脊髄空洞症

INTRODUCTION: Despite many years of research and advanced technology aiding in the diagnosis and treatment of Chiari 1 malformation (CM1), ideal surgical techniques remain controversial. When duraplasty is necessary, tonsillar coagulation is often performed to restore cerebrospinal fluid (CSF) pathways, though its benefits are unclear. Extensive intradural manipulation may increase surgical risk and reoperation rates secondary to arachnoid adhesions. The objective of our study is to delineate whether tonsillar manipulation is safe and ultimately necessary for adequate posterior fossa decompression in CM1 surgery. METHODS: A retrospective review of all patients who underwent initial posterior fossa decompression and duraplasty for CM1 at a single institution from 1997 to 2024 was performed with IRB approval. Fourth ventricular stents were excluded. Indications for surgery included intractable occipital headache, neurological deficits, and/or syringomyelia. Demographics, radiographic details, and surgical outcomes were compared between patients with (PFDD + TM) and without (PFDD) tonsillar manipulation. RESULTS: A total of 151 patients met inclusion criteria, with 73% undergoing PFDD + TM and 27% undergoing PFDD alone. The only significant difference in baseline characteristics was extent of tonsillar herniation, with all patients with > 20 mm herniation undergoing PFDD + TM (p = 0.01). Attending surgeon preference was also significantly associated with surgical approach (p < 0.0001). Thirty-day complication rates were similar between groups (PFDD 29.3% vs. PFDD + TM 14.5%, p = 0.06). Over a mean follow-up of 49.8 months, reoperation rates were 7.3% in PFDD and 4.5% in PFDD + TM (p = 0.68). Symptomatic improvement occurred in > 70% of patients across all symptom categories without significant differences between surgical approaches, with syrinx improvement in 85.2% of PFDD and 75.8% of PFDD + TM patients (p = 0.51). CONCLUSION: There were no significant differences between CM1 patients that underwent duraplasty with or without tonsillar manipulation regarding complications, reoperations, or symptomatic outcomes. Thus, there is no significant advantage to performing tonsillar manipulation nor any meaningful disadvantage. Multi-institutional studies are needed to uncover potential statistical differences in outcomes that may identify a superior surgical technique, especially over longer periods of follow-up.

BACKGROUND: Idiopathic syringomyelia (IS) in adults is rare, and its clinical course remains poorly defined. This study aimed to describe the clinical and radiological course of adult IS and to assess the relationship between imaging change and clinical outcome. METHODS: Retrospective single-center study (2010-2025) including adult patients with IS after exclusion of secondary causes on whole-spine and craniovertebral junction MRI, including flow-sensitive sequences. The absence of a secondary cause was established by a senior neuroradiologist and confirmed on independent review by two neurosurgeons. Maximal anteroposterior syrinx diameter was measured on T2-weighted MRI (sagittal plane to localize the level of maximal diameter, axial plane for the measurement itself), interpreted by the senior neuroradiologist and re-read by the neurosurgeons. Given the physical resolution limits of spinal MRI, a post hoc, clinically meaningful threshold of ≥2 mm was applied as a sensitivity analysis for radiological change. Association between continuous radiological change and clinical outcome was assessed using Pearson and Spearman coefficients with 95% confidence intervals (CI). RESULTS: Among 357 patients with syringomyelia, 26 (7.3%) were classified as idiopathic. Radiological follow-up was available for 20/26 patients (77%), following exclusion of 6 patients (loss to follow-up, unreliable retrieval of prior imaging, or absence of a comparable repeat MRI; Fig. 1); median follow-up was 23 months (interquartile range [IQR] 8-56; mean 36 months). New or additional symptoms, mostly mild, were reported by 17 patients (65%, 95%CI 46-81%); of these, 7 patients (27%, 95%CI 14-46%) met criteria for clinically significant worsening (new neurological symptoms or aggravation of pre-existing symptoms impacting daily function). Four patients (15%) improved. No patient developed a motor deficit or required surgery during follow-up. Using the ≥2 mm threshold, no patient (0/20) showed a clinically meaningful increase or decrease in syrinx diameter; all 20 evaluable patients were radiologically stable by this criterion. No significant correlation was found between continuous radiological change and clinical outcome (Pearson r=0.18, 95%CI -0.30 to 0.59, p=0.47; Spearman ρ=0.18, 95%CI -0.29 to 0.59, p=0.46), although the study was underpowered to exclude a small-to-moderate association. results CONCLUSIONS: In this retrospective single-center cohort, adult idiopathic syringomyelia was characterized by frequent new or mildly additional symptoms but limited severe neurological deterioration, while clinically meaningful radiological progression, defined using a post hoc, clinically meaningful threshold applied as a sensitivity analysis, was absent in the evaluable cohort. Clinical evolution was far more variable than radiological evolution, and radiological change did not correlate with clinical course, although this cohort had limited statistical power. These findings are hypothesis-generating and do not, by themselves, establish an optimal follow-up strategy for adult idiopathic syringomyelia.

BACKGROUND: Syringomyelia, secondary to adhesive arachnoiditis, is an intractable disease characterized by progressive extension cranially and caudally, resulting in severe neurological deficits. Subarachnoid-subarachnoid bypass has recently been reported for syringomyelia from trauma or spinal tumor surgery. METHODS: We investigated whether subarachnoid-subarachnoid bypass is a salvage treatment for refractory adhesive arachnoiditis of various etiologies, including arachnoid abnormality and hemorrhage. Patients who underwent subarachnoid-subarachnoid bypass between 2021 and 2025 for recurrent adhesive syringomyelia after conventional treatments were retrospectively reviewed. The primary outcome was the change in syrinx length from baseline to follow-up. Secondary outcomes included neurological outcomes and surgical complications. RESULTS: Six patients (median age 55 years; 2 men) were included. Patients had undergone a median of 2.5 conventional treatments, such as arachnoidolysis or intradural shunt placement, before subarachnoid-subarachnoid bypass. The syrinx showed temporary regression followed by re-expansion in all cases, attributed to extensive adhesions. Two patients presented with upper extremity paresis and pain, two with paraparesis, and two with severe paresthesia of the body trunk and lower extremities. After subarachnoid-subarachnoid bypass, the syrinx length showed a significant overall reduction (median, preoperative vs. postoperative: 9.5 vs. 5.0 levels; p = 0.014) in the median follow-up of 36 months. Neurological symptoms improved in five patients. Two patients were complicated with tube occlusion, which resolved with re-operation. CONCLUSIONS: Subarachnoid-subarachnoid bypass may be an effective option for refractory cases of syringomyelia not only from trauma or spinal tumor surgery but also from adhesive arachnoiditis due to arachnoid abnormality and hemorrhage.

BACKGROUND: Intramedullary spinal cord tumors are rare neoplasms but frequently cause significant neurological deficits because of the limited compensatory capacity of the spinal cord. Magnetic resonance imaging (MRI) is the imaging modality of choice and often allows a reliable differential diagnosis based on characteristic imaging findings. OBJECTIVES: To provide a practical neuroradiological approach to the diagnosis of intramedullary spinal cord tumors, including recent developments in the World Health Organization (WHO) classification. MATERIALS AND METHODS: Narrative review of the current literature regarding epidemiology, imaging characteristics, WHO classification, and differential diagnosis of intramedullary spinal cord tumors. RESULTS: Ependymomas, astrocytomas, and hemangioblastomas account for the majority of intramedullary tumors. Tumor location, longitudinal extent, enhancement pattern, hemorrhagic components, syringomyelia, and flow voids substantially narrow the differential diagnosis. Recent WHO classifications increasingly incorporate molecular markers, including MYCN-amplified spinal ependymoma and H3 K27-altered diffuse midline glioma. CONCLUSION: Structured MRI assessment frequently enables a reliable preoperative diagnosis. Inflammatory, vascular, and ischemic disorders must always be considered as important differential diagnoses.

Sir Wilfrid Edward Le Gros Clark (1895-1971) was a pioneering British anatomist, physician, and evolutionary biologist whose legacy spans the foundational development of twentieth century neuroanatomy, primate biology, and medical education. From his formative experiences as a young medical officer in the First World War to his later academic ascendancy at the University of Oxford, Le Gros Clark exemplified a rare fusion of clinical insight, anatomical precision, and philosophical curiosity. His tenure in Borneo, where he studied primates in their natural habitats, enriched his evolutionary perspective, while his later role in debunking the Piltdown Man fraud cemented his place as a steadfast defender of scientific integrity. At Oxford, Le Gros Clark assembled a singular collection of neuroanatomical teaching specimens, many of which remain preserved today within the Department of Physiology, Anatomy & Genetics, University of Oxford. Through detailed analysis of selected slides, including cases of tabes dorsalis, disseminated sclerosis, amyotrophic lateral sclerosis, syringomyelia, and the pineal gland's nervus conarii, we reflect on how Le Gros Clark's anatomical interpretations anticipated many of the concepts central to contemporary neuroscience, and on how his legacy has influenced generations of students and scientists. What emerges from these materials is that Le Gros Clark taught students not simply to memorize, but to observe, interpret, and understand the functional significance of anatomical structures in health and disease.