Dorsal column mapping in resection of intramedullary spinal cord tumors: a prospective comparison of two methods and neurological follow-up.

PURPOSE: In surgery for intramedullary spinal cord tumors (imSCT), distortion of the anatomy challenges the visual identification of dorsal columns (DC) for midline myelotomy. Dorsal column mapping (DCM) and spinal cord stimulation (SCS) can identify DC neurophysiologically. We compare application and feasibility of both methods. METHODS: Patients with surgically treated imSCT were prospectively included between 04/2017 and 06/2019. The anatomical midline (AM) was marked. SSEPs at the DC after stimulation of tibial/median nerve with an 8-channel DCM electrode and cortical SSEP phase reversal at C3/C4 after SCS using a bipolar concentric probe were recorded. Procedural and technical aspects were compared. Standardized neurological examinations were performed preoperatively, 1 week postoperatively and after more than 12 months. RESULTS: The DCM electrode detected the midline in 9/13 patients with handling limitations in the remaining patients. SCS was applicable in all patients with determination of the midline in 9/13. If both recordings could be acquired (6/13), concordance was 100%. If baseline SSEPs were poor, both methods were limited. SCS was less time-consuming (p = 0.001), cheaper, and easier to handle. In 92% of cases, the AM and neurophysiologic midlines were concordant. After myelotomy, 3 patients experienced > 50% reduction in amplitude of SSEPs. Despite early postoperative worsening of DC function, long-term follow-up showed significant recovery and improvement in quality of life. CONCLUSION: DCM and SCS may help confirm and correct the AM for myelotomy in imSCT, leading to a favorable long-term neurological outcome in this cohort. SCS evolved to be superior concerning applicability, cost-effectiveness, and time expenditure.

Case Report: A Case of Severe Clinical Deterioration in a Patient With Multiple Sclerosis.

Tumefactive multiple sclerosis (MS) is a rare variant of MS that may lead to a rapidly progressive clinical deterioration requiring a multidisciplinary diagnostic workup. Our report describes the diagnostic and therapeutic approach of a rare and extremely severe course of MS. A 51-year-old man with an 8-year history of relapsing-remitting MS (RRMS) was admitted with a subacute progressive left lower limb weakness and deterioration of walking ability. After extensive investigations including repeated MRI, microbiological, serological, cerebrospinal fluid (CSF) studies, and finally brain biopsy, the diagnosis of a tumefactive MS lesion was confirmed. Despite repeated intravenous (IV) steroids as well as plasma exchanges and IV foscarnet and ganciclovir owing to low copy numbers of human herpesvirus 6 (HHV-6) DNA in polymerase chain reaction (PCR) analysis, the patient did not recover. The clinical presentation of tumefactive MS is rare and variable. Brain biopsy for histopathological workup should be considered in immunocompromised patients with rapidly progressive clinical deterioration with brain lesions of uncertain cause.

Fear of heights in virtual reality saturates 20 to 40 m above ground.

Recent epidemiological studies indicate that about one-third of the general population suffers from a more or less disabling height intolerance, with a relevant impact on quality of life in many of them. Acrophobia, the most severe form of visual height intolerance, has a life-time prevalence of around 5%. Although it is commonly believed that fear of heights should continuously aggravate with increasing elevation, this issue has not been systematically investigated yet. Here, we examined this topic using immersive virtual reality, an established tool in therapy for fear of heights, that allows to flexibly manipulate height stimuli. In a comprehensive cohort (including insusceptible subjects as well as subjects with height intolerance up to acrophobia) height intolerance severity was graded by an established metric scale (vHISS). Participants were randomly exposed to different virtual elevations using a head-mounted display. Behavioral responses to virtual height exposure were analogous to exposure in vivo. Participants exhibited increased anxiety and musculoskeletal stiffening with enhanced high-frequency body sway, to an extend that corresponded to the individual subjective height intolerance rating. For all behavioral responses, we observed a saturation above a certain altitude. Body sway and musculoskeletal stiffening became maximal at 20 m above ground, whereas anxiety saturated above 40 m. These results suggest that fear of heights is characterized by a nonlinear stimulus-response relationship and a dissociation between visual-height-induced bodily and emotional reactions.

Correction to: Fear of heights in virtual reality saturates 20 to 40 m above ground.

The original version of this article unfortunately contained a mistake. The surnames of all authors have been interchanged. The corrected author names are given below.