Brainstem cavernous malformations: anatomical, clinical, and surgical considerations

Abstract

<jats:p>Symptomatic brainstem cavernous malformations carry a high risk of permanent neurological deficit related to recurrent hemorrhage, which justifies aggressive management. Detailed knowledge of the microscopic and surface anatomy is important for understanding the clinical presentation, predicting possible surgical complications, and formulating an adequate surgical plan. In this article the authors review and illustrate the surgical and microscopic anatomy of the brainstem, provide anatomoclinical correlations, and illustrate a few clinical cases of cavernous malformations in the most common brainstem areas.</jats:p>

Microsurgical anatomy and internal architecture of the brainstem in 3D images: surgical considerations

“…Damage to the oculomotor nucleus causes ipsilateral paresis of eye movements. 14,29,43,49 The mesencephalic tract nucleus of the trigeminal nerve continues from the pons.…”

“…49 It is an extrapyramidal motor nucleus that participates in the control of muscle tonus, and damage to it results in contralateral ataxia and tremor. 14,29,30,49 The substantia nigra (Soemmering's locus niger 49 ) extends from the lateral mesencephalic sulcus to the oculomotor sulcus lateromedially, and from the highest part of the pons to the subthalamic nucleus (Luys's body 49 ) craniocaudally (Fig. 6).…”

“…Recent improvements in neuroimaging, microsurgical techniques, and electrophysiological monitoring, in association with detailed knowledge of regional and functional anatomy, have allowed surgical procedures at this region to become safer and more likely to be successful. To plan the most appropriate approaches, to choose the safest entry zones, and to minimize possible surgical complications, 14,41 it is important for the neurosurgeon to keep in mind both the surface anatomy and the internal architecture of the brainstem. obJective Brainstem surgery remains a challenge for the neurosurgeon despite recent improvements in neuroimaging, microsurgical techniques, and electrophysiological monitoring.…”

Lateral inferior cerebellar peduncle approach to dorsolateral medullary cavernous malformation

“…For lesions that are deep to the pia or ependyma, safe entry zones into the brainstem include the middle cerebellar peduncle and the lateral mesencephalic sulcus, among others. 5,15 We introduce an approach to intrinsic medullary lesions through the foramen of Luschka with an incision in the inferior cerebellar peduncle. The limits of the incision are the origin of cranial nerves (CNs) IX and X anteriorly, the dorsal and ventral cochlear nuclei and the junction of CNs VII and VIII with the brainstem rostrally, the floor of the fourth ventricle posteriorly, and the cuneate nuclei below the CNs IX, X, and XI origin inferiorly.…”

“…2,6 Medial approaches to the dorsal medulla and inferior cerebellar peduncle have been described and include the transvermian, telovelar, and supratonsillar approaches. 2,5,6 In this report, we describe the cases of 4 patients who underwent excision of a dorsolateral medullary cavernous malformation via a novel lateral inferior cerebellar peduncle (ICP) approach.…”