Hemianopia and Features of Bálint Syndrome following Occipital Lobe Hemorrhage: Identification and Patient Understanding Have Aided Functional Improvement Years after Onset

Abstract

Introduction. Cerebral visual impairment (CVI) can present around birth or any time thereafter. Homonymous hemianopia is a common feature. The concept that functional improvement is unattainable augurs against active management. Dorsal stream dysfunction (or Bálint syndrome when severe) results from bilateral posterior parietal dysfunction but may go undetected, especially in children. Case Presentation. At 16 the patient suffered spontaneous left occipital lobe brain hemorrhage from a ruptured arteriovenous malformation. This was surgically excised. Short lived right upper limb intermittent jerking, with additional left sided weakness, ensued. Anomalous EEG recordings, with right-sided bias, arose from the posterior temporoparietal area. A right homonymous hemianopia was evident. During the ensuing 17 years she experienced multiple complex difficulties, until, at a lecture describing how to identify and support children with CVI, she realized she herself had many of the difficulties described. Visual assessment identified hemianopia and dorsal stream dysfunction. Discussion. Following identification, characterization, and explanation of the impact of her visual difficulties, she both gained greater awareness of her visual difficulties and their impact and developed a range of strategies leading to functional improvement of her visual field loss and amelioration of her dorsal stream dysfunction, with great improvement in quality of life.

Assessing Higher-Order Visual Processing in Cerebral Visual Impairment Using Naturalistic Virtual-Reality-Based Visual Search Tasks

“…We assessed visual search performance while study participants interacted with two novel VR-based naturalistic environments as a means to objectively characterize functional vision abilities. The results obtained from this study are consistent with the prominence of higher-order visual processing deficits observed in CVI [ 9 , 12 ] and reports of how individuals with CVI face challenges with selecting and extracting visual information from complex scenes [ 12 , 13 , 14 , 15 ].…”

“…Consistent with clinical accounts [ 12 , 13 , 14 , 15 ], we hypothesized that CVI participants would show an overall impairment in search performance as indexed by multiple behavioral outcome measures (including success rate and reaction time) as compared to age-matched controls with neurotypical development. Further, we hypothesized that as a group, individuals with CVI would show greater impairment with increasing task demands associated with scene complexity.…”

“…Individuals with CVI often report challenges with searching and extracting visual information from complex (i.e., cluttered or crowded) scenes [ 12 , 13 , 14 , 15 ]. These perceptual difficulties can make an individual feel overwhelmed and anxious or, in some cases, appear inattentive.…”

“…For example, they may easily identify a favorite toy when presented in isolation, yet have difficulties finding it when placed in a box filled with other toys [ 11 ]. They may also struggle to identify a familiar person (including a family member) in a very busy crowd [ 13 , 14 , 15 ].…”

Neural correlates associated with impaired global motion perception in cerebral visual impairment (CVI)

“…Even in the case where visual acuity and visual field functions are within normal range, deficits with higher order visuospatial processing (including the perception of complex motion) are also frequently observed which can have a profound impact on an individual’s functioning and independence ( Dutton et al, 2006 , Boot et al, 2010 , Dutton, 2013 ). Indeed, individuals with CVI often report feeling overwhelmed in crowded environments, and have difficulty walking down stairs or following the flow of moving traffic ( Lam et al, 2010 , McDowell and Dutton, 2019 ). These visual impairments are thought to be linked to the timing, location, and severity of the underlying neurological injury ( Anderson et al, 2011 ) that affect the development of key visual processing networks within the brain ( Volpe, 2009 ).…”