Neurosurgical on-call systems play a central role in ensuring continuous access to specialized cranial and spinal emergency care. Over the past two decades, several European and North American centres have reported a sustained increase in emergency neurosurgical referrals, affecting both cranial trauma and spinal pathologies, as well as non-urgent consultations [[1], [2], [3], [4]]. These trends reflect broader changes in healthcare organisation, including population ageing, increased availability of neuroimaging in peripheral hospitals, and structural modifications within emergency and primary care systems [3,5].

Recent multicentre evaluations have highlighted a steady rise in neurosurgical workload,particularly out-of-hours, with growing contributions from degenerative spine disease, spinal trauma, and tumour-related emergencies [2,4,6]. Parallel analyses have also shown a markedexpansion in non-urgent referrals requiring specialist advice, raising concerns regarding theappropriate use of neurosurgical on-call resources [7,8]. In addition to increasing case volume,several studies have emphasised the organisational impact of prolonged on-call duties, the expansion of nighttime surgical activity, and their potential contribution to burnout among neurosurgeons, emergency physicians, and trainees [[9], [10], [11]].

Despite this extensive international literature, long-term data from France remain scarce. French neurosurgical services rely on continuous 24-h on-call duties, without shift-based division, which may accentuate the impact of rising referral volumes. Furthermore, recent changes in the French healthcare landscape—reduction in the number of permanent emergency physicians, increased dependence on temporary staff, difficulties in recruiting general practitioners, and heightened medico-legal pressure in emergency settings—may significantly influence referral behaviours and neurosurgical on-call demand [[12], [13], [14]].

Caen University Hospital (CHU de Caen) provides 24/7 cranial and spinal emergency coveragefor a catchment area of nearly two million inhabitants in the former Basse-Normandie region. However, no study has yet examined how neurosurgical on-call activity has evolved over the past decade in this setting.

The objective of this study was to compare neurosurgical on-call activity between 2014 and 2024, with a focus on (1) overall call volume; (2) patient demographics; (3) origin of referrals; (4) distribution between cranial and spinal cases; and (5) urgent and semi-urgent surgical activity.