No abstract

Summary Human Coronaviruses (HCoVs) have long been known as respiratory viruses. However, there are reports of neurological findings in HCoV infections, particularly in patients infected with the novel severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) amid Coronavirus disease 2019 (COVID‐19) pandemic. Therefore, it is essential to interpret the interaction of HCoVs and the nervous system and apply this understanding to the COVID‐19 pandemic. This review of the literature analyses how HCoVs, in general, and SARS‐CoV‐2, in particular, affect the nervous system, highlights the various underlying mechanisms, addresses the associated neurological and psychiatric manifestations, and identifies the neurological risk factors involved. This review of literature shows the magnitude of neurological conditions associated with HCoV infections, including SARS‐CoV‐2. This review emphasises, that, during HCoV outbreaks, such as COVID‐19, a focus on early detection of neurotropism, alertness for the resulting neurological complications, and the recognition of neurological risk factors are crucial to reduce the workload on hospitals, particularly intensive‐care units and neurological departments.

The purpose of this study was to analyze the significance of perinidal T₂ hyperintensity appearance after radiosurgery of arteriovenous malformations (AVMs), as a predictor of treatment response. Our initial experience with linear accelerator (LINAC) radiosurgery at University of California, Los Angeles, between 1990 and 1997 involved treatment of 129 patients affected by cerebral AVMs. Based upon availability of neuroimaging follow-up, 48 patients with 50 AVMs were selected for review. Forty (80%) of the AVMs underwent complete obliteration or significant reduction on follow-up MRI, on average 20 months after radiosurgery. Thirteen (72%) of 18 obliterated AVMs were associated with perinidal T₂ hyperintensity signal, on average 18 months (6–49) after radiosurgery. Ten (20%) of 50 AVMs (average volume 23.1 cm³, ranging 7.5–46.5) were unchanged. Furthermore, only 3 AVMs in this group showed reversible T₂ signal changes. In patients with complete nidal obliteration, appearance of T₂ hyperintensity signal achieves 72% sensitivity in predicting successful treatment response.

Background: Bone marrow is a readily accessible source for autologous adult bone marrow stem cells which can be applied therapeutically without possessing the risk of immune rejection and without raising ethical concerns. The purpose of this study is to determine the feasibility, safety, and effectiveness of direct transplantation of autologous adult bone marrow stem cells in patients with chronic cord injuries.Methods: Thirty consecutive patients (5 females and 25 males, aged 6 to 64 y) having chronic traumatic dorsal spinal cord injury with durations of at least 6 months were included in the study. Twenty patients were treated with autologous adult bone marrow stem cells transplantation through open surgical intraparenchymal and intralesional injection into the site of cord injury. The treatment was continued with monthly intrathecal injection of stem cells through lumbar or cisternal punctures. Ten other patients were not treated with stem cells and served as control cases.Results: Clinical improvement was observed in 6 (30%) of 20 patients treated with stem cells transplantation. Short duration of injury and small cord lesions correlated with good outcome. Follow-up electrophysiologic studies did not show statistically significant changes. Follow-up magnetic resonance imaging did not show significant changes. Minor and temporary treatmentrelated morbidity were recorded.Conclusions: The application of autologous adult bone marrow mesenchymal stem cells directly into the spinal cord is relatively safe and has clinical benefits in patients with chronic spinal cord injury. However, multicenter studies should be conducted to further elucidate the safety and efficacy of stem cells therapy in patients with spinal cord injury.

Meningiomas are mostly benign but some are atypical or malignant. Surgical resection is curative when complete removal of benign meningiomas is contemplated. Incompletely excised and recurrent tumors are frequently treated with fractionated radiation therapy or stereotactic radiosurgery. The purpose of this study is to evaluate the short-term radiological and functional outcomes of a single center using linear accelerator (Linac) stereotactic radiosurgery for the treatment of intracranial meningiomas. Twenty-nine patients (12 males and 17 females) with 30 meningiomas, in different brain locations (skull base and non-skull base meningiomas), were treated with Linac-based stereotactic radiosurgery. The mean tumor volume was 6.3 cm³, and the mean tumor marginal and maximum doses were 10.9 and 15 Gy, respectively. The median prescribed isodose line was 80%. The patients were followed-up for a minimum of 3 years. Regarding radiological outcome, nine (30%) meningiomas demonstrated evident volume reduction, 19 (63.3%) meningiomas remained unchanged, and two (6.7%) meningiomas increased in size after radiosurgery. The local tumor control rates for skull base meningiomas and non-skull base meningiomas after radiosurgery were 90.9% and 100%, respectively. Regarding functional outcomes, 64% of patients presenting with cranial neuropathies showed improvement of their cranial nerve functions and 29% of patients remained unchanged. One patient had temporary trigeminal neuropathy. Although radiosurgery for meningiomas is generally effective and quite safe in achieving high control rates with minimum morbidity over short- and intermediate-term periods of follow-up, tumor progression might occur in a delayed manner after initial apparent control for few years. We recommend continued follow-up for longer periods to better assess the long-term outcomes.