Background: Anomalies of the middle cerebral artery (MCA) are rare; among the different types of anomalies, the aplastic or twig-like (Ap/T) MCA is extremely rare and has been reported under various names, including aplastic, unfused, or rete type anomaly. The occurrence of a brain aneurysm associated with this anatomic variant is an even rare event, and probably their development and rupture are related to hemodynamic stress of the tinny wall of vessels forming the network. Case Description: We present a 43-year-old male patient with an explosive and persistent right orbitofrontal headache. A computed tomography showed a right frontobasal hematoma with intraventricular disruption. Magnetic resonance angiography showed a right MCA aneurysm and what seems to be a MCA trunk stenosis. Cerebral digital subtraction angiography demonstrated a plexiform arterial network and one aneurysm arising from the network. The patient was successfully treated by surgical clipping to evacuate the hematoma and to prevent further intracranial hemorrhages. Conclusion: The Ap/T-MCA may be associated with hemodynamic stress with a significant effect through the tinny wall of the vessels causing hemorrhage or leading to the formation and rupture of cerebral aneurysms. Based on a correct diagnosis of the anomaly, treatment can be completed successfully through different standard methods.

Background: Surgical resection for carotid body tumors (CBTs) is the gold standard of treatment and continues to be a challenging procedure, commonly associated with high vascular injury rates and neurological complications. Methods: It is a retrospective case series study between January 2002 and November 2020, with a mean follow-up of 29 months in a single nationwide referral center. Thirty-one patients diagnosed with a carotid body tumor and treated with microsurgical periadventitial resection were included in the study. Patients’ demographics, comorbidities, clinical, radiological factors, and tumor grade, evaluated by the Shamblin scale, were obtained. Statistical analysis was performed on all collected data. Results: In this study, we included 31 patients (32 tumors), 80% of the patients were female, and 20% were male, with a mean age of 53 years. One patient presented with bilateral lesions, while 17 tumors were located on the left side. The most frequent symptom was a painless, slow-growing neck mass in 74% of patients. Using the Shamblin classification, 13% of tumors were Grade I, 53% Grade II, and 34% Grade III. In the postoperative period, 3% of patients presented with permanent cranial nerve deficit, while none had vascular injuries or postoperative stroke. A tumor >5 cm increased the risk for nerve lesion by 11 times (OR 12.6, CI 95% 7.4-11.4, P < 0.001). Conclusion: Preoperative embolization followed by periadventitial resection by means of a microsurgical technique is a safe and effective approach to remove CBT, with 3% cranial nerve injury rate and no need for vascular sacrifice or reconstruction.

The visual pathway and its defects have been thoroughly studied in clinical correlation to temporal lobe lesions related to epilepsy and traumatic lesions. Nevertheless, its clinical correlation and other decisionmaking have not been addressed regarding neoplastic lesions. We present a case report of a 28-year-old man with a one-year history of generalized seizures and left superior homonymous quadrantanopia, with no other neurological disturbance on physical examination. According to diffusion tensor imaging tractography, MRI demonstrated a non-enhancing, right temporal lesion disrupting the visual pathway. An awake surgery with direct cortical electrostimulation of visual pathways was performed with subtotal resection of the tumor to preserve visual function, confirmed with postoperative MRI. Histopathological studies revealed a fibrillary astrocytoma.Surgical technique aided with intraoperative cortical and subcortical stimulation involving low-grade gliomas in eloquent areas is an exceptionally suitable procedure for complex cases where the visual pathway is compromised. Our objective is to describe how intraoperative mapping of visual function is performed in our institution and to comment on the relevant technical nuances, which can serve as a practical guideline for young neurosurgeons, as no previous cases have been reported in our country.

Background: The intracranial migration of a ventriculoperitoneal shunt (VPS) has been previously described, it is a very rare event, and the mechanisms of this migration have not yet been elucidated. Case Description: Newborn at 38 weeks of gestation by cesarean section, with congenital hydrocephalus due to Dandy–Walker malformation that required right Frazier VPS placement. At 2-month follow-up, computed tomography of the skull showed cranial migration of VPS and dysfunction. At evaluation, there were signs of systemic infection. External ventricular drainage was placed and an intravenous antibiotic scheme for Gram-positive bacteria was started. After 3 months, cerebrospinal fluid cultures were negative and definitive VPS was decided. Conclusion: Different possible mechanisms have been proposed, such as negative intraventricular pressure, positive intra-abdominal pressure, use of valveless catheters, excessive burr hole size, as well as such as occipital ventricular access, thin cortical mantle, incorrect distal and proximal fixation, short distance between the peritoneum and ventricles, and a possible inflammatory reaction to the catheter material (silicone). A combination of these different mechanisms contributes to proximal shunt migration. Although the placement of a VPS is a procedure well taught since the 1st years of neurosurgical residency, it is not exempt from complications. Although, as was previously stated in this paper, the incidence of a complete cranial VPS migration is extremely rare, and only a few cases are documented, it is still important to report this type of cases and to try to elucidate the possible mechanisms involved.

Fahr's syndrome, recently named "primary brain calcification," is a rare disorder with a variable clinical presentation ranging from behavioral changes to seizures. It can be idiopathic or have multiple causes, hypoparathyroidism the most frequent. In the current coronavirus 2019 (COVID-19) pandemic, these electrolyte imbalances have acquired importance, and there has been a correlation between the lowest serum calcium levels and severe COVID-19 disease. It is known that calcium accomplishes many normal physiologic functions.We present a case of a 63-year-old woman who arrived at the emergency room with a fever of 10-day duration, odynophagia, dry cough, dyspnea, and drowsiness. Upon her arrival, computed tomography of the brain and chest was performed, showing areas of calcification in the basal nuclei and infiltrates with a ground-glass pattern, respectively. In addition, laboratory studies were conducted in which hypocalcemia and hyperphosphatemia stand out. Furthermore, a positive result was obtained from acute Respiratory Syndrome Coronavirus 2 (SARS-COV2) from bronchial secretion. According to the clinical presentation data in the imaging and laboratory studies, Fahr's syndrome and COVID-19 pneumonia were diagnosed.We consider evaluating electrolyte imbalances at case presentations essential and continuously monitoring them. Appropriate and prompt corrections were achieved in patients with hypoparathyroidism history and severe COVID-19 disease. This case shows the vital collaboration between endocrinologists and other physicians that care for patients with COVID-19 infection.