Functional MRI-Guided Motor Cortex and Deep Brain Stimulation for Intractable Facial Pain: A Novel, Personalized Approach in 1 Patient.

BACKGROUND: Facial neuropathic pain syndromes such as trigeminal neuralgia are debilitating disorders commonly managed by medications, vascular decompression, and/or ablative procedures. In trigeminal neuralgia cases unresponsive to these interventions, trigeminal deafferentation pain syndrome (TDPS) can emerge and remain refractory to any further attempts at these conventional therapies. Deep brain stimulation (DBS) and motor cortex stimulation are 2 neuromodulatory treatments that have demonstrated efficacy in small case series of TDPS yet remain largely underutilized. In addition, functional MRI (fMRI) is a tool that can help localize central processing of evoked stimuli such as mechanically triggered facial pain. In this study, we present a case report and operative technique in a patient with TDPS who underwent fMRI to guide the operative management and placement of dual targets in the sensory thalamus and motor cortex. OBJECTIVE: To evaluate the safety, efficacy, and outcome of a novel surgical approach for TDPS in a single patient. METHODS: The fMRI and operative technique of unilateral DBS targeting the ventroposteromedial nucleus of the thalamus and facial motor cortex stimulator placement through a single burr hole is illustrated as well as the patient's clinical outcome. RESULTS: In less than 1 year, the patient had near complete resolution of his facial pain with no postoperative complications. CONCLUSION: We present the first published case of successful treatment of TDPS using simultaneous DBS of the ventroposteromedial and motor cortex stimulation. fMRI can be used as an effective imaging modality to guide neuromodulation in this complex disorder.

A Clinical Review of Slipping Rib Syndrome.

ABSTRACT: Slipping rib syndrome is pain created at the lower, anterior border of the rib cage when performing upper-extremity activities, coughing, laughing, or leaning over. Defects in the costal cartilage of ribs 8 to 10 result in increased movement of the ribs, impinging soft tissue and intercostal nerves. Advancements have been made in the diagnosis of slipping rib syndrome by dynamic ultrasound. Ultrasound can identify abnormalities in the rib and cartilage anatomy, as well as soft tissue swelling. Although the mainstays of treatment continue to be reassurance, nonsteroidal anti-inflammatory drugs, physical therapy, intercostal nerve injections, osteopathic manipulative treatment, surgery for refractory pain, and botulinum toxin injections have been attempted, and there may be a role for prolotherapy in treatment. Surgical techniques are being examined secondary to recurrence of pain following resection. The hooking maneuver and surgery remain important for identification and treatment, respectively.

Cervical Cordotomy for Intractable Pain: Do Postoperative Imaging Features Correlate with Pain Outcomes and Mirror Pain?

BACKGROUND AND PURPOSE: Percutaneous cervical cordotomy offers relief of unilateral intractable oncologic pain. We aimed to find anatomic and postoperative imaging features that may correlate with clinical outcomes, including pain relief and postoperative contralateral pain. MATERIALS AND METHODS: We prospectively followed 15 patients with cancer who underwent cervical cordotomy for intractable pain during 2018 and 2019 and underwent preoperative and up to 1-month postoperative cervical MR imaging. Lesion volume and diameter were measured on T2-weighted imaging and diffusion tensor imaging (DTI). Lesion mean diffusivity and fractional anisotropy values were extracted. Pain improvement up to 1 month after surgery was assessed by the Numeric Rating Scale and Brief Pain Inventory. RESULTS: All patients reported pain relief from 8 (7-10) to 0 (0-4) immediately after surgery (P = .001), and 5 patients (33%) developed contralateral pain. The minimal percentages of the cord lesion volume required for pain relief were 10.0% on T2-weighted imaging and 6.2% on DTI. Smaller lesions on DWI correlated with pain improvement on the Brief Pain Inventory scale (r = 0.705, P = .023). Mean diffusivity and fractional anisotropy were significantly lower in the ablated tissue than contralateral nonlesioned tissue (P = .003 and P = .001, respectively), compatible with acute-phase tissue changes after injury. Minimal postoperative mean diffusivity values correlated with an improvement of Brief Pain Inventory severity scores (r = -0.821, P = .004). The average lesion mean diffusivity was lower among patients with postoperative contralateral pain (P = .037). CONCLUSIONS: Although a minimal ablation size is required during cordotomy, larger lesions do not indicate better outcomes. DWI metrics changes represent tissue damage after ablation and may correlate with pain outcomes.

Neuroablative surgical treatments for pain due to cancer.

Cancer pain is common and challenging to manage - it is estimated that approximately 30% of cancer patients have pain that is not adequately controlled by analgesia. This paper discusses safe and effective neuroablative treatment options for refractory cancer pain. Current management of cancer pain predominantly focuses on the use of medications, resulting in a relative loss of knowledge of these surgical techniques and the erosion of the skills required to perform them. Here, we review surgical methods of modulating various points of the neural axis with the aim to expand the knowledge base of those managing cancer pain. Integration of neuroablative approaches may lead to higher rates of pain relief, and the opportunity to dose reduce analgesic agents with potential deleterious side effects. With an ever-increasing population of cancer patients, it is essential that neurosurgeons maintain or train in these techniques in tandem with the oncological multi-disciplinary team.

CT-Guided Percutaneous Trigeminal Tractotomy-Nucleotomy for Intractable Craniofacial Pain.

OBJECT: In this report, we aimed to analyze the outcome results of our patients who underwent percutaneous trigeminal tractotomy (TR) and nucleotomy (NC) procedures, which are defined as destructive procedures targeting the descending trigeminal tractus and nucleus caudalis of the spinal trigeminal nucleus, respectively, for intractable craniofacial pain. METHODS: The medical records of a total of 12 patients who underwent a total of 14 computed tomography (CT)-guided TR-NC procedures at our clinics between 2005 and 2017 were retrospectively reviewed. RESULTS: A significant increase in patients' performance status (p = 0.015) as well as a significant decrease in the VAS score (p < 0.001) were achieved. Grade I pain relief (VAS = 0, no pain) was established in 66.7% of the patients, whereas grade II pain relief was observed in the remaining patients. Two of the patients suffered from recurrent pain after the initial procedure. Both patients underwent a second trigeminal TR-NC procedure, and grade I pain relief was re-established. The mean VAS score at 3-month follow-up was 1.4 ± 1.1, whereas this score at 6-month follow-up was 2 ± 1.3. The trigeminal TR-NC procedure resulted in a significant decrease in patients' VAS scores at 3- and 6-month follow-up visits compared with preoperative VAS scores (p < 0.001). Transient ataxia was noted in only one patient (8.3%) early after the procedure. CONCLUSIONS: The results presented in the current study support the efficacy of the percutaneous CT-guided trigeminal TR-NC procedure in the management of intractable facial pain in selected patients. The use of CT guidance allows direct visualization of the target area, thereby enhancing the safety and success of the procedure.

Computed tomography-guided paravertebral doxorubicin injection for refractory pain in patients with spinal metastases: Two case reports.

RATIONALE: Diagnosing and treating refractory cancer pain have become standardized and effective procedures with guidance from the Expert Consensus on Refractory Cancer Pain released in 2017 by the Committee of Rehabilitation and Palliative Care of China. Doxorubicin has been used for perineural injection in the treatment of chronic non-cancer pain owing to its retrograde sensory ganglion resection effect. Our study reports a new fourth-ladder treatment for cancer pain: CT-guided paravertebral doxorubicin injection for patients with refractory cancer pain caused by paraspinal metastasis. PATIENT CONCERNS: A 48-year-old female and a 47-year-old male patients suffered from refractory cancer pain over the past months. They had both undergone surgical tumor resection, chemotherapy, and precision radiotherapy but result in limited analgesic effect. The daily oral morphine dosage was around 60 to 100 mg and rescue analgesic methods had been used at the time. DIAGNOSES: Refractory cancer pain in 2 patients with renal cancer and hepatobiliary adenocarcinoma. INTERVENTIONS: The patients both received computed tomography (CT)-guided 1 mL of 0.5% doxorubicin paravertebral injection at each affected nerve root segments. OUTCOMES: The Visual Analog Scale and Douleur Neuropathique four Questions were used for 6-month follow-up, and the analgesic requirement was also recorded. The patients enjoyed satisfactory analgesia for up to 6 months without adverse reaction. In addition, the oral opioid analgesic doses were significantly reduced after the neurolytic block. LESSONS: The CT-guided paravertebral doxorubicin injection was an effective fourth-step analgesic interventional technology that allowed our 2 patients with refractory cancer pain to maintain satisfactory analgesia. This analgesia method taken at an appropriate stage, according to the latest analgesic concept, results in good analgesia and opioid use reduction. Also, with the imaging guidance, only a small amount of neurolytic agent is needed to achieve analgesia in a precise and safe way.

Neurolytic abdominal wall blocks with alcohol for intractable gastrostomy site pain in a cancer patient -a case report.

BACKGROUND: There have been reports of neurolytic transversus abdominis plane (TAP) block using different agents such as alcohol or phenol for the treatment of chronic abdominal pain caused by malignant abdominal wall invasion. However, to date, there have been no reports on neurolytic abdominal wall blocks for pain with non-cancer-related origin in cancer patients. CASE: We performed subcostal TAP neurolysis using ethanol in a patient with esophageal cancer with constant pain at the site of gastrostomy. After neurolysis, the patient's overall pain decreased, with the exception of pain in the medial part of the gastrostomy site. We performed additional rectus sheath neurolysis using ethanol for the treatment of continuous pain at the medial site, and the effect of neurolysis has persisted for over 4 months. CONCLUSIONS: Alcohol-based TAP neurolysis and rectus sheath neurolysis provide effective pain control in a cancer patient with chronic treatment-related pain involving the abdominal wall.

Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation for the Treatment of Lower Extremity Pain: A Rare Case Report.

OBJECTIVE: This case report presents an application of percutaneous peripheral nerve stimulation to the right superficial peroneal nerve to treat a patient with chronic intractable L5-S1 radiculopathy pain that conventional treatment failed to ameliorate. METHODS: The patient underwent an uneventful implantation of a percutaneous peripheral nerve stimulator. The implanted lead (15 cm in length and 1.2 mm in diameter) containing the receiver coil and 3 stimulation electrodes (Bioness Stimrouter® , Valencia, CA, U.S.A.) was implanted parallel with the trajectory of the right superficial peroneal nerve. RESULTS: Two weeks after implantation of the percutaneous peripheral nerve stimulator, the patient experienced excellent pain relief and reported a significant increase in mobility. At the 3-month follow-up consultation, the patient reported maintenance of the reduction of pain in his right lower extremity as well as improved performance in his daily activities. CONCLUSION: Percutaneous peripheral nerve stimulation offers an alternative treatment option for intractable pain associated with chronic radiculopathy, especially for patients in whom conventional treatment options have been exhausted. Further clinical series involving larger numbers of patients are warranted in order to assess the definitive role of percutaneous peripheral nerve stimulation for the treatment of chronic intractable radiculopathy pain.

Drug-induced paraspinal myositis mimicking acute bilateral sciatica.

Although cocaine induced myopathy and myotoxicity are described in the literature, we report a rare case of cocaine induced paraspinal myositis presenting with acute sciatic symptoms. A 35-year-old man presented with acute left-sided sciatica and was discharged from the emergency department (ED). He subsequently attended ED the following day in severe pain and bilateral sciatic symptoms, but denied symptoms of neurogenic bowel/bladder disturbance. Clinical examination was limited by severe pain: focal midline lumbar tenderness was elicited on palpation, per rectal and limb examinations were within normal limits with no significant neurological deficit. He was admitted for observation and pain management. His blood tests revealed a leucocyte count of 21.5×109/L, C reactive protein of 89 mg/L and deranged renal function with creatinine of 293 µmol/L. An urgent lumbar spine MRI was arranged to rule out a discitis or epidural abscess. Lumbar MRI did not demonstrate any features of discitis but non-specific appearances of paraspinal inflammation raised the suspicion of a paraspinal myositis. Creatinekinase (CK) was found to be 66329 IU/L and a detailed history revealed he was a cocaine user. Paraspinal muscle biopsy confirmed histological features compatible with myositis. Other serological tests were negative, including anti-GBM, ANCA, ANA, Rheumatoid factor, Hep B, Hep C, myositis specific ENA, Treponema pallidum, Borrelia burgdorferi, Rickettsia, Leptospira, EBV and CMV. There was good clinical response to treatment with prednisolone 20 mg OD with an improvement in renal function, CK levels and CRP. He had resumed normal activities and return to work at 6-week follow-up. A detailed social history including substance misuse is important in patients presenting to the ED-especially in cases of severe musculoskeletal pain with no obvious localising features. Drug induced myotoxicity, although rare, can result in symptomatic patients with severe renal failure.

Medial Gamma Knife thalamotomy for intractable pain.

OBJECTIVEAblative procedures are still useful in the treatment of intractable pain despite the proliferation of neuromodulation techniques. In the paper the authors present the results of Gamma Knife thalamotomy (GKT) in various pain syndromes.METHODSBetween 1996 and 2016, unilateral GKT was performed in 30 patients suffering from various severe pain syndromes in whom conservative treatment had failed. There were 20 women and 10 men in the study population, with a median age of 80 years (range 53-89 years). The pain syndromes consisted of 8 patients with classic treatment-resistant trigeminal neuralgia (TN), 6 with postherpetic TN, 5 with TN and constant pain, 1 with TN related to multiple sclerosis, 3 with trigeminal neuropathic pain, 4 with thalamic pain, 1 with phantom pain, 1 with causalgic pain, and 1 with facial pain. The median follow-up period was 24 months (range 12-180 months). Invasive procedures for pain release preceded GKT in 20 patients (microvascular decompression, glycerol rhizotomy, balloon microcompression, Gamma Knife irradiation of the trigeminal root, and radiofrequency thermolesion). The Leksell stereotactic frame, GammaPlan software, and T1- and T2-weighted sequences acquired at 1.5 T were used for localization of the targeted medial thalamus, namely the centromedian (CM) and parafascicularis (Pf) nucleus. The CM/Pf complex was localized 4-6 mm lateral to the wall of the third ventricle, 8 mm posterior to the midpoint, and 2-3 mm superior to the intercommissural line. GKT was performed using the Leksell Gamma Knife with an applied dose ranging from 145 to 150 Gy, with a single shot, 4-mm collimator. Pain relief after radiation treatment was evaluated. Decreased pain intensity to less than 50% of the previous level was considered successful.RESULTSInitial successful results were achieved in 13 (43.3%) of the patients, with complete pain relief in 1 of these patients. Relief was achieved after a median latency of 3 months (range 2-12 months). Pain recurred in 4 (31%) of 13 patients after a median latent interval of 24 months (range 22-30 months). No neurological deficits were observed.CONCLUSIONSThese results suggest that GKT in patients suffering from severe pain syndromes is a relatively successful and safe method that can be used even in severely affected patients. The only risk of GT for the patients in this study was failure of treatment, as no clinical side effects were observed.

CT guided neurolytic blockade of the coeliac plexus in patients with advanced and intractably painful pancreatic cancer.

BACKGROUND AND AIMS: Pain caused by infiltrating pancreatic cancer is complex in nature and may therefore be difficult to treat. In addition to conventional analgesics, neurolytic blockade of the coeliac plexus is often recommended. However, different techniques are advocated, and procedures vary, and the results may therefore be difficult to compare. Therefore strong evidence for the effect of this treatment is still lacking, and more studies are encouraged. Our aim was to describe our technique and procedures using a Computer Tomograph (CT) guided procedure with a dorsal approach and present the results. METHODS: The procedures were performed in collaboration between a radiologist and an anaesthesiologist. All patients had advanced pancreatic cancer. The patients were placed in prone position on pillows, awake and monitored. Optimal placement of injection needles was guided by CT, and the radiologist injected a small dose of contrast as a control. When optimal needle position, the anaesthesiologist took over and completed the procedure. At first 40 mg methylprednisolone was injected to prevent inflammation. Thereafter a mixture of 99% ethanol diluted to 50% by ropivacaine 7.5 mg/mL to a total amount of 20-30 mL per needle was slowly injected. Repeated aspiration was performed during injection to avoid intravasal injection. Pain treatment and pain score was recorded and compared before and after the treatment. RESULTS: Eleven procedures in 10 patients were performed. Age 49-75, mean 59 years. Median rest life time was 36 days (11-140). Significant reduction of analgesics was observed 1 week after the procedure, and most patients also reported reduction of pain. No serious side effects were observed. CONCLUSIONS: CT guided neurolytic celiac plexus blockade is a safe and effective treatment for intractable pain caused by advanced pancreatic cancer. Not all patients experience a significant effect, but the side effects are minor, and the procedure should therefore be offered patients experiencing intractable cancer related pain.

Gamma Knife Surgery for Recurrent Trigeminal Neuralgia in Cases with Previous Microvascular Decompression.

BACKGROUND: Microvascular decompression (MVD) and Gamma Knife surgery (GKS) are the primary treatments for trigeminal neuralgia (TN). However, many patients require further surgical treatment after initial surgery for recurrent TN. The aim of this study was to evaluate efficacy and safety of GKS for recurrent TN cases with prior MVD. METHODS: From October 2008 to June 2015, 658 patients at West China Hospital underwent GKS as the only surgical treatment, and 42 patients underwent GKS with prior MVD. The single 4-mm isocenter was located at the cisternal portion of the trigeminal nerve in all patients. Median maximum prescription dose was 85 Gy (range, 70-90 Gy). RESULTS: Median follow-up time was 6.2 years (range, 1.1-10 years). The percentage of patients with or without previous MVD within 1 year was 56.81%, and the percentage of patients who were pain-free was 74.74%. The recurrence rates within 10 years were 49.11% and 43.74% for patients with and without MVD, respectively. Also, 9.52% and 11.04% of patients with and without previous MVD experienced complications as a result of GKS during the long-term follow-up period. Patients who underwent previous MVD showed a significantly lower pain-free rate compared with patients without previous MVD (P = 0.01). There was no statistical significance in the recurrence rate (P = 0.82) or the complications (P = 0.93) in the 2 groups during the long-term follow-up period. CONCLUSIONS: For patients with recurrent TN who previously underwent MVD, GKS remains an efficacious and safe mode of treatment.

Surgical Treatment of Thoracic Spinal Tuberculosis: A Multicenter Retrospective Study.

OBJECTIVE: The aim of the present multicenter, retrospective study was to assess the safety and effectiveness of different surgery strategies for the treatment of thoracic tuberculosis and to provide a reference for surgical treatment of thoracic tuberculosis. MATERIALS AND METHODS: This study reviewed 394 patients with thoracic tuberculosis who were treated in 6 institutions between January 2000 and January 2015. There were 208 men and 186 women with an average age of 34.92 ± 13.14 years (range 5-76 years). A total of 73 patients underwent one-stage anterior surgery (group A); 84 underwent an anterior combined posterior surgery (group B); and 237 underwent one-stage posterior surgery (group C). Clinical outcome, laboratory indexes, and radiologic results were analyzed to observe the advantage of posterior approach surgery. RESULTS: All cases were followed up for about 26-60 months (average of 37 months). At the last follow-up, all patients reached bone fusion, pain relief, and neurologic recovery. There were significant differences before and after treatment in terms of the visual analog scale and Oswestry Disability Index scores (P < 0.05). Posterior approach significantly improved kyphosis (P < 0.05). CONCLUSIONS: Posterior fixation is superior to anterior fixation in the correction of kyphosis and maintenance of spinal stability. One-stage posterior surgery can achieve the same efficacy as anterior-only or combined surgery, with less trauma, less blood loss, and shorter operative times. However, for wide lesions or paraspinal abscesses, severe bone destruction, and anterior and middle column defects that are too large after debridement to require long segment bone grafting, the anterior combined posterior approach is indispensable.

Limited Midline Myelotomy for Intractable Visceral Pain: Surgical Techniques and Outcomes.

BACKGROUND: Limited midline myelotomy targets the midline nociceptive pathway for intractable visceral pain. Multiple techniques are available for limited midline myelotomy; however, outcome data for each technique are sparse. OBJECTIVE: To review our experience with open and percutaneous approaches for limited midline myelotomy for intractable visceral pain. METHODS: Patients who underwent limited midline myelotomy for intractable visceral pain were reviewed. Myelotomy was performed using 3 techniques: open limited myelotomy, percutaneous radiofrequency myelotomy, and percutaneous mechanical myelotomy. Demographic and perioperative clinical data were recorded. In addition to the visual analog scale and Karnofsy performance score, outcomes were categorized as excellent (no pain), good (considerable reduction in pain, not requiring opioids stronger than codeine), fair (minimal reduction in pain, but no change in opioid medication requirement), and poor (no reduction in pain). RESULTS: Eight patients (median age 56.5 yr, 6 females) underwent limited myelotomy. Four patients underwent open limited thoracic myelotomy with excellent pain outcomes. Three patients underwent percutaneous radiofrequency lesioning with fair (n = 1) and poor outcomes (n = 2). One patient underwent percutaneous mechanical lesioning with a good outcome (n = 1). The median duration of follow-up was 11 wk (2-54 wk). Two patients reported minor sensory complications after the procedure. CONCLUSION: In our preliminary experience, outcomes for open limited thoracic myelotomy were superior to percutaneous approaches. Given the limited utilization of this technique, multicenter registries are needed to further evaluate the best surgical technique for limited midline myelotomy.

Sonographic Signs of Adenomyosis Are Prevalent in Women Undergoing Surgery for Endometriosis and May Suggest a Higher Risk of Infertility.

OBJECTIVES: To determine the prevalence of ultrasound features suggestive of adenomyosis in women undergoing surgery for endometriosis compared with a control group of healthy women without endometriosis. METHODS: Retrospective case-control study comparing women with intractable pain or infertility, who underwent transvaginal ultrasound and subsequent laparoscopic surgery, with a control group of healthy women without a previous history of endometriosis. A diagnosis of adenomyosis on TVUS was made based on asymmetrical myometrial thickening, linear striations, myometrial cysts, hyperechoic islands, irregular endometrial-myometrial junction, parallel shadowing, and localized adenomyomas and analyzed for one sign and for three or more signs. RESULTS: The study and control groups included 94 and 60 women, respectively. In the study group, women were younger and had more dysmenorrhea and infertility symptoms. The presence of any sonographic feature of adenomyosis, as well as three or more signs, was found to be more prevalent in the study group, which persisted after controlling for age, for all features but linear striations. Women in the study group who had five or more sonographic features of adenomyosis had more than a threefold risk of suffering from infertility (OR = 3.19, p = 0.015, 95% CI; 1.25-8.17). There was no association with disease severity at surgery. CONCLUSIONS: Sonographic features of adenomyosis are more prevalent in women undergoing surgery for endometriosis compared to healthy controls. Women with more than five features had an increased risk of infertility.

Open thoracic anterolateral cordotomy for pain relief in children: report of 2 cases.

Open anterolateral cordotomy is an effective treatment option for adults with intractable pain, but it has seldom been attempted in children. In the 2 previously reported cases in children, the procedure was used within 10 days of death from neoplastic disease. In this paper the authors describe 2 cases in which open cordotomy was used successfully in children outside the immediate terminal phase of disease. Both patients experienced effective analgesia with minimal adverse effects. The authors propose that consideration of cordotomy as an option for the management of intractable pain in children does not need to be delayed until death is imminent.

Modified dorsal root entry zone lesioning for intractable pain relief in patients with root avulsion injury.

OBJECTIVE Dorsal root entry zone (DREZ) lesioning has been the most effective surgical treatment for the relief of intractable pain due to root avulsion injury, but residual pain and a decrease in pain relief in the follow-up period have been reported in 23%-70% of patients. Based on pain topography in the most recent studies on neuropathic pain, the authors modified the conventional DREZ lesioning procedure to improve clinical outcomes. The presumed rationale for this procedure is to eliminate the spontaneous discharges of neurons in the superficial spinal dorsal horn as well as wide dynamic range neurons in the deep spinal dorsal horn. METHODS Ten patients with avulsion-related pain underwent surgery between 2011 and 2015. The surgical procedure was described and postoperative pain relief was assessed as follows: excellent (residual pain never exceeded 3 on the visual analog scale [VAS] without medication), good (residual pain never exceeded 5 on the VAS with medication), and poor (residual pain was greater than 5 with medication). Specific perioperative complications were assessed. RESULTS The aim of this surgical procedure was to destroy the deeper layers of the posterior horn of spinal gray matter, which was in contrast to the procedures of Nashold and Sindou, which were to destroy the superficial layers. All patients achieved excellent (n = 7, pain relief without medication) or good (n = 3, pain relief with medication) pain relief postoperatively, and the recurrence of pain was not reported in any patients (median 29 months after surgery, range 12-64 months). Nine patients (90%) achieved complete pain relief (a score of 0 or 1 on the VAS) with or without medication. No surgical site complications such as infection or CSF leakage were noted. No motor deficit was observed in any patient. A sensory deficit was observed in 2 patients and disappeared within 1 month in 1 patient. New pain at the adjacent level of DREZ lesioning was observed in 3 patients and disappeared within 1 month in 2 patients. In the other patient, new pain persisted and required analgesics. CONCLUSIONS These preliminary results demonstrated that total and persistent global pain relief was achieved with the modified DREZ lesioning procedure in 90% of patients without major neurological deficits. The clinical improvements achieved by this modified surgical procedure support the hypothesis that not only the superficial layers, but also deeper layers of the spinal dorsal horn are associated with intractable pain due to root avulsion injury.

Causes of Aseptic Persistent Pain after Total Knee Arthroplasty.

BACKGROUND: Persistent pain after total knee arthroplasty (TKA) is dissatisfying to the patient and frustrating to the surgeon. The purpose of this study is to evaluate the aseptic causes and clinical course of intractable pain following TKA. METHODS: Of the total 2,534 cases of primary TKA reviewed, 178 cases were classified as having aseptic persistent pain that was not resolved within 1 year after surgery. Except for the cases with periprosthetic fracture (56 knees), 122 cases of aseptic painful TKA were divided into two groups: intra-articular group (83 knees) and extra-articular group (39 knees). RESULTS: In the intra-articular group, the main reasons for pain were aseptic loosening (n = 40), polyethylene wear (n = 16), instability (n = 10), recurrent hemarthrosis (n = 5), patellar maltracking (n = 4), tendon ruptures (n = 4), and stiffness (n = 2). In the extraarticular group, 10 knees (25.6%) were found to have nerve entrapment in the spine, 6 knees (15.4%) were found to have hip osteoarthritis or femoral head avascular necrosis. The reasons for persistent knee pain in the remaining 23 knees (59.0%) still remain elusive. CONCLUSIONS: Persistent pain after TKA originated from pathology of extra-articular origin in a considerable number of cases in this study. Therefore, it is important to perform thorough preoperative evaluations to reduce pain resulting from extra-articular causes. Furthermore, meticulous surgical procedures and optimal alignment are required to reduce pain of intra-articular origin related to implant wear, instability, and patellar maltracking.