Response to Letter to the Editor: Headache After Sealing of Cerebrospinal Fluid Leaks in Patients With Spontaneous Intracranial Hypotension

We thank Irshad and Nizami for their letter to the editors commenting on our article “Headache After Sealing of Cerebrospinal Fluid Leaks in Patients With Spontaneous Intracranial Hypotension.” We agree that rebound intracranial hypertension is a well-known complication in SIH patients following successful sealing of a CSF leak. However, there is no consensus on how to approach these patients. Fortunately, rebound hypertension has been found to be self-limited in most cases. Consequently, lumbar punctures are not warranted for these patients. Indeed, a repeat lumbar puncture might actually be harmful by causing a second lumbar leak with subsequent post-punctional headache or even worse complications in subjects who are just recovering from intracranial hypotension. It is true that from a purely methodological point of view, a control population of untreated SIH patients would most certainly strengthen our findings. However, given the known risks of persisting CSF leaks such as superficial siderosis, subdural hematoma and bibrachial atrophy [1], we strongly recommend treating every SIH patient with a proven CSF leak. A control group with primary headache disorders such as migraine would not be adequate since they are both fundamentally different in respect to clinical and pathophysiological mechanisms. In our study, we were able to explore pre-existing primary headache and other co-morbidities (e.g., medication overuse) as potential risk factors for persistent headache despite successful sealing of the CSF leak. It is true that we did not elaborate in detail on our treatment protocol for sealing CSF leaks in SIH patients, which have been described elsewhere [2, 3]. Rather than classifying CSF leaks as high- vs. low- flow leaks, as suggested by Nizami and Irshad, anatomical location and type of the CSF have proven to be the key determinants in selecting the appropriate management strategy (microsurgical repair vs. endovascular embolization). As detailed in the method section, this is a retrospective study of a large population of a rare disorder. This comes with inherent limitations, such as no standardized follow-up and the lack of psychometric- and headache-related scores as listed by the authors of the comment. Similarly, we did not explore central pain sensitization using methods such as cutaneous allodynia or “permanent pain pathways changes.” Although being interesting, data on central sensitization would not allow assessing whether headaches are due to ongoing CSF disturbances, as central sensitization is not specific with regard to the etiologies of chronic pain syndromes. Still, we agree that such patient-reported outcomes, scores and measures of central sensitization would be interesting, and we encourage the authors and other researchers worldwide to set up prospective and controlled studies to better understand and treat patients with SIH. Adrian Scutelnic: conceptualization, writing – review and editing, validation. Nedelina Slavova: writing – review and editing, validation. Eric Morel: writing – review and editing, validation. Franz Riederer: writing – review and editing, validation. Tomas Dobrocky: writing – review and editing, validation. Eike I. Piechowiak: conceptualization, writing – review and editing, validation. Ralph T. Schär: conceptualization, writing – review and editing, validation. Christoph J. Schankin: conceptualization, writing – review and editing, validation. The authors declare no conflicts of interest. The authors have nothing to report.