Intracranial hypotension due to lumbar puncture presenting as a pseudo-subarachnoid hemorrhage on imaging

Abstract

Background A radiological pseudo subarachnoid hemorrhage pseudo SAH is defined as anincreased attenuation along the tentorium cerebelli and falx the basal cisterns the Sylvian fissures and the subarachnoid spaces resembling a subarachnoid hemorrhage SAH on brain computed tomography CT scan Several causes of pseudo SAH have been reported We present a female patient with headache and intracranial hypotension due to lumbar puncture LP in which the CT scan showed similar features to a typical SAH The adequate diagnosis and treatment of intracranial hypotension was delayed until CT angiography CTA digital subtraction angiography DSA and magnetic resonance images MRI were performed to rule out SAH and its potential cause Case presentation We present a year old woman who suffered from a severe post lumbar puncture headache PLPH A non contrast brain CT scan revealed blurred frontal and parietal right sulci and increased attenuation of the ipsilateral Sylvian fissure SAH was diagnosed but the results of CTA and DSA were negative A brain MRI demonstrated right brain sagging Intracranial hypotension due to LP presenting as a pseudo SAH was finally diagnosed and her headache subsided after conservative therapy Conclusion In patients with PLPH intracranial hypotension should be considered in thedifferential diagnosis between SAH and pseudo SAH Although these two entities can share some clinical and radiologic features intracranial hypotension has some distinctive MRI and CT findings Brain sagging bilateral subdural effusions or hematoma and pachymeningeal enhancement on MRI may be valuable findings for distinguishing between intracranial hypotension and SAH These findings should be recognized to avoid unnecessary invasive procedures delays in the diagnosis and implementing an adequate treatment