Ravindran, Krishnan

Abstract Objective: Reading is a complex cognitive process requiring the integration of orthographic, phonological, and semantic information. The visual word form area, located in the ventral occipitotemporal cortex, is critically involved in orthographic decoding, and damage to this region is known to cause alexia. In contrast, the contributions of white matter pathways supporting reading are less well understood. Method: We present a unique neurosurgical case undergoing awake brain surgery for resection of a metastasis in the left occipitotemporal cortex. A tubular retractor was used to access the lesion and during the insertion of the retractor the patient underwent careful, continuous neuropsychological testing, including evaluation of reading. fMRI language mapping and diffusion MRI were performed preoperatively. Postoperative neuropsychological testing was completed two weeks after surgery to assess cognitive outcome. Results: The patient developed an alexia with letter-by-letter reading in real time during insertion of the tubular retractor. Stealth imaging enabled localization of the tubular retractor at the exact onset of the alexia and, by correlating this with tractography, showed that the tubular retractor was in the vertical occipital fasciculus (VOF). Conclusions: We present the first detailed case report linking the VOF to the acute onset of alexia observed intraoperatively during awake brain surgery. We discuss the connectomics of reading and possible contributions of the VOF in reading.

OBJECTIVE Spinal cord cavernous malformations (SCCMs) are rare vascular malformations with a capricious prognosis. Given the eloquent nature of the spinal cord, considerable surgical morbidity may be encountered. Therefore, conservative management has emerged as a valid alternative, especially for incidental lesions diagnosed on ubiquitous imaging. The aim of this systematic review and meta-analysis was to evaluate the safety and efficacy of surgical versus conservative management of SCCMs. METHODS Following PRISMA guidelines, this study included articles published in full-text form comparing the outcomes following conservative and surgical management of SCCMs. Collected variables included the total number of patients, spine level, resection, myelotomy, follow-up duration, bleeding, motor weakness, pain, bladder and/or bowel dysfunction, and neurological improvement or deterioration after discharge. The primary outcome of interest was long-term functional outcome. RESULTS Eleven articles comprising 515 patients were included, of whom 343 (66.6%) underwent resection and 172 (33.4%) were managed conservatively. Patients who underwent surgery were more likely to have preoperative motor deficits, hemorrhagic episodes, and bladder and/or bowel dysfunction, indicating increased disease severity. Resection was associated with significantly improved long-term functional outcomes (OR 3.27, 95% CI 1.72–6.24) compared with conservative management. There was no significant difference between the two groups regarding odds of long-term clinical deterioration (OR 1.03, 95% CI 0.35–3.03). However, the risk of hemorrhagic episodes during follow-up was higher in the conservative group (17.3%) compared with the surgical group (1.69%). The odds of hemorrhage during follow-up were lower in the surgical group, although not statistically significant (OR 0.24, 95% CI 0.05–1.05). CONCLUSIONS This study highlights that while surgical management of SCCMs is associated with better long-term functional outcomes and reduced risk of recurrent hemorrhage, treatment decisions must be carefully tailored to the individual patient, particularly given the potential risks associated with surgery. Conservative management, although less invasive, carries a nonnegligible risk of hemorrhage during follow-up, warranting close monitoring. These findings parallel management strategies used for brainstem cavernomas, for which surgery is reserved for cases with low surgical risk and worsening neurological symptoms. However, the limitations of current data, including selection bias and heterogeneity in reporting, emphasize the need for a multi-institutional registry to better define the natural history of SCCMs and inform future management strategies.

OBJECTIVE Chordomas are rare tumors of the skull base and spine believed to arise from the vestiges of the embryonic notochord. These tumors are locally aggressive and frequently recur following resection and adjuvant radiotherapy. Proton therapy has been introduced as a tissue-sparing option because of the higher level of precision that proton-beam techniques offer compared with traditional photon radiotherapy. This study aimed to compare recurrence in patients with chordomas receiving proton versus photon radiotherapy following resection by applying tree-based machine learning models. METHODS The clinical records of all patients treated with resection followed by adjuvant proton or photon radiotherapy for chordoma at Mayo Clinic were reviewed. Patient demographics, type of surgery and radiotherapy, tumor recurrence, and other variables were extracted. Decision tree classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS Fifty-three patients with a mean ± SD age of 55.2 ± 13.4 years receiving surgery and adjuvant proton or photon therapy to treat chordoma were identified; most patients were male. Gross-total resection was achieved in 54.7% of cases. Proton therapy was the most common adjuvant radiotherapy (84.9%), followed by conventional or external-beam radiation therapy (9.4%) and stereotactic radiosurgery (5.7%). Patients receiving proton therapy exhibited a 40% likelihood of having recurrence, significantly lower than the 88% likelihood observed in those treated with nonproton therapy. This was confirmed on logistic regression analysis adjusted for extent of tumor resection and tumor location, which revealed that proton adjuvant radiotherapy was associated with a decreased risk of recurrence (OR 0.1, 95% CI 0.01–0.71; p = 0.047) compared with photon therapy. The decision tree algorithm predicted recurrence with an accuracy of 90% (95% CI 55.5%–99.8%), with the lowest risk of recurrence observed in patients receiving gross-total resection with adjuvant proton therapy (23%). CONCLUSIONS Following resection, adjuvant proton therapy was associated with a lower risk of chordoma recurrence compared with photon therapy. The described machine learning models were able to predict tumor progression based on the extent of tumor resection and adjuvant radiotherapy modality used.

Objectives To investigate the impact of the COVID-19 pandemic as well as concomitant COVID-19 itself on stroke care, focusing on middle cerebral artery (MCA) territory infarctions. Design Registry-based study. Setting We used the National Inpatient Sample (NIS) database, which covers a wide range of hospitals within the USA. Participants The NIS was queried for patients with MCA strokes between 2016 and 2020. In total, 35 231 patients were included. Outcome measures Outcome measures were postprocedural complications, length of stays (LOSs), in-hospital mortality and non-routine discharge. Propensity score matching using all available baseline variables was performed to reduce confounders when comparing patients with and without concomitant COVID-19. Results Mechanical thrombectomy (MT) was performed in 48.4%, intravenous thrombolysis (IVT) in 38.2%, and both MT and IVT (MT+IVT) in 13.4% of patients. A gradual increase in the use of MT and an opposite decrease in the use of IVT (p<0.001) was detected during the study period. Overall, 25.0% of all patients were admitted for MCA strokes during the pandemic period (2020), of these 209 (2.4%) were concomitantly diagnosed with COVID-19. Patients with MCA strokes and concomitant COVID-19 were significantly younger (64.9 vs 70.0; p<0.001), had significantly worse NIH Stroke Severity scores, and worse outcomes in terms of LOS (12.3 vs 8.2; p<0.001), in-hospital mortality (26.3% vs 9.8%; p<0.001) and non-routine discharge (84.2% vs 76.9%; p=0.013), as compared with those without COVID-19. After matching, only in-hospital mortality rates remained significantly higher in patients with COVID-19 (26.7% vs 8.5%; p<0.001). Additionally, patients with COVID-19 had higher rates of thromboembolic (12.3% vs 7.6%; p=0.035) and respiratory (11.3% vs 6.6%; p=0.029) complications. Conclusions Among patients with MCA stroke, those with concomitant COVID-19 were significantly younger and had higher stroke severity scores. They were more likely to experience thromboembolic and respiratory complications and in-hospital mortality compared with matched controls.