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outcome. In this scenario, new promising strategies should include pleiotropic molecules with neuroprotective properties (4). The mechanisms of neuroprotection appear to be multifaceted and may essentially range from vasodilation of the cerebral arteries to anti-inflammatory, antioxidative, and antiapoptotic effects. Giovanni Grasso Section of Neurosurgery, Department of Experimental Biomedicine and Clinical Neurosciences (BIONEC), University of Palermo, Palermo, Italy To whom correspondence should be addressed: Giovanni Grasso, M.D., Ph.D. [E-mail: [email protected]] Published online 20 November 2014; http://dx.doi.org/10.1016/j.wneu.2014.11.010.
REFERENCES 1. Billingsley JT, Hoh BL: Vasospasm in aneurysmal subarachnoid hemorrhage. World Neurosurg 83:250-251, 2014. 2. Dankbaar JW, Rijsdijk M, van der Schaaf IC, Velthuis BK, Wermer MJ, Rinkel GJ: Relationship between vasospasm, cerebral perfusion, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. Neuroradiology 51:813-819, 2009. 3. Grasso G: An overview of new pharmacological treatments for cerebrovascular dysfunction after experimental subarachnoid hemorrhage brain research. Brain Res Brain Res Rev 44:49-63, 2004. 4. Grasso G, Tomasello F: Erythropoietin for subarachnoid hemorrhage: is there a reason for hope? World Neurosurg 77:46-48, 2012. 5. Vergouwen MD, Ilodigwe D, Macdonald RL: Cerebral infarction after subarachnoid hemorrhage contributes to poor outcome by vasospasm-dependent and -independent effects. Stroke 42:924-929, 2011.
Mavridis’ Area and Electrode Target Localization in Nucleus Accumbens Deep Brain Stimulation LETTER: brain stimulation (DBS) of the human nucleus accumbens D eep (NA) for the treatment of psychiatric disorders became a clinical reality during the first decade of the 21st century (6). I read the recent article by Voges et al. (7) entitled “Deep Brain Stimulation Surgery for Alcohol Addiction” with great interest, and I would like to make a few comments on this important article. These authors reported their first experiences with bilateral NA DBS for the treatment of severe alcohol addiction (7). It is one of the very first reports on the use of NA DBS for the treatment of human alcohol dependence. Motivated by an accidental observation, Voges et al. (7) used the NA, which has a central position in the dopaminergic reward system, as a target for DBS in alcohol addiction with promising results. Electrical NA stimulation probably counterbalances the effect of drugrelated stimuli triggering involuntarily drug-seeking behavior (7).
Regarding their surgical procedure, they defined the target, referred to the most distal contact of the electrode, to a point 2 mm rostral to the anterior commissure at the level of the midsagittal plane, 3e4 mm ventral and 6e8 mm lateral of the midline (7). This is translated into target area coordinates (X, X0 , Y, Y0 , Z, Z0 ) ¼ (6, 8, 2, 2, 3, 4), with the anterior commissure anterior border defining the stereotactic reference point with coordinates (X, Y, Z) ¼ (0, 0, 0).
WORLD NEUROSURGERY 83 [2]: 257-260, FEBRUARY 2015
Figure 1. Mavridis’ area (M) in comparison with the electrode target area used by Voges et al. (7) (human brain, left hemisphere, coronal section at stereotactic level Y ¼ 2, zoom on basal ganglia). The pinhead represents the target point with stereotactic coordinates (X, Y, Z) ¼ (7, 2, 4). 1) nucleus accumbens; 2) head of the caudate nucleus; 3) anterior limb of the internal capsule; 4) putamen; 5) external capsule; 6) claustrum; 7) extreme capsule; 8) corpus callosum; 9) frontal horn of the lateral ventricle. e, electrode trajectory coronal projection; T, target area reported by Voges et al. (7); Y, Z, stereotactic coordinates [modified from (6)].
Voges et al. (7) defined their target area in projection onto the caudomedial, subventricular part of the NA (respective of the shell area) (7). To confirm the desired electrode localization, they intraoperatively used stereotactic computed tomography (CT), integrating the preoperative treatment planning magnetic resonance imaging via image fusion, stereotactic x-ray imaging, and postoperatively CT examination. CT as well as radiographs were fused with the planning magnetic resonance imaging in each case, confirming that the distal contacts of the DBS electrode were placed in the caudomedial NA as intended and the third contact within the transition area to the medial border of the abutting internal capsule and the highest (fourth) contact at a point in the most medial part of the capsule or in the transition area to the caudate (7). Interestingly, their target area is close to the recently described Mavridis’ area (MA) (2-6), the most reliable stereotactically standard part of the human NA, regardless of side or sex (5). MA is defined by coordinates (X, X0 , Y, Y0 , Z, Z0 ) ¼ (6, 9, 2, 2, 0.8, 2) in stereotactic space, based on the same stereotactic reference point (2-6) as those used by Voges et al.
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(7). Their target area is located approximately 2 mm deeper than MA (Figure 1). It should be mentioned here that Voges et al. (7) used Medtronic quadripolar electrode model 3387 (Medtronic, Minneapolis, Minnesota, USA), which has a 1.5-mm contact length and 1.5-mm contacts spacing (1). Moreover, they started stimulation using the 2 most distal electrode contacts (i.e., contacts 0 and 1) in a bipolar mode (7). Consequently, considering the aforementioned details, as well as the electrode trajectory angles, coronal and sagittal, shown on their article’s first figure (7), we see that contact 1 was placed just in front of MA and used, together with contact 0 (placed just below MA), for NA DBS. Regarding the interesting questions that Voges et al. (7) raised in their article’s discussion section, it is true that the NA has a central anatomical position, located close to several other functionally relevant structures and the question “which anatomical units in the surrounding of the stimulation site have to be electrically affected to achieve maximum clinical improvement in addictive patients” (7) is as crucial as it is difficult to be answered. Further research is definitely needed to approach this issue. Answering the question “whether the NA represents a universal site for DBS treatment of addiction or if different types of substance dependence require different stimulation targets” (7) appears simpler. Given that the human NA (6) is a major pleasure center of the brain involved in addictive behavior, it seems purposeless to look for different “responsible” brain areas regarding different addictive substances. However, the theoretical necessity of different microtargets within the NA for different kinds of addiction could potentially be an issue. MA, an accurate stereotactic anatomical guide for targeting the human NA (2), is a representative example of the evolution of
stereotactic anatomy into stereotactic microanatomy (2). Voges et al. (7) have provided evidence that bipolar stimulation of the NA, with one contact below MA and the other in front of MA, can be effective in treating alcohol addiction. Future research is mandatory to help functional neurosurgeons to define even more precisely the desired stimulation targets (as well as other stimulation parameters) within the NA to achieve the best possible clinical outcome. Ioannis N. Mavridis Department of Neurosurgery, ‘K.A.T.-N.R.C.’ General Hospital of Attica, Athens, Greece To whom correspondence should be addressed: Ioannis N. Mavridis, M.D., Ph.D. [E-mail: [email protected]] Published online 20 November 2014; http://dx.doi.org/10.1016/j.wneu.2014.11.010.
REFERENCES 1. Kuhn J, Lenartz D, Huff W, Lee S, Koulousakis A, Klosterkoetter J, Sturm V: Remission of alcohol dependency following deep brain stimulation of the nucleus accumbens: valuable therapeutic implications? J Neurol Neurosurg Psychiatry 78: 1152-1153, 2007. 2. Mavridis IN: Anatomic guidance for stereotactic microneurosurgery: a modern necessity and the example of Mavridis’ area. Surg Radiol Anat, 2014 [Epub ahead of print]. 3. Mavridis IN: Mavridis’ area of the human brain: mathematically analysed anatomy assists stereotactic neurosurgery. OA Anat 2:11, 2014. 4. Mavridis IN: Nucleus accumbens stereotactic surgery: achieving accuracy through area M. World J Neurol 3:7-9, 2013. 5. Mavridis IN: Stereotactic neurosurgical anatomy of the nucleus accumbens: four-year outcomes. Surg Radiol Anat 35:637-638, 2013. 6. Mavridis IN: Stereotactic neurosurgical anatomy of the nucleus accumbens [in Greek]. PhD Thesis, National and Kapodistrian University of Athens (School of Medicine), Athens, Greece, 2012. 7. Voges J, Müller U, Bogerts B, Münte T, Heinze HJ: Deep brain stimulation surgery for alcohol addiction. World Neurosurg 80:S28.e21-S28.e31, 2013.
Contact the Editorial Office Edward C. Benzel, M.D. Chairman, Department of Neurosurgery, Cleveland Clinic WORLD NEUROSURGERY Editor-in-Chief 9500 Euclid Avenue / S-40 Cleveland, OH 44195 Tel: 216-444-7381 Fax: 216-445-4527 E-mail: [email protected] Website: www.WORLDNEUROSURGERY.org
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outcome. In this scenario, new promising strategies should include pleiotropic molecules with neuroprotective properties (4). The mechanisms of neuroprotection appear to be multifaceted and may essentially range from vasodilation of the cerebral arteries to anti-inflammatory, antioxidative, and antiapoptotic effects. Giovanni Grasso Section of Neurosurgery, Department of Experimental Biomedicine and Clinical Neurosciences (BIONEC), University of Palermo, Palermo, Italy To whom correspondence should be addressed: Giovanni Grasso, M.D., Ph.D. [E-mail: [email protected]] Published online 20 November 2014; http://dx.doi.org/10.1016/j.wneu.2014.11.010.
REFERENCES 1. Billingsley JT, Hoh BL: Vasospasm in aneurysmal subarachnoid hemorrhage. World Neurosurg 83:250-251, 2014. 2. Dankbaar JW, Rijsdijk M, van der Schaaf IC, Velthuis BK, Wermer MJ, Rinkel GJ: Relationship between vasospasm, cerebral perfusion, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. Neuroradiology 51:813-819, 2009. 3. Grasso G: An overview of new pharmacological treatments for cerebrovascular dysfunction after experimental subarachnoid hemorrhage brain research. Brain Res Brain Res Rev 44:49-63, 2004. 4. Grasso G, Tomasello F: Erythropoietin for subarachnoid hemorrhage: is there a reason for hope? World Neurosurg 77:46-48, 2012. 5. Vergouwen MD, Ilodigwe D, Macdonald RL: Cerebral infarction after subarachnoid hemorrhage contributes to poor outcome by vasospasm-dependent and -independent effects. Stroke 42:924-929, 2011.
Mavridis’ Area and Electrode Target Localization in Nucleus Accumbens Deep Brain Stimulation LETTER: brain stimulation (DBS) of the human nucleus accumbens D eep (NA) for the treatment of psychiatric disorders became a clinical reality during the first decade of the 21st century (6). I read the recent article by Voges et al. (7) entitled “Deep Brain Stimulation Surgery for Alcohol Addiction” with great interest, and I would like to make a few comments on this important article. These authors reported their first experiences with bilateral NA DBS for the treatment of severe alcohol addiction (7). It is one of the very first reports on the use of NA DBS for the treatment of human alcohol dependence. Motivated by an accidental observation, Voges et al. (7) used the NA, which has a central position in the dopaminergic reward system, as a target for DBS in alcohol addiction with promising results. Electrical NA stimulation probably counterbalances the effect of drugrelated stimuli triggering involuntarily drug-seeking behavior (7).
Regarding their surgical procedure, they defined the target, referred to the most distal contact of the electrode, to a point 2 mm rostral to the anterior commissure at the level of the midsagittal plane, 3e4 mm ventral and 6e8 mm lateral of the midline (7). This is translated into target area coordinates (X, X0 , Y, Y0 , Z, Z0 ) ¼ (6, 8, 2, 2, 3, 4), with the anterior commissure anterior border defining the stereotactic reference point with coordinates (X, Y, Z) ¼ (0, 0, 0).
WORLD NEUROSURGERY 83 [2]: 257-260, FEBRUARY 2015
Figure 1. Mavridis’ area (M) in comparison with the electrode target area used by Voges et al. (7) (human brain, left hemisphere, coronal section at stereotactic level Y ¼ 2, zoom on basal ganglia). The pinhead represents the target point with stereotactic coordinates (X, Y, Z) ¼ (7, 2, 4). 1) nucleus accumbens; 2) head of the caudate nucleus; 3) anterior limb of the internal capsule; 4) putamen; 5) external capsule; 6) claustrum; 7) extreme capsule; 8) corpus callosum; 9) frontal horn of the lateral ventricle. e, electrode trajectory coronal projection; T, target area reported by Voges et al. (7); Y, Z, stereotactic coordinates [modified from (6)].
Voges et al. (7) defined their target area in projection onto the caudomedial, subventricular part of the NA (respective of the shell area) (7). To confirm the desired electrode localization, they intraoperatively used stereotactic computed tomography (CT), integrating the preoperative treatment planning magnetic resonance imaging via image fusion, stereotactic x-ray imaging, and postoperatively CT examination. CT as well as radiographs were fused with the planning magnetic resonance imaging in each case, confirming that the distal contacts of the DBS electrode were placed in the caudomedial NA as intended and the third contact within the transition area to the medial border of the abutting internal capsule and the highest (fourth) contact at a point in the most medial part of the capsule or in the transition area to the caudate (7). Interestingly, their target area is close to the recently described Mavridis’ area (MA) (2-6), the most reliable stereotactically standard part of the human NA, regardless of side or sex (5). MA is defined by coordinates (X, X0 , Y, Y0 , Z, Z0 ) ¼ (6, 9, 2, 2, 0.8, 2) in stereotactic space, based on the same stereotactic reference point (2-6) as those used by Voges et al.
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CORRESPONDENCE
(7). Their target area is located approximately 2 mm deeper than MA (Figure 1). It should be mentioned here that Voges et al. (7) used Medtronic quadripolar electrode model 3387 (Medtronic, Minneapolis, Minnesota, USA), which has a 1.5-mm contact length and 1.5-mm contacts spacing (1). Moreover, they started stimulation using the 2 most distal electrode contacts (i.e., contacts 0 and 1) in a bipolar mode (7). Consequently, considering the aforementioned details, as well as the electrode trajectory angles, coronal and sagittal, shown on their article’s first figure (7), we see that contact 1 was placed just in front of MA and used, together with contact 0 (placed just below MA), for NA DBS. Regarding the interesting questions that Voges et al. (7) raised in their article’s discussion section, it is true that the NA has a central anatomical position, located close to several other functionally relevant structures and the question “which anatomical units in the surrounding of the stimulation site have to be electrically affected to achieve maximum clinical improvement in addictive patients” (7) is as crucial as it is difficult to be answered. Further research is definitely needed to approach this issue. Answering the question “whether the NA represents a universal site for DBS treatment of addiction or if different types of substance dependence require different stimulation targets” (7) appears simpler. Given that the human NA (6) is a major pleasure center of the brain involved in addictive behavior, it seems purposeless to look for different “responsible” brain areas regarding different addictive substances. However, the theoretical necessity of different microtargets within the NA for different kinds of addiction could potentially be an issue. MA, an accurate stereotactic anatomical guide for targeting the human NA (2), is a representative example of the evolution of
stereotactic anatomy into stereotactic microanatomy (2). Voges et al. (7) have provided evidence that bipolar stimulation of the NA, with one contact below MA and the other in front of MA, can be effective in treating alcohol addiction. Future research is mandatory to help functional neurosurgeons to define even more precisely the desired stimulation targets (as well as other stimulation parameters) within the NA to achieve the best possible clinical outcome. Ioannis N. Mavridis Department of Neurosurgery, ‘K.A.T.-N.R.C.’ General Hospital of Attica, Athens, Greece To whom correspondence should be addressed: Ioannis N. Mavridis, M.D., Ph.D. [E-mail: [email protected]] Published online 20 November 2014; http://dx.doi.org/10.1016/j.wneu.2014.11.010.
REFERENCES 1. Kuhn J, Lenartz D, Huff W, Lee S, Koulousakis A, Klosterkoetter J, Sturm V: Remission of alcohol dependency following deep brain stimulation of the nucleus accumbens: valuable therapeutic implications? J Neurol Neurosurg Psychiatry 78: 1152-1153, 2007. 2. Mavridis IN: Anatomic guidance for stereotactic microneurosurgery: a modern necessity and the example of Mavridis’ area. Surg Radiol Anat, 2014 [Epub ahead of print]. 3. Mavridis IN: Mavridis’ area of the human brain: mathematically analysed anatomy assists stereotactic neurosurgery. OA Anat 2:11, 2014. 4. Mavridis IN: Nucleus accumbens stereotactic surgery: achieving accuracy through area M. World J Neurol 3:7-9, 2013. 5. Mavridis IN: Stereotactic neurosurgical anatomy of the nucleus accumbens: four-year outcomes. Surg Radiol Anat 35:637-638, 2013. 6. Mavridis IN: Stereotactic neurosurgical anatomy of the nucleus accumbens [in Greek]. PhD Thesis, National and Kapodistrian University of Athens (School of Medicine), Athens, Greece, 2012. 7. Voges J, Müller U, Bogerts B, Münte T, Heinze HJ: Deep brain stimulation surgery for alcohol addiction. World Neurosurg 80:S28.e21-S28.e31, 2013.
Contact the Editorial Office Edward C. Benzel, M.D. Chairman, Department of Neurosurgery, Cleveland Clinic WORLD NEUROSURGERY Editor-in-Chief 9500 Euclid Avenue / S-40 Cleveland, OH 44195 Tel: 216-444-7381 Fax: 216-445-4527 E-mail: [email protected] Website: www.WORLDNEUROSURGERY.org
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