Improving the ability to discriminate medical multiple-choice questions through the analysis of the competitive examination to assign residency positions in Spain.

INTRODUCTION: Psychometrics plays a vital role in evaluating educational research, including the analysis of multiple-choice exams. This study aims to improve the discriminatory ability of the "Médico Interno Residente" (MIR) medical exam in Spain, used to rank candidates for specialized healthcare training, through psychometric analysis. METHODS: We analyzed 2,890 MIR exam questions from 2009 to 2021 (totaling 147,214 exams), categorizing them based on methodology and response type. Evaluation employed classical test theory and item response theory (IRT). Classical test theory determined difficulty and discrimination indices, while IRT assessed the relationship between knowledge levels and question performance. RESULTS: Question distribution varied across categories and years. Frequently addressed knowledge areas included various medical specialties. Non-image-associated clinical cases were the easiest, while case-based clinical questions exhibited the highest discriminatory capacity, differing significantly from image-based case or negative questions. High-quality questions without images had longer stems but shorter answer choices. Adding images reduced discriminatory power and question difficulty, with image-based questions being easier. Clinical cases with images had shorter stems and longer answer choices. CONCLUSIONS: For improved exam performance, we recommend using a clinical case format followed by direct short-answer questions. Questions should be of low difficulty, providing clear and specific answers based on scientific evidence and avoiding ambiguity. Typical clinical cases with key characteristic features should be presented, excluding uncertain boundaries of medical knowledge. Questions should have lengthy stems and concise answer choices, minimizing speculation. If images are used, they should be typical, clear, consistent with the exam, and presented within clinical cases using clinical semiotics and propaedeutics.

[Elusive thoracic spine tumour. Report of an exceptional case and literature review]. / Tumor elusivo dorsal. Presentación de un caso excepcional y revisión de la bibliografía.

Elusive tumours in the spine, most of them schwannomas of the cauda equina, have been reported very rarely. We present the case of a woman with a preoperative radiological diagnosis of schwannoma at D10 level in whom a laminectomy was performed to remove the tumour. Although the laminectomy was correctly positioned, there was no tumour upon opening the dura and the laminectomy had to be extended cephalad to find and remove the tumour. Mobile intradural extramedullary spinal tumours, the so-called «elusive tumours¼, occur very rarely, and it is exceptional when they are located in the thoracic spine. Knowing preoperatively which tumour is going to behave in this way is almost impossible. However, in the reported cases there are common features such as symptoms changing with different body positions, small tumour size and weak attachment to nearby structures. Neurosurgeons must be able to resolve this situation when confronted with a negative correctly-positioned laminectomy.

[Ruptured cerebral artery blister aneurysm]. / Aneurisma cerebral roto tipo «blíster¼

We report the case of a young patient with subarachnoid haemorrhage secondary to a ruptured blister-like aneurysm. Since this kind of aneurysms have fragile walls without a well-defined neck, their treatment is difficult. We initially planned the deployment of a flow-diverter stent, but an angiogram obtained after 10 days revealed a morphological change of the aneurysm. Therefore, we finally deployed a conventional stent and introduced 2 micro coils into the point of rupture, obtaining a good morphological result without rebleeding. Follow-up at 1 and 6 months did not observe regrowth of the aneurysm. We offer a brief introduction and discussion of this pathology and its treatment.

Efficacy and Safety of Endovascular Treatment in Acute Tandem Carotid Occlusions: Analysis of a Single-Center Cohort.

INTRODUCTION: Acute ischemic strokes with tandem occlusions, which represent 10-20% of all ischemic strokes, have a particularly poor prognosis. Since emergent treatment of tandem lesions has not been specifically addressed in randomized trials, there is an absence of standardized management. OBJECTIVE: We sought to assess the efficacy and safety of acute endovascular treatment in stroke due to tandem occlusions in our center and compare the results with previous reports. METHODS: From a prospective registry we analyzed data of 99 consecutive patients (males: 77.7%, mean age ± SD: 67.5 ± 9.5 years) with stroke due to tandem occlusions who underwent treatment with emergent carotid stenting and intracranial mechanical thrombectomy. Successful recanalization was defined as a TICI score of 2b-3 and a good functional outcome was defined as a modified Rankin scale score ≤2 at 90 days. Symptomatic intracranial hemorrhage (sICH) was considered when associated with worsening on the National Institutes of Health Stroke Scale (≥4 points). RESULTS: A successful recanalization rate was achieved in 87.8 and 48.5% of the patients had a good functional outcome. sICH and mortality rates were 12.1 and 20.2%, respectively, and 21.2% of the patients received combined treatment with intravenous thrombolysis, which did not affect neither the prognosis nor the recanalization or sICH rates. The time from symptom onset to recanalization and the degree of recanalization were the main factors associated with prognosis and the occurrence of sICH. CONCLUSIONS: Our results suggest that endovascular treatment with emergent carotid stenting and intracranial thrombectomy in patients with acute stroke due to tandem occlusions is an effective and safe procedure.

Analysis of endovascular treatment of ruptured microaneurysms compared with ruptured larger aneurysms.

OBJECTIVE: To retrospectively analyze the complications and outcome of the endovascular treatment of ruptured microaneurysms compared with the treatment of ruptured larger aneurysms. METHODS: 40 ruptured cerebral microaneurysms treated by endovascular techniques were selected retrospectively and compared with 207 larger ruptured cerebral aneurysms treated by endovascular techniques during the same time period. Medical charts and imaging studies were reviewed to analyze baseline clinical and epidemiologic characteristics, procedural complications, and clinical outcomes RESULTS: Cerebral microaneurysms had a higher incidence of intraoperative technical ruptures (13.5% vs 2.9%, p<0.005). The number of thromboembolic complications was not increased. Patient prognosis was similar for the two groups (mean modified Rankin Scale score 1.81 vs 2.09, p>0.1). CONCLUSIONS: Coiling of cerebral microaneurysms has a reasonable safety profile with good clinical outcomes, similar to coiling of larger aneurysms. In our experience, the systematic use of remodeling balloons, operator experience, and the ability to manage complications are the reasons for the satisfactory results.

Analysis of endovascular treatment of ruptured aneurysms of the middle cerebral artery compared to other anatomical locations.

OBJECTIVE: The objective of this article is to compare the results of endovascular treatment of ruptured middle cerebral artery (MCA) aneurysms with ruptured aneurysms of other anatomic locations. METHODS: Fifty consecutive ruptured aneurysms of the MCA and 209 aneurysms at other anatomical locations were selected retrospectively. We compared epidemiological, clinical and radiological variables, prognosis and complications. RESULTS: The MCA aneurysms had a greater size and a poor dome/neck ratio. There were no significant differences in endovascular technique complications, occlusion rate or rebleeding between the two groups (p > 0.1). There were no significant differences in the mortality and number of dependent patients after one month. CONCLUSION: The endovascular treatment of ruptured MCA aneurysms without hematoma is as safe and effective as other aneurysm localizations. Complication rates, occlusion rates and rebleeding of ruptured MCA aneurysms are comparable to other locations.

Endovascular reconstruction of internal carotid artery dissection in patients with acute ischemic stroke using the Wingspan stent.

OBJECTIVE: The purpose of this study is to demonstrate our experience in endovascular reconstruction of carotid dissections using the Wingspan Stent System™ (Boston Scientific, Natick, MA, USA), a device we use because of its high radial force and its navigation in extreme curves. METHODS: We treated 11 consecutive patients with acute ischemic stroke due to carotid dissection with the Wingspan stent, in the cervical carotid artery. RESULTS: Functional evaluation revealed that 10 of the 11 patients were independent at 3 months post surgery and that the 11 stents used were found to be patent at the 6-month follow-up digital subtraction angiography (DSA). CONCLUSIONS: The Wingspan stent is an alternative to classic carotid stents and flow diverters for the treatment of cervical internal carotid artery (ICA) dissection associated with ectasias or large loops. The device remains patent over the long term and it is not associated with arterial wall complications.

Anatomical results, rebleeding and factors that affect the degree of occlusion in ruptured cerebral aneurysms after endovascular therapy.

OBJECT: To present a series of ruptured cerebral aneurysms in consecutive non-selected patients treated with endovascular therapy, analyzing the initial degree of occlusion, its anatomical evolution mid-term and the variables that could statistically affect them. METHODS: 251 aneurysms were first treated with coiling (embolization). 203 patients were followed up with conventional angiography for 6-8 months after the initial treatment and 182 were followed up with three-dimensional time of flight MR angiography at 18-24 months. Postoperative and mid-term anatomical results were evaluated anonymously and independently using the modified Montreal Scale. RESULTS: The initial rate of complete occlusion was 70.9%, with rates of neck remnants and aneurysm remants of 18.3% and 10.7%, respectively. The recurrence rate was 13% after 6 months and 2% between 6 months and 2 years. The rate of retreatment was 11%. Statistically, the variables that were found to be related to the initial degree of occlusion were the use of a remodeling balloon technique (p=0.012), the size of the aneurysm neck (p=0.044) and the size of the aneurysm (p=0.004). The recanalization rate at mid-term depended on the size of the aneurysm. Although aneurysms with partial occlusion initially tended to evolve to a worse degree of closure than those with complete occlusion initially, the relationship was not statistically significant (p=0.110). CONCLUSIONS: Embolized aneurysms can develop a worse degree of closure even when the initial occlusion is complete. The degree of occlusion depends directly on morphological factors and the use of balloon-assisted techniques. The recanalization rate at mid-term depends on the size of the aneurysm and probably on the density of the packing achieved with the initial treatment.

[Endovascular treatment of carotid stenosis: an experience in the Hospital Universitario Central de Asturias]. / Tratamiento endovascular de la estenosis carotídea: experiencia en el Hospital Universitario Central de Asturias.

INTRODUCTION: Carotid stenosis accounts for about 25% of all ischaemic cerebrovascular events. Carotid angioplasty and stenting (CAS) is a minimally invasive procedure used as an alternative to carotid endarterectomy, especially in high surgical risk patients. AIM: To analyse the effectiveness and safety of the endovascular treatment of carotid stenosis in the Hospital Universitario Central de Asturias. PATIENTS AND METHODS: The study consisted in a retrospective analysis of the carotid stenoses treated by means of CAS between February 2005 and April 2010, and the following information was recorded: demographic data, clinical diagnosis, indication of treatment, time between the onset of symptoms and beginning of treatment, angiographic findings, complications and long-term follow-up (including the rate of restenosis). RESULTS: Altogether 121 patients were treated (77.8% males and 22.2% females), with a mean age of 70.8 ± 10.7 years. The main vascular risk factors were arterial hypertension (65.3%), smoking (61.2%) and dyslipidaemia (42.1%). In 86% of cases the stenoses were symptomatic and in the remaining 14% they were asymptomatic. In 60.3% of cases they were stenoses > 70%, in 30.6% they were preocclusive stenoses and in 9.1% they were recanalisations of unstable carotid occlusions. The mean treatment time was 17.0 ± 8.3 days after the ischaemic event. The residual stenosis was less than 30% in all cases. The morbidity and mortality rate at 30 days was 4.1% and the rate of restenosis throughout a mean follow-up of 31.2 ± 10.8 months was 2.4%. CONCLUSIONS: In our hospital CAS is considered an effective and safe technique, with a rate of complications that is within the parameters that justify its indication.