DELAYED ISCHEMIC DEFICIT AFTER RESECTION OF A LARGE INTRACRANIAL DERMOID: CASE REPORT AND REVIEW OF THE LITERATURE Robert D. Ecker, M.D. Department of Neurologic Surgery and Division of Neuroradiology, Mayo Clinic and Foundation, Rochester, Minnesota John L. Atkinson, M.D. Department of Neurologic Surgery and Division of Neuroradiology, Mayo Clinic and Foundation, Rochester, Minnesota Douglas A. Nichols, M.D. Department of Neurologic Surgery and Division of Neuroradiology, Mayo Clinic and Foundation, Rochester, Minnesota Reprint requests: Robert D. Ecker, M.D., Department of Neurological Surgery, Joseph 1–229, St. Mary’s Hospital, 1216 Second Street SW, Rochester, MN 55905. Email: ecker.robert@mayo.edu Received, May 21, 2002. Accepted, July 23, 2002. OBJECTIVE AND IMPORTANCE: A unique case of delayed ischemic deficit after resection of a large intracranial dermoid is presented. CLINICAL PRESENTATION: A 23-year-old woman, 36 hours after the uneventful gross total resection of a large intracranial dermoid cyst, slowly developed a progressive mixed aphasia and right hemiparesis. Magnetic resonance imaging and magnetic resonance angiography revealed small infarcts of the left putamen and temporal-occipital junction and a vasospastic tapering of the left M1 segment. INTERVENTION: Angiography confirmed severe vasospastic tapering of the left M1 and M2 segments. Endovascular treatment successfully restored flow in the left superior division. However, the initial attempt at low-pressure dilation of the inferior division led to vessel rupture. Seven months after reoperation for emergent trapping of the M1 segment, the patient made an excellent recovery, with only mild right-hand incoordination. CONCLUSION: Ruptured dermoid cysts are a risk for early and delayed cerebral ischemia, and endovascular treatment of dermoid-encased vessels may carry a higher risk for rupture. KEY WORDS: Delayed ischemic deficit, Dermoid, Stroke, Vasospasm Neurosurgery 52:706-710, 2003 DOI: 10.1227/01.NEU.0000048482.27700.3B I ntracranial dermoids comprise less than 1% of all intracranial neoplasms (1, 8, 12). Multiple complications secondary to dermoid rupture have been reported; however, cerebral ischemia has been rarely described (1, 3, 5, 10, 12, 13). Although intracranial vasospasm is the presumed mechanism for ischemia, there is only one previous report with angiographic confirmation of vasospasm after dermoid rupture (10). We report what is, to our knowledge, the first case of delayed ischemic deficit after resection of a large intracranial dermoid cyst, likely the result of superimposed vasospasm on top of an already present preoperative vasculopathy. CASE REPORT A 23-year-old previously healthy woman reported the sudden onset of a severe, leftsided headache 2 months before our evaluation. During the ensuing weeks, the headache increased in intensity, requiring progressive escalation of nonsteroidal antiinflammatory agents. One month before our 706 | VOLUME 52 | NUMBER 3 | MARCH 2003 www.neurosurgery-online.com evaluation, she developed persistent nausea and intermittent problems finding words. At neurological examination, her mental status, speech, visual fields, fundus, motor, sensory, and reflex examinations were normal. Magnetic resonance imaging (MRI) scans revealed a 3.5- ⫻ 3- ⫻ 6-cm left sylvian heterogeneous cyst, bright on T1- and T2weighted sequences with leakage of cyst contents over the left frontal lobe (Fig. 1). The most likely diagnosis was a ruptured dermoid cyst. Clinically, her intermittent speech symptoms and headache may have signified a low-grade vasculitis. However, the preoperative MRI scan revealed no evidence of cerebral ischemia, and the left M1 appeared to be of normal size. The patient underwent a left pterional craniotomy and a gross total resection of the dermoid mass through a transsylvian approach. Dermoid contents could be observed throughout the subarachnoid space before the fissure was split. The lesion was completely resected except for the densely adherent capsule layering over the insular cortex and deep frontal lobe. The middle www.neurosurgery-online.com DELAYED ISCHEMIC DEFICIT AFTER DERMOID RESECTION FIGURE 1. A and B, sequential coronal T1-weighted MRI images revealing a large frontotemporal dermoid with ruptured contents spilled over the left hemisphere. cerebral artery (MCA) could be observed through the remaining capsule and was never physically manipulated during the operation. It appeared normal through the opaque dermoid membrane overlying it. We deliberately did not irrigate the tumor cavity because we wanted to avoid further spread of the dermoid products; the lesion FIGURE 2. A–D, axial T2-weighted MRI scans revealing postoperative bed and left lentiform nucleus infarct. NEUROSURGERY was surgically incurable as a result of the previous rupture of its contents. Pathological findings confirmed the diagnosis of dermoid. The patient awoke from the operation neurologically intact. Thirty-six hours after the operation, the patient slowly developed word-finding difficulty and a mild right upperextremity drift. A computed tomographic scan of the head revealed a 2.5- ⫻ 1-cm putaminal infarct. An MRI scan revealed a left lentiform nucleus infarct with extension to the corona radiata and a small left temporo-occipital infarct (Fig. 2). Magnetic resonance angiography revealed a tapered highgrade stenosis of the M1 segment with no appreciable flow in the M2 segments. Although clinically stable, the patient was placed in the intensive care unit, and cerebral augmentation therapy was initiated by hypervolemia and mild hypertensive therapy. There was no significant clinical improvement, and a cerebral angiogram was performed. Cerebral angiography revealed severe vasospasm of the left M1 segment and the inferior division M2 segment, a tapered vasospastic-appearing occlusion of the superior M2 segment, and moderately good collaterals from the left anterior cerebral and posterior cerebral to the distal left MCA circulation (Fig. 3). Balloon angioplasty of the M1 and superior division segment was performed successfully, and flow was restored. However, with attempted lowpressure balloon dilation of the inferior segment, the MCA ruptured at the superior aspect of the bifurcation. Heparinization was reversed, the balloon was reinflated across FIGURE 3. A–D, sequential angiograms. A, severe left MCA vasospasm, with moderately good collaterals. B, after papaverine injection and angioplasty of M1 and superior division, filling defects consistent with thrombus can be visualized. C, rupture of M1-inferior M2 junction with attempted dilation. D, M1 segment with balloon reinflated. VOLUME 52 | NUMBER 3 | MARCH 2003 | 707 ECKER ET AL. the ruptured segment, and the patient was emergently brought to the operating room. After reopening the craniotomy, the dura was extremely tense, and a ventricular drain was placed, resulting in good relaxation of the brain. Minimal clot could be evacuated. Inspection of the M1 and its bifurcation revealed an extensive blowout of the backwall. With coordinated efforts, the balloon was deflated, and two microclips were placed on the superior and inferior M2 divisions and on the M1, distal to the anterior temporal branch. A bypass was thought to be unnecessary as the angiogram revealed good collateral flow. The patient was placed in the intensive care unit and received hypervolemic and hypertensive therapy. She awoke after the operation worse than before, with a mild right hemiparesis and mixed aphasia. One week later, MRI and magnetic resonance angiography revealed temporal evolution of the known strokes and the expected occlusion of the left M1 and M2 segments with increased leptomeningeal collateral. However, the previously robust flow in the left A1 was now vasospastically tapered (Fig. 4). The patient remained asymptomatic from this new finding secondary to excellent filling of both A2 segments from a patent anterior communicating artery. During the next 2 weeks, both her aphasia and hemiparesis resolved almost completely. At a 7-month follow-up examination, her speech was normal, but she displayed mild difficulty with right-sided fine motor tasks. DISCUSSION Multiple complications of intracranial dermoid rupture have been reported, including headache, seizures, meningitis, acute hemiparesis, cheiro-oral syndrome, arachnoiditis, ventriculitis, and hydrocephalus (1, 3, 4, 7–9, 13, 16). However, there are only three reports of symptomatic ce- rebral ischemia (5, 10, 12). The first involved a 26-year-old man who, after a prodrome of right hand numbness, developed right-sided weakness, aphasia, headache, and vertigo (5). The symptoms disappeared in 3 hours. Angiography revealed no cause for the transient ischemic attack. The second case involved a 37-year-old man who presented with an acute left hemiparesis (10). Angiography revealed significant vasospasm of the supraclinoid carotid artery. Both the hemiparesis and the angiographic findings resolved in 6 weeks’ time. Finally, a recent report described the case of a 15-year-old girl whose dermoid caused headache and a cheiro-oral syndrome (12). After angiography and electroencephalography revealed nothing abnormal, a transient vasospasm was thought to be mechanistically possible. To our knowledge, our case is the first report of delayed ischemic deficit revealed angiographically after resection of a large, ruptured intracranial dermoid. The delayed clinical onset and staged progression of both M1 and A1 narrowing strongly suggest arterial vasospasm as the mechanism. Experimental studies have induced arterial vasospasm with lipid metabolites and hyperkalemia—both of which are plausible effects of ruptured dermoid cysts (14, 15). Although no preoperative angiogram was performed in our case, the clinical course of headaches for 2 months and MCA rupture during low-pressure balloon dilation suggest a prolonged vasculopathy, probably the result of ruptured dermoid products surrounding the MCA and its branches, compounded by postsurgically induced vasospasm. Complete surgical resection of dermoid tumors is the treatment of choice (2, 3, 6, 8, 16). Frequently, the dermoid’s outer membrane is so densely adherent to intracranial vasculature or brain parenchyma that it cannot be removed safely (2, 6, 16). Additionally, there have been two documented cases of dermoid cysts fully encasing intracranial arteries (11). Even with residual membrane, dermoids rarely recur (8, 16). However, as in our case, by leaving dermoid residue, there is invariably dermoid material left in the tumor bed that may precipitate postoperative meningitis (9, 16). We deliberately did not irrigate the dermoid cavity, hoping that dermoid products would not be spread over an already seeded brain. In retrospect, gentle but copious irrigation might have lowered the concentration of dermoid byproducts and the risk of delayed cerebral ischemic deficit. CONCLUSION FIGURE 4. A and B, sequential magnetic resonance angiograms. A, left anterior cerebral circulation demonstrating good flow through the left A1 segment. B, left anterior cerebral circulation demonstrating poor flow through the left A1 1 week later. 708 | VOLUME 52 | NUMBER 3 | MARCH 2003 Patients with ruptured intracranial dermoid cysts can present with symptoms of cerebral ischemia. We present the first case of delayed cerebral ischemic deficit after dermoid resection. Preoperative vessel encasement and dermoid products aggravated by surgical resection were likely contributory. Endovascular treatment of these diseased vessels may carry a higher risk of rupture. www.neurosurgery-online.com DELAYED ISCHEMIC DEFICIT AFTER DERMOID RESECTION REFERENCES 1. Abramson RC, Morawetz RB, Schlitt M: Multiple complications from an intracranial epidermoid cyst: Case report and literature review. Neurosurgery 24:574–578, 1989. 2. Bucciero A, De Caro ML, Tedeschi E, Vizioli L, Cerillo A, Tedeschi G: Intracranial epidermoid and dermoid cysts: Results of microneurosurgery. Minerva Chir 52: 863–866, 1997. 3. Bucciero A, Del Basso De Caro ML, Carraturo S, Vizioli L, Cerillo A, Tedeschi G: Supratentorial dermoid cysts: Presentation and management of five cases. J Neurosurg Sci 39:7–11, 1995. 4. Currarino G, Rutledge JC: Temporoparietal dermoid cysts with intracranial extension. AJNR Am J Neuroradiol 9:385–387, 1988. 5. Ford K, Drayer B, Osborne D, Dubois P: Case report: Transient cerebral ischemia as a manifestation of ruptured intracranial dermoid cyst. J Comput Assist Tomogr 5:895–897, 1981. 6. Fornari M, Solero CL, Lasio G, Lodrini S, Balestrini MR, Cimino C, Visintini S, Pluchino F: Surgical treatment of intracranial dermoid and epidermoid cysts in children. Childs Nerv Syst 6:66–70, 1990. 7. Hahn FJ, Ong E, McComb RD, Mawk JR, Leibrock LG: MR imaging of ruptured intracranial dermoid. J Comput Assist Tomogr 10:888–889, 1986. 8. Lunardi P, Missori P: Supratentorial dermoid cysts. J Neurosurg 75:262–266, 1991. 9. Lunardi P, Missori P, Rizzo A, Gagliardi FM: Chemical meningitis in ruptured intracranial dermoid: Case report and review of the literature. Surg Neurol 32:449– 452, 1989. 10. Mikhael MA: Transient spasm of carotid siphon complicating ruptured cranial dermoid cyst. Radiology 144:824, 1982. 11. Mikhael MA, Mattar AG: Intracranial pearly tumors: The roles of computed tomography, angiography, and pneumoencephalography. J Comput Assist Tomogr 2:421–429, 1978. 12. Nakamura M, Mizuguchi M, Momoi MY, Chou H, Masuzawa T: Transient cheiro-oral syndrome due to a ruptured intracranial dermoid cyst. Brain Dev 23:261–263, 2001. 13. Roeder MB, Bazan C, Jinkins JR: Ruptured spinal dermoid cyst with chemical arachnoiditis and disseminated intracranial lipid droplets. Neuroradiology 37:146–147, 1995. 14. Sasaki T, Wakai S, Asano T, Watanabe T, Kirino T, Sano K: The effect of a lipid hydroperoxide of arachidonic acid on the canine basilar artery: An experimental study on cerebral vasospasm. J Neurosurg 54:357–365, 1981. 15. Toda N, Shimizu K, Ohta T: Mechanism of cerebral arterial contraction induced by blood constituents. J Neurosurg 53:312–322, 1980. 16. Yaşargil MG, Abernathey CD, Sarioglu AC: Microneurosurgical treatment of intracranial dermoid and epidermoid tumors. Neurosurgery 24:561–567, 1989. ought to be clearly provided, although in the case the authors describe, they thought that there was good collateral flow. Ecker et al. achieved a good result in a complicated situation. M. Gazi Yaşargil Little Rock, Arkansas Saleem I. Abdulrauf St. Louis, Missouri T he report of Ecker et al. heightens the awareness of the complication of vasospasm with subsequent delayed cerebral ischemia after resection of tumors, a complication well described in the literature (1). Dermoid tumors in particular, and more than any other tumor, are severely irritating and can induce aseptic meningitis as well as complications (2). Ecker et al. present the development of vasospasm and subsequent thrombosis. We had such a case in a 44-year-old woman who developed an ischemic deficit a few days after uneventful resection of a parasellar dermoid tumor. Angiography demonstrated severe vasospasm, and the patient was treated with an endovascular injection of papaverine (Fig. C1). Because ruptured vessels are a complication of balloon dilation, Ecker et al. consider whether vasculopathy after dermoid resection makes the vessels more apt to rupture after angioplasty. However, one cannot ascertain this from a single Acknowledgment No extramural or intramural funding was used for completion of this project. COMMENTS E cker et al. present an extremely unusual manifestation of a dermoid cyst with severe middle cerebral artery (MCA) vasospasm. The tumor in this case completely traversed the sylvian fissure, and it is possible that the microsurgical resection of the lesion off the proximal M1 segment may have contributed to the vasospasm. Endovascular balloon dilation of severely spastic intracranial vessels (with an occlusive appearance on the angiogram) does carry an appreciable risk of vascular injury, as demonstrated in this case report. Strong consideration of a bypass procedure (short graft or superficial temporal artery-to-MCA bypass) or primary microvascular repair of the ruptured vascular area in a young patient with intraoperative findings of complete focal MCA occlusion NEUROSURGERY FIGURE C1. Patient with dermoid tumor who developed vasospasm and ischemic deficit a few days after uneventful resection of a parasellar dermoid tumor. Endovascular papaverine injection was used to open the middle cerebral branches. A, preoperative MRI scan. B, anteroposterior angiogram revealing occlusion of middle cerebral branches and vasospasm. C, lateral angiogram. D, follow-up MRI scan revealing tumor resection and ischemic changes. VOLUME 52 | NUMBER 3 | MARCH 2003 | 709 ECKER ET AL. case. I share the authors’ dilemma regarding the conflict between minimal irrigation to limit the spread of the material versus copious irrigation to wash it out and dilute it. Ossama Al-Mefty Little Rock, Arkansas 1. Aoki N, Origitano TC, Al-Mefty O: Vasospasm after resection of skull base tumors. Acta Neurochir (Wien) 132:53–58, 1995. 2. DeMonte F, Al-Mefty O: Ruptured dermoid tumor of the cavernous sinus associated with the syndrome of fat embolism. J Neurosurg 7:312–315, 1992. E cker et al. report an unusual complication from resection of a dermoid involving the sylvian fissure region. Even though the surgeons were careful not to manipulate the sylvian vessels during surgery, the patient developed severe vasospasm of the M1 segment of the MCA, resulting in significant brain ischemia. Balloon angioplasty resulted in rupture of an M2 branch, requiring surgical clipping of all branches of the MCA. I would have been tempted to go ahead with a superficial temporal artery bypass to at least one distal M2 branch at the time of the reexploration. Because the patient made a surprisingly excellent recovery even after complete occlusion of the M1 segment, it is hard to argue with the reported treatment. This report makes the point that delayed vasospasm may occur in the setting of a dermoid and that angioplasty carries an additional risk in this setting. William F. Chandler Ann Arbor, Michigan Evolution of the Operating Microscope. A, Lister and Tulley’s (1830) achromatic microscope. B, Nylén and Holmgren (1922), first binocular operating microscope (Zeiss Jena). C, Littman (Zeiss and Oberkochen, 1953), multiversatile operating microscope. D, Heller, Schattmeier, and Yaşargil (1972), counterbalanced Contraves Stand attached to a Zeiss microscope. E, Hensler and Yaşargil (1992), modified Contraves Stand attached to a Zeiss microscope. F, range of a surgeon’s mobility coordinated between the hydraulic chair, arm support, and the counterbalanced operating microscope with the mouth switch (from, Yaşargil MG: The history of optical instruments and microneurosurgery, in Barrow DL, Kondziolka D, Laws ER Jr, Traynelis VC [eds]: Fifty Years of Neurosurgery. Baltimore, Lippincott Williams & Wilkins, 2000, pp 105–142).