Introduction: Brain monitoring requires computer support because the recorded signals can be very complex and identification of clinically relevant models is frequently required.

Methods: The ICM plus (ICM+) software was introduced in the CSF Dynamics Lab in 2003. Since then 1447 constant rate infusion tests and 123 overnight ICP monitoring (using intraparenchymal bolt) have been performed.

Results: Various configurations have been used: ICP only [identification of CSF dynamics model (Dr. Marmarou) and overnight ICP monitoring with analysis of compensatory reserve and B waves] (1); ICP and arterial blood pressure (ABP; analysis of Pressure Reactivity Index); ICP, ABP and Transcranial Doppler Blood flow velocity (for assessment of cererebral autoregulation) (2); ICP, ABP and Near-Infrared Spectroscopy (for analysis of fluctuation of Cerebral Blood Volume); ICP, sagittal sinus pressure and jugular venous pressure (in patients with pseudotumour cerebri syndrome to assess the hydrodynamic consequences of cerebral venous sinus stenosis). Combination of CSF infusion study with CO2 reactivity and PET-CBF studies have been performed in order to assess vascular factors of hydrocephalus (3). The software contains a database of shunts tested in the Cambridge Shunt Evaluation Laboratory aiding shunt assessment in-vivo in case of possible under-drainage or over-drainage. The software enables digital recording of data, ready for post-hoc manual or batch analysis, creation of virtual signals (such as critical closing pressure, cerebral compliance, etc.) and analysis of their dependency on primary modalities.

Conclusions: Recording of multi-modal data supported by identification of CSF compensation model can be used in diagnosing patients with CSF circulation disorders. The collected database of cases and signals forms a powerful reference tool in investigation and understanding of the complex pathophysiology of hydrocephalus.

Patient Care: The ICM+ software is useful in the management of patients with CSF circulation disorders.

Learning Objectives: By the conclusion of this session, participants should be able to discuss the utility of the ICM+ software in the management of patients with CSF circulation disorders.

References: 1. Weerakkody RA et al. Acta Neurol Scand. 2011. 124(2):85-98. 2. Czosnyka ZH et al. Neurosurgery. 2002. 50(3):526-32 3. Momjian S et al. Brain. 2004. 127:965-72.