Long-term outcome after medical reversal of transtentorial herniation in patients with supratentorial mass lesions

Objective: To determine the short- and long-term outcomes after successful reversal of transtentorial herniation by medical treatment. Although it has been recognized that aggressive medical management can reverse transtentorial herniation, it is believed that overall outcome in such patients is poor. Design: Prospective cohort study. Setting: Neurocritical care unit of a university hospital. Patients: A total of 28 consecutive patients who underwent an episode of transtentorial herniation (defined as decrease in level of consciousness accompanied by pupillary dilation) secondary to a supratentorial mass lesion followed by successful reversal. Intervention: Herniation was reversed by using a combination of hyperventilation, mannitol and hypertonic saline. Measurements and Main Results: The following outcomes were analyzed: risk of second herniation, radiologic evidence of structural damage or vascular compromise related to herniation on post-herniation computed tomographic scan, in-hospital mortality, and-long-term functional outcome using Rankin score and Barthel index. A total of 32 episodes of transtentorial herniations were reversed in 28 patients during a 14-month period. The most common precipitating cause were edema (n = 23) or new/ expanding intracerebral hematoma (n = 5). After first reversal of transtentorial herniation in 28 patients, a second herniation episode was observed in 16 patients after a mean interval of 88.2 hrs (range, 23-432 hrs); four were successfully reversed. On follow-up computed tomographic scan, hypodense lesion in midbrain (n = 6), temporal lobe contusion (n = 2), posterior cerebral artery (n = 3), and middle cerebral artery (n = 1) infarction were visualized in a minority of patients. The in-hospital mortality was 60% (n = 15) with brain death being the cause of death in 13 patients; care was withdrawn in eight patients. Second episode of herniation (p = .002) and midbrain involvement during herniation (p = .02) were associated with in-hospital mortality. During a mean follow-up period of 11.4 +/- 4.2 months, two patients died of cerebral neoplasm and human immunodeficiency virus-related sepsis, respectively. Of the 11 survivors, 7 were functionally independent (Rankin score <3 and Barthel index >60). Conclusions: Although mortality after transtentorial herniation is high, we found a prominent potential for meaningful recovery with aggressive medical reversal of transtentorial herniation. Our study implies that timely medical intervention for reversing transtentorial herniation can result in preservation of neurologic function.