Enhancing Medical Student Education in Neurosurgery: The Impact of the Sub-Internship Rotation

The neurosurgical sub-internship is widely recognized as one of the most influential experiences for medical students pursuing this specialty. These four-week rotations serve multiple roles, including validating specialty choice, expanding involvement in patient care, and developing core competencies. From a residency program perspective, sub-internships are heavily weighted during applicant evaluation. Neurosurgery applicants typically complete between three and four sub-internships, but despite their significance, rotations remain highly variable and unstandardized. As a result, many students enter residency feeling underprepared, with as many as half of surgical interns nationwide reporting gaps in readiness for independent responsibilities. This mismatch between time invested and educational yield highlights the need to objectively assess and refine the sub-internship experience. To address this gap, we conducted a prospective study evaluating the impact of our institution’s neurosurgery sub-internship on fourth-year medical students between May 2022 and August 2024. A structured survey was designed to assess seven domains of intern-level neurosurgical knowledge: basic neurosurgical patient care, neurologic physical examination, bedside procedures, imaging, drain management, consultations, and operating room experience. Surveys were administered at the start and end of each four-week rotation. Pre- and post-test results were compared using paired t-tests to measure knowledge acquisition and to identify domains of both strength and persistent challenge. Data were collected from 32 students over the study period. Results demonstrated statistically significant improvements in all seven domains, confirming the sub-internship as an effective educational tool. The most substantial gains were observed in bedside procedures (23.4% improvement, p