Acute carbon monoxide poisoning (ACOP) is the most common form of gas poisoning and typically occurs at night when doors and windows are closed [1,2]. While most patients recover after the acute phase of carbon monoxide (CO) poisoning, a subset may develop delayed neurological sequelae (DNS) [3,4]. DNS is a severe complication that can emerge days to weeks after the initial CO exposure, even in patients who initially appeared to have recovered [5,6]. It manifests as a range of neurological impairments, including dementia, psychiatric symptoms, and extrapyramidal dysfunction [[7], [8], [9]]. Neuroimaging studies have revealed both structural and functional changes in the brains of patients with ACOP and DNS, notably involving extensive damage to white matter [[10], [11], [12]]. However, whether brain waste clearance dysfunction occurs following ACOP or DNS remains unclear.

The glymphatic system (GS) plays a crucial role in waste removal, fluid balance, and neuroinflammatory regulation in the brain. Dysfunction of the GS has been implicated in various neurological conditions, including neuroinflammation, cognitive impairment, and neurodegenerative diseases [13,14]. Impaired GS function is associated with reduced diffusion of water molecules along the perivascular space (PVS), leading to diminished clearance capacity.

Recently, a novel imaging technique, diffusion tensor imaging–analysis along the perivascular space (DTI-ALPS), has gained increasing attention for its non-invasive nature, high reproducibility, and strong stability [15]. DTI-ALPS analyzes the diffusion behavior of water molecules along the PVS, partially reflecting the activity of the GS system [16]. Previous studies used DTI-ALPS index to partially evaluate the GS function, for example, Yang et al. assessed the associations of GS impairment using DTI-ALPS index and cognitive impairment in mild traumatic brain injury [17]. Similarly, a study has found that the DTI-ALPS values of patients with multiple sclerosis are also affected [18]. However, to date, no study has explored the connection between GS function using DTI-ALPS index and global white matter damage in patients with ACOP and DNS.

Therefore, this study aims to partially evaluate the GS function using DTI-ALPS in patients with ACOP and DNS and to integrate DTI-ALPS indices with clinical biomarkers to develop a classifier for distinguishing DNS from non-DNS cases in the acute phase.