Experience of treatment of moyamoya disease at the Clinic of Neurosurgery of Kaunas University of Medicine

130 Experience of treatment of moyamoya disease at the Clinic of Neurosurgery of Kaunas University of Medicine Clinic of Neurosurgery, Kaunas University of Medicine, Lithuania Key words: moyamoya disease, cerebral revascularization. Summary. Background. Moyamoya disease was first described in Japan and represents characteristic appearance on cerebral angiography an abnormal network ( puff of smoke ) of collaterals around stenotic arteries. This disease is characterized by progressive intracranial vascular obliterations of the circle of Willis, resulting in successive ischemic or hemorrhagic events. Moyamoya disease primarily occurs among orient people (Japanese, Koreans, Caucasians) and is very rare in Lithuania. Aim of the study. To evaluate long-term effectiveness of cerebral revascularization in order to prevent cerebral ischemic and hemorrhagic events in patients with moyamoya disease. Material and methods. Since 1995, 14 patients with moyamoya disease have been treated at the Clinic of Neurosurgery of Kaunas University of Medicine. All patients underwent neurological examination, computed tomography or/and magnetic resonance imaging, transcranial Doppler sonography, single photon emission computed tomography and four vessels cerebral angiography investigations. The diagnosis of moyamoya disease was confirmed by cerebral angiography. Cerebral ischemia was observed in 7 cases and cerebral hemorrhage was detected in the other 7 moyamoya disease patients. Neurological disability was evaluated using the Scandinavian Stroke Scale, and performance in the active daily life using the Barthel Index. The degree of handicap was assessed with the Rankin Scale. Different surgical procedures (superficial temporal artery to middle cerebral artery anastomosis, encephalosynangiosis, bifrontal free omental flap) were applied for cerebral revascularization of moyamoya disease patients. Results. The diagnosis of moyamoya disease was confirmed by cerebral angiography in all our patients. Ten patients were selected for surgical brain revascularization. The main criterion for selection of patients for surgery was hypoperfusion of the brain on single photon emission computed tomography. During follow-up period (mean follow-up period was 36 months) there were no rebleeding or ischemic events in both surgical groups. Conclusions. Cerebral angiography is the main diagnostic procedure which confirms the diagnosis of moyamoya disease. Cerebral hypoperfusion on single photon emission computed tomography is the main criterion for selection of patients for cerebral revascularization. Extraintracranial anastomosis is an effective procedure for preventing both ischemic and hemorrhagic events in moyamoya patients. Introduction Moyamoya, puff of smoke, is a Japanese term to define a classic angiographic appearance of multiple small collateral intracranial vessels around stenotic arteries of the circle of Willis. Moyamoya disease (MMD) is an extremely rare disorder in the most part of the world except in Japan and Korea (1 4). There have been reports of increased familial incidence of the disease (5). This disease is characterized by progressive intracranial vascular obliterations of the circle of Willis, resulting in successive ischemic or hemorrhagic events. It leads to irreversible blockage of the main blood vessels to the brain, as they enter into the skull. This lesion tends to affect children and adults in the third to fourth decades of their life. There are no specific symptoms or signs related to MMD. Among children it tends to cause cerebral ischemia or seizures. Adults usually present with cerebral hemorrhage, most frequently in basal ganglia. Subarachnoid or intraventricular hemorrhage may also be observed. Some times there are symptoms of cerebral ischemia (recurrent transient ischemic attacks (TIAs), sen- Correspondence to D. Liutkus, Clinic of Neurosurgery, Kaunas University of Medicine, Eivenių 2, 50009 Kaunas, Lithuania. E-mail: daniusliu@gmail.com

Treatment of moyamoya disease 131 sory impairment, and visual disturbances), involuntary movements, convulsions and migraine-like headache (3, 4). The natural history of untreated MMD is poor, with a 73% rate of major neurological deficit or death in 2 3 years after diagnosis in children (6) and a similarly poor prognosis in adults (7, 8). Cerebral angiography is a basic procedure to confirm the diagnosis of MMD. The characteristic findings are: a symmetrical stenosis or occlusion of the intracranial internal carotid artery, as well as the origin of the anterior and middle cerebral arteries associated with an enlargement of the basal penetrating branches of these arteries in an apparent attempt to provide collateral circulation (Fig. 1). Cerebral revascularization is believed to prevent cerebral ischemic attacks in moyamoya patients by improving cerebral blood supply (9). The first superficial temporal artery to middle cerebral artery (extraintra anastomosis (EIA)) bypass for MMD was performed by M. G. Yasargil and Y. Yonekawa in 1972 (10), and since then several small series have been reported. Many authors concluded that direct revascularization is the procedure of choice over indirect revascularization whenever possible (11, 12). The longterm outcome in patients who have undergone EIA for the treatment of MMD was satisfactory with regard to activities of daily living (ADL) (13). However, measures preventing the occurrence of hemorrhage in moyamoya patients have not been established yet in the literature (14). Fig. 1. Obliteration of the right middle cerebral artery (M1) with collateral moyamoya network Materials and methods Since 1995, 14 patients with MMD have been treated at the Clinic of Neurosurgery of Kaunas University of Medicine. Patients age ranged from 8 to 64 years (3 under 20 years old, 3 between 20 and 40 years old, 7 between 40 and 60 years old). Cerebral ischemia was observed in 7 cases of MMD. Cerebral hemorrhage was detected in the other 7 patients (Tables 1, 2). All patients underwent neurological examination, computed tomography (CT) or/and magnetic resonance imaging (MRI), transcranial Doppler sonography (TCD), single photon emission computed tomography (SPECT) and four vessels cerebral angiography (CA) investigations. Conventional cerebral arteriograms were reviewed to grade the severity of the MMD according to the classification of J. Suzuki (14, 15). All the patients underwent neurological examination in the acute phase and were followed up from 6 to 96 months after the cerebrovascular event. Neurological disability was evaluated using the Scandinavian Stroke Scale (SSS) (16), and performance in the ADL using the Barthel Index (BI) (17). The degree of handicap was assessed with the Rankin Scale (18, 19). The patients were categorized according to their clinical symptoms into the following groups: A asymptomatic (patients who were cognitively and neurologically stable), LD light disabled (patients with occasional (less than once a month) TIAs, dizziness), MD moderately disabled (mild hemiparesis), and SD severe disabled (patients with moderate or severe neurological deficit) (Tables 1, 2). SPECT was performed in 8 patients who received surgical treatment. Cerebral hypoperfusion was demonstrated bilaterally in temporal and paraventricular regions in all patients. Perfusion defect on cerebral lobes was observed in 3 cases (one patient had perfusion defect on right parietal and occipital lobes, one on left temporal and right parietal lobes and one patient had hypoperfusion on left frontal, temporal and parietal lobes). These findings on SPECT accorded with infarction areas on CT and/or MRI. Cerebral revascularization was performed in 10 moyamoya patients (in 6 patients with cerebral ischemia, and in 4 patients with cerebral or subarachnoid hemorrhage). We always attempted to perform direct cerebral revascularization with EIA in all our MMD patients and if it failed, other methods of indirect revascularization were applied. Surgery was usually performed initially in the symptomatic and hemodynamically affected hemisphere. EIA was performed in 6 patients with cerebral

132 Table 1. Moyamoya patients with cerebral ischemia Neurological Infarction area Age/sex disability on CT/MRT Cerebral angiography SPECT Surgery 8/F severe hemiparesis basal ganglia stenosis of M1 12/M aphasia, moderate basal ganglia occlusion and EIA+ES hemiparesis stenosis of ICA 28/M seizures, mild MCA region occlusion of M1 and A1 bilateral EIA hemiparesis hypoperfusion 42/M partial aphasia, MCA and ACA bilateral occlusion perfusion defect EIA mild hemiparesis region of MCA and ACA on right P, O 43/M seizures, moderate MCA/ACA occlusion of MCA, hypoperfusion EIA hemiparesis watershade on left F, T, P 52/F headache, dizziness normal bilateral occlusion bilateral EIA+EIA of MCA and PCA hypoperfusion 58/M dizziness, mild MCA region stenosis of M1, distal bilateral EIA hemiparesis part of VA, occlusion hypoperfusion of MCA ACA anterior cerebral artery; CT computerized tomography; EIA extra-intracranial anastomosis; ES encephalosynangiosis; F frontal lobe; ICA internal carotid artery; MCA middle cerebral artery; MRT magnetic resonance tomography; O occipital lobe; P parietal lobe; T temporal lobe; TIA transient ischemic attack; VA vertebral artery. Table 2. Moyamoya patients with cerebral hemorrhage Age/sex Neurological Hemorrhage on Cerebral angiography SPECT Surgery disability CT/MRT 15/M meningeal syndrome intraventricular, bilateral stenosis bilateral EIA+EIA basal ganglia of MCA paraventricular hypoperfusion 47/F meningeal syndrome intraventricular, bilateral occlusion interhemispherical of ICA 50/M meningeal syndrome intraventricular, bilateral occlusion interhemispherical of MCA and ACA 50/F meningeal syndrome subarachnoidal occlusion of left MCA 50/F meningeal syndrome subarachnoidal bilateral occlusion bifrontal free of MCA and ACA omental flap 60/M meningeal syndrome, basal ganglia bilateral occlusion perfusion defect EIA+EIA right hemiparesis of MCA T left and parietal right 62/F meningeal syndrome subarachnoidal bilateral occlusion bilateral EIA+ES of ICA hypoperfusion ACA anterior cerebral artery; CT computerized tomography; EIA extra-intracranial anastomosis; ES encephalosynangiosis; ICA internal carotid artery; MCA middle cerebral artery; MRT magnetic resonance tomography; P parietal lobe; PCA posterior carotid artery; T temporal lobe. ischemia. One patient with obliteration of middle cerebral artery and cerebral infarction underwent medical treatment (Table 1). Microvascular omentum bifrontal flap was applied for cerebral revascularization in one patient with cerebral hemorrhage and encephalosynangiosis was performed in 3 patients. The other 3 MMD patients with subarachnoidal hemorrhage received medical treatment (Table 2). Results There were no perioperative deaths. The mean follow-up was 36 months, ranging from 6 month to 8 years. There were no rebleeding or ischemic events

Treatment of moyamoya disease 133 in both surgical groups during the follow up period. All patients improved their neurological condition after treatment. According to SSS improvement was observed in 9 patients, according BI and Rankin scale in 8 patients. One LD patient remained stable. We observed improvement of cerebral perfusion on SPECT after cerebral revascularization in patients with EIA (Fig. 2). Evaluation of postoperative patency of EIA was made by palpation of subcutaneous segment of donor superficial temporal artery and by TCD. EIA was patent in all patients. The mean blood flow velocity was from 20 to 59 cm/s. Discussion Patients with MMD were selected for cerebral revascularization according to neurological symptoms, cerebral angiography, CT and SPECT results. Severity of angiographic changes in cerebral arteries had no predictable value for neurological deficit, recurrent episodes of cerebral ischemia or hemorrhage and postoperative results, but full four-vessel CA was essential to confirm diagnosis of MMD. The computed tomography, magnetic resonance imaging, transcranial Doppler sonography and single photon emission computed tomography data were nonspecific and insufficient to make diagnosis of moyamoya disease in all our cases. Because of the excellent diagnostic yield and noninvasive nature of MRI, it has been proposed that MR angiography can be used as the primary diagnostic imaging modality for MMD instead of conventional cerebral angiography. While MR angiography affords the ability to detect stenosis of the major intracranial vessels, visualization of basal moyamoya collateral vessels and smaller vessel occlusions is frequently subject to artifact. Therefore, to confirm the diagnosis of MMD and to visualize the anatomy of MMD vessels involved and the patterns of flow through the hemispheres, conventional cerebral angiography is typically required (20). External carotid imaging is essential to identify pre-existing collateral vessels, so that surgery, if performed, will not disrupt them (20). Many authors also agree that cerebral blood flow studies, utilizing techniques such as transcranial Doppler ultrasonography and SPECT with acetazolamide challenge, also can be helpful in the diagnostic evaluation of patients with MMD as well as assisting in treatment decisions. For example, transcranial Doppler examination provides a noninvasive way to follow changes in blood flow patterns over time in larger cerebral vessels and EIA function, while SPECT can be used to detect regional perfusion Fig. 2. Improvement of cerebral perfusion after extra-intracranial anastomosis on single photon emission computerized tomography

134 instability prior to treatment and to determine the extent of improvement of functional perfusion after surgery (20). Patients neurological condition, severity of obliteration of cerebral arteries on CA and cerebral hypoperfusion demonstrated on SPECT were our main criteria for cerebral revascularization. The main dilemma in the management of patients with MMD is the identification of individuals who are most likely to benefit from surgical revascularization (21). However, as found here, the angiographic severity of cerebrovascular disease does not appear to predict the hemodynamic status of brain tissue. These issues may also be relevant to adults with severe carotid stenosis or occlusion due to atheroma since there is an active debate in the literature regarding any potential benefit from surgical revascularization (22). Delineation of areas of abnormal tissue perfusion, in combination with clinical symptoms, may direct the target for revascularization and provide the means of evaluating the efficacy of treatment. SPECT can detect hemodynamic changes after revascularization, indicating which areas have been affected by the surgery (20, 23). However, interpretation of these findings in terms of true tissue perfusion status is not straightforward since the direct comparison of quantitative measures on two separate occasions may be misleading (23). In spite of improvement of neurological deficit, it was difficult to evaluate the effect of cerebral revascularization on SPECT in patients revascularized by omentum flap or other methods of indirect revascularization. As is well known, two different types of initial clinical presentation are observed in moyamoya disease: cerebral ischemic attack, seen mainly in pediatric patients, and cerebral hemorrhage, seen mainly in adults (24, 25). In general, however, the same surgical strategy has been used to treat these apparently different pathological conditions. The basic and established treatment of MMD is to induce a revascularization channel from the extracerebral arterial system to the brain surface, although numerous variations of surgical management, such as encephalo-myo-synangiosis, encephalo-galeo-synangiosis, encephalo-duroarterio-synangiosis, and omentum transplantation, have been reported (26, 27). Our basic strategy for this disease principally follows this general concept. We combine direct and indirect revascularization methods. Postoperatively our patients are free from cerebral ischemic attack and other symptoms such as retractable epilepsy after successful revascularization surgery. Similar results are published by other authors (28). Direct revascularization by EIA is much more effective than indirect revascularization in adult MMD (29). EIA is an effective and save method of brain revascularization, minimizing neurologic deficit and decreasing the incidence of ischemic episodes (22). However, in pediatric moyamoya disease, indirect revascularization is suggested to be 100% effective, whereas direct revascularization has failed in some cases because of the extraordinarily small donor and recipient vessels. It potentially improves cerebral circulation and decreases the caliber of the moyamoya vessels (30). Conclusions Cerebral angiography is the basic procedure to confirm the diagnosis of moyamoya disease. Cerebral hypoperfusion is the main criterion for selection of patients with moyamoya disease for cerebral revascularization. Direct revascularization by superficial temporal artery to middle cerebral artery anastomosis is an indispensable method for effective revascularization, especially in adult patients. Direct or indirect cerebral revascularization surgery can prevent both hemorrhagic and ischemic events in moyamoya disease patients. Mojamoja ligos gydymas Kauno medicinos universiteto Neurochirurgijos klinikoje Kauno medicinos universiteto Neurochirurgijos klinika Raktažodžiai: mojamoja liga, smegenų revaskulizacija. Santrauka. Manoma, kad mojamoja yra paveldima smegenų arterijų liga, pasireiškianti savaiminiu vidinių miego, priekinių ar vidurinių smegenų arterijų užakimu, vystantis kolateraliniam smulkiųjų arterijų tinklui. Ši liga pirmą kartą aprašyta XX a. 6-ajame dešimtmetyje Japonijoje. Mojamoja liga dažniausiai serga japonai, korėjiečiai bei kaukaziečiai. Lietuvoje ši liga gana reta. Liga pasireiškia smegenų kraujotakos sutrikimais, sukeliančiais smegenų išemiją arba kraujosruvas. Dėl gydymo taktikos diskutuojama. Dabar pasaulyje dažniau taikomas chirurginis šios ligos gydymas smegenų revaskulizacijos operacijos.

Treatment of moyamoya disease 135 Darbo tikslas. Įvertinti smegenų revaskulizacijos veiksmingumą sergantiesiems mojamoja liga siekiant išvengti smegenų išemijos pasikartojimo ar kraujosruvų atsiradimo. Darbo metodai. Kauno medicinos universiteto Neurochirurgijos klinikoje per pastaruosius 10 metų diagnozuota tik 14 mojamoja ligos atvejų. Septyniems ligoniams liga pasireiškė išeminiu smegenų pažeidimu, dar 7 smegenų kraujosruvomis. Neurologinė būklė vertinta pagal Skandinavijos insulto skalę, Barthel indeksą bei Rankin skalę. Ligoniai buvo tiriami smegenų kompiuterinės tomografijos, magnetinio rezonanso tomografijos, transkranialinės doplerografijos, radionuklidinės kompiuterinės tomografijos, smegenų angiografijos metodais. Dešimčiai ligonių atliktos įvairios smegenų revaskulizacijos operacijos, keturi ligoniai gydyti medikamentais. Rezultatai. Visiems ligoniams mojamoja ligos diagnozė patvirtinta tik atlikus galvos smegenų angiografinį tyrimą. Chirurginis gydymas taikytas 10 ligonių. Pagrindinis kriterijus, atrenkant ligonius revaskulizacijos operacijoms, buvo radionuklidinės kompiuterinės tomografijos tyrimo metu randama nepakankama smegenų kraujotaka. Ligonių stebėjimo trukmė po operacijos vidutiniškai 36 mėnesiai. Tuo laikotarpiu pakartotinių smegenų išemijos epizodų ar kraujosruvų neužfiksuota. Išvados. Svarbiausias tyrimas, kuriuo patvirtinama mojamoja ligos diagnozė, yra galvos smegenų angiografija. Chirurginiam gydymui turėtų būti atrenkami ligoniai, kuriems nustatoma būdingų mojamoja ligai angiografinių požymių ir nepakankama galvos smegenų kraujotaka. Smegenų revaskulizacija efektyvus būdas išvengti smegenų išemijos pasikartojimo ar kraujosruvų atsiradimo. Adresas susirašinėti: D. Liutkus, KMU Neurochirurgijos klinika, Eivenių 2, 50009 Kaunas El. paštas: daniusliu@gmail.com References 1. Ikezaki K, Han DH, Kawano T. Clinical comparison of definite moyamoya disease between South Korea and Japan. Stroke 1997;2:2513-17. 2. Shetty-Alva N, Alva S. Familial moyamoya disease in Caucasians. Pediatr Neurol 2000;23:445-47. 3. Yonekawa Y, Ogata N, Kaku Y. Moyamoya disease in Europe, past and present status. Clin Neurol Neurosurg 1997;99(Suppl 2):58-60. 4. Chiu D, Shedden P, Bratina P. Clinical features of moyamoya disease in United States. Stroke 1998;29:1347-51. 5. Gosalakkal JA. Moyamoya disease: a review. Neurology India 2002;50:6-10. 6. Olds MV, Griebel RW, Hoffman HI, Craven M, Chuang S, Schutz H. The surgical treatment of childhood moyamoya disease. J Neurosurg 1987;66:675-80. 7. Quest D, Correll JW. Basal arterial occlusive disease. Neurosurgery 1985;17:937-41. 8. Karasawa J, Kikuchi H, Furuse S, Kawamura I, Sakaki T. Treatment of moyamoya disease with STA-MCA anastomosis. J Neurosurg 1978;49:679-88. 9. Scott MR. Surgery for moyamoya syndrome: Yes. Arch Neurol 2001;58:128-29. 10. Yasargil MG, Yonekawa Y. Results of microsurgical extraintracranial arterial bypass in the treatment of cerebral ischemia. Neurosurgery 1977;1:22-24. 11. Ishikawa T, Houkin K, Kamiyama H, Abe H. Effects of surgical revascularization on outcome of patients with pediatric moyamoya disease. Stroke 1997;28:1170-73. 12. Matsushima T, Inoue T, Ikezaki K, Matsukado K, Natori Y, Inamura T, et al. Multiple combined indirect procedure for the surgical treatment of children with moyamoya disease. A comparison with single indirect anastomosis with direct anastomosis. Neurosurg Focus 1998;5(5):Article 4. 13. Miyamoto S, Akiyama Y, Nagata I, Karasawa J, Nozaki K, Hashimoto N, et al. Long-term outcome after STA-MCA anastomosis for moyamoya disease. Neurosurg Focus 1998; 5(5):Article 5. 14. Suzuki J, Takaku A. Cerebrovascular moyamoya disease: disease showing abnormal net-like vessels in base of the brain. Arch Neurol 1969;20:288-99. 15. Suzuki J, Kodama N. Moyamoya disease: a review. Stroke 1983;14:104-9. 16. Multicenter trial of hemodilution in ischemic stroke background and study protocol. Scandinavian Stroke Study Group. Stroke 1985;16(5):885-90. 17. Mahoney FI, Barthel DW. Functional evaluation: the Barthel Index. Md State Med J 1965;14:61-5. 18. Rankin J. Cerebral vascular accidents in patients over the age of 60. II. Prognosis. Scot Med J 1957;2:200-15. 19. De Haan R, Limberg, Bossuyt P, et al. The clinical meaning of Rankin handicap grades after stroke. Stroke 1995;26: 2027-30. 20. Smith ER, Scott RM. Surgical management of Moyamoya syndrome. Skull Base 2005;15(1):15 26. 21. Zipfel GJ, Fox DJ Jr, Rivet D. Moyamoya disease in adults: the role of cerebral revascularization. Skull Base 2005;15(1): 27 41. 22. Marcinkevičius E. Smegenų kraujotakos atstatymo galimybės sergantiems išemine smegenų liga. (The possibility of cerebral revascularization in patients with ischemic cerebrovascular disease). Medicina (Kaunas) 1997;33:225-32. 23. Ueno M, Nishizawa S, Toyoda H, Shimono T, Miyamoto S, Hashimoto N et al. Assessment of cerebral hemodynamics before and after revascularization in patients with occlusive cerebrovascular disease by means of quantitative IMP-SPECT with double-injection protocol. Ann Nucl Med 2001;15(3): 209-15. 24. Han DH, Kwon OK, Byun BJ. A cooperative study: clinical characteristics of 334 Korean patients with moyamoya disease

136 treated at neurosurgical institutes (1976 1994). The Korean Society for Cerebrovascular Disease. Acta Neurochir 2000; 142:1263-73. 25. Yilmaz EY, Pritz MB, Bruno A, Lopez-Yunez A, Biller J. Moyamoya: Indiana University Medical Center experience. Arch Neurol 2001;58:1274-78. 26. Kim SK, Wang KC, Kim IO, Lee DS, Cho BK. Combined encephaloduroarteriosynangiosis and bifrontal encephalogaleo(periosteal)synangiosis in pediatric moyamoya disease. Neurosurgery 2002;50(1):88-96. 27. Houkin K, Kuroda S, Nakayama N. Cerebral revascularization for moyamoya disease in children. Neurosurg Clin N Am 2001;12(3):575-84. 28. Kim SK, Seol HJ, Cho BK, Hwang YS, Lee DS, Wang KC. Moyamoya disease among young patients: its aggressive clinical course and the role of active surgical treatment. Neurosurgery 2004;54(4):840-4. 29. Okada Y, Shima T, Nishida M, Yamane K, Yamada T, Yamanaka C. Effectiveness of superficial temporal arterymiddle cerebral artery anastomosis in adult moyamoya disease: cerebral hemodynamics and clinical course in ischemic and hemorrhagic varieties. Stroke 1998;29(3):625-30 30. Kuroda S, Houkin K, Kamiyama H, Abe H. Effects of surgical revascularization on peripheral artery aneurysms in moyamoya disease: report of three cases. Neurosurgery 2001;49(2):463-7. Received 12 October 2005, accepted 7 December 2005 Straipsnis gautas 2005 10 12, priimtas 2005 12 07