Comparison of Dentatorubrothalamic Tractography Methods Based on the Anatomy of the Rubral Wing.

BACKGROUND AND OBJECTIVES: Precise localization of the dentatorubrothalamic (DRT) tract can facilitate anatomic targeting in MRI-guided high-intensity focused ultrasound (HIFU) thalamotomy and thalamic deep brain stimulation for tremor. The anatomic segment of DRT fibers adjacent to the ventral intermediate nucleus of the thalamus (VIM), referred to as the rubral wing (RW), may be directly visualized on the fast gray matter acquisition T1 inversion recovery. We compared reproducibility, lesion overlap, and clinical outcomes when reconstructing the DRT tract using a novel anatomically defined RW region of interest, DRT-RW, to an existing tractography method based on the posterior subthalamic area region of interest (DRT-PSA). METHODS: We reviewed data of 23 patients with either essential tremor (n = 18) or tremor-predominant Parkinson's disease (n = 5) who underwent HIFU thalamotomy, targeting the VIM. DRT tractography, ipsilateral to the lesion, was created based on either DRT-PSA or DRT-RW. Volume sections of each tract were created and dice similarity coefficients were used to measure spatial overlap between the 2 tractographies. Post-HIFU lesion size and location (on postoperative T2 MRI) was correlated with tremor outcomes and side effects for both DRT tractography methods and the RW itself. RESULTS: DRT-PSA passed through the RW and DRT-RW intersected with the ROIs of the DRT-PSA in all 23 cases. A higher percentage of the RW was ablated in patients who achieved tremor control (18.9%, 95% CI 15.1, 22.7) vs those without tremor relief (6.7%, 95% CI% 0, 22.4, P = .017). In patients with tremor control 6 months postoperatively (n = 12), those with side effects (n = 6) had larger percentages of their tracts ablated in comparison with those without side effects in both DRT-PSA (44.8, 95% CI 31.8, 57.8 vs 24.2%, 95% CI 12.4, 36.1, P = .025) and DRT-RW (35.4%, 95% CI 21.5, 49.3 vs 21.7%, 95% CI 12.7, 30.8, P = .030). CONCLUSION: Tractography of the DRT could be reconstructed by direct anatomic visualization of the RW on fast gray matter acquisition T1 inversion recovery-MRI. Anatomic planning is expected to be quicker, more reproducible, and less operator-dependent.

Percutaneous Endoscopic Lumbar Foraminoplasty for Lumbar Foraminal Stenosis of Elderly Patients with Unilateral Radiculopathy: Radiographic Changes in Magnetic Resonance Images.

BACKGROUND AND STUDY AIMS/OBJECTIVE: Clinical outcomes of percutaneous endoscopic lumbar foraminoplasty (PELF) performed for lumbar foraminal stenosis (LFS) have been reported in the literature. However, no study has reported the radiographic changes in magnetic resonance imaging (MRI) after surgery. This report presents the clinical outcome as well as radiographic changes in MRI after PELF for elderly patients with unilateral radiculopathy. We also describe detailed operative nuances to expand the foraminal space and mobilize the affected nerve root. MATERIAL AND METHODS: Between January 2015 and December 2016, 24 patients over 65 years of age underwent PELF to treat unilateral radiculopathy caused by LFS. The demographics, medical history, visual analog scale (VAS), and Oswestry Disability Index (ODI) were reviewed retrospectively. MRI radiographic data, cross-sectional area (CSA) of the affected foramen and nerve root, were evaluated before and after surgery. RESULTS: Preoperative radiculopathy improved in 23 of 24 patients (96%). The VAS score significantly improved from 7.89 ± 1.8 to 2.57 ± 2.5 (67.4%). The ODI also significantly improved from 33.15 ± 9.2 to 10.24 ± 6.7 (69.1%). Foraminal width increased ∼ 1.67 mm (21.4%), foraminal height increased 5.00 mm (36.9%), and CSA increased about 55.27 mm2 (60.6%) (p < 0.001). The CSA and the shape of the affected nerve section also expanded, but these were not statistically significant. CONCLUSION: We performed PELF in elderly patients with LFS. There were considerable radiographic changes in MRI, and the patients also showed clinically relevant improvement. Thus PELF resulted in sufficient decompression of the nerve root in LFS.

Spontaneous cervical epidural hematoma causing brown-sequard syndrome.

Spontaneous cervical epidural hematoma (SCEH) is a rare clinical entity and has a varied etiology. Urgent surgical decompression should be done to prevent serious permanent neurologic deficits. We describe a 59-year-old female who presented with Brown-Sequard syndrome due to spontaneous cervical epidural hematoma. Initially, she was misdiagnosed as cerebrovascular accident. Cervical magnetic resonance imaging revealed epidural hematoma to the right of the spinal cord extending from C3 to C6. She later underwent surgical evacuation and had complete restoration of neurologic function. The outcome in SCEH is essentially determined by the time taken from onset of the symptom to operation. Therefore, early and precise diagnosis such as careful history taking and MRI evaluation is mandatory.