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Background and Purpose-Cerebral cavernous malformations (CCMs) are prevalent cerebral vascular lesions involving aberrant angiogenesis. However, the underlying mechanism is poorly understood. Phosphatase and tension homolog deleted on chromosome 10 (PTEN), a tumor suppressor, is frequently deficient in various pathologies due to mutation or epigenetic alterations. PTEN promoter hypermethylation is a major epigenetic silencing mechanism leading to activation of angiogenesis in tumors. The present study aimed to investigate whether PTEN promoter methylation was involved in CCMs. Methods-PTEN promoter methylation was detected in surgical specimens of CCMs (nϭ69) by methylation-specific polymerase chain reaction. The methylation status was correlated to the clinical manifestations and to PTEN expression, which was analyzed by both Western blot and immunohistochemistry. To investigate the endothelial proliferation and the potential signaling pathways affected by PTEN methylation, proliferating cell nuclear antigen as well as phosphor-Akt and phosphor-Erk1,2 were detected by immunofluorescence and Western blot, respectively, in CCM specimens. Results-Methylation-specific polymerase chain reaction revealed PTEN promoter methylation in 15.9% CCMs.Strikingly, 5 of 6 familial CCMs showed PTEN promoter methylation (83.3%), which was significantly higher than in sporadic cases (9.4%; PϽ0.001). In addition, PTEN promoter methylation appeared more frequently in multiple CCMs, including familial cases (46.7%), than that in single-lesioned CCMs (11.8%; PϽ0.05). Immunostaining and Western blot revealed a more significant PTEN downregulation in PTEN-methylated CCMs in comparison to PTENunmethylated CCMs. Reduced PTEN expression was inversely correlated to the expression of proliferating cell nuclear antigen and to the activation of Erk1,2, but not of Akt. Conclusion-We

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Background: Spinal cord stimulation (SCS) is an established treatment for neuropathic pain. Severe long-term complications are rare. Only recently secondary mass lesions associated with chronic stimulation were noted to occur. Objectives: To report the rare occurrence of cervical myelopathy secondary to an epidural cervical spinal mass after chronic cervical SCS. Methods: Implantation of a paddle electrode at C2-C4 for chronic neuropathic pain resulted in improvement of pain for several years but it lost its efficacy after 8 years. Myelography and postmyelographic CT detected an epidural mass surrounding the electrode and compressing the spinal cord when cervical myelopathy had developed 17 years after electrode implantation. Results: The mass which consisted of dense fibrous scar tissue was removed via hemilaminectomy. At postoperative follow-up at 8 months there was no further progression of gait disorder. Conclusion: Long-term cervical SCS in a rare case may lead to fibrous epidural mass lesions which may not only cause loss of efficacy but which may also result in new neurological deficits.

Background: Deep brain stimulation (DBS) is an established therapy for movement disorders. It is currently under investigation in neuropsychiatric disorders. Neurophobia is a common phenomenon that might have a negative impact in medical education. Little is known about medical students' knowledge about DBS when they enter university and what they learn about it during their medical formation. Methods: A 10-item questionnaire was designed. Questions addressed indications for DBS, costs of DBS, complications, the percentage of Parkinson disease (PD) patients who might profit from DBS, etc. Students at Hannover Medical School were asked to complete the questionnaire in the preclinical study period and in the last year of the study. Results: Comparing the “early group” (204 students) and the “advanced group” (162 students), there was a significant gain of knowledge. More common disorders such as PD and tremor were known to be indications for DBS. Knowledge about the impact of DBS on specific symptoms in PD and about DBS targets was limited in both groups. Conclusions: DBS is partly known among medical students in the preclinical phase with a gain of knowledge during further study. Future studies on this topic addressing general practitioners as neurologists are needed to better understand why knowledge on DBS is still limited.

Background: Chronic deep brain stimulation (DBS) of the globus pallidus internus (GPi) has become an established treatment for dystonia. While bradykinetic symptoms may occur on chronic stimulation, the appearance of hyperkinetic movements has not been well characterized.Case Report: We report on the development of hyperkinesias after more than 10 years of GPi DBS.Discussion: Hyperkinesias may evolve upon long-term GPi DBS in dystonia. This might be related to a combined effect consisting of a reduced threshold for effective GPi stimulation for dystonia and spread of current to the globus pallidus externus.

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