Non-invasive monitoring of intracranial pressure waveforms using Braincare® BCMM 2000 monitor in dogs with myelopathies undergoing myelography

Abstract

ABSTRACT: Intracranial pressure (ICP) monitoring is considered the gold standard for optimizing the treatment of humans in intensive care units. However, this procedure is not commonly performed in veterinary medicine because of the limitations and complications of the method. There are some new promising non-invasive techniques for monitoring ICP, but they have not been validated in veterinary medicine. This study aimed to correlate the non-invasive intracranial pressure (NI-ICP) waveforms obtained with the BCMM-2000 Brain4care monitor during myelography in dogs with myelopathies undergoing this exam for diagnostic purposes with the waveforms obtained through invasive monitoring of the subarachnoid pressure (SP). The NI-ICP waveform was monitored in six dogs with myelopathies before (M1), during (M2), and after (M3) contrast medium injection into the subarachnoid space. Cerebrospinal fluid (CSF) was collected before contrast injection. The SP waveform was simultaneously monitored in three of the six dogs. Correlations between the two methods were performed using Pearson’s coefficient. The analysis of the morphology and amplitude of the waves at each moment was performed, and at M2, an increase in the P2:P1 ratio (p<0.05) was observed in both monitoring methods. In M3, the values were similar to those of M1, demonstrating the return of cerebral compliance. The comparison of the NI-ICP and SP had a positive correlation in those moments (Pearson’s coefficient r=0.76; p=0.027). The speed of contrast administration, degree of spinal cord compression, and volume of CSF previously collected may affect P2:P1 and ICP dynamics. The BCMM-2000 Brain4care monitor was effective in detecting changes in ICP dynamics and abnormal pulse waveforms in dogs with meningoencephalitis of unknown origin, vertebral neoplasm and intervertebral disc disease with and without hemorrhagic myelomalacia, suggesting increased ICP induced by myelography.