Monitoring intracranial pressure in patients with malignant middle cerebral artery infarction: is it useful?

OBJECTIVE

Intracranial pressure (ICP) monitoring is increasingly used in the treatment of patients with malignant middle cerebral artery (MCA) infarction. However, neurological deterioration may exist independent from intracranial hypertension. This study aimed to present the findings of continuous ICP monitoring in a cohort of patients with malignant MCA infarction and to correlate these findings with clinical and radiological features.

METHODS

The authors studied a prospective cohort of 25 patients with malignant MCA infarction consecutively admitted to the neurotrauma intensive care unit of the Vall d'Hebron University Hospital between March 2002 and September 2006. The patients were treated using a combined protocol of initial moderate hypothermia and hemicraniectomy. The latter was performed when patients showed a midline shift (MLS) > or = 5 mm or ICP > 20 mm Hg. Six patients had an MLS > or = 5 mm on the first CT scan and underwent surgery without prior ICP monitoring. This study focuses on the subgroup of 19 patients who underwent intraparenchymatous ICP monitoring before surgery.

RESULTS

Intracranial pressure readings were evaluated and correlated with pupillary abnormalities, MLS, and ischemic tissue volume. In 12 of the 19 patients, ICP values were always < or = 20 mm Hg, despite a mean (+/- SD) MLS of 6.7 +/- 2 mm and a mean ischemic tissue volume of 241.3 +/- 83 cm(3). In 2 patients with anisocoria, ICP values were also normal.

CONCLUSIONS

In patients with a malignant MCA infarction, pupillary abnormalities and severe brainstem compression may be present despite normal ICP values. Therefore, continuous ICP monitoring cannot substitute for close clinical and radiological follow-up in the management of these patients.