T he brainstem forms the central axis of the brain and comprises the midbrain, pons, and medulla oblongata; it occupies the anterior portion of the cranial posterior fossa (Fig. 1). It is composed of neurons aggregated into nuclei and nerve fibers grouped into bundles called tracts, fasciculi, or lemnisci. These elements of the internal structure may be related to prominences or depressions on the surface, which must be identified by the surgeon. The brainstem is basically composed of 4 types of structures: 1) ascending and descending pathways that connect the spinal cord with the prosencephalon; 2) reflex centers associated with control of breathing, the cardiovascular system, and also consciousness, along the reticular formation; 3) most of the nuclei of the cranial nerves (from CN III to XII); and 4) cerebellar peduncles. 23,36,41,43,49 Brainstem surgery remains a challenge for the neurosurgeon. 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. A detailed knowledge of the microsurgical anatomy of the brainstem surface and its internal architecture is mandatory to plan appropriate approaches to the brainstem, to choose the safest point of entry, and to avoid potential surgical complications. methods An extensive review of the literature was performed regarding the brainstem surgical approaches, and their correlations with the pertinent anatomy were studied and illustrated through dissection of human brainstems properly fixed with 10% formalin. The specimens were dissected using the fiber dissection technique, under ×6 to ×40 magnification. 3D stereoscopic photographs were obtained (anaglyphic 3D) for better illustration of this study. results The main surgical landmarks and their relationship with the cerebellum and vascular structures were identified on the surface of the brainstem. The arrangements of the white matter (ascending and descending pathways as well as the cerebellar peduncles) were demonstrated on each part of the brainstem (midbrain, pons, and medulla oblongata), with emphasis on their relationships with the surface. The gray matter, constituted mainly by nuclei of the cranial nerves, was also studied and illustrated. coNclusioNs The objective of this article is to review the microsurgical anatomy and the surgical approaches pertinent to the brainstem, providing a framework of its external and internal architecture to guide the neurosurgeon during its ...

Object The main objective was to study the epidemiological data obtained in patients with cervical spinal trauma (CST) in the north area of São Paulo City between 1997 and 2006. Methods All patients with severe CST in the north area of São Paulo City were studied. The data analyzed were age, sex, incidence, causes of trauma, level of trauma, morbidity, deaths, and complications. Analytical tests were performed to study risks of trauma and complications. The chi-square and analysis of variance tests were used for analytical data (significance level p < 0.05). Results The study population consisted of 217 patients who were hospitalized for CST. The average incidence rate was 21.6 cases annually or 1.8 cases monthly. The mean patient age was 36.75 years. The 20–40-year-old age bracket was found to be most highly represented, corresponding to 52.6% of total patients. Patients were predominantly male; 191 patients (88.01%) were male compared with only 26 female patients (11.99%). The ratio of men to women was 7.35:1. Injuries in the craniocervical region corresponded to 43 (19.8%) of the cases; injuries in the cervical subaxial region corresponded to 174 (80.2%) of the cases and were associated with worse neurological lesions. Additionally, 40.6% of patients presented with complications in other organs and systems; several patients presented with multiple complications, and 33 patients (15.02%) died. During the hospitalization period, 4 patients presenting as Grade A on the American Spinal Injury Association (ASIA) Scale evolved to Grade C, 1 patient presenting as ASIA Grade A evolved to Grade B, and 2 patients evolved to Grade E. Two patients who had been admitted without neurological lesions evolved to ASIA Grade C (1 patient postsurgery and 1 patient post-traction). Two patients presenting initially as ASIA Grade E evolved to Grade D, and another to central cord syndrome. On average, patients with incomplete lesions improved 1 grade in ASIA classification during hospitalization. Conclusions Data from severe CST observed in the current study suggest many differences in the characteristics described in the majority of published epidemiological studies and those found in patients in the north area of São Paulo City. It is likely that these differences reflect the urban and cultural habits and behaviors of the population specific to this area.

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