Background
Idiopathic intracranial hypotension syndrome (SHII) is one of the most infrequent causes of headache in the general population.
Thanks to nuclear magnetic resonance (NMR) it has been proven that it originates from a small leak of CSF through the dura mater. This syndrome seems to be associated with different systemic connective tissue diseases such as Marfan syndrome and Ehlers-Danlos syndrome.
It usually affects women between the ages of 40 and 60. Being extraordinarily infrequent in childhood age.
The following is the case of a 10-year-old female patient studied for a one-year history of continous headache. Because of the clinical characteristics of the picture presented, CT and MRI with and without contrast were requested. These imaging tests ruled alterations compatible with (SHII) were found.

Methods
We present a clinical case of a female patient 10 years of age with spontaneous intracranial hypotension syndrome, in which a complete response to a blood patch was observed.
The patient had no medical or surgical history of interest.
Clinical signs and symptoms such as a migraine-like headache which appeared suddenly after performing rhythmic gymnastics exercises. The headache was of the holocranial kind, worsening during standing and sitting and improving and disappearing with decubitus. Physical examination was normal. This headache increased in intensity and frequency with the passage of time.
Cranial NMR, which showed: Cerebellar tonsillar descent one centimetre below McRae’s line, with moderate mesencephalic descent and normal loss of pontomesencephalic confluence. (Image 1). Besides an enlargement in the thickness of the meningeal coverings and especially of the anterior epidural space in the spine, with marked contrast uptake relating to the CSF hypotension process (Image 2). No intracranial focal lesions or meningoceles or signs of CSF leak were seen in the images obtained.
With these findings the suspicion of spontaneous intracranial hypotension syndrome was confirmed and it was decided to initiate pharmacological treatment with caffeine, at a dose of 50 mg per day.
Consequently, given the resistance of the clinical picture to the pharmacological treatment it was decided to undertake an epidural blood patch.
The punchure was at L2-L3 with a 18G Tuohy needle using the loss of resistance technique.
Under aseptic conditions, 20 mL of blood were extracted from the upper left arm. Of these 20 mL, 10mL were discarded, inserting the rest into the epidural space.
Results.
One month after performing the epidural blood patch, the patient was evaluated at outpatients where a clear clinical improvement was noted. She reported a single headache with a duration of several hours and with a VAS score of 2.
Six months after the blood patch the patient reported a relapse with migraine crises more spaced out and of less intensity than at the beginning, VAS 4, therefore it was decided to repeat the epidural blood patch, given the good response obtained on the first occasion.
In subsequent follow-ups at 30, 90 and 180 days after the second blood patch the patient was asymptomatic. During the 2-year follow-up period the patient continued asymptomatic without developing any migraine crises.At that time it was decided to carry out complementary follow-up tests (Image 3) that also confirmed the imaging ones.
Conclusions
Spontaneous intracranial hypotension, called headache attributed to a spontaneous or idiopathic decrease in CSF pressure in the International Headache Society classification. It is a clinical entity that is probably under-diagnosed and more frequent than we think, its clinical spectrum is broad.
Complementary test confirmation is done using MR confirmation of dural enhancement as a reflection of low CSF pressure, evidence of CSF loss using CT myelography or cisternography or conventional myelography, or CSF opening pressure less than 60 mm H2O while sitting.
Treatment of idiopathic cases is the same as those with a known cause (post-operative fistulas in spinal surgery due to a break in the dura mater, post-anaesthesia...) conservative. In refractory cases epidural patches using autologous blood that is injected in order to generate scarring to close the fistula have been used successfully. 
Intracranial hypotension is a much less frequent syndrome than intracranial hypertension but even so we must always bear it in mind since it is very incapacitating for patients who suffer from it.

IDIOPATHIC INTRACRANIAL HYPOTENSION SYNDROME (IIHS) IN A 10 YEAR-OLD PATIENT