- Email: [email protected]
Postoperative mutism after removal of an anterior falcine meningioma
Case reports / Journal of Clinical Neuroscience 14 (2007) 793–796
Because VIM stimulation via the DBS electrodes produced excellent tremor control and the expected sensory responses, only one electrode penetration was used for each surgery. One week later, device implantation was completed under general anesthesia, consistent with previous reports.2,3 Postoperative CT scan (merged with preoperative MRI) confirmed excellent coincidence between planned target and final electrode position for the right (Fig. 1) and left electrodes. Subsequent stimulation therapy produced excellent bilateral tremor control without side-effects. Of the two different head support systems used, the modified Philadelphia cervical collar provided better comfort and support. Although some centers utilizing frameless guidance prefer to implant both electrodes simultaneously,4 it is the preference of the surgeon (RRG) to stage the procedure in order to confirm that there has been no post-implant hemorrhage or other morbidity following the first implant before proceeding with the contralateral implant. Comparative experience with frame-based electrode implants has shown us that for most patients, placement of skull fiducials has approximately the same degree of discomfort as frame placement. However, a number of patients find the frame application itself to be uncomfortable or painful, while patients having the screw implants have rarely complained of any pain at each of the implant sites. Additionally, the experience of having the head inside the frame during surgery is uncomfortable to many patients, and may induce respiratory obstruction due to fixation of the neck. The freedom of small neck motion allowed with the Philadelphia collar when we used the skull-mounted guide provided greater patient comfort. Our experience with this patient demonstrates that the skull-mounted guide can be used successfully for DBS implants.4 The planned target being well inside the MRI artifact (Fig. 1) indicates that the final electrode tip placement was certainly within 1.5 mm of the intended target, which is
793
comparable to the accuracy that has been documented with frame-based implants.2,3 In conclusion, we present an experience with staged DBS utilizing frameless stereotactic guidance. Staged electrode placement using a frameless skull-mounted guide was accurate, efficacious, increased patient comfort, allowed the convenience of advanced preoperative imaging and planning, eliminated the need for a stereotactic frame, and permitted the use of one reference system for staged procedures. 2. Financial disclosure information None of the authors received any financial support in conjunction with the generation of this article. Acknowledgement We would like to thank Mary Marshall for invaluable assistance. References 1. Benabid AL, Pollak P, Gross C, et al. Acute and long-term effects of subthalamic nucleus stimulation in Parkinson’s disease. Stereotact Funct Neurosurg 1994;62:76–84. 2. Starr PA, Christine CW, Theodosopoulos PV, et al. Implantation of deep brain stimulators into the subthalamic nucleus: technical approach and magnetic resonance imaging-verified lead locations. J Neurosurg 2002;97:370–87. 3. McClelland S 3rd, Ford B, Senatus PB, et al. Subthalamic stimulation for Parkinson disease: determination of electrode location necessary for clinical efficacy. Neurosurg Focus 2005;19:E12. 4. Holloway KL, Gaede SE, Starr PA, et al. Frameless stereotaxy using bone fiducial markers for deep brain stimulation. J Neurosurg 2005;103:404–13. 5. Woodworth GF, McGirt MJ, Elfert P, et al. Frameless stereotactic ventricular shunt placement for idiopathic intracranial hypertension. Stereotact Funct Neurosurg 2005;83:12–6.
doi:10.1016/j.jocn.2006.03.032
Postoperative mutism after removal of an anterior falcine meningioma Kadir Tahta a, Bayram Cirak a
a,*
, Emre Pakdemirli b, Tuncer Suzer a, Fatma Tahta
Department of Neurosurgery, Pamukkale University School of Medicine, Zeytinkoy mh. Aksemsettin cd. No.16, Denizli, Turkey b Department of Radiology, Pamukkale University, School of Medicine, Denizli, Turkey c Faculty of Education, Pamukkale University, Faculty of Education, Denizli, Turkey Received 23 February 2006; accepted 24 May 2006
*
Corresponding author. Tel.: +90 258 2664039; fax: +90 258 2134922. E-mail address: [email protected] (B. Cirak).
c
794
Case reports / Journal of Clinical Neuroscience 14 (2007) 793–796
Abstract Postoperative mutism is rare. We present a 65-year-old man who had transient mutism after resection of anterior falx meningioma. Mild left hemiparesis and palmomental reflex on the right were the only abnormal signs on neurological examination. CT scan and MRI demonstrated a mass at the anterior one-third portion of the falx just superior to the corpus callosum. The mass enhanced homogenously with administration of gadolinium DTPA. The patient underwent surgical resection of the lesion and adjacent falx cerebri. The operation was uneventful. On the second postoperative day he became mute. He could follow verbal commands, and write and read. Postoperative CT scan revealed a hypodense area in the right frontal lobe including a part of the anterior cingulate cortex and the anterior part of the corpus callosum. Histopathological examination revealed a mixed meningioma. Ten days postoperatively, he began to say simple words, and three weeks later he could talk normally. We consider that lesion of the supplementary motor area (SMA) may be responsible for postoperative mutism. 2006 Published by Elsevier Ltd. Keywords: Meningioma; Mutism; Supplementary motor area
1. Introduction The term ‘mutism’ is a clinical state in which a conscious patient is unwilling to or unable to speak, resulting in the absense or marked pause of verbal output.1,2 Mutism in conscious neurological patients is infrequent. Speech disturbances associated with cerebral lesions have been previously defined as akinetic mutism.3 Mechanisms implicated in the development of the syndrome have included callosotomy4,5 and extensive destruction of the frontal lobe,6,7 supplementary motor area (SMA)8–10 and cingulum.11 Naksu4 reported three patients with mutism following transcallosal surgery for epilepsy. He noted that mutism may be the result of division of the corpus callosum. Suppression of the limbic system by lesions in the anterior cingulate gyrus, septum pellucidum, and fornix may also have been of importance in at least two of these three cases. Impairment of the supplementary motor cortex, thalamus and basal ganglia may also contribute to reduced speech production. The mechanism of such transient mutism seems to be a complex of two or more of these factors, and their combination may be different from one patient to the next. A few authors have contributed their case materials but the overall number of cases remains small. We present a patient who developed transient mutism after resection of a falx meningioma.
A bifrontal bone flap was made with its posterior margin at 3 cm posterior to the bregma. The right frontal lobe was gently retracted, a small bridging vein was sacrificed. Initially, the proximal part of the tumor was dissected. After initial debulking of the dense tumor capsule, the anterior part of the falx cerebri, which was invaded by the tumor, was removed with the aid of an operating microscope. No damage was seen to the corpus callosum and the gyrus cinguli. Histopathologic evaluation confirmed the diagnosis of meningioma. Operation and recovery from anesthesia were uneventful. In response to verbal commands the patient could open his mouth. On the second postoperative day, he was alert but totally mute. He suffered fits of crying. He could follow verbal commands and was able to read and write. After mutism was diagnosed, neuropsychological examination was performed and he showed no psychiatric symptoms. A follow-up CT scan on the second postoperative day, showed a hypodense area indicating edema in the right frontal lobe including a part of the anterior cingulate cortex and the anterior part of the corpus callosum (Fig. 2). Intensive speech rehabilitation was instituted. He started speaking again at postoperative day 10, starting with responses to simple questions. He began to say simple words, and three weeks later the patient had good speech with mild left hemiparesis. 3. Discussion
2. Case report A 65-year-old man suffered from recurrent headache, seizure and an associated loss of consciousness lasting approximately 10 min. Physical examination was normal. Neurological examination revealed a mild left hemiparesis and positive palmomental reflex on the right. The fundus oculi examination revealed papilledema. Corticosteroid therapy was initiated. CT scan revealed a large lesion at the anterior one-third of the falx. MRI demonstrated a 50 · 52 · 48 mm mass at the anterior one-third of the falx just superior to the corpus callosum which enhanced after administration of gadolinium DTPA (Fig. 1).
Mutism caused by intracranial surgical intervention has been described in the following areas: (i) Broca’s area;12 (ii) the anterior cingulate area;11 (iii) the descending tracts bilaterally;4 (iv) the mesencephalic reticular formation;12 (v) after callosotomy for medically intractable epilepsy; (vi) the SMA;8,10,13 and (vii) the midline cerebellar structures.14 Penfield et al.15 in extensive stimulation experiments involving conscious humans, demonstrated SMA regions to be important for speech: the Rolandic and superior frontal areas within the SMA. Anatomical studies demonstrate connections between the SMA and all components of the motor system, including the bilateral motor cortex, cingulate
Case reports / Journal of Clinical Neuroscience 14 (2007) 793–796
gyri, contralateral SMA (which may be the basis for return of function after unilateral lesions) and caudate and spinal cord with basal ganglia input via the thalamus. There have been few reports of speech disturbances caused by lesions in the SMA of both hemispheres. Most were caused by parasagittal tumors or vascular lesions. Aphasia may result from infarction in the territory of the anterior cerebral artery of the dominant hemisphere or from tumors of the dominant SMA. Arseni and Batez16 reported 12 patients and Alajuanine et al.17 reported four cases of tumors affecting the supplementary motor regions in which arrest of speech was a prominent clinical feature. Rostomly et al.10 presented patients with seizures consisting of speech arrest. Caplan and Zervas8 indicated speech arrest in a patient with an astrocytoma involving the supplementary motor area. Crutchfield9 reported two patients who became mute in the immediate postoperative period and one developed mutism following removal of a parasagittal meningioma. It is believed that transient injury may have occurred to the supplementary motor cortex in the first case and to the dentate nuclei in the second
Fig. 1. T1-weighted enhanced axial MRI of the falx meningioma with a dural tail.
Fig. 2. Postoperative axial CT scan with marked edema in the frontal deep white matter with mild compression of right lateral ventricule.
795
case. It is interesting that these two areas are connected via pathways involving the ventrolateral nucleus of the thalamus, and that lesions of this thalamic nucleus can also lead to mutism. It therefore appears plausible that interruption of these pathways may be involved in the pathogenesis of mutism. Although mutism is an infrequent complication of brain surgery, neurosurgeons should be aware that it may occur following removal of lesions in these areas and that it is generally a transient condition. Peled et al.13 reported a patient with a metastasis in the left SMA. Epileptic arrest of speech was confused with a transient ischemic attack of the dominant hemisphere and the mutism continued for 10 days. The causes of mutism in our patient were a large midline supratentorial tumor, and pressure on the corpus callosum, the cingulum and the SMA. Additional aetiological factors may include transient vascular disturbances of the cingulum and the SMA, and postoperative swelling of the brain. The mutism in our patient could be assessed as a seizure, but no definite focal spike was seen on EEG. Magnetic resonance imaging indicated the tumour was localized to the falx cerebri directly anterior to the primary motor cortex in the mesial frontal lobe. Although previous reports4 of postoperative mutism demonstrate a hypointense area on T1-weighted images in the frontal lobe including a part of the anterior cingulate cortex and the anterior part of the corpus callosum, postoperative imaging of our patient did not reveal an underlying etiology for the observed deficits, such as infarct or hemorrhage. It appears that a dominant hemisphere lesion of both the anterior cingulate cortex and the corpus callosum may be responsible for the development of postoperative mutism. Surgical schock may be in part responsible for the transient weakness seen in some patients but it is unlikely to explain changes of initiation of function documented long after surgical edema would have resolved. Tumor infiltration into adjacent tissues and epileptic foci adjacent to the tumor may be responsible for mutism, as may vascular disturbances, either of ischemic origin (such as arterial spasm) or edema. A circulatory disturbance of the pericallosal arteries would cause dysfunction of this region and cause weakness of the lower extremities. However, Babinski sign, snout reflex, forced grasping and other interhemispheric frontal lobe signs were not observed in our patient. The outcome for postoperative mutism is favorable. Slight disturbances of speech production may result from right cerebral lesions in right-handed patients.8,18 But permanent, significant aphasia from such lesions is rare. In addition to deficits concerning initiation-related functions, several patients were unable to inhibit certain inappropriate speech and motor functions. Mutism has a very low incidence in the geriatric age group. We think that the location of the surgical intervention had a direct influence on mutism. Proposed etiology of postoperative mutism following supratentorial surgery has been summarized in Table 1. In most reported cases
796
Case reports / Journal of Clinical Neuroscience 14 (2007) 793–796
Table 1 Proposed etiology for postperative mutism following supratentorial surgery from previous reports in the literature Author
Patient
Pathology
Proposed etiology of mutism
1997 Kunishio et al.19
32-year-old woman
Left frontal malignant astrocytoma
Dominant hemisphere lesion of both the anterior cingulate cortex and the corpus callosum
1994 Crutchfield et al.9
2 cases
Parasagittal meningioma
1. Transient injury to the supplementary motor cortex and the dentate nuclei of the thalamus 2. Lesions of ventrolateral thalamic nucleus
1991 Nakasu et al.4
3 cases
Transcallosal surgery; tumors in the lateral and third ventricle
1. Division of the corpus callosum 2. Suppression of the limbic system caused by lesions in the anterior cingulate gyrus, septum pellucidum, and fornix 3. Impairments of the supplementary motor cortex, thalamus and basal ganglia
1997 Quattrini et al.20
10 cases
Transcallosal surgery for epilepsy
Surgical manupilation of the parasagittal cortex, cingulum, corpus callosum
1993 Shinoda et al.21
1 case
Post-traumatic mutism
Lesions in the left interlaminal nucleus of the thalamus, right globus pallidus, and right dorsomedial nucleus of the hypothalamus
1996 Kadota et al.22
3-year-old boy
Hypothalamic glioma
Disruption of the dopaminergic pathway via the hypothalamus causes akinetic mutism
1983 Susman et al.5
1 case
Callosotomy
Severing interhemispheric connections (commissurotomy and callosotomy) where both hemispheres are required for speech production
postoperative mutism is described as a transient abnormality and it resolves in less than 2 weeks with no treatment. In rare cases such as when dopaminergic pathways are injured, dopamine replacement may be necessary. In conclusion, major factors in the genesis of postoperative mutism in the elderly would seem to be unilateral or bilateral involvement of the SMA. The additional cause of the mutism seen after removal of the tumor of the falx localization seems to be a disconnection of the callosal fibers and an impairment of the neighbouring structures, such as the cingulum, and possibly others. References 1. Altschuler LL, Cummins JL, Mills MJ. Mutism: review, differential diagnosis, and report of 22 cases. Am J Psychiatry 1986;143:1409–14. 2. Geschwind N. Current concepts: aphasia. N Engl J Med 1971;284:654–6. 3. Anderson B. Relief of akinetic mutism from obstructive hydrocephalus using bromocriptine and ephedrine. J Neurosurg 1992;76:152–5. 4. Nakasu Y, Isozumi T, Nioka H, et al. Mechanism of mutism following the transcallosal approach to the ventricles. Acta Neurochir(Wien) 1991;110:146–53. 5. Sussman NM, Gur RC, Gur RE, et al. Mutism as a consequence of callosotomy. J Neurosurg 1983;59:514–9. 6. Borggreve F, DeDeyn PP, Marien P, et al. Bilateral infarction in the anterior cerebral artery vascular territory due to an unusual anomaly of the circle of Willis. Stroke 1994;25:1279–81. 7. Selcuklu A, Kurtsoy A, Oktem IS, et al. Postoperative mutism after the clipping of a distal anterior cerebral artery aneurysm. A case report. Neurosurg Rev 1997;20:214–6. 8. Caplan LR, Zervas NT. Speech arrest in a dextral with a right mesial frontal astrocytoma. Arch Neurol 1978;35:252–3. 9. Crutchfield JS, Sawaya R, Meyers CA, et al. Postoperative mutism in neurosurgery. Report of two cases. J Neurosurg 1994;81:115–21.
doi:10.1016/j.jocn.2006.05.010
10. Rostomily RC, Berger MS, Ojemann GA, et al. Postoperative deficits and functional recovery following removal of tumors involving the dominant hemisphere supplementary motor area. J Neurosurg 1991;75:62–8. 11. Cummins JL, Benson DF, Houlihan JP, et al. Mutism: loss of neocortical and limbic localisation. J Nerv Ment Dis 1983;171:255–9. 12. Benson DF. Aphasia, Alexia, and Agraphia. New York: Churchill Livingstone; 1979, pp.163-4. 13. Peled R, Harnes B, Borovich B, et al. Speech arrest and supplementary motor area seizures. Neurology (Cleveland) 1984;34:110–1. 14. Ersahin Y, Mutluer S, Caglı S, et al. Cerebellar mutism: report of seven cases and review of the literature. Neurosurgery 1996;38: 60–6. 15. Penfield W, Welch K. The supplemental motor area of the cerebral cortex: a clinical and experimental study. Arch Neurol Psychiatry 1951;66:289–317. 16. Arseni C, Botez MI. Speech disturbances caused by tumors of the supplementary motor area. Acta Psychiatr Neurol Scand 1961;36:279–99. 17. Alajouanine T, Castaigna P, Sabouraud O, et al. Palilie paroxystique et localisations iteratives au cours de crises epileptiques par lesion interescant l’ aire motrice supplementaire. Rev Neurol 1959;101:685–97. 18. Gaab MR, Schroeder HWS. Neuroendoscopic approach to intraventricular lesions. J Neurosurg 1998;88:496–505. 19. Kunishio K, Matsumoto K, Asari S, et al. Transient mutism after resection of left frontal lobe astrocytoma in adult: case report. No Shinkei Geka 1997;25:61–5. 20. Quattrini A, Del Pesce M, Provinciali L, et al. Mutism in 36 patients who underwent callosotomy for drug-resistant epilepsy. J Neurosurg Sci 1997;41:93–6. 21. Shinoda M, Tsugu A, Oda S, et al. Development of akinetic mutism and hyperphagia after left thalamic and right hypothalamic lesions. Childs Nerv Syst 1993;9:243–5. 22. Kadota Y, Kondo T, Sato K. Akinetic mutism and involuntary movements following radical resection of hypothalamic glioma – case report. Neurol Med Chir (Tokyo) 1996;36:447–50.
Because VIM stimulation via the DBS electrodes produced excellent tremor control and the expected sensory responses, only one electrode penetration was used for each surgery. One week later, device implantation was completed under general anesthesia, consistent with previous reports.2,3 Postoperative CT scan (merged with preoperative MRI) confirmed excellent coincidence between planned target and final electrode position for the right (Fig. 1) and left electrodes. Subsequent stimulation therapy produced excellent bilateral tremor control without side-effects. Of the two different head support systems used, the modified Philadelphia cervical collar provided better comfort and support. Although some centers utilizing frameless guidance prefer to implant both electrodes simultaneously,4 it is the preference of the surgeon (RRG) to stage the procedure in order to confirm that there has been no post-implant hemorrhage or other morbidity following the first implant before proceeding with the contralateral implant. Comparative experience with frame-based electrode implants has shown us that for most patients, placement of skull fiducials has approximately the same degree of discomfort as frame placement. However, a number of patients find the frame application itself to be uncomfortable or painful, while patients having the screw implants have rarely complained of any pain at each of the implant sites. Additionally, the experience of having the head inside the frame during surgery is uncomfortable to many patients, and may induce respiratory obstruction due to fixation of the neck. The freedom of small neck motion allowed with the Philadelphia collar when we used the skull-mounted guide provided greater patient comfort. Our experience with this patient demonstrates that the skull-mounted guide can be used successfully for DBS implants.4 The planned target being well inside the MRI artifact (Fig. 1) indicates that the final electrode tip placement was certainly within 1.5 mm of the intended target, which is
793
comparable to the accuracy that has been documented with frame-based implants.2,3 In conclusion, we present an experience with staged DBS utilizing frameless stereotactic guidance. Staged electrode placement using a frameless skull-mounted guide was accurate, efficacious, increased patient comfort, allowed the convenience of advanced preoperative imaging and planning, eliminated the need for a stereotactic frame, and permitted the use of one reference system for staged procedures. 2. Financial disclosure information None of the authors received any financial support in conjunction with the generation of this article. Acknowledgement We would like to thank Mary Marshall for invaluable assistance. References 1. Benabid AL, Pollak P, Gross C, et al. Acute and long-term effects of subthalamic nucleus stimulation in Parkinson’s disease. Stereotact Funct Neurosurg 1994;62:76–84. 2. Starr PA, Christine CW, Theodosopoulos PV, et al. Implantation of deep brain stimulators into the subthalamic nucleus: technical approach and magnetic resonance imaging-verified lead locations. J Neurosurg 2002;97:370–87. 3. McClelland S 3rd, Ford B, Senatus PB, et al. Subthalamic stimulation for Parkinson disease: determination of electrode location necessary for clinical efficacy. Neurosurg Focus 2005;19:E12. 4. Holloway KL, Gaede SE, Starr PA, et al. Frameless stereotaxy using bone fiducial markers for deep brain stimulation. J Neurosurg 2005;103:404–13. 5. Woodworth GF, McGirt MJ, Elfert P, et al. Frameless stereotactic ventricular shunt placement for idiopathic intracranial hypertension. Stereotact Funct Neurosurg 2005;83:12–6.
doi:10.1016/j.jocn.2006.03.032
Postoperative mutism after removal of an anterior falcine meningioma Kadir Tahta a, Bayram Cirak a
a,*
, Emre Pakdemirli b, Tuncer Suzer a, Fatma Tahta
Department of Neurosurgery, Pamukkale University School of Medicine, Zeytinkoy mh. Aksemsettin cd. No.16, Denizli, Turkey b Department of Radiology, Pamukkale University, School of Medicine, Denizli, Turkey c Faculty of Education, Pamukkale University, Faculty of Education, Denizli, Turkey Received 23 February 2006; accepted 24 May 2006
*
Corresponding author. Tel.: +90 258 2664039; fax: +90 258 2134922. E-mail address: [email protected] (B. Cirak).
c
794
Case reports / Journal of Clinical Neuroscience 14 (2007) 793–796
Abstract Postoperative mutism is rare. We present a 65-year-old man who had transient mutism after resection of anterior falx meningioma. Mild left hemiparesis and palmomental reflex on the right were the only abnormal signs on neurological examination. CT scan and MRI demonstrated a mass at the anterior one-third portion of the falx just superior to the corpus callosum. The mass enhanced homogenously with administration of gadolinium DTPA. The patient underwent surgical resection of the lesion and adjacent falx cerebri. The operation was uneventful. On the second postoperative day he became mute. He could follow verbal commands, and write and read. Postoperative CT scan revealed a hypodense area in the right frontal lobe including a part of the anterior cingulate cortex and the anterior part of the corpus callosum. Histopathological examination revealed a mixed meningioma. Ten days postoperatively, he began to say simple words, and three weeks later he could talk normally. We consider that lesion of the supplementary motor area (SMA) may be responsible for postoperative mutism. 2006 Published by Elsevier Ltd. Keywords: Meningioma; Mutism; Supplementary motor area
1. Introduction The term ‘mutism’ is a clinical state in which a conscious patient is unwilling to or unable to speak, resulting in the absense or marked pause of verbal output.1,2 Mutism in conscious neurological patients is infrequent. Speech disturbances associated with cerebral lesions have been previously defined as akinetic mutism.3 Mechanisms implicated in the development of the syndrome have included callosotomy4,5 and extensive destruction of the frontal lobe,6,7 supplementary motor area (SMA)8–10 and cingulum.11 Naksu4 reported three patients with mutism following transcallosal surgery for epilepsy. He noted that mutism may be the result of division of the corpus callosum. Suppression of the limbic system by lesions in the anterior cingulate gyrus, septum pellucidum, and fornix may also have been of importance in at least two of these three cases. Impairment of the supplementary motor cortex, thalamus and basal ganglia may also contribute to reduced speech production. The mechanism of such transient mutism seems to be a complex of two or more of these factors, and their combination may be different from one patient to the next. A few authors have contributed their case materials but the overall number of cases remains small. We present a patient who developed transient mutism after resection of a falx meningioma.
A bifrontal bone flap was made with its posterior margin at 3 cm posterior to the bregma. The right frontal lobe was gently retracted, a small bridging vein was sacrificed. Initially, the proximal part of the tumor was dissected. After initial debulking of the dense tumor capsule, the anterior part of the falx cerebri, which was invaded by the tumor, was removed with the aid of an operating microscope. No damage was seen to the corpus callosum and the gyrus cinguli. Histopathologic evaluation confirmed the diagnosis of meningioma. Operation and recovery from anesthesia were uneventful. In response to verbal commands the patient could open his mouth. On the second postoperative day, he was alert but totally mute. He suffered fits of crying. He could follow verbal commands and was able to read and write. After mutism was diagnosed, neuropsychological examination was performed and he showed no psychiatric symptoms. A follow-up CT scan on the second postoperative day, showed a hypodense area indicating edema in the right frontal lobe including a part of the anterior cingulate cortex and the anterior part of the corpus callosum (Fig. 2). Intensive speech rehabilitation was instituted. He started speaking again at postoperative day 10, starting with responses to simple questions. He began to say simple words, and three weeks later the patient had good speech with mild left hemiparesis. 3. Discussion
2. Case report A 65-year-old man suffered from recurrent headache, seizure and an associated loss of consciousness lasting approximately 10 min. Physical examination was normal. Neurological examination revealed a mild left hemiparesis and positive palmomental reflex on the right. The fundus oculi examination revealed papilledema. Corticosteroid therapy was initiated. CT scan revealed a large lesion at the anterior one-third of the falx. MRI demonstrated a 50 · 52 · 48 mm mass at the anterior one-third of the falx just superior to the corpus callosum which enhanced after administration of gadolinium DTPA (Fig. 1).
Mutism caused by intracranial surgical intervention has been described in the following areas: (i) Broca’s area;12 (ii) the anterior cingulate area;11 (iii) the descending tracts bilaterally;4 (iv) the mesencephalic reticular formation;12 (v) after callosotomy for medically intractable epilepsy; (vi) the SMA;8,10,13 and (vii) the midline cerebellar structures.14 Penfield et al.15 in extensive stimulation experiments involving conscious humans, demonstrated SMA regions to be important for speech: the Rolandic and superior frontal areas within the SMA. Anatomical studies demonstrate connections between the SMA and all components of the motor system, including the bilateral motor cortex, cingulate
Case reports / Journal of Clinical Neuroscience 14 (2007) 793–796
gyri, contralateral SMA (which may be the basis for return of function after unilateral lesions) and caudate and spinal cord with basal ganglia input via the thalamus. There have been few reports of speech disturbances caused by lesions in the SMA of both hemispheres. Most were caused by parasagittal tumors or vascular lesions. Aphasia may result from infarction in the territory of the anterior cerebral artery of the dominant hemisphere or from tumors of the dominant SMA. Arseni and Batez16 reported 12 patients and Alajuanine et al.17 reported four cases of tumors affecting the supplementary motor regions in which arrest of speech was a prominent clinical feature. Rostomly et al.10 presented patients with seizures consisting of speech arrest. Caplan and Zervas8 indicated speech arrest in a patient with an astrocytoma involving the supplementary motor area. Crutchfield9 reported two patients who became mute in the immediate postoperative period and one developed mutism following removal of a parasagittal meningioma. It is believed that transient injury may have occurred to the supplementary motor cortex in the first case and to the dentate nuclei in the second
Fig. 1. T1-weighted enhanced axial MRI of the falx meningioma with a dural tail.
Fig. 2. Postoperative axial CT scan with marked edema in the frontal deep white matter with mild compression of right lateral ventricule.
795
case. It is interesting that these two areas are connected via pathways involving the ventrolateral nucleus of the thalamus, and that lesions of this thalamic nucleus can also lead to mutism. It therefore appears plausible that interruption of these pathways may be involved in the pathogenesis of mutism. Although mutism is an infrequent complication of brain surgery, neurosurgeons should be aware that it may occur following removal of lesions in these areas and that it is generally a transient condition. Peled et al.13 reported a patient with a metastasis in the left SMA. Epileptic arrest of speech was confused with a transient ischemic attack of the dominant hemisphere and the mutism continued for 10 days. The causes of mutism in our patient were a large midline supratentorial tumor, and pressure on the corpus callosum, the cingulum and the SMA. Additional aetiological factors may include transient vascular disturbances of the cingulum and the SMA, and postoperative swelling of the brain. The mutism in our patient could be assessed as a seizure, but no definite focal spike was seen on EEG. Magnetic resonance imaging indicated the tumour was localized to the falx cerebri directly anterior to the primary motor cortex in the mesial frontal lobe. Although previous reports4 of postoperative mutism demonstrate a hypointense area on T1-weighted images in the frontal lobe including a part of the anterior cingulate cortex and the anterior part of the corpus callosum, postoperative imaging of our patient did not reveal an underlying etiology for the observed deficits, such as infarct or hemorrhage. It appears that a dominant hemisphere lesion of both the anterior cingulate cortex and the corpus callosum may be responsible for the development of postoperative mutism. Surgical schock may be in part responsible for the transient weakness seen in some patients but it is unlikely to explain changes of initiation of function documented long after surgical edema would have resolved. Tumor infiltration into adjacent tissues and epileptic foci adjacent to the tumor may be responsible for mutism, as may vascular disturbances, either of ischemic origin (such as arterial spasm) or edema. A circulatory disturbance of the pericallosal arteries would cause dysfunction of this region and cause weakness of the lower extremities. However, Babinski sign, snout reflex, forced grasping and other interhemispheric frontal lobe signs were not observed in our patient. The outcome for postoperative mutism is favorable. Slight disturbances of speech production may result from right cerebral lesions in right-handed patients.8,18 But permanent, significant aphasia from such lesions is rare. In addition to deficits concerning initiation-related functions, several patients were unable to inhibit certain inappropriate speech and motor functions. Mutism has a very low incidence in the geriatric age group. We think that the location of the surgical intervention had a direct influence on mutism. Proposed etiology of postoperative mutism following supratentorial surgery has been summarized in Table 1. In most reported cases
796
Case reports / Journal of Clinical Neuroscience 14 (2007) 793–796
Table 1 Proposed etiology for postperative mutism following supratentorial surgery from previous reports in the literature Author
Patient
Pathology
Proposed etiology of mutism
1997 Kunishio et al.19
32-year-old woman
Left frontal malignant astrocytoma
Dominant hemisphere lesion of both the anterior cingulate cortex and the corpus callosum
1994 Crutchfield et al.9
2 cases
Parasagittal meningioma
1. Transient injury to the supplementary motor cortex and the dentate nuclei of the thalamus 2. Lesions of ventrolateral thalamic nucleus
1991 Nakasu et al.4
3 cases
Transcallosal surgery; tumors in the lateral and third ventricle
1. Division of the corpus callosum 2. Suppression of the limbic system caused by lesions in the anterior cingulate gyrus, septum pellucidum, and fornix 3. Impairments of the supplementary motor cortex, thalamus and basal ganglia
1997 Quattrini et al.20
10 cases
Transcallosal surgery for epilepsy
Surgical manupilation of the parasagittal cortex, cingulum, corpus callosum
1993 Shinoda et al.21
1 case
Post-traumatic mutism
Lesions in the left interlaminal nucleus of the thalamus, right globus pallidus, and right dorsomedial nucleus of the hypothalamus
1996 Kadota et al.22
3-year-old boy
Hypothalamic glioma
Disruption of the dopaminergic pathway via the hypothalamus causes akinetic mutism
1983 Susman et al.5
1 case
Callosotomy
Severing interhemispheric connections (commissurotomy and callosotomy) where both hemispheres are required for speech production
postoperative mutism is described as a transient abnormality and it resolves in less than 2 weeks with no treatment. In rare cases such as when dopaminergic pathways are injured, dopamine replacement may be necessary. In conclusion, major factors in the genesis of postoperative mutism in the elderly would seem to be unilateral or bilateral involvement of the SMA. The additional cause of the mutism seen after removal of the tumor of the falx localization seems to be a disconnection of the callosal fibers and an impairment of the neighbouring structures, such as the cingulum, and possibly others. References 1. Altschuler LL, Cummins JL, Mills MJ. Mutism: review, differential diagnosis, and report of 22 cases. Am J Psychiatry 1986;143:1409–14. 2. Geschwind N. Current concepts: aphasia. N Engl J Med 1971;284:654–6. 3. Anderson B. Relief of akinetic mutism from obstructive hydrocephalus using bromocriptine and ephedrine. J Neurosurg 1992;76:152–5. 4. Nakasu Y, Isozumi T, Nioka H, et al. Mechanism of mutism following the transcallosal approach to the ventricles. Acta Neurochir(Wien) 1991;110:146–53. 5. Sussman NM, Gur RC, Gur RE, et al. Mutism as a consequence of callosotomy. J Neurosurg 1983;59:514–9. 6. Borggreve F, DeDeyn PP, Marien P, et al. Bilateral infarction in the anterior cerebral artery vascular territory due to an unusual anomaly of the circle of Willis. Stroke 1994;25:1279–81. 7. Selcuklu A, Kurtsoy A, Oktem IS, et al. Postoperative mutism after the clipping of a distal anterior cerebral artery aneurysm. A case report. Neurosurg Rev 1997;20:214–6. 8. Caplan LR, Zervas NT. Speech arrest in a dextral with a right mesial frontal astrocytoma. Arch Neurol 1978;35:252–3. 9. Crutchfield JS, Sawaya R, Meyers CA, et al. Postoperative mutism in neurosurgery. Report of two cases. J Neurosurg 1994;81:115–21.
doi:10.1016/j.jocn.2006.05.010
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