| Identifier |
walsh_2020_s3_c5-pdf |
| Title |
Close Encounters of the Third Kind (PDF) |
| Creator |
Trishal Jeeval-Patel; Danny Mandell |
| Affiliation |
(TJ) (DM) University of Toronto, Toronto, Canada |
| Subject |
3rd Nerve Palsy, Subarachnoid Hemorrhage |
| History |
A 65-year old woman started experiencing headaches which increased in severity over two weeks. She eventually sought care in the emergency department. Neurological examination was reported as normal. Unenhanced CT of the brain was performed and reported as normal. Headaches continued and she was prescribed oral morphine by her family physician to control the pain without a definite diagnosis. 1 week later she developed oblique binocular diplopia and left upper lid ptosis. She saw her family physician again who referred her for neuro-ophthalmological consultation. On exam, central acuities were normal in each eye, there was obvious left upper lid ptosis, left pupil was 2 mm larger than the right, there was no relative afferent pupillary defect, there were obvious supra-, infra- and adduction motility deficits in the left eye. A diagnosis of partial pupillary involving left third cranial nerve palsy was made. Urgent admission for CT angiogram (CTA) was arranged. After arrival to the hospital the patient collapsed in the cafeteria but regained consciousness in less than a minute which was felt to be a vaso-vagal episode. CT demonstrated smooth, homogeneously hyperdense abnormal thickening along the dura of the falx, tentorium cerebellum, clivus, and floor of the posterior fossa (Figure 1). The distribution was felt to be unusual for subdural hemorrhage and the possibility of inflammatory (IgG-4 disease) or neoplastic infiltrate was raised. Long-standing dural venous thrombosis was also entertained. No aneurysm was identified on CTA. CT of the chest, abdomen and pelvis was performed and was interpreted as unremarkable. A diagnostic procedure was performed. |
| Disease/Diagnosis |
It is taught that recognizing PCOM aneurysms on non-invasive modern neuro-imaging by experienced neuro-radiologist should be possible when aneurysmal size is at least 2-3mm . This case emphasizes that PCOM aneurysms can be very difficult to diagnose despite high quality imaging interpreted by experienced neuro-radiologists. The skullbase with its many bony structures can obscure small aneurysms near big vessels and bones and very thin axial slices are required for its visualization which are not generated in all centres. It also teaches us that aneurysms can rarely rupture into subdural rather than subarachnoid space. Resulting subdural hematoma can be difficult to recognize on imaging as the spacial distribution of blood can be very unusual: instead of localizing along convexity, blood can pool around the entire tentorium/falx/posterior fossa. This in turn can lead to the incorrect focus of differential diagnosis on inflammatory and neoplastic entities. PCOM aneurysms big enough to produce a compressive third nerve palsy can also be occasionally very difficult to see on CTA and in our case it was missed by a very experienced interventional neuro- radiologist. Intracranial aneurysms rupturing into subdural space are very rare and only a few reports describing it were published. No cases of third nerve palsies were described in PCOM aneurysms rupturing into subdural space. Several theories were proposed to explain it: successive small bleeding can cause adhesion of aneurysm to adjacent arachnoid membrane thus when rupturing, aneurysm will bleed into subdural space; stream of blood could also rupture through subarachnoid membrane at its weak point producing blood in the subdural space; lastly, decompression of intracerebral hematoma into subdural space following disruption of the arachnoid covering of cerebral cortex may occur. |
| Date |
2020-03 |
| References |
1. Oh SY, Kwon JT, Park YS, Nam TK, Park SW, Hwang SN. Clinical features of acute subdural hematomas caused by ruptured intracranial aneurysms. J Korean Neurosurg Soc. 2011 Jul;50(1):6-10. 2. Tsao JW, Waldman JL, Manley GT. Ruptured posterior communicating artery aneurysm presenting as acute subdural hematoma. Am J Emerg Med. 2003 Mar;21(2):162-4. 3. Mrfka M, Pistracher K, Augustin M, Kurschel-Lackner S, Mokry M. Acute subdural hematoma without subarachnoid hemorrhage or intraparenchymal hematoma caused by rupture of a posterior communicating artery aneurysm: case report and review of the literature. J Emerg Med. 2013 Jun;44(6):e369-73. 4. Verhey LH, Wang W, Adel JG. True Cortical Saccular Aneurysm Presenting as an Acute Subdural Hematoma. World Neurosurg. 2018 May;113:58-61. |
| Language |
eng |
| Format |
application/pdf |
| Type |
Text |
| Source |
2020 North American Neuro-Ophthalmology Society Annual Meeting |
| Relation is Part of |
NANOS Annual Meeting Frank B. Walsh Sessions; 2020 |
| Collection |
Neuro-Ophthalmology Virtual Education Library: Walsh Session Annual Meeting Archives: https://novel.utah.edu/Walsh/ |
| Publisher |
North American Neuro-Ophthalmology Society |
| Holding Institution |
Spencer S. Eccles Health Sciences Library, University of Utah |
| Rights Management |
Copyright 2020. For further information regarding the rights to this collection, please visit: https://NOVEL.utah.edu/about/copyright |
| ARK |
ark:/87278/s6rc2c47 |
| Setname |
ehsl_novel_fbw |
| ID |
1534168 |
| Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6rc2c47 |
