Posttraumatic cerebrospinal fluid leak with cognitive dysfunction, especially visual memory disturbance: illustrative case.

backgroundCerebrospinal fluid (CSF) leaks are associated with various clinical and neurological manifestations. Although cognitive dysfunction has been reported in patients with a CSF leak, its detailed characteristics and cognitive profile remain unclear. OBSERVATIONS: A 17-year-old male patient developed progressive cognitive decline after minor head trauma. The initial neuroimaging findings were unremarkable; however, over several months, he exhibited memory impairment, academic decline, and personality changes. Neuropsychological testing has demonstrated significant deficits in visual memory, reduced working memory, and reduced processing speed. A detailed interview revealed a subtle orthostatic headache that had been present since the head injury, prompting further evaluation. Spinal MRI and CT myelography confirmed a CSF leak in the cervical spine. The patient underwent placement of a blind lumbar epidural blood patch, which resulted in immediate headache relief and gradual cognitive improvement, particularly in visual memory. LESSONS: CSF leaks can manifest primarily as cognitive dysfunction, even without typical headache or imaging findings, leading to diagnostic delays and potential misdiagnosis of psychiatric illnesses. Visual memory impairment might represent a characteristic and underrecognized feature of a CSF leak. Comprehensive neuropsychological assessment with domain-specific testing is essential for accurate diagnosis of atypical presentations. https://thejns.org/doi/10.3171/CASE25939.