Cerebrospinal fluid dynamics in non-acute post-traumatic ventriculomegaly

Matthew Garnett,Laurent Gergelé,Marek Czosnyka,Afroditi D Lalou,Zofia Czosnyka,Angelos Kolias,Virginia Levrini,Peter J Hutchinson

doi:10.1186/s12987-020-00184-6

Abstract

BackgroundPost-traumatic hydrocephalus (PTH) is potentially under-diagnosed and under-treated, generating the need for a more efficient diagnostic tool. We aim to report CSF dynamics of patients with post-traumatic ventriculomegaly.Materials and methodsWe retrospectively analysed post-traumatic brain injury (TBI) patients with ventriculomegaly who had undergone a CSF infusion test. We calculated the resistance to CSF outflow (Rout), AMP (pulse amplitude of intracranial pressure, ICP), dAMP (AMPplateau-AMPbaseline) and compensatory reserve index correlation coefficient between ICP and AMP (RAP). To avoid confounding factors, included patients had to be non-decompressed or with cranioplasty > 1 month previously and Rout > 6 mmHg/min/ml. Compliance was assessed using the elasticity coefficient. We also compared infusion-tested TBI patients selected for shunting versus those not selected for shunting (consultant decision based on clinical and radiological assessment and the infusion results). Finally, we used data from a group of shunted idiopathic Normal Pressure Hydrocephalus (iNPH) patients for comparison.ResultsGroup A consisted of 36 patients with post-traumatic ventriculomegaly and Group B of 45 iNPH shunt responders. AMP and dAMP were significantly lower in Group A than B (0.55 ± 0.39 vs 1.02 ± 0.72; p < 0.01 and 1.58 ± 1.21 vs 2.76 ± 1.5; p < 0.01. RAP baseline was not significantly different between the two. Elasticity was higher than the normal limit in all groups (average 0.18 1/ml). Significantly higher Rout was present in those with probable PTH selected for shunting compared with unshunted. Mild/moderate hydrocephalus, ex-vacuo ventriculomegaly/encephalomalacia were inconsistently reported in PTH patients.ConclusionsRout and AMP were significantly lower in PTH compared to iNPH and did not always reflect the degree of hydrocephalus or atrophy reported on CT/MRI. Compliance appears reduced in PTH.

Highlights

Post-traumatic hydrocephalus (PTH) is potentially under-diagnosed and under-treated, generating the need for a more efficient diagnostic tool
Mild/moderate hydrocephalus, ex-vacuo ventriculomegaly/ encephalomalacia were inconsistently reported in PTH patients
resistance to CSF outflow (Rout) and amplitude of Intracranial pressure (ICP) pulse (AMP) were significantly lower in PTH compared to idiopathic Normal Pressure Hydrocephalus (iNPH) and did not always reflect the degree of hydrocephalus or atrophy reported on CT/MRI

Summary

Introduction

Post-traumatic hydrocephalus (PTH) is potentially under-diagnosed and under-treated, generating the need for a more efficient diagnostic tool. We aim to report CSF dynamics of patients with post-traumatic ventriculomegaly. Post-traumatic hydrocephalus (PTH) is potentially under-diagnosed and under-treated, creating the need for a more efficient diagnostic tool [1,2,3]. PTH is diagnosed using a combination of clinical assessment and brain imaging. By nature of the vast and varied sequelae of traumatic brain injury (TBI), clinical signs and symptoms are variable and difficult to identify consistently. The need to distinguish between ventriculomegaly secondary to PTH versus brain atrophy by imaging techniques, poses a further challenge to diagnosis [4,5,6]. Different forms of PTH can be classified according to the phase after injury. In the first few days to weeks, there may be obstruction of normal pathways

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