Thalamic Volume Reduction in Cerebral Visual Impairment: Relationship to Visual Dysfunction.

Abstract

The thalamus is critical for the relay and modulation of visual information. As such, injury to the developing thalamus may result in cerebral visual impairment (CVI). This study investigated quantitative volume reductions of the thalamus in cerebral visual impairment compared to controls and probed the association between thalamic volume and the severity of cerebral visual impairment-related visual dysfunctions. Thalamic volumes were quantified using T1-weighted magnetic resonance imaging (MRI) data from 23 participants with cerebral visual impairment and 42 controls. Nineteen participants with cerebral visual impairment also completed the CVI Questionnaire. Cerebral visual impairment was associated with significant volume reductions of the global thalami, anterior, lateral, and ventral thalamic regions, as well as several nuclei, particularly in those with cerebral visual impairment due to periventricular leukomalacia. Within the cerebral visual impairment group, smaller volumes of the right thalamus and lateral pulvinar were significantly associated with more reported difficulties moving through space. Together, these results provide empirical evidence supporting aberrant thalamic development as a potential mechanism underlying cerebral visual impairment.