Plain Language Summary Publication: Mild cognitive impairment in spontaneous intracranial hypotension and its rapid reversal by repair of a spinal cerebrospinal fluid leak

Main Finding: There may be a relationship between “brain fog” or cognitive dysfunction and spinal cerebrospinal fluid (CSF) loss. We suggest considering spinal CSF leaks as a treatable cause in patients with mild cognitive impairment and with pre-dementia. Motivation (Problem): Spontaneous intracranial hypotension (SIH) occurs when CSF leaks from the spine, affecting about 4–5 people per 100,000 each year. Different types of spontaneous leaks are known, yet can be difficult to diagnose. This condition can lead to severe headaches that are often characterized as orthostatic (worsening when standing). Furthermore, various other symptoms can occur, including cognitive issues commonly referred to as “brain fog.” This study aimed to assess cognitive function in patients with SIH before and after treatment to better understand these cognitive complaints. Methods: We conducted a retrospective analysis of 18 patients consecutively admitted to a tertiary center between May and July 2023. They underwent standard cognitive assessments, including the Montreal Cognitive Assessment (MoCA) and the Trail Making Test Part B (TMT B). These tests were administered before and again 36–72 h after treatment. Results: The patients were on average aged 54 years and 40% were female. The initial cognitive tests showed that nearly one-third of patients had mild cognitive impairment, and half struggled with the TMT B task. Following treatment, which typically involved minimally invasive surgery to repair leaks, cognitive scores significantly improved. The MoCA scores rose from an average of 26.5–28.5, indicating better cognitive function, particularly in visual–spatial and executive tasks. Implications (for the future): The findings suggest a link between the closure of spinal CSF leaks and the improvement of cognitive deficits, possibly implying that restoration of normal CSF dynamics may enhance brain function. The study highlights the importance of considering SIH as a potential cause of mild cognitive impairment, especially in younger patients, advocating for more comprehensive cognitive evaluations in these cases. However, the study had limitations, including a small sample size and its observational nature. The thresholds for cognitive impairment may not fully reflect younger patients’ capabilities, suggesting a need for more targeted research and standardized cognitive testing for SIH. Overall, this work calls for further exploration of the underlying relationship between CSF circulation and cognitive health. Katharina Wolf, Florian Volz, Amir El Rahal, M. Overstijns, Niklas Lützen, Charlotte Zander, Mukesch J. Shah, Horst Urbach, and Jürgen Beck declare that there are no competing financial and/or non-financial interests in relation to the work described.