Abnormalities On Sagittal T2 Weighted MRI Of The Spine In Spontaneous Intracranial Hypotension
Purpose: To demonstrate the utility of sagittal MRI of the spine in the diagnosis of spontaneous intracranial hypotension.
Spontaneous (‘idiopathic’) intracranial hypotension is under-diagnosed. It is caused by spontaneous spinal CSF leaks. These leaks can be detected by various imaging techniques, but the most sensitive of these is not known. We report on the MRI findings in 2 patients recently diagnosed with spontaneous intracranial hypotension.
Methods: Case Reports
Case 1: 28 year old female who presented to the emergency department with a sudden onset, severe, posturally dependant headache. She had been lifting a heavy fridge the day before.
Case 2: 35 year old female who presented to the emergency department with severe, posturally dependant headache, as well as nausea and vomiting.
Results: A clinical diagnosis of headache secondary to intracranial hypotension was made in both patients. CT of the brain and CSF examination was normal, although CSF pressure was not measured. MRI of the brain with gadolinium showed dural thickening and enhancement but no other abnormalities. Sagittal T2 weighted MRI of the spine in case 1 showed a dorsal extradural fluid collection from C7 to L1 consistent with a CSF leak, and in case 2 a dorsal extradural fluid collection from C3 to L4.
Conclusions:
• Extradural fluid collections identified on sagittal T2 weighted MRI of the spine can assist in the diagnosis of spontaneous intracranial hypotension.
• It remains unclear whether such collections are the direct result of spinal CSF leakage, or alternatively are subdural transudates secondary to hydrostatic pressure changes related to decreased CSF volume (the Monroe-Kellie Hypothesis).
