Neurosurg. Rev. 20 (1997) 214-216 Postoperative mutism after the dipping of a distal anterior cerebral artery aneurysm. A case report Ahmet Selcuklu, Ali Kurtsoy, I. Suat Oktem, R. Kemal Koc, and I. Argun Kavuncu Department of Neurosurgery, Erciyes University Medical School, Kayseri, Turkey Abstract 2 Case report A 40-year-old man with mutism developed after clipping a left distal anterior cerebral artery aneurysm is presented. The most characteristic presenting symptom was complete absence of speech with unimpaired consciousness which occured on the fourth day after operation. The patient recovered spontaneously within three weeks. A 40-year-old right-handed man was brought to our hospital with a history of sudden severe headache, vomiting, and brief unconsciousness five days before. He became drowsy, confused, and complained of headache. On admission, he was drowsy but oriented, with marked neck stiffness, and very slight left hemiparesia. He had a 5-year history of hypertension. In this paper we discuss the possible pathogenesis and anatomical location of mutism related to a distal anterior cerebral aneurysm in view of the literature. Keywords: Aneurysm surgery, mutism, supplementary motor area. 1 Introduction Postoperative mutism may result from extensive callosotomy, lesions involving the supplementary motor area (SMA), deep cerebellar nuclei, or multiple shunt revisions for hydrocephalus. It is described as a complete absence of speech that is not associated with unimpaired consciousness [1, 3, 5, 12, 14, 15, 16]. Postoperative mutism is most often a transient condition and resolves within few days to months [5, 9]. Although mutism is an infrequent complication of brain surgery, it is useful to understand the pathogenesis and the possible anatomical involvement responsible for the development of this deficit. We present a patient who developed mutism following surgical clipping of a left distal anterior cerebral artery aneurysm. © 1997 by Walter de Gruyter & Co. Berlin. New York 2.1 Examination Brain CT-scanning confirmed the diagnosis of subarachnoid hemorrhage and demonstrated a hematoma in the right cingulate gyrus (Figure 1). Fourvessel angiography revealed a left distal anterior cerebral artery aneurysm and vasospasm (Figure 2). 2.2 Operation On day 10, the aneurysm was clipped surgically as described byYA~AROIL[17]. The aneurysm was embedded in the right cingulate gyrus, and there was a clot around the dome. The patient awoke from surgery without neurologie deficit. 2.3 Postoperative course Four days after surgery, he became drowsy, developed right hemiparesia, especially dominant in the leg, and mutismbutwould follow simple commands. CT-scanning taken on the 4~ day after operation was normal, except hematoma which was slightly enlarged when corn- Selcukluet al. Postoperativemutism 215 Figure 1. CT scanshowinga hematoma locatedin the right cingulate gyrus Figure 3. PostoperativeCT scan showingslightlyenlarged localizedhematoma in the operation area pared to previous CT-scanning (Figure 3). As transcranial Doppler and clinical examination indicated vasospasm, hemodilution, hypertension, and hypervolemia therapies were started as described previously [4]. On the following days, he remained mute but his consciousness improved and he was able to follow verbal commands. His right hemiparesia showed a similar course of recovery. After 20 days, he started speaking and was oriented but still had a slight right hemiparesia. sive callosotomy, lesions involving the SM~;s, deep cerebellar nuclei, or multiple shunt revisions for hydrocephalus. The pathogenesis and anatomical location of mutism is still unclear but bilateral damage to dentatothalamocortical pathways may be responsible for this phenomenon [1, 3, 5, 12, 14, 15, 16]. 3 Discussion Recently, articles have been published on postoperative mutism which generally results from exten- In the supratentorial location, SMA lesions were thought to cause mutism [2, 7, 15]. Studies on the SMA showed that there are connections between the SMA and superior temporal and infraparietal sulci, frontal eye field, caudate nucleus, pontine nuclei, amygdala, thalamus, and spinal cord [15]. It has been suggested that the SMA plays a role in the planning and initiation of motor activity including speech [7, 8, 13]. LARSENet al. [10] showed that during speech, rCBF of both SM~s is increased, with a slight predominance of flow on the left. Mutism has been seen after the occlusion of the callosomarginal artery which caused SMA infarction [11] and after left carotid artery occlusion [6]. Figure 2. Digital subtraction angiographyshowingthe distal anterior cerebral aneurysm and moderate vasospasm of left A1 and A2 segments Neurosurg.Rev.20(1997) ROSYOMILY et al. [15] saw postoperative mutism without disturbance of sensorium or comprehension and reversible contralateral weakness and/or neglect of the contralateral extremities within the first 24 hours after tumor resection involving the SMA in the dominant hemisphere. They claimed that "surgical shock" is not enough to explain postoperative mutism and contralateral weakness with similar recovery courses, since resection sites were very distant from primary motor speech areas. They believe that these deficits are related to one of the putative functions of SMA, namely motor initiation including speech function. 216 KINGMA et al. [9] suggested that postoperative mutism may b e related to the vascular disturbances due to ischemia a n d edema. In our case, m u t i s m and contralateral weakness emerged four days after a n e u r y s m clipping and re- Selcuklu et al. Postoperative mutism covered 20 days after operation. Since there was n o postoperative hydrocephalus or cerebral disorders, we think that this s y n d r o m e might have resulted f r o m S M A ischemia due to postoperative vasospasm. References [1] ANDERSON B: Relief of akinetic mutism from obstructive hydrocephalus using bromocriptine and ephedrine. J Neurosurg 76 (1992) 152-155 [2] ARSENIC, MI BOTEZ: Speech disturbances caused by tumors of the supplementary motor area. Acts Psychiatr Neurol Scand 36 (1961) 279-299 [3] CAKIRY~D KARKISI,O KOCANOGULLARI:Cerebellar mutism in an adult. Neurology 41 (1994) 342-344 [4] CASTEL JP: Aspect of the medical management in aneurysmal subarachnoid hemorrhage. In: SYMONet al (eds): Advances and Technical Standards in Neurosurgery. 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Neurology 28 (1978) 1220-1223 [12] REKATEJL, RL GRUBB, DM ARAM, JF HAHN, RA RATHESON: Muteness of cerebellar origin. Arch Neuro142 (1985) 69%698 [13] ROLAND PE, B LARSEN, NA LASSES, et al: Supplementary motor area and other cortical areas in organization of voluntary movements in man. J Neurophysio143 (1980) 118-136 [14] Ross MK, AG REEVES, DW ROBERTS: Postcommissurotomy mutism. Ann Neurol 16 (1984) 114 (Abstract) [15] ROSTOMILYRC, MS BERGEN, GA OJEMANN,E LETTICH: Postoperative deficits and functional recovery following removal involving the dominant hemisphere supplementary motor area. J Neurosurg 75 (1991) 62-68 [16] SHUCARTWA, BM STEIN: Transcallosal approach to the anterior ventricular system. Neurosurgery 3 (1978) 339-343 [17] YASAROILMG: Distal anterior cerebral artery aneurysms. Microneurosurgery. Vol. 2. George Thieme Verlag, Stuttgart, New York 1984 Submitted June 14, 1995. Revised September 5, 1996. Accepted October 21,1996. All Kurtsoy, MD. Department of Neurosurgery Erciyes University Medical School 38039 Kayseri Turkey Neurosurg. Rev.20 (1997)