ABSTRACT
BACKGROUND AND PURPOSE: Identify patients with a dorsal epidural hematoma at C1-C2 and examine the major craniocervical junction ligaments for injury on follow-up magnetic resonance imaging. MATERIALS AND METHODS: Adult and pediatric trauma patients who suffered a dorsal epidural hematoma at C1-C2 were identified using Nuance mPower software (Nuance Communications, United States). The cervical computed tomography and magnetic resonance imaging exams for these patients were reviewed for craniocervical junction osteoligamentous injuries. An age-matched control group was obtained. RESULTS: Eight trauma patients were identified with a dorsal epidural fluid collection at C1-C2. All patients with a dorsal epidural hematoma, who underwent follow-up cervical magnetic resonance imaging demonstrated a stripping injury of the posterior atlanto-occipital membrane from the C1 posterior arch with increased short tau inversion recovery signal in the posterior atlanto-occipital membrane complex. Disruption of additional major craniocervcial ligaments on magnetic resonance imaging was relatively common with the most frequently associated ligamentous injuries involving the tectorial membrane (five patients) followed by the alar ligaments and anterior altanto-occiptial membrane (four patients each). Conclusions: A C1-C2 dorsal epidural hematoma is a rare injury that may be identified on cervical spine computed tomography but may be easily overlooked by the radiologist. We propose that a C1-C2 dorsal epidural hematoma is a direct result of a significant hyperflexion-hyperextension force with subsequent stripping of the posterior atlanto-occipital membrane from the posterior C1 arch. Trauma patients with a C1-C2 dorsal epidural hematoma on cervical spine computed tomography should undergo a cervical magnetic resonance imaging examination to evaluate the integrity of the posterior atlanto-occipital membrane complex and remaining craniocervical junction ligaments for injury.
ABSTRACT
Classic anatomical studies describe two membranes – atlanto-occipital and atlanto-axial in the posterior aspect of the craniocervical region. During many surgical procedures in this area, however, we have not found such membranes. Objective To clarify the anatomical aspects and structures taking part of the posterior atlanto-occipital and atlanto-axial area. Method Analysis of histological cuts of three human fetuses and anatomical studies of 8 adult human cadavers. Results In both atlanto-occipital and atlanto-axial areas, we have observed attachment between suboccipital deep muscles and the spinal cervical dura. However, anatomical description of such attachments could not be found in textbooks of anatomy. Conclusion Our study shows the absence of the classical atlanto-occipital and atlanto-axial membranes; the occipito-C1 and C1-C2 posterior intervals are an open area, allowing aponeurotic attachment among cervical dura mater and posterior cervical muscles. .
Em livros clássicos de anatomia é referida a existência de duas membranas, atlanto-occipital e atlanto-axial, participando do fechamento da região cranio-cervical. Entretanto, em frequentes procedimentos cirúrgicos que envolvem esta região, jamais detectamos a presença de tais membranas. Objetivo Estudar os aspectos anatômicos e as estruturas que participam do fechamento posterior dos espaços atlanto-occipital e atlanto-axial. Método Estudo de cortes histológicos de três fetos humanos e estudos anatômicos em 8 cadáveres humanos adultos. Resultados Em ambos os espaços, atlanto-occipital e atlanto-axial, encontramos uma aderência entre as estruturas musculares profundas e a dura-mater, sem as membranas atlanto-occipital e atlanto-axial descritas nos livros clássicos de anatomia. Conclusão Não foram encontradas as membranas atlanto-occipital e atlanto-axial no material estudado; os espaços atlanto-occipital e atlanto-axial são abertos permitindo expansões aponeuróticas entre os músculos profundos e a dura-mater. .
