[Magnetic resonance in dural post-puncture headache in patient with cerebrospinal fluid hypotension]

Magnetic resonance imaging (MRI) has allowed us to establish a set of radiologic signs associated with intracranial hypotension syndrome. Findings are partly influenced by cerebral displacement. Intracranial hypotension syndrome is characterized by a decrease in cerebrospinal fluid (CSF) pressure to less than 60 mm H2O associated with occipital headache radiating to the frontal and temporal zones. For diagnostic purposes, the most common cause is anesthetic or therapeutic dural puncture, although spontaneous CSF leakage can occur. CSF protein and lymphocyte counts may be high, while the cranial meninges biopsy is normal. MRI images may show a descended brain, taking the start of the sylvian aqueduct and the location of the cerebellar amygdalae as points of reference; diminished size of the subarachnoidal cisterns and occasionally of the cerebral ventricles; meningeal enhancement from increased uptake of the contrast solution; subdural hygromas and hematomas; and pituitary enlargement. Paraspinal fluid and dilated epidural veins may be observed. Radiologic images and clinical signs are related. When CSF pressure is very low, there is greater meningeal enhancement, subdural collection and cerebral displacement. Findings gradually disappear as symptoms diminish. The signs and symptoms that might develop during intracranial hypotension syndrome vary according to the brain structure that might be affected during descent, repositioning and the traction of anchoring structures. MRI allows the degree of cerebral and spinal involvement to be ascertained, to predict whether resolution of the clinical picture will be early or late and to visualize the effect of approaches to reducing CSF leakage.