[Spontaneous intracranial hypotension: findings of cerebral NMR].

INTRODUCTION: The intracranial hypotension syndrome is characterized by a cerebrospinal fluid (CSF) pressure of less than 60 mmH2O and presents as postural hypotension which is often accompanied by nausea, vomiting, cervicalgia and some degree of neck rigidity. It is considered to be spontaneous when there is no known precipitating factor. It is believed that there is a CSF leak across the subarachnoid space, although it is not always possible to detect this. In recent years several authors have described different pathological findings on magnetic resonance (MR) studies.

CLINICAL CASE: We present the radiological studies of a patient with clinical evidence of headache which was worse on standing and improved when lying down. The outflow pressure of CSF was 6 mmH2O when lying down. On isotopic cisternography using Tc DTPA-99m there was no detectable CSF leak. On cerebral MR there was diffuse pachymeningeal thickening with increased signals in T1 sequences. This was more pronounced in T2 with lineal dural uptake of contrast at infra and supratentorial levels. The brain stem meninges were intact. In parallel with a favorable clinical course, following clinical resolution the radiological images were seen to have returned to normal.

CONCLUSIONS: Radiological findings, together with a compatible clinical condition, help to establish the diagnosis of spontaneous intracranial hypotension and avoids the use of unnecessary clinical investigations.