Jörg Herdmann

Prognostic Value of 18F-FDG PET in Monosegmental Stenosis and Myelopathy of the Cervical Spinal Cord

MRI offers perfect visualization of spondylotic stenosis of the cervical spine, but morphologic imaging does not correlate with clinical symptoms and postoperative recovery after decompression surgery. In this prospective study, we investigated the role of 18F-FDG PET in patients with degenerative stenosis of the cervical spinal cord in relation to postsurgical outcome. Methods: Twenty patients with monosegmental spondylotic stenosis of the middle cervical spine (C3/C4 or C4/C5) showing intramedullary hyperintensity on T2-weighted MRI and clinical symptoms of myelopathy (myelopathic patients) were investigated by 18F-FDG PET. Maximum standardized uptake values (SUVmax) were measured at all levels of the cervical spine (C1–C7). Decompression surgery and anterior cervical fusion were performed on all patients, and clinical status (Japanese Orthopedic Association [JOA] score) was assessed before and 6 mo after surgery. The 18F-FDG data of 10 individuals without cervical spine pathology were used as a reference (controls). Results: The myelopathic patients showed a significant decrease in 18F-FDG uptake in the area of the lower cervical cord, compared with the control group (C7 SUVmax, 1.49 ± 0.18 vs. 1.71 ± 0.27, P = 0.01). Ten myelopathic patients exhibited focally increased 18F-FDG uptake at the level of the stenosis (SUVmax, 2.27 ± 0.41 vs. 1.75 ± 0.22, P = 0.002). The remaining 10 patients showed inconspicuous 18F-FDG uptake at the area of the stenosis. Postoperatively, the patients with focally increased 18F-FDG accumulation at the level of stenosis showed good clinical recovery and a significant improvement in JOA scores (13.6 ± 2.3 vs. 9.5 ± 2.5, P = 0.001), whereas no significant improvement was observed in the remaining patients (JOA score, 12.0 ± 2.4 vs. 11.6 ± 2.5, not statistically significant). Multiple regression analysis identified the presence of focally increased 18F-FDG uptake at the level of the stenosis as an independent predictor of postoperative outcome (P = 0.002). Conclusion: The results suggest that regional changes in 18F-FDG uptake have prognostic significance in compression-induced cervical myelopathy that may be helpful in decisions on the timing of surgery.

Intralesional hemorrhage and thrombosis without rupture in a pure spinal epidural cavernous angioma: a rare cause of acute lumbal radiculopathy.

Pure spinal epidural cavernous angiomas are extremely rare lesions, and their normal shape is that of a fusiform mass in the dorsal aspects of the spinal canal. We report a case of a lumbo-sacral epidural cavernous vascular malformation presenting with acute onset of right-sided S1 radiculopathy. Clinical aspects, imaging, intraoperative findings, and histology are demonstrated. The patient, a 27-year-old man presented with acute onset of pain, paraesthesia, and numbness within the right leg corresponding to the S1 segment. An acute lumbosacral disc herniation was suspected, but MRI revealed a cystic lesion with the shape of a balloon, a fluid level and a thickened contrast-enhancing wall. Intraoperatively, a purple-blue tumor with fibrous adhesions was located between the right S1 and S2 nerve roots. Macroscopically, no signs of epidural bleedings could be denoted. After coagulation of a reticular venous feeder network and dissection of the adhesions the rubber ball-like lesion was resected in total. Histology revealed a prominent venous vessel with a pathologically thickened, amuscular wall surrounded by smaller, hyalinized, venous vessels arranged in a back-to-back position typical for the diagnosis of a cavernous angioma. Lumina were partially occluded by thrombi. The surrounding fibrotic tissue showed signs of recurrent bleedings. There was no obvious mass hemorrhage into the surrounding tissue. In this unique case, the pathologic mechanism was not the usual rupture of the cavernous angioma with subsequent intraspinal hemorrhage, but acute mass effect by intralesional bleedings and thrombosis with subsequent increase of volume leading to nerve root compression. Thus, even without a sudden intraspinal hemorrhage a spinal cavernous malformation can cause acute symptoms identical to the clinical features of a soft disc herniation.

Regional impairment of 18F-FDG uptake in the cervical spinal cord in patients with monosegmental chronic cervical myelopathy

ObjectiveThe aim of this preliminary report was to assess glucose metabolism in the cervical spine of patients with chronic compressive myelopathy by using FDG PET.MethodsTen patients with monosegmental chronic degenerative stenosis and local cord compression of the upper/middle cervical spine with signs of myelopathy on MRI and 10 control patients without known cervical abnormalities were investigated by FDG PET. Maximum standardised uptake values (SUVmax) were measured at all levels of the cervical spine (C1–C7).ResultsWhile the controls showed the typical pattern of homogeneous linear FDG uptake along the entire cervical cord, the patients with chronic compressive myelopathy had a normal glucose utilisation only above the level of stenosis and a significant decrease in FDG uptake below their individual level of cord compression. This may be caused by atrophy of anterior grey horn cells and the loss of glucose-consuming neurons below the level of cord compression.ConclusionFDG PET of the spine of patients with chronic compressive myelopathy may be helpful to determine the stage and severity of cervical myelopathy.

Chronic dura erosion and intradural lumbar disc herniation: CT and MR imaging and intraoperative photographs of a transdural sequestrectomy

IntroductionA 47-year-old male with a history of recurrent low-back pain presented with acute left radiculopathy.Material and methods The CT and MR scans showed a severe osteochondrosis of the L4/5 segment, a broad protrusion of the disc annulus and extrusion of nucleus material into the spinal canal on the left side.Results The caudally dislocated sequester pieces were visualised intradurally and the intraoperative finding confirmed this rare pathology. After dorsal durotomy-free sequester material was found between the nerve rootlets within the subarachnoid space and altogether ten fragments were removed. Further transdural exploration visualised ventrally a round dura defect surrounded by a thickened arachnoid layer with enlarged veins as a sign of a chronic erosive process.DiscussionPatients history, imaging and the intraoperative findings support the thesis, that chronic degenerative disc disease and adhesions between the posterior longitudinal ligament and the dura are the predisposing pathogenetic factors for an intradural disc herniation.Conclusion Intradural disc herniation is a rare condition and requires durotomy to remove the pathology. Therefore an actual high resolution MRI is mandatory in all cases of intraspinal space occupying lesions.

Hypermetabolism in 18F-FDG PET Predicts Favorable Outcome Following Decompressive Surgery in Patients with Degenerative Cervical Myelopathy

The aim of this study was to prospectively assess the regional changes of glucose metabolism of the cervical spinal cord in patients with degenerative cervical spine stenosis and symptomatic cervical myelopathy after decompressive surgery using 18F-FDG PET. Methods: Twenty patients with symptomatic degenerative monosegmental cervical stenosis with neuroradiologic signs of spinal cord compression underwent decompressive surgery. The clinical course using a functional status score (Japanese Orthopedic Association [JOA] score), 18F-FDG uptake, and MR imaging were assessed before and at follow-up 12 mo after surgery. Pre- and postoperative changes of 18F-FDG PET were correlated to the patients’ clinical outcome. Results: Ten patients demonstrated preoperatively a focally increased 18F-FDG uptake at the level of the stenosis. At follow-up, the uptake declined significantly (P = 0.008), and a significant improvement of JOA scores (P < 0.001) could be observed. The remaining 10 patients were characterized preoperatively by an inconspicuous glucose uptake at the level of cord compression in combination with a poststenotic decrease of 18F-FDG uptake. At follow-up, both JOA scores and 18F-FDG uptake changed insignificantly. Conclusion: Focal glucose hypermetabolism at the level of cervical spinal cord compression may predict an improved outcome after surgical decompression. Thus, this finding on 18F-FDG PET suggests a functional damage in a reversible phase of cervical myelopathy.

Transtubular microsurgical approach to treating extraforaminal lumbar disc herniations

OBJECT Approaches to treating extraforaminal lumbar disc herniations can be challenging due to the unique anatomy and the need to prevent spinal instability. Numerous approaches, including conventional midline, paramedian, minimally invasive, and full endoscopic approaches, have been described. The purposes of this study were to point out the outcome and clinical advantages of a transtubular microsurgical approach and to describe and illustrate this technique. METHODS Between 2009 and 2012, a series of 51 patients underwent a minimally invasive dilative transtubular microsurgical approach for the treatment of extraforaminal lumbar disc herniations. All patients were clinically evaluated using the visual analog scale (VAS) and Oswestry Disability Index preoperatively and 6 months postoperatively. RESULTS Both pain scores and functional status showed significant improvement after surgery (p < 0.001): radicular pain decreased from VAS score of 7.9 to one of 1.3, lower back pain from VAS score of 2.4 to 1.4, and the Oswestry Disability Index from 42.0 to 12.3. Subgroup analyses revealed no differences in outcome regarding obesity or timing of surgery (early vs late intervention). Highly significant was the correlation between preoperative radicular pain activity and timing of surgical intervention (p < 0.001). CONCLUSIONS The dilative transtubular microsurgical approach combines the advantages of the conventional open muscle-splitting approach and the endoscopic approach. The technique is easy to use with a steep learning curve. Less muscle trauma and the absence of bony resection prevent facet pain and instability, thereby contributing to a rapid recovery. Patients in this series improved excellently in the short-term follow-up.

Open microsurgical tumor excavation and vertebroplasty for metastatic destruction of the second cervical vertebra-outcome in seven cases.

BACKGROUND CONTEXT Metastatic osteolytic involvement of the second cervical vertebra (C2) is rare, but usually very painful. Percutaneous vertebroplasty has shown to be effective regarding pain control, but carries the risk of cement leakage. PURPOSE To describe an alternative microsurgical procedure suitable for patients suffering from C2 osteolysis who are considered to be high risk with respect to cement leakage. STUDY DESIGN A technical report. PATIENT SAMPLE It included seven patients. OUTCOME MEASURES They include the assessment of clinical safety regarding approach- and procedure-related morbidity and radiologic safety regarding extravertebral cement leakage and the assessment of clinical efficacy by monitoring the pain activity using the visual analog scale (VAS). MATERIALS AND METHODS Seven patients (five men, two women; mean age 70 years) presented with an acute onset of excruciating neck pain (VAS>6) due to osteolytic destruction of the axis vertebra. There was no neurologic deficit and no compression of the spinal cord preoperatively requiring surgical decompression or stabilization in any of the cases. An open treatment strategy via an anterolateral microsurgical approach was performed. Under biplanar fluoroscopic control, the soft tumor tissue was resected out of the vertebral body through a drilled entry in the anterior wall. After the excavation procedure, the resection cavity was filled with minimal pressure with polymethylmethacrylate bone cement. RESULTS All patients suffered from severe spontaneous neck pain (mean VAS 8.1, range 6-9), with head motion-dependent pain exacerbation despite high dose of opiates and fixation of the head with a brace.Mean duration of the operative procedure was 51 minutes. Histologic analysis revealed a diagnosis of cancer metastasis in all cases. On average, 1.9 mL cement was placed within the vertebral body, and no cement leakage was observed in postoperative computed tomography and X-ray controls. All patients experienced immediate pain relief at Day 1 after the procedure (mean VAS 4.0, range 2-6), and a further decrease of pain levels was observed at Week 6 after the completion of radiation therapy (mean VAS 2.0, range 0-5). CONCLUSIONS In cases of metastatic C2 destruction, tumor excavation via an anterolateral approach and subsequent filling of the resection cavity with bone cement offers a safe and effective alternative to percutaneous approaches.

Clinical value of 2-deoxy-[18F]fluoro-d-glucose positron emission tomography in patients with cervical spondylotic myelopathy

Cervical spondylotic myelopathy (CSM) is one of the most common spinal cord disorders in the elderly. It is usually diagnosed by MRI, but in a significant number of patients the clinical course of CSM does not correlate with the extent of the spinal cord compression. Recent studies have suggested that a distinct metabolic pattern of the cervical cord, as assessed by PET with 2-deoxy-[(18)F]fluoro-D-glucose ((18)F-FDG) may predict a patients clinical outcome after decompressive surgery for cervical spine stenosis. The authors provide an overview of the recent literature regarding the value of PET with (18)F-FDG of the cervical cord in patients with CSM, paying attention to prognostic aspects and the potential role of inflammatory processes in the acute phase of the disease.