Subarachnoid hemorrhage due to intradural cerebral aneurysm and simultaneous spinal subdural hematoma: illustrative case.

Background: Spontaneous spinal subdural hematomas (SSDHs) are unusual. Among their probable etiologies, an association with ruptured brain aneurysms has been described in an extraordinary way. The underlying pathophysiological mechanism is not conclusively described in the literature.

Observations: The authors reported an exceptional case of a 59-year-old woman admitted for a condition that included sudden headache, stiff neck, and vomiting associated with pain in the left flank area that radiated to the leg. Computed tomography (CT) of the brain evidenced acute subarachnoid hemorrhage distributed in the bilateral posterior parieto-occipital fossa and occipital horns of the ventricles. CT angiography detected a dissecting aneurysm in the left vertebral artery (V4) that was treated urgently via the endovascular route. In the next hours, the patient's symptoms worsened, with paraplegia of the lower extremities. Magnetic resonance imaging showed SSDH at T4-6 and extensive associated myelopathy.

Lessons: The origin of the spinal hematoma may be the rupture of the aneurysm of the V4 segment in the dura mater of the foramen magnum and subsequent rostrocaudal migration of the hemorrhage to the spinal subdural space, enhanced by an intracranial pressure increase. This hypothesis is discussed, as is a brief literature review.