1. Rupture and spontaneous resolution of a P1 perforator pseudoaneurysm
Teaching NeuroImages
Neurology
Resident and Fellow Section
Giordan et al.
© 2018 American Academy of Neurology

2. Vignette
47 year-old male with history of smoking and hypertension
Sudden onset of headache
Admission Head CT showed subarachnoid hemorrhage with epicenter in the interpeduncular cistern
Develops progressive ophthalmoplegia and brain MRI documented bilateral thalamic infarcts
Admission catheter angiography showed no vascular lesions
Repeat catheter angiography four days later showed a 2 mm dissecting pseudoaneurysm of a thalamoperforator artery
The pseudoaneurysm was managed conservatively and a follow-up catheter angiogram six weeks later demonstrated spontaneous obliteration
Giordan et al.
© 2018 American Academy of Neurology

3. Images Giordan et al. A A B C D F E G F Figure 1
A. Admission CT shows SAH (arrow). B. Initial catheter angiography shows no visible abnormalities. C. Brain MRI DWI: bilateral thalamic infarcts (arrows). D. Follow-up angiography, 3D reconstruction, demonstrated a 2 mm pseudoaneurysm arising from a large left thalamoperforator (arrow); E. 2-D of the same study. F. Angiography six weeks after presentation documents spontaneous resolution of the pseudoaneurysm (circle).
Giordan et al.
© 2018 American Academy of Neurology

4. Rupture and spontaneous resolution of a P1 perforator pseudoaneurysm
Dissecting pseudoaneurysms of perforating posterior circulation vessels can present with a pattern suggestive of perimesencephalic SAH.
Presence of neurological deficits should increase the level of suspicion.
Spontaneous resolution can occur without invasive treatment [1].
1. Park SQ, Kwon OK, Kim SH, Oh CW, Han MH. Pre-mesencephalic subarachnoid hemorrhage: rupture of tiny aneurysms of the basilar artery perforator. Acta Neurochir (Wien) Dec;151(12): doi: /s Epub 2009 Jun 5.
Giordan et al.
© 2018 American Academy of Neurology