur due to disturbances of peripheral vestibular function. Stafuzza et al reported a patient with episodes of palinopsia after the functional loss of the 3 semicircular canals of the right ear with preservation of the otolithic function [9]. The abnormal temporal integration of the visual and vestibular inputs may result in palinopsia if there is a delay in the vestibular inputs [9].…”