Spontaneous Intracranial Hypotension Manifesting as a Unilateral Subdural Hematoma with a Marked Midline Shift

Abstract

Spontaneous intracranial hypotension (SIH) is a syndrome in which hypovolemia of the cerebrospinal fluid (CSF) results in various symptoms. Although its prognosis is usually benign, cases with a rapid neurologic deterioration resulting in an altered mental status have been reported. One of the characteristic radiographic findings in such cases is the presence of bilateral accumulation of subdural fluid (hematoma/hygroma). When SIH-related subdural hematoma is present only unilaterally with a concomitant midline shift, making an accurate diagnosis may be challenging, and inadvertent hematoma evacuation may result in further neurologic deterioration. We report a 58-year-old woman with an altered mental status who had visited a local hospital and in whom a brain CT showed a unilateral subdural hematoma with a marked midline shift. She was referred to our department because of her neurologic deterioration after hematoma evacuation. A CT myelography revealed a massive CSF leakage in the entire thoracic epidural space. She made a full neurologic recovery following blood patch therapy. Our case is unique and educational because the suspicion for SIH as an underlying cause of subdural hematoma is warranted in nongeriatric patients not only with bilateral but also unilateral lesions. An immediate search for CSF leakage may be important in cases with failed hematoma evacuation surgery.

Dinosaur Tail Sign: A Useful Spinal MRI Finding Indicative of Cerebrospinal Fluid Leakage

“…In contrast to SMRM, FST2WI is a time-saving and costeffective technique that is useful for revealing various disorders including fluid collections more clearly than other techniques, and is recommended as one of the minimum required sequences. 13,14 As SIH has confounding symptoms including initial low back pain and lumbosacral radiculopathy, 15,16 that might lead clinicians to perform a SMRI examination, it is important to understand imaging findings of routine SMRI techniques including the "Dinosaur tail sign" on sagittal FST2WI. The spinal epidural space lies between the dura mater and the periosteal and ligamentous lining of the vertebral canal.…”

Epidural blood patch for spontaneous intracranial hypotension (SIH): a report of two cases

“…SIH needs to be differentiated from the pathophysiologically similar post-lumbar puncture headache, as well as orthostatic headache due to postoperative CSF leakage or shunt over-drainage where there is an obvious trigger. 12 The estimated incidence of SIH is 5 per 100,000 inhabitants, 10 though the real figure might be significantly higher. Women are twice as likely to be affected than men.…”

“…SIH needs to be differentiated from the pathophysiologically similar post-lumbar puncture headache, as well as orthostatic headache due to postoperative CSF leakage or shunt over-drainage where there is an obvious trigger. 12…”

Cerebrospinal fluid leakage at the lumbar spine: A unique cause of delayed neurologic deterioration in a traumatic acute subdural hematoma patient

“…It has been reported that IC can be the underlying cause of SDH. [ 9 10 11 12 13 14 ] Inadvertent hematoma evacuation may not only be ineffective but also be harmful in such circumstances because further decrease in the intracranial pressure after hematoma evacuation may pull cortical bridging veins downward, resulting in venous wall laceration and acute SDH. [ 9 10 11 12 13 14 ] Interestingly, those cases have manifested almost invariably as chronic SDH from the beginning.…”

“…[ 9 10 11 12 13 14 ] Inadvertent hematoma evacuation may not only be ineffective but also be harmful in such circumstances because further decrease in the intracranial pressure after hematoma evacuation may pull cortical bridging veins downward, resulting in venous wall laceration and acute SDH. [ 9 10 11 12 13 14 ] Interestingly, those cases have manifested almost invariably as chronic SDH from the beginning. [ 9 10 11 12 13 14 ] Spinal CSF leakage as the cause of conversion to subacute symptomatic SDH, as shown in the present case, has never been reported in the literature.…”