Lumbar Spinous Process-Splitting Technique for Ligamentum Flavum Cyst Removal.

BACKGROUND: Laminotomy for lumbar stenosis is a well-defined procedure and represents a routine in every neurosurgical department. It is a common experience that the uni- or bilateral paraspinal muscle detachment, together with injury of the supra- and interspinous ligaments, can lead to postoperative pain. In the literature, the application of a minimally invasive technique, the lumbar spinous process-splitting (LSPS) technique, has been reported. METHODS: In this study, we present a case series of 12 patients who underwent LSPS from September 2019 to April 2020. Two patients had a cyst of the ligamentum flavum, eight a single-level lumbar canal stenosis (LCS), and two a two-level LCS. Moreover, we propose a novel morphological classification of postoperative muscle atrophy and present volumetric analysis of the decompression achieved. RESULTS: There were no complications related to this technique. In all patients, the vertebral canal area was more than doubled by the procedure. The muscle sparing showed grade A, according to our classification. CONCLUSION: To our knowledge, this is the first description of this surgical technique and the first LSPSL case series in Europe. Furthermore, cases of ligamentum flavum cyst removal using this safe and effective technique have not yet been reported.

Coexistence of Two Distinct Tumor Types Within One Posterior Fossa Mass Lesion in an Adult Patient Verified by DNA-Methylation Analysis: A Case Report.

We report an 81-year-old patient who underwent microsurgical resection of a posterior fossa mass lesion. Intraoperative findings were suggestive of the presence of two distinctly different tumor types within the lesion, one of which was well-circumscribed and avascular, whereas the other one showed an adhesive growth pattern and extensive vascularisation. Histopathological analysis, including deoxyribonucleic acid (DNA)-methylation-based classification, substantiated the intraoperative impression and confirmed the presence of a subependymoma central nervous system (CNS) World Health Organization (WHO) grade 1 as well as the presence of a hemangioblastoma CNS WHO grade 1. To our knowledge, our patient represents only the second reported case of such a rare constellation. Even though DNA-methylation-based classification is not yet required for the classification of all CNS tumor types by the 2021 WHO classification of tumors of the CNS, it proved to be crucial to verify the final diagnosis in our patient. In the future, DNA-methylation analysis will most likely become an important asset in neuro-oncological diagnostics and further help to guide treatment strategies in complex or rare clinical cases.

Osteoarthritis Progression after ACL Reconstruction Was Significantly Higher Than That of the Healthy Contralateral Knees: Long-Term Follow Up Study of Mean 16.4 Years.

BACKGROUND: This study aimed to assess long-term progression of osteoarthritis (OA) after isolated anterior cruciate ligament (ACL) reconstruction in athletes compared to the healthy contralateral side. METHODS: The study included 15 patients and 30 knees with a mean age of 40 years (range, 35-46) years, none of whom had had revision surgery or an injury to the contralateral side. The mean follow-up period was 16.4 years (range, 13-22). Clinical and radiographic assessment included the Tegner activity scale (TAS), International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Kellgren and Lawrence (KL) grade. The long-term results of the injured knees were compared with the status of the healthy contralateral side and compared with previously published mid-term results of the same cohort of patients. RESULTS: Patients generally remained clinically asymptomatic or mildly symptomatic at final follow-up, which is reflected by a KOOS pain score of 33 points (maximum 36 points) and an IKDC total subjective score of 87% (maximum 100%). There was a significant difference between mid-term and final follow-up in terms of the function score of the IKDC subjective questionnaire (p = 0.031), compartment findings and donor site morbidity of the IKDC functional examination (both p = 0.034), and the total KOOS score (p = 0.047). The KL score indicated significant progression of OA from mid-term to final follow-up in the injured knees (p = 0.004) and healthy contralateral knees (p = 0.014). Mean OA grades of the injured knees were significantly higher compared with the healthy contralateral side (p = 0.006) at final follow-up, and two patients showed moderate to severe signs of OA in the injured knee. CONCLUSIONS: Although most patients remained clinically asymptomatic or mildly symptomatic, long-term progression of OA after isolated ACL reconstruction in athletes was significantly higher compared with the healthy contralateral knee.

From natalizumab to fingolimod in eight weeks - Immunological, clinical, and radiological data in quest of the optimal switch.

Natalizumab (NZB) discontinuation during a treatment change is associated with recurrence of disease activity in a significant proportion of multiple sclerosis (MS) patients. The immunological basis why disease reactivation occurs in selected patients is unresolved. In search of a prognostic biomarker for a safe and effective transition from NZB to fingolimod, we monitored five parameters related to pharmacokinetic and pharmacodynamic effects of the two drugs in 12 MS patients until six months on fingolimod. Clearance of free and cell-bound NZB, re-expression of alpha-4, and fingolimod-mediated changes on CD8+ and CD4+ T cell subsets showed pronounced interindividual variability. Higher frequencies of memory CD8+ T cells after six months on fingolimod were the sole association with disease reactivation. None of the investigated parameters thus had potential as prognostic biomarker for the outcome of the switch. Our findings rather support the thesis of broad interindividual differences in the immunopathogenesis of MS.

Direct comparison of (68)Ga-DOTA-TOC and (18)F-FDG PET/CT in the follow-up of patients with neuroendocrine tumour treated with the first full peptide receptor radionuclide therapy cycle.

PURPOSE: To determine the value of (68)Ga-DOTA-TOC and (18)F-FDG PET/CT for initial and follow-up evaluation of patients with neuroendocrine tumour (NET) treated with peptide receptor radionuclide therapy (PRRT). METHODS: We evaluated 66 patients who had histologically proven NET and underwent both PRRT and three combined (68)Ga-DOTA-TOC and (18)F-FDG PET/CT studies. (68)Ga-DOTA-TOC PET/CT was performed before PRRT, 3 months after completion of PRRT and after a further 6 - 9 months. (18)F-FDG PET/CT was done within 2 months of (68)Ga-DOTA-TOC PET/CT. Follow-up ranged from 11.8 to 80.0 months (mean 34.5 months). RESULTS: All patients were (68)Ga-DOTA-TOC PET-positive initially and at follow-up after the first full PRRT cycle. Overall, 62 of the 198 (18)F-FDG PET studies (31 %) were true-positive in 38 of the 66 patients (58 %). Of the 66 patients, 28 (5 grade 1, 23 grade 2) were (18)F-FDG-negative initially and during follow-up (group 1), 24 (5 grade 1, 13 grade 2, 6 grade 3) were (18)F-FDG-positive initially and during follow-up (group 2), 9 patients (2 grade 1, 6 grade 2, 1 grade 3) were (18)F-FDG-negative initially but (18)F-FDG-positive during follow-up (group 3), and 5 patients (all grade 2) were (18)F-FDG-positive initially but (18)F-FDG-negative during follow-up (group 4).(18)F-FDG PET showed more and/or larger metastases than (68)Ga-DOTA-TOC PET in five patients of group 2 and four patients of group 3, all with progressive disease. In three patients with progressive disease who died during follow-up tumour SUVmax increased by 41 - 82 % from the first to the last follow-up investigation. CONCLUSION: In NET patients, the presence of (18)F-FDG-positive tumours correlates strongly with a higher risk of progression. Initially, patients with (18)F-FDG-negative NET may show (18)F-FDG-positive tumours during follow-up. Also patients with grade 1 and grade 2 NET may have (18)F-FDG-positive tumours. Therefore, (18)F-FDG PET/CT is a complementary tool to (68)Ga-DOTA-TOC PET/CT with clinical relevance for molecular investigation.