Neuroanatomical predictors of awakening in acutely comatose patients.

OBJECTIVE: Lateral brain displacement has been associated with loss of consciousness and poor outcome in a range of acute neurologic disorders. We studied the association between lateral brain displacement and awakening from acute coma. METHODS: This prospective observational study included all new onset coma patients admitted to the Neurosciences Critical Care Unit (NCCU) over 12 consecutive months. Head computed tomography (CT) scans were analyzed independently at coma onset, after awakening, and at follow-up. Primary outcome measure was awakening, defined as the ability to follow commands before hospital discharge. Secondary outcome measures were discharge Glasgow Coma Scale (GCS), modified Rankin Scale, Glasgow Outcome Scale, and hospital and NCCU lengths of stay. RESULTS: Of the 85 patients studied, the mean age was 58 ± 16 years, 51% were female, and 78% had cerebrovascular etiology of coma. Fifty-one percent of patients had midline shift on head CT at coma onset and 43 (51%) patients awakened. In a multivariate analysis, independent predictors of awakening were younger age (odds ratio [OR] = 1.039, 95% confidence interval [CI] = 1.002-1.079, p = 0.040), higher GCS score at coma onset (OR = 1.455, 95% CI = 1.157-1.831, p = 0.001), nontraumatic coma etiology (OR = 4.464, 95% CI = 1.011-19.608, p = 0.048), lesser pineal shift on follow-up CT (OR = 1.316, 95% CI = 1.073-1.615, p = 0.009), and reduction or no increase in pineal shift on follow-up CT (OR = 11.628, 95% CI = 2.207-62.500, p = 0.004). INTERPRETATION: Reversal and/or limitation of lateral brain displacement are associated with acute awakening in comatose patients. These findings suggest objective parameters to guide prognosis and treatment in patients with acute onset of coma.

Anatomic considerations, nomenclature, and advanced cross-sectional imaging techniques for visualization of the cranial nerve segments by MR imaging.

Various methods of cross-sectional imaging are used for visualization of the cranial nerves, relying heavily on MR imaging. The success of the MR imaging sequences for visualization of cranial nerves depends on their anatomic context at the point of evaluation. The heterogeneity of opinion regarding optimal evaluation of the cranial nerves is partly a function of the complexity of cranial nerve anatomy. A variety of approaches are advocated and variations in equipment and terminology cloud the field. This article proposes a segmental classification and corresponding nomenclature for imaging evaluation of the cranial nerves and reviews technical considerations and applicable literature.

High-resolution CISS MR imaging with and without contrast for evaluation of the upper cranial nerves: segmental anatomy and selected pathologic conditions of the cisternal through extraforaminal segments.

The authors review the course and appearance of the major segments of the upper cranial nerves from their apparent origin at the brainstem through the proximal extraforaminal region, focusing on the imaging and anatomic features of particular relevance to high-resolution magnetic resonance imaging evaluation. Selected pathologic entities are included in the discussion of the corresponding cranial nerve segments for illustrative purposes.