Abstract
INTRODUCTION: Idiopathic intracranial hypertension (IIH) is a clinical syndrome characterized by increased intracranial pressure (ICP) without any identifiable cause. However, restrictions of cerebrospinal fluid absorption from the cerebral venous system, the glymphatic system overflow, and the cerebrospinal fluid's lymphatic pathways may be involved in the pathophysiology of IIH. Furthermore, an impaired glymphatic system is also implicated in the initiation and progression of cerebral small vessel disease (CSVD). Here, we reported a case of CSVD with concomitant IIH, possibly associated with the brain's glymphatic and lymphatic system dysfunction. CASE CONCERN: A 39-year-old male presented with worsening headaches over the bilateral parietal areas during the past year and nausea for 2 days. Fundus examination revealed bilateral papilledema and lumbar puncture suggestive of elevated ICP, laboratory results showed hyperhomocysteinemia and mutation of methylenetetrahydrofolate reductase C677T. On magnetic resonance imaging, subcortical small infarct, white matter lesions, lacunes, enlarged perivascular spaces and dilatation of the optic nerve sheaths was detected, and right transverse sinus stenosis and a hypoplastic left sinus were showed on contrast-enhanced magnetic resonance venography. DIAGNOSIS: The diagnoses of IIH, CSVD, transverse sinus stenosis, and hyperhomocysteinemia were performed. INTERVISION AND OUTCOMES: The patient received antihypertensive, antiplatelet, anti-atherosclerotic, and homocysteine-lowering therapies. Finally, the patient's symptoms remised, and the increased ICP returned to normal; however, the bilateral TSS persisted after 3 months of follow-up. CONCLUSIONS: In this case, we speculate that the normal glymphatic outflow pathway may serve as a compensatory mechanism for regulating increased ICP in patients with bilateral venous sinus obstruction, indicating impaired venous outflow pathway, possibly associated with dysfunction of the glymphatic and lymphatic systems in patients with CSVD.