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Background: Automated supervised text classification methods require preclassified training data. Their application in scenarios that a large amount of preclassified data is not accessible is challenging. Neurosurgical literature classification into subspecialties is an example of this situation. We have introduced an automated similarity-based text classification method, evaluated it along with two other automated methods and applied the introduced method in neurosurgical literature classification. Methods: Performance of an introduced similarity-based text classification method along with two other automated methods (Lbl2Vec and keyword counting-based methods) was compared with performance of two senior neurosurgery registrars in classification of neurosurgical literature to 5 subspecialties. The Kappa-statistic measure of interrater agreement, overall marginal homogeneity using the Stuart-Maxwell test, marginal homogeneity relative to individual categories using McNemar tests and the sensitivity and specificity of each of the three methods were calculated.The introduced method was used to classify 211617 neurosurgical publications indexed in Pubmed to different subspecialties based on keywords extracted from subspecialty sections of a neurosurgery textbook. Results: The introduced similarity-based method showed the highest agreement with the registrars (raw agreement and Kappa value) followed by the Lbl2Vec and the counting-based method. Classifications of the English neurosurgical publications indexed in Pubmed into categories of Oncology, Vascular, Spine and functional using the introduced similarity-based method were more reliable (closer to the registrars’ classifications) than Cranial trauma. The classifications and future forecast showed highest publications in Oncology, followed by Cranial trauma, Vascular, spine and functional neurosurgery. Conclusion: The classification of the English neurosurgical publications indexed in Pubmed to different subspecialties, using the introduced method, shows that Oncology and tumour has been the main battleground for the neurosurgeons over years and probably in the near future. The performance of the introduced classification method in comparison with the human performance shows its potential application in the situations that enough preclassified data are not accessible for automated text classification.

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

Epidural injections are routinely used for short-term management of radicular pain and chronic low back pain. Prescription of this intervention, in the presence of intracranial abnormalities, is a topic of debate. Intracranial arachnoid cysts are cerebrospinal fluid-filled spaces, which are usually asymptomatic despite being a formidable size. As far as the authors know, there have been no cases depicted in indexed literature regarding asymptomatic supratentorial arachnoid cysts becoming symptomatic post undertaking of spinal epidural injections. We depict this phenomenon in a 53-year-old woman, who ultimately required a craniotomy to address their symptoms. Asymptomatic supratentorial arachnoid cysts can become symptomatic post undertaking of spinal epidural injections. In cases of known cranial arachnoid cysts with mass effect, the small risk that the cranial arachnoid cyst may become symptomatic during or after epidural injections should be a consideration and the patients should be informed of the potential associated risks.

Objective: Endovascular chemical angioplasty has been in practice in patients with symptomatic cerebral vasospasm secondary to aneurysmal subarachnoid haemorrhage in many neurosurgical centres. However, the evidence base is derived from clinical case series and expert consensus. The aim of this retrospective cohort study is to evaluate the immediate and functional outcomes of endovascular intervention in aneurysmal subarachnoid haemorrhage cerebral vasospasm treated with a combination of vasodilators. Methods: A cohort of 25 patients was identified. Each patient underwent surgical clipping, and endovascular treatment for vasospasm. A combination of Verapamil and Nimodipine was intra-arterially administered. Statistical analysis was performed to determine the rate of response. The angiographic response and functional outcome on discharge (modified Rankin score - MRS) were used as markers of outcome. Results: The study cohort consisted of 25 patients with a mean age of 50.3 (SD 11.2). A total of 135 therapeutic DSA’s were performed. There was an associated between MRS outcomes and number of vasodilation’s each patient received. For each additional vasodilation episode, the odds of a poor outcome increased by 1.190. An angiographic response was demonstrated in 88% of patients, a clinical response in 27%. A good functional outcome was achieved in 17/25, 71% at discharge. Conclusion: The combination therapy of Intra-arterial nimodipine and verapamil in patients with aneurysmal subarachnoid haemorrhage vasospasm appears to have a synergistic, if not comparable, outcome to from solitary vasodilatory treatment results and potentially promote future studies with prospective designs to measure the outcomes.