Neurosurgery Blog

J Neurosurg 113:1326–1330, 2010. (DOI: 10.3171/2010.8.JNS1067)

Managing symptomatic ventriculoperitoneal shunts with no clear evidence of shunt malfunction either clinically or radiologically can be a difficult task. The aim of this study was to assess intracranial pressure (ICP) monitoring as a method of investigating shunt function.

Methods. The authors performed a retrospective analysis of 38 continuous ICP monitoring procedures done in patients with ventriculoperitoneal shunts and suspected shunt malfunction.

Results. Thirty-eight procedures were performed in 31 patients between January 2005 and October 2008. Sixteen recordings were normal, 6 revealed overdrainage or low pressure, 11 indicated underdrainage or high pressure, and 5 showed variable shunt function. Based on the findings after 20 procedures (53%), patients were treated conservatively: 4 by readjusting the valve setting and 16 by referral to the headache neurologist for medical treatment. Forty-five percent of the conservatively treated patients improved. Surgical exploration was undertaken following 18 procedures (47%); 72% of the surgically treated patients improved.

Conclusions. Continuous ICP monitoring using an intraparenchymal probe is a safe and effective method of investigating adult hydrocephalus.

J Neurosurg 112:648–657, 2010. DOI: 10.3171/2009.7.JNS081677

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 hemi-craniectomy. The latter was performed when patients showed a midline shift (MLS) ≥ 5 mm or ICP > 20 mm Hg. Six patients had an MLS ≥ 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 ≤ 20 mm Hg, despite a mean (± SD) MLS of 6.7 ± 2 mm and a mean ischemic tissue volume of 241.3 ± 83 cm3. 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.

Neurosurgery 66:80-91, 2010 DOI: 10.1227/01.NEU.0000363408.69856.B8

OBJECTIVE: To review our experience of managing idiopathic normal pressure hydrocephalus (iNPH) during the 6-year period from 2002 to 2007, when intracranial pressure (ICP) monitoring was part of the diagnostic workup.

METHODS: The review includes all iNPH patients undergoing diagnostic ICP monitoring during the years 2002 to 2007. Clinical grading was done prospectively using a normal pressure hydrocephalus (NPH) grading scale (scores from 3 to 15). The selection of patients for surgery was based on clinical symptoms, enlarged cerebral ventricles, and findings on ICP monitoring. The median follow-up time was 2 years (range, 0.3-6 years). Both static ICP and pulsatile ICP were analyzed.

RESULTS: A total of 214 patients underwent the diagnostic workup, of whom 131 went on to surgery. Although 1 patient died shortly after treatment, 103 of the 130 patients (79%) improved clinically. This improvement lasted throughout the observation period. The static ICP observed during ICP monitoring was a poor predictor of the response to surgery. In contrast, among 109 of 130 patients with increased ICP pulsatility (ie, ICP wave amplitude >4 mm Hg on average and >5 mm Hg in >10% of recording time), 101 (93%) were responders (ie, increase in the NPH score of >2). Correspondingly, only 2 of 21 (10%) without increased ICP pulsatility were responders. Superficial wound infection was the only complication of ICP monitoring and occurred in 4 (2%) patients.

CONCLUSION: Surgical results in iNPH were good with almost 80% of patients improving after treatment. The data indicate that improvement after surgery can be anticipated in 9 of 10 iNPH patients with abnormal ICP pulsatility, but in only 1 of 10 with normal ICP pulsatility. Diagnostic ICP monitoring had a low complication rate