A 52-year-old man with a 10-year history of treatment-resistant asthma presented with repeated exacerbations over the course of 10 months. His symptoms were not responsive to salbutamol or inhaled corticosteroid agents, and he developed avascular necrosis of his left hip as a result of prolonged steroid therapy. Physical examination and radiography revealed signs consistent with diffuse idiopathic skeletal hyperostosis (DISH), including a C7–T1 osteophyte causing severe tracheal compression. The patient underwent C6–T1 anterior discectomy and fusion, and the compressive osteophyte was removed, which completely resolved his “asthma.” Postoperative pulmonary function tests showed normalization of his FEV1/FVC ratio, and there was no airway reactivity on methacholine challenge. DISH is a systemic, noninflammatory condition characterized by ossification of spinal entheses, and it can present with respiratory disturbances due to airway compression by anterior cervical osteophytes. The authors present, to the best of their knowledge, the first documented case of asthma as a presentation of DISH.
Karim Mithani, Ying Meng, David Pinilla, Nova Thani, Kayee Tung, Richard Leung and Howard J. Ginsberg
Yusuke Nishimura, Nova B. Thani, Satoru Tochigi, Henry Ahn and Howard J. Ginsberg
Symptomatic thoracic disc herniations (TDHs) are relatively uncommon, and the technical challenges of resecting the offending disc are formidable due to the location of spinal cord that has relatively poor perfusion characteristics within a narrow canal. The majority of disc herniations are long-standing calcified discs that can be adherent to the ventral dura. Real-time intraoperative ultrasound (RIOUS) visualization of the spinal cord during the retraction and resection of the disc greatly enhances the safety and efficacy of disc resection. The authors have adopted the posterior laminectomy with pedicle-sparing transfacet approach with real-time ultrasound guidance in their practice, and they present the clinical outcome in their patients to illustrate the safety profile of this technique.
Sixteen consecutive patients undergoing operative management of TDHs were identified from the authors' database. All patients underwent microdiscectomy through a posterior transfacet pedicle-sparing approach under RIOUS. Outcomes and complications were retrospectively assessed in this patient series. Clinical records and pre- and postoperative imaging studies were scrutinized to assess levels and types of disc herniation, blood loss, surgical time, pre- and postoperative Nurick grades, Japanese Orthopaedic Association (JOA) scores, and complications.
All patients had single-level symptomatic TDHs. The patients presented with symptoms including thoracic myelopathy, axial back pain, urinary symptoms, and thoracic radiculopathy. Thoracic disc herniations involved levels T2–3 to T12–L1. Discs were classified as central or paracentral, and as calcified or noncalcified. All discs were successfully removed with no incidence of neural injury or CSF leak. The mean estimated blood loss was 523 ml, and the mean surgical time was 159 minutes. Nurick grades improved on average from 3.3 to 1.6. The mean JOA scores improved from 5.7 to 8.3 out of 11. The mean Hirabayashi recovery rate of the JOA score was 57%. All patients reported improvement in symptoms compared with preoperative status except for 1 patient with an American Spinal Injury Association Grade A spinal cord injury prior to surgery. The average duration of follow-up was 10.5 months. One patient developed postoperative wound infection that required additional operative debridement and revision of hardware.
Thoracic discectomy via a posterior pedicle-sparing transfacet approach is an adequate method of managing herniations at any thoracic level. The safety of the operation is significantly enhanced by the use of realtime intraoperative ultrasonography.
Omar K. Bangash, Arosha S. Dissanayake, Shirley Knight, John Murray, Megan Thorburn, Nova Thani, Arul Bala, Rick Stell and Christopher R. P. Lind
Posterior subthalamic area (PSA) deep brain stimulation (DBS) targeting the zona incerta (ZI) is an emerging treatment for tremor syndromes, including Parkinson’s disease (PD) and essential tremor (ET). Evidence from animal studies has indicated that the ZI may play a role in saccadic eye movements via pathways between the ZI and superior colliculus (incerto-collicular pathways). PSA DBS permitted testing this hypothesis in humans.
Sixteen patients (12 with PD and 4 with ET) underwent DBS using the MRI-directed implantable guide tube technique. Active electrode positions were confirmed at the caudal ZI. Eye movements were tested using direct current electrooculography (EOG) in the medicated state pre- and postoperatively on a horizontal predictive task subtending 30°. Postoperative assessments consisted of stimulation-off, constituting a microlesion (ML) condition, and high-frequency stimulation (HFS; frequency = 130 Hz) up to 3 V.
With PSA HFS, the first saccade amplitude was significantly reduced by 10.4% (95% CI 8.68%–12.2%) and 12.6% (95% CI 10.0%–15.9%) in the PD and ET groups, respectively. With HFS, peak velocity was reduced by 14.7% (95% CI 11.7%–17.6%) in the PD group and 27.7% (95% CI 23.7%–31.7%) in the ET group. HFS led to PD patients performing 21% (95% CI 16%–26%) and ET patients 31% (95% CI 19%–38%) more saccadic steps to reach the target.
PSA DBS in patients with PD and ET leads to hypometric, slowed saccades with an increase in the number of steps taken to reach the target. These effects contrast with the saccadometric findings observed with subthalamic nucleus DBS. Given the location of the active contacts, incerto-collicular pathways are likely responsible. Whether the acute finding of saccadic impairment persists with chronic PSA stimulation is unknown.