origin. We will address the current state of surgical pain management in two sections: ablative surgery and neuromodulation. Ablative surgery will be further divided into three topics: noncancer pain, TN, and cancer-related pain. Our neuromodulation discussion will deal predominantly with neuropathic pain. Ablative Surgery Noncancer Pain Ablative, or more properly destructive, procedures for noncancer (i.e., nonmalignant) pain represent the foundation for much of pain surgery. The litany of these procedures includes cingulotomy, thalamotomy, hypophysectomy
JNSPG 75th Anniversary Invited Review Article
Kim J. Burchiel and Ahmed M. Raslan
Marwan I. Hariz, Patric Blomstedt and Ludvic Zrinzo
approved by the US Food and Drug Administration, probably due to lack of controlled trials to prove its efficacy. 18 Deep brain stimulation for chronic pain along with occasional stereotactic ablative surgery continued to be used in Europe, 43 and interest has resurged in recent years, riding on the wave of success of DBS in movement disorders. 16 Epilepsy was another indication that caught the early interest of the DBS pioneers listed above. The exploration and identification of epileptic foci rapidly adopted the technique of stereotactic chronic electrode
Philip A. Starr, Thyagarajan Subramanian, Roy A. E. Bakay and Thomas Wichmann
properties of each of the subcortical targets (as defined in previous experiments in animals) are quite distinct. Features that are helpful in the localization of a nucleus or surrounding structure include the rate and pattern of spontaneous action potential discharge, neuronal responses to somatosensory examination, and sensory or motor responses to microstimulation. Ablative surgery and long-term deep-brain stimulation can alleviate symptoms of PD, but do not directly address its underlying pathophysiological mechanisms. The fundamental defect in PD is the degeneration
Joshua Pepper, Marwan Hariz and Ludvic Zrinzo
bilateral procedures in motor areas of the basal ganglia and thalamus could be performed with less risk of side effects on speech, swallowing, cognition, and balance. However, the rationale for DBS of nonmotor subcortical areas in psychiatric disorders is less clear, other than it is perceived as nonablative and assumed to be reversible and more forgiving than lesions, and therefore more acceptable. Unlike the case of DBS versus ablative surgery in movement disorders, there has been no previous comparison between outcomes of patients with OCD who received DBS in the
Ludvic Zrinzo, Thomas Foltynie, Patricia Limousin and Marwan I. Hariz
Stimulation Versus Ablative Surgery It has been suggested that lesioning surgery carries a higher risk of hemorrhage than DBS surgery but this stance has been contested. 9 , 25 , 61 One mechanism that would explain the former observation would be adherence of the coagulum to the radiofrequency probe and rupture of vessels on probe withdrawal. However, the method of coagulation (rate of temperature increase, duration of coagulation and maximal temperature reached) may all have a bearing on this observation in clinical practice. Differing practices in lesion production may
Report of two cases
Todd P. Thompson, Douglas Kondziolka and A. Leland Albright
✓ Surgery for movement disorders is most commonly performed in patients with dyskinesia and tremor associated with Parkinson's disease or in those with essential tremor. The role of ablative surgery or deep brain stimulation in patients with choreiform movements is poorly defined.
The authors placed thalamic stimulation systems in two children with disabling choreiform disorders due to intracerebral hemorrhage or cerebral palsy. Each patient displayed choreiform movements in the upper extremities both at rest and with intention, which interfered with daily activities and socialization. Both children obtained significant improvement in their choreiform movements, and their upper extremity function improved with no incidence of morbidity. Thalamic stimulation appears to be a promising and nonablative approach for children with choreiform movement disorders.
Kristopher G. Hooten, Klaus Werner, Mohamad A. Mikati and Carrie R. Muh
Cortical tubers associated with tuberous sclerosis complex (TSC) are potential epileptic foci that are often amenable to resective or ablative surgeries, and controlling seizures at a younger age may lead to improved functional outcomes. MRI-guided laser interstitial thermal therapy (MRgLITT) has become a popular minimally invasive alternative to traditional craniotomy. Benefits of MRgLITT include the ability to monitor the ablation in real time, a smaller incision, shorter hospital stay, reduced blood loss, and reduced postoperative pain. To place the laser probe for LITT, however, stereotaxy is required—which classically involves head fixation with cranial pins. This creates a relative minimum age limit of 2 years old because it demands a mature skull and fused cranial sutures. A novel technique is presented for the application of MRgLITT in a 6-month-old infant for the treatment of epilepsy associated with TSC. To the authors’ knowledge this is the youngest patient treated with laser ablation. The authors used a frameless navigation technique with a miniframe tripod system and intraoperative reference points. This technique expands the application of MRgLITT to younger patients, which may lead to safer surgical interventions and improved outcomes for these children.
Ashley Ralston, Patti Ogden, Michael H. Kohrman and David M. Frim
Vagus nerve stimulators (VNSs) are currently an accepted treatment for intractable epilepsy not amenable to ablative surgery. Battery death and lead damage are the main reasons for reoperation in patients with VNSs. In general, any damage to the lead requires revision surgery to remove the helical electrodes from the vagus nerve and replace the electrode array and wire. The electrodes are typically scarred and difficult to remove from the vagus nerve without injury. The authors describe 6 patients with VNSs who presented with low lead impedance on diagnostic testing, leading to the intraoperative finding of lead insulation disruption, or who were found incidentally at the time of implantable pulse generator battery replacement to have a tear in the outer insulation of the electrode wire. Instead of replacement, the wire insulation was repaired and reinforced in situ, leading to normal impedance testing. All 6 devices remained functional over a follow-up period of up to 87 months, with 2 of the 6 patients having a relatively shorter follow-up of only 12 months. This technique, applicable in a subset of patients with VNSs requiring lead exploration, obviates the need for lead replacement with its attendant risks.
Patricia T. Molloy, Anthony T. Yachnis, Lucy B. Rorke, James J. Dattilo, Michael N. Needle, William S. Millar, Joel W. Goldwein, Leslie N. Sutton and Peter C. Phillips
✓ Medulloepithelioma is an uncommon childhood tumor of the central nervous system (CNS) whose histopathological appearance has been confused with medulloblastoma and other childhood primitive neuroectodermal tumors (PNETs), but which has a vastly different clinical course. The authors have reviewed the clinical features and treatment responses of eight children with these rare tumors, the largest series to date.
In this series, the medulloepitheliomas were equally distributed between supratentorial and infratentorial primary sites. Four patients underwent gross- or near-total resections, one patient's tumor was partially resected, and one patient had biopsy only. Biopsy and ablative surgery were not attempted in two children with pontine tumors. Treatment included both radiation and chemotherapy (four patients), radiation alone (one patient), chemotherapy alone (one patient), and no postoperative treatment (two patients). Six patients died with a mean survival of 10 months and two are disease free with neurological impairment. Both long-term survivors underwent gross-total resections of their tumors. Postmortem examination revealed diffuse CNS tumor dissemination in four patients.
Medulloepithelioma, often confused with less aggressive PNETs, can mimic intrinsic brainstem glioma, responds poorly to treatment, and is prone to CNS dissemination at the time of tumor progression.
Andre F. Gentil, Antonio C. Lopes, Darin D. Dougherty, Christian Rück, David Mataix-Cols, Teagan L. Lukacs, Miguel M. Canteras, Emad N. Eskandar, K. Johan Larsson, Marcelo Q. Hoexter, Marcelo C. Batistuzzo, Benjamin D. Greenberg and Euripedes C. Miguel
Recent findings have suggested a correlation between obsessive-compulsive disorder (OCD) symptom dimensions and clinical outcome after limbic system surgery for treatment-refractory patients. Based on previous evidence that the hoarding dimension is associated with worse outcome in conventional treatments, and may have a neural substrate distinct from OCD, the authors examined a large sample of patients undergoing limbic surgery (40 with capsulotomy, 37 with cingulotomy) and investigated if symptom dimensions, in particular hoarding, could influence treatment outcome.
Data from 77 patients from 3 different research centers at São Paulo (n = 17), Boston (n = 37), and Stockholm (n = 23) were analyzed. Dimensional Yale-Brown Obsessive Compulsive Scale (Y-BOCS; São Paulo) or Y-BOCS Symptom Checklist scores (Boston and Stockholm) were used to code the presence of 4 well-established symptom dimensions: forbidden thoughts, contamination/cleaning, symmetry/order, and hoarding. Reductions in YBOCS scores determined clinical outcome.
Mean Y-BOCS scores decreased 34.2% after surgery (95% CI 27.2%–41.3%), with a mean follow-up of 68.1 months. Patients with hoarding symptoms had a worse response to treatment (mean Y-BOCS decrease of 22.7% ± 25.9% vs 41.6% ± 32.2%, respectively; p = 0.006), with no significant effect of surgical modality (capsulotomy vs cingulotomy). Patients with forbidden thoughts apparently also had a worse response to treatment, but this effect was dependent upon the co-occurrence of the hoarding dimension. Only the negative influence of the hoarding dimension remained when an ANOVA model was performed, which also controlled for preoperative symptom severity.
The presence of hoarding symptoms prior to surgery was associated with worse clinical outcome after the interventions. Patients with OCD under consideration for ablative surgery should be carefully screened for hoarding symptoms or comorbid hoarding disorder. For these patients, the potentially reduced benefits of surgery need to be carefully considered against potential risks.