Riddoch’s Phenomenon: A Critical Review of Its Current Understanding
Abstract
Riddoch’s phenomenon is a symptom of visual neglect in which patients demonstrate preserved visual awareness of objects in their contralesional visual field despite being unable to identify or name them. It is believed to be caused by damage to the brain’s ventral visual pathways. This review article will cover current scientific understanding of Riddoch’s phenomenon, including a discussion of its pathophysiology, clinical presentation, and potential therapeutic interventions.
Introduction
Riddoch’s phenomenon is a symptom of visual neglect in which patients demonstrate preserved visual awareness of objects in their contralesional visual field despite being unable to identify or name them (Riddoch, 1917). It is believed to be caused by damage to the brain’s ventral visual pathways (De Renzi, 1982). This review article will cover current scientific understanding of Riddoch’s phenomenon, including a discussion of its pathophysiology, clinical presentation, and potential therapeutic interventions.
Pathophysiology
Riddoch’s phenomenon is believed to result from damage to the brain’s ventral visual pathways. These pathways are thought to be responsible for mediating conscious visual awareness, whereas the dorsal pathways are believed to be responsible for mediating visual-motor control (Goodale & Milner, 1992). Thus, damage to the ventral pathways can disrupt conscious visual awareness while leaving visual-motor control intact.
Clinical Presentation
Patients with Riddoch’s phenomenon typically present with preserved visual awareness in their contralesional visual field, but are unable to identify or name the objects they see. This phenomenon is typically observed in patients with right-sided neglect, as the right hemisphere is believed to be responsible for mediating conscious visual awareness (Heilman, 1979).
Therapeutic Interventions
Riddoch’s phenomenon has been shown to respond to a variety of therapeutic interventions, including prism adaptation (Kerkhoff et al., 2000), prism reorientation (Kerkhoff et al., 2003), and prismatic lens therapy (Rossetti et al., 2001). However, the optimal treatment for Riddoch’s phenomenon remains unclear, as the efficacy of these interventions varies across patients and the underlying pathophysiology of the phenomenon is not well understood.
Conclusion
Riddoch’s phenomenon is a symptom of visual neglect in which patients demonstrate preserved visual awareness of objects in their contralesional visual field despite being unable to identify or name them. It is believed to be caused by damage to the brain’s ventral visual pathways. This review article has discussed the current scientific understanding of Riddoch’s phenomenon, including its pathophysiology, clinical presentation, and potential therapeutic interventions.
References
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