Last modified by Max Gosey on 2010/06/18 15:52
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... ... @@ -27,8 +27,238 @@ 27 27 28 28 = Section IV.4.2: Laminectomy Electrode Implantation, General Methods = 29 29 30 +(% class="FreeForm" style="text-align: justify; line-height: 200%;" %) 31 +(% style="font-family: ~"Times New Roman~",~"serif~";" %)For a number of conditions, particularly the “postlaminectomy syndrome” (aka “failed back”) [25, 26, 31], and Complex Regional Pain Syndrome (CRPS I and II) [31, 32], spinal cord stimulation (SCS) has been found to be one of the more effective therapies [30, 31] cost effective [27-29]. Originally, it was based, conceptually, on the gate control theory of pain introduced by Melzack and Wall in 1965 [16], which proposed that the activity of large-diameter fibers (α/β fibers) in the DC plays an inhibitory role in transmission of pain signals to the brain. SCS subsequently received FDA approval in 1979 as a class II device for chronic pain of the trunk and limbs. Over 50,000 SCS systems are implanted for pain disorders around the world each year. Certain principles have become clear through the use of SCS: 1) paresthesia coverage must precisely overlap the painful areas, the cathode is the “active” contact and must deliver its energy to the DC, and 2) accurate identification of the "physiological" midline (PM) is essential for treatment of bilateral pain. Displacement of the cathode up to 1 mm from the affected (% style="font-size: 8pt; line-height: 200%; font-family: ~"Times New Roman~",~"serif~"; color: windowtext;" %) (% style="font-family: ~"Times New Roman~",~"serif~";" %)side works well for unilateral pain [18]. Placement of stimulating electrodes in the subdural space was initially described by Shealy [17]. This resulted in a high complication rate leading to placement of the electrodes in the epidural space. Percutaneous placement of spinal cord stimulator electrodes has several advantages including: minimal invasiveness, reduced cost, and increased flexibility in lead repositioning. Percutaneous placement of electrodes is achieved with local anesthesia and fluoroscopic image guidance to ensure the proper placement of the leads [20, 34] and is routinely used for trial electrodes. However, percutaneous placement is still associated with a comparatively high rate of migration of the electrode (up to 13.5%)[19, 20, 34, 41]. Higher power requirements with omni-directional contacts result in increased battery drain and decreased device durability when used for permanent implants. Accordingly, many centers prefer a laminectomy approach with placement of a “paddle lead” configuration. This approach also allows the electrode to be directly anchored to the lamina at the site of entry to the epidural space [21, 33]. Due to its invasiveness and associated patient discomfort, this approach is often performed under general anesthesia with fluoroscopic guidance to determine the anatomic midline by bony landmarks. As mentioned previously, experience has shown that outcome is critically dependent on symmetric placement of the electrode on the PM(% style="font-size: 8pt; line-height: 200%; font-family: ~"Times New Roman~",~"serif~"; color: windowtext;" %) (% style="font-family: ~"Times New Roman~",~"serif~";" %), and that the physiologic and anatomic midlines are frequently not identical, differing by up to 2 mm in up to 40% of patients [40]. In the author’s experience, it is not at all uncommon for comparative midlines to deviate significantly over as little as a single spinal level(% style="font-size: 8pt; line-height: 200%; font-family: ~"Times New Roman~",~"serif~"; color: windowtext;" %) (% style="font-family: ~"Times New Roman~",~"serif~";" %). The importance of proper positioning of electrodes during SCS is reinforced by the computer models developed by Holsheimer et al. [39], in which they show that thickness of the dorsal CSF layer and precise midline positioning of the electrodes are the most significant factors determining the perception threshold of stimulation-induced paresthesias. 32 + 33 +(% class="FreeForm" style="text-align: justify; line-height: 200%;" %) 34 +(% style="font-family: ~"Times New Roman~",~"serif~";" %)In order to address these concerns, some centers have employed a “wake up test” to demonstrate that the paresthesia maps to the painful areas before closing. This has received very limited acceptance because of discomfort to the patient and the difficulty obtaining trustworthy feedback from an intubated patient. Other centers have gone to laminectomy under only local anesthesia. Difficulty obtaining adequate intraoperative pain control has limited the acceptance of this technique. Some centers perform the procedure under a high (midthoracic) spinal or epidural anesthetic producing a regional anesthesia, which in experienced hands, does not interfere with the distal patterns of paresthesia coverage. However, it is prone to difficulties in execution, which can lead to dense anesthesia or significant additional intravenous sedation inhibiting patient examination. 35 + 36 +(% class="FreeForm" style="text-align: justify; line-height: 200%;" %) 37 +(% style="font-family: ~"Times New Roman~",~"serif~";" %)The remainer of this chapter is devoted to an alternative technique, which allows the comfort and safety of general anesthetic, while determining the PM by objective neurophysiological testing(% style="font-size: 8pt; line-height: 200%; font-family: ~"Times New Roman~",~"serif~"; color: windowtext;" %) (% style="font-family: ~"Times New Roman~",~"serif~";" %). The identification of PM by use of evoked potentials was introduced by Claudio Feler, who obtained a patent for a device to perform the mapping [US 6,027,456].(% style="font-family: ~"Times New Roman Bold~";" %) (% style="font-family: ~"Times New Roman~",~"serif~";" %)While the device did not gain widespread usage, a few centers adopted the methodology using standard intraoperative electrophysiologic monitoring equipment. To obtain the optimal coverage over painful areas, two major criteria must be met: the applied stimulation should be positioned longitudinally along the DC and the PM must be identified. When general anesthesia is used, intraoperative neurophysiological monitoring with evoked potentials becomes the only way to determine the PM. Stimulation of various portions of the dorsal spinal cord produces paresthesia in a given distribution in the conscious patient, as well as reliable patterns of sensory (SSEP) and motor unit action potentials (MUAP’s) of the EMG in the patient under anesthesia. In addition, the output data may include interpolations between specific measured points for optimal assessment of applied stimulation between evaluated lateral positions [US 6,027,456]. 38 + 39 + 40 + 41 +(% style="font-family: ~"Times New Roman~",~"serif~";" %) 42 +These fundamental findings have been implemented in practice by the senior author (KA), who began using this approach in 1999, noting a marked improvement in outcomes over the previous flouroscopically guided technique. In this technique, MUAP’s via EMG activation are used to determine the PM by examining the symmetry of the evoked potentials with presumed midline stimulation. In addition, it became clear that objective MUAP’s via EMG activation of specific muscles corresponded with postoperative induced paresthesia in particular regions depending on laminectomy level. For example, EMG activation of the external oblique muscle from a T9-10 thoracic paddle consistently correlates with low back paresthesia (Figure 4.1). 43 + 44 +(% style="font-family: ~"Times New Roman~",~"serif~";" %) 45 +[[image:Figure4.1-.png||height="80%" width="80%"]](% cite="mailto:Max%20Gosey" datetime="2010-06-13T22:36" %),,// 46 +//,, 47 + 48 +((( 49 +(% class="FreeForm" style="text-align: justify;" %) 50 +(% style="font-size: 10pt; font-family: ~"Times New Roman~",~"serif~";" %)//Figure 4.1: Intraoperative view of thoracic paddle lead implantation. A.: The electrode is behind the body of T9 and T10. Stimulation is right-sided with the cathode at the second position and the anode at the third. B.: With right-sided stimulation, there is right-side gastrocnemius activation, which will correlate to an S1 dermatomal paresthesia.// 51 +))) 52 + 53 +(% style="font-family: ~"Times New Roman~",~"serif~";" %) 54 +~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~__ 55 + 56 +These correlations are summarized in Table 1. Additional correlations have been made for cervical SCS (Figure 2) and sacral nerve root stimulator (SNRS) (Figure 3) laminectomy placements (Tables 2 and 3). 57 + 58 + 59 +(% class="FreeForm" style="text-align: justify; line-height: 200%;" %) 60 +[[image:Figure4.2.png||height="75%" width="75%"]] 61 + 62 + 63 + 64 +(% class="FreeForm" style="margin-bottom: 16pt;" %) 65 +(% style="font-family: ~"Times New Roman~",~"serif~";" %),,//Figure 4.2. Intraoperative view of cervical paddle lead implantation. A. The electrode is behind the body of C3 and C4, entering at the C4/5 interspace. B. With left sided stimulation, there is left side triceps activation, which will correlate to a C7 dermatomal paresthesia.//,, 66 + 67 +~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~__ 68 + 69 +[[image:Figure4.3.png]] 70 + 71 +(% class="FreeForm" style="margin-bottom: 16pt;" %) 72 +(% style="font-family: ~"Times New Roman~",~"serif~";" %),,//Figure 4.3. Permanent retrograde implantation of sacral root paddle leads. A. Stimulation is left sided, with the cathode at the second position and the anode at the third. B. In this older tracing, the stimulation in the second left contact produces primarily adductor hallucis activation, solely on the left side. This correlated with the postoperative paresthesia felt in the S3 perineal region.//,, 73 + 74 +(% style="font-family: ~"Times New Roman~",~"serif~";" %),,//~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_//,, 75 + 76 +((( 77 +(% border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="background: white none repeat scroll 0% 0%; margin-left: 2.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; border-collapse: collapse;" %) 78 +(% style="page-break-inside: avoid; height: 41pt;" %)|(% style="border: 1pt solid rgb(191, 191, 191); padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.9pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 41pt;" valign="top" width="312" %)(% class="xwiki-document" %) 79 +((( 80 +((( 30 30 82 +))) 31 31 84 +(% align="center" class="FreeForm" style="text-align: center;" %) 85 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)EMG activation, muscle group 86 +)))|(% style="border-style: solid solid solid none; border-color: rgb(191, 191, 191) rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: 1pt 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 197.1pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 41pt;" valign="top" width="263" %)(% class="xwiki-document" %) 87 +((( 88 +((( 89 + 90 +))) 91 + 92 +(% align="center" class="FreeForm" style="text-align: center;" %) 93 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Induced paresthesia 94 +))) 95 +(% style="page-break-inside: avoid; height: 42.75pt;" %)|(% style="border-style: none solid solid; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191); border-width: medium 1pt 1pt; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.9pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="312" %)(% class="xwiki-document" %) 96 +((( 97 +((( 98 + 99 +))) 100 + 101 +(% align="center" class="FreeForm" style="text-align: center;" %) 102 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Deltoid 103 +)))|(% style="border-style: none solid solid none; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 197.1pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="263" %)(% class="xwiki-document" %) 104 +((( 105 +((( 106 + 107 +))) 108 + 109 +(% align="center" class="FreeForm" style="text-align: center;" %) 110 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Shoulder 111 +))) 112 +(% style="page-break-inside: avoid; height: 42.75pt;" %)|(% style="border-style: none solid solid; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191); border-width: medium 1pt 1pt; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.9pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="312" %)(% class="xwiki-document" %) 113 +((( 114 +((( 115 + 116 +))) 117 + 118 +(% align="center" class="FreeForm" style="text-align: center;" %) 119 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Biceps 120 +)))|(% style="border-style: none solid solid none; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 197.1pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="263" %)(% class="xwiki-document" %) 121 +((( 122 +((( 123 + 124 +))) 125 + 126 +(% align="center" class="FreeForm" style="text-align: center;" %) 127 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)C5-6 128 +))) 129 +(% style="page-break-inside: avoid; height: 42.75pt;" %)|(% style="border-style: none solid solid; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191); border-width: medium 1pt 1pt; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.9pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="312" %)(% class="xwiki-document" %) 130 +((( 131 +((( 132 + 133 +))) 134 + 135 +(% align="center" class="FreeForm" style="text-align: center;" %) 136 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Triceps 137 +)))|(% style="border-style: none solid solid none; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 197.1pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="263" %)(% class="xwiki-document" %) 138 +((( 139 +((( 140 + 141 +))) 142 + 143 +(% align="center" class="FreeForm" style="text-align: center;" %) 144 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)C7 145 +))) 146 +(% style="page-break-inside: avoid; height: 42.75pt;" %)|(% style="border-style: none solid solid; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191); border-width: medium 1pt 1pt; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.9pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="312" %)(% class="xwiki-document" %) 147 +((( 148 +((( 149 + 150 +))) 151 + 152 +(% align="center" class="FreeForm" style="text-align: center;" %) 153 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Intrinsics 154 +)))|(% style="border-style: none solid solid none; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 197.1pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 42.75pt;" valign="top" width="263" %)(% class="xwiki-document" %) 155 +((( 156 +((( 157 + 158 +))) 159 + 160 +(% align="center" class="FreeForm" style="text-align: center;" %) 161 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)C8 162 +))) 163 + 164 +(% class="FreeForm" style="margin-left: 0.5in; text-align: justify; text-indent: -0.5in;" %) 165 +(% style="font-family: ~"Times New Roman~",~"serif~";" %),,//Table 4.2: Correlations between EMG activation of specific muscles with postoperative induced paresthesia - Cervical Paddle C3-4 (laminectomy C4/5)// ,, 166 + 167 +(% style="font-family: ~"Times New Roman~",~"serif~";" %)~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_ 168 + 169 +(% border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="background: white none repeat scroll 0% 0%; margin-left: 2.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; border-collapse: collapse;" %) 170 +(% style="page-break-inside: avoid; height: 58.35pt;" %)|(% style="border: 1pt solid rgb(191, 191, 191); padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 58.35pt;" valign="top" width="311" %)(% class="xwiki-document" %) 171 +((( 172 +(% align="center" class="FreeForm" style="text-align: center;" %) 173 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)EMG activation, muscle group 174 +)))|(% style="border-style: solid solid solid none; border-color: rgb(191, 191, 191) rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: 1pt 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 58.35pt;" valign="top" width="311" %)(% class="xwiki-document" %) 175 +((( 176 +((( 177 + 178 +))) 179 + 180 +(% align="center" class="FreeForm" style="text-align: center;" %) 181 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Induced paresthesia 182 +))) 183 +(% style="page-break-inside: avoid; height: 62pt;" %)|(% style="border-style: none solid solid; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191); border-width: medium 1pt 1pt; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 62pt;" valign="top" width="311" %)(% class="xwiki-document" %) 184 +((( 185 +((( 186 + 187 +))) 188 + 189 +(% align="center" class="FreeForm" style="text-align: center;" %) 190 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Gastrocnemius 191 + 192 + 193 +)))|(% style="border-style: none solid solid none; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 62pt;" valign="top" width="311" %)(% class="xwiki-document" %) 194 +((( 195 +((( 196 + 197 +))) 198 + 199 +(% align="center" class="FreeForm" style="text-align: center;" %) 200 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)S1(undesired) 201 +))) 202 +(% style="page-break-inside: avoid; height: 58.35pt;" %)|(% style="border-style: none solid solid; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191); border-width: medium 1pt 1pt; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 58.35pt;" valign="top" width="311" %)(% class="xwiki-document" %) 203 +((( 204 +((( 205 + 206 +))) 207 + 208 +(% align="center" class="FreeForm" style="text-align: center;" %) 209 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Adductor Hallucis 210 +)))|(% style="border-style: none solid solid none; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 58.35pt;" valign="top" width="311" %)(% class="xwiki-document" %) 211 +((( 212 +((( 213 + 214 +))) 215 + 216 +(% align="center" class="FreeForm" style="text-align: center;" %) 217 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)S2-3 218 +))) 219 +(% style="page-break-inside: avoid; height: 58.35pt;" %)|(% style="border-style: none solid solid; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191); border-width: medium 1pt 1pt; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 58.35pt;" valign="top" width="311" %)(% class="xwiki-document" %) 220 +((( 221 +((( 222 + 223 +))) 224 + 225 +(% align="center" class="FreeForm" style="text-align: center;" %) 226 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)Perianal 227 +)))|(% style="border-style: none solid solid none; border-color: -moz-use-text-color rgb(191, 191, 191) rgb(191, 191, 191) -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 2.5pt; background: rgb(154, 154, 154) none repeat scroll 0% 0%; width: 233.5pt; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous; height: 58.35pt;" valign="top" width="311" %)(% class="xwiki-document" %) 228 +((( 229 +(% align="center" class="FreeForm" style="text-align: center;" %) 230 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %) 231 + 232 +(% align="center" class="FreeForm" style="text-align: center;" %) 233 +(% style="font-size: 18pt; font-family: ~"Times New Roman~",~"serif~";" %)S4 234 +))) 235 + 236 +(% style="font-family: ~"Times New Roman~",~"serif~";" %)//Table 4.3: Correlation between EMG activation of specific muscles with postoperative induced paresthesia - Sacral Paddle(s) S2-3 (laminectomy S1)// 237 + 238 +~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~__ 239 + 240 +(% style="font-family: ~"Times New Roman~",~"serif~";" %)The general concept of using intraoperative EMG in the placement of the SCS on the PM of the spinal cord is similar with respect to the 2- and 3-column paddle configuration and differs in terms of whether the “expected” pattern should be symmetric (the middle column of a 3-column array) or “equally asymmetric” (a 2-column array). The newest 5 column array (Penta, St. Jude Medical, Plano, Texas) has just begun PM evaluation with this technique. 241 + 242 +((( 243 + 244 +))) 245 +))) 246 + 247 +((( 248 +(% align="left" class="msocomoff" size="1" width="33%" %) 249 +---- 250 + 251 +((( 252 +(% class="msocomtxt" id="_com_5" language="JavaScript" onmouseout="msoCommentHide('_com_5')" onmouseover="msoCommentShow('_anchor_5','_com_5')" %) 253 +((( 254 + 255 +))) 256 +))) 257 +))) 258 + 259 +[[previous page>>http://noddle.myxwiki.org/xwiki/bin/view/EMGForElectrodePlacement/GeneralUsesOfNeurologicalMonitoringInSpineSurgery]] | [[next page>>TechniqueOfMidlinePositioningOfTheSpinalCordStimulator]] 260 + 261 + 32 32 = Section IV.4.3: Technique of Midline Positioning of the Spinal Cord Stimulator – Tripolar paddle = 33 33 34 34 = Section IV.4.4: New frontiers of intraoperative EMG application =