Ashwin Viswanathan and Kim J. Burchiel
Ashwin Viswanathan and Eduardo Bruera
Many neurosurgical interventions for the management of cancer-related pain have been tried, but their role in today's advanced supportive and palliative care is not well described. The authors discuss the current knowledge gaps that prevent successful integration of neurosurgical interventions and patients with cancer-related pain.
Two patients underwent percutaneous CT-guided cordotomy for refractory cancer-related pain: one patient had melanoma and the other had ovarian carcinoma. Both patients seemed to have unilateral, somatic, nociceptive cancer-related pain.
Cordotomy was effective for only 1 patient.
Percutaneous CT-guided cordotomy is a low-risk intervention that can benefit carefully selected patients with cancer-related pain. There is a clear need for prospective controlled studies to evaluate the effectiveness of cordotomy for patients receiving optimal medical treatment. A multidisciplinary study design could help to identify factors correlated with a positive outcome.
M. Benjamin Larkin, Robert Y. North, and Ashwin Viswanathan
Cordotomy has evolved since the first open procedure by Spiller and the first percutaneous radiofrequency cordotomy by Mullan in 1965. Today, the minimally invasive, CT-guided percutaneous radiofrequency cordotomy is mostly used for the palliative management of medically intractable somatic pain related to malignancy in well-selected patients. The risk of adverse events is minimized with the use of intraoperative stimulation monitoring. This video highlights the spinal cord anatomy at the level of C1–2, the approach to patient selection, the associated risks and benefits, and, finally, the procedural setup and key steps involved in this unique neurosurgical procedure.
The video can be found here: https://youtu.be/a-0ORqy0W2o
M. Benjamin Larkin, Robert Y. North, Aditya Vedantam, and Ashwin Viswanathan
The traditional commissural myelotomy consists of a sagittal cut in the midline and was originally described by Greenfield and performed by Armour in 1926. Today, myelotomy refers to the selective disruption of the ascending visceral pain pathway. The success of the procedure is incumbent on the correct identification of the midline. Limited midline open myelotomy for the treatment of medically intractable abdominal or pelvic visceral cancer pain, with the aid of somatosensory evoked potentials to identify midline, offers patients superior pain relief over similar percutaneous techniques. Multicenter registries are needed to better elucidate the best surgical technique for this procedure.
The video can be found here: https://youtu.be/0unlmwp08po
Jacob R. Joseph, Ashwin Viswanathan, and Daniel Yoshor
Corpus callosotomy offers useful palliation for selected patients with medically intractable seizures, particularly those with uncontrolled and disabling drop attacks. Here the authors present their technique for performing a corpus callosotomy that allows for complete sectioning of the callosum while avoiding entry into the lateral ventricles. The anatomical basis for the technique is the presence of a definable cleft just ventral to the corpus callosum in the midline, formed by the fusion of the two laminae of the septum pellucidum. This small cleft is typically present even in the absence of a cavum septum pellucidum on MR imaging. The authors have found that dividing the body of the corpus callosum by exploiting the cleft of the septum pellucidum in the absolute midline is a simple and expeditious way to perform a callosotomy without entering the lateral ventricles.
Ashwin Viswanathan, Viraat Harsh, Erlick A. C. Pereira, and Tipu Z. Aziz
Cingulotomy has been reported in the literature as a potential treatment option for refractory cancer-related pain. However, the optimal candidates for this intervention and the outcomes are not well characterized. The goal of this study was to review the available literature on cingulotomy, specifically for cancer-related pain.
A search of PubMed, PubMed Central, the Cochrane Library, and MEDLINE was performed to identify all articles discussing cingulotomy for cancer pain. The text strings “cingul*” and “pain” were separated by the Boolean AND operator, and used to perform the query on PubMed. Only studies in which a stereotactic technique was used, as opposed to an open technique, and specifically detailing outcomes for cancer pain were included. For centers with multiple publications, care was taken not to double-count individual patients.
The literature review revealed only 8 unique studies describing outcomes of stereotactic cingulotomy for cancer pain. Between 32% and 83% of patients had meaningful pain relief. The location of the lesion was variable, ranging between 1 cm and 4 cm posterior to the tip of the anterior horn. Although serious adverse events are rare, a decline in focused attention can been seen in the early postoperative period, along with apathy and decreased activity.
For patients with cancer pain with diffuse pain syndromes, head and neck malignancies, and significant emotional distress, cingulotomy may be a safe treatment option with minimal cognitive changes.
Gaddum D. Reddy, Regina Okhuysen-Cawley, Viraat Harsh, and Ashwin Viswanathan
Percutaneous cordotomy using CT guidance has been shown to be a safe and effective means of reducing pain in adults with cancer in 2 large case series. Its effectiveness in pediatric patients, however, has not been reported. Here, the authors present a case of CT-guided percutaneous cordotomy being used effectively for the treatment of unilateral limb pain in a 9-year-old boy suffering from metastatic medulloblastoma. The efficacy and minimally invasive nature of this procedure support its use in selected pediatric cases.
Ashwin Viswanathan, Katherine Relyea, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen, and Andrew Jea
The authors describe a rare case of pneumothorax as a complication of thoracic pedicle screw placement in an 11-year-old girl undergoing posterior segmental instrumentation for a kyphotic deformity. Spontaneous pneumothorax after posterior fusion for adolescent idiopathic scoliosis has been reported in the orthopedic literature; however, to the best of the authors' knowledge, pneumothorax directly related to pedicle screw placement for spinal deformity has not been previously described. The authors discuss the anatomical and technical aspects leading to this complication and the lessons learned from it.
M. Benjamin Larkin, John P. McGinnis, Rita I. Snyder, Eric A. Storch, Wayne K. Goodman, Ashwin Viswanathan, and Sameer A. Sheth
Posttraumatic stress disorder (PTSD) is a widespread and often devastating psychiatric condition. Core symptoms include intrusive and distressing thoughts, heightened reactivity, mood changes, cognitive impairments, and consequent avoidance of trauma-related stimuli. Symptoms of PTSD are often refractory to standard treatments, and neuromodulatory techniques have therefore drawn significant interest among the most treatment-resistant patients. Transcranial magnetic stimulation has demonstrated minimal efficacy, and deep brain stimulation trials are currently ongoing. PTSD is a disorder of neural circuitry; the current understanding includes involvement of the amygdala (basolateral and central nuclei), the prefrontal cortex (ventral medial and dorsolateral regions), and the hippocampus. Neuroimaging and optogenetic studies have improved the understanding of large-scale neural networks and the effects of microcircuitry manipulation, respectively. This review discusses the current PTSD literature and ongoing neurostimulation trials, and it highlights the current understanding of neuronal circuit dysfunction in PTSD. The authors emphasize the anatomical correlations of PTSD’s hallmark symptoms, offer another potential deep brain stimulation target for PTSD, and note the need for continued research to identify useful biomarkers for the development of closed-loop therapies. Although there is hope that neuromodulation will become a viable treatment modality for PTSD, this concept remains theoretical, and further research should involve institutional review board–approved controlled prospective clinical studies.