The Impact of Heat and Bushfire Smoke on Health System Utilisation in Australia.

The midbrain is an important hub for integrating the motor, sensory, and cerebellar pathways. Its nuclei and white matter tracts are crucial not only for ocular motor control and arousal but also for higher cognitive functions such as attention, memory, and executive processing (,). This cognitive influence is mediated by two key systems: the ascending reticular activating system (ARAS), which sustains cortical arousal (), and dopaminergic projections arising from the ventral tegmental area (VTA) and substantia nigra pars compacta, which modulate executive functions, including attention and motivation (,). A cognitive impairment from a midbrain infarction is typically associated with extensive lesions, including in the pons or bilateral thalamus (). In contrast, in isolated midbrain infarction, one case has been reported in which the main clinical feature was executive dysfunction (), whereas attentional-predominant presentations are extremely rare. We herein describe a case of isolated right midbrain infarction in which the primary manifestation was marked attentional deficit. This impairment manifested not as a subtle finding on examination, but as a notable everyday behavioral change that prompted a medical evaluation. A review of the literature indicates that this presentation is rarely reported in cases of isolated midbrain infarctions. This case illustrates a dissociation between mild classical neurological signs and marked, functionally impairing attentional dysfunction, suggesting the midbrain's role within the cognitive networks.