StephanieLenck, Interventional Neuroradiologist, Department of Neuroradiolgy, Groupe Hospitalier Pitié-Salpêtrière, Université Paris Sorbonne (Paris, France)
PatrickNicholson, Interventional Neuroradiologist, Department of Medical Imaging, Toronto Western Hospital, University of Toronto (Toronto, Canada)
Published October 30, 2018
We thank Drs. Kronenberg and Kunte for their comments and interest in our Medical Hypothesis.1 Several authors have suggested that most patients with idiopathic CSF leaks have underlying idiopathic intracranial hypertension (IIH).2,3 Several clinical and radiologic arguments support this. First, there is the common clinical pattern in which the disease occurs (young obese women), then the high prevalence of radiologic signs of IIH in patients with idiopathic CSF leaks,4 the development of IIH symptoms following CSF leak repair, as well as the high rate of recurrence after surgery.5 We, therefore, suggest that the leaks are directly caused by overflow from the overburdened lymphatic CSF outflow pathway in these cases. The chronic excess of increased CSF pressure in the sheaths of the cranial nerves, and especially the olfactory bulbs, would lead to the progressive erosion of the bone and the dura matter at the level of the skull base (e.g., the cribriform plate), eventually resulting in CSF leaks. The leak will immediately relieve the headache and the IIH symptoms experienced by the patient, since it is a “natural” CSF diversion procedure. However, its surgical repair may result either in the development of IIH symptoms or in a recurrence of a leak. This recognition of this entity is important in clinical practice, when facing a patient with a CSF leak caused by IIH, since the treatment of the leak should be performed in conjunction with treatment of IIH, which is the often the underlying cause of the leak.
Lenck S, Radovanovic I, Nicholson P, et al. Idiopathic intracranial hypertension: The veno glymphatic connections. Neurology 2018;91:515–522.
Pérez MA, Bialer OY, Bruce BB, Newman NJ, Biousse V. Primary spontaneous cerebrospinal fluid leaks and idiopathic intracranial hypertension. J Neuroophthalmol 2013;33:330–337.
Bialer OY, Rueda MP, Bruce BB, et al. Meningoceles in idiopathic intracranial hypertension. AJR Am J Roentgenol 2014;202:608–613.
Martínez-Capoccioni G, Serramito-García R, Martín-Bailón M, García-Allut A, Martín-Martín C. Spontaneous cerebrospinal fluid leaks in the anterior skull base secondary to idiopathic intracranial hypertension. Eur Arch Otorhinolaryngol 2017;274:2175–2181.
Teachey W, Grayson J, Cho DY, Riley KO, Woodworth BA. Intervention for elevated intracranial pressure improves success rate after repair of spontaneous cerebrospinal fluid leaks. Laryngoscope 2017;127:2011–2016.
We thank Drs. Kronenberg and Kunte for their comments and interest in our Medical Hypothesis.1 Several authors have suggested that most patients with idiopathic CSF leaks have underlying idiopathic intracranial hypertension (IIH).2,3 Several clinical and radiologic arguments support this. First, there is the common clinical pattern in which the disease occurs (young obese women), then the high prevalence of radiologic signs of IIH in patients with idiopathic CSF leaks,4 the development of IIH symptoms following CSF leak repair, as well as the high rate of recurrence after surgery.5 We, therefore, suggest that the leaks are directly caused by overflow from the overburdened lymphatic CSF outflow pathway in these cases. The chronic excess of increased CSF pressure in the sheaths of the cranial nerves, and especially the olfactory bulbs, would lead to the progressive erosion of the bone and the dura matter at the level of the skull base (e.g., the cribriform plate), eventually resulting in CSF leaks. The leak will immediately relieve the headache and the IIH symptoms experienced by the patient, since it is a “natural” CSF diversion procedure. However, its surgical repair may result either in the development of IIH symptoms or in a recurrence of a leak. This recognition of this entity is important in clinical practice, when facing a patient with a CSF leak caused by IIH, since the treatment of the leak should be performed in conjunction with treatment of IIH, which is the often the underlying cause of the leak.
For disclosures, please contact the editorial office at journal@neurology.org.