Intracranial pressure (ICP) monitoring has become integral in the diagnosis and management of many forms of brain injury. Notably, Hurth et al. investigated the utility of perioperative ICP monitoring in monosuture synostosis, revealing a significant incidence of elevated ICP, particularly in sagittal synostosis – a previously unclear aspect [1]. However, its use in cases of ventriculomegaly or equivocal hydrocephalus has been limited [2], [3], [4]. When used appropriately, contemporary methods of ICP monitoring provide precise, accurate, and otherwise unobtainable information for decision-making in the management of intracranial hypertensive pathologies such as hydrocephalus [5], [6], [7]. The most common cause of non-traumatic pediatric intracranial hypertension is pressure-active hydrocephalus which, when treated promptly, can alleviate apparent signs, symptoms, and imaging findings such as transependymal flow and worsening/progressive ventriculomegaly and neurological decline [8].

Arrested or pressure-compensated hydrocephalus is characterized clinically by asymptomatic/non-progressive ventriculomegaly [9], [10]. These children often demonstrate no overt signs or symptoms concerning for baseline ICP elevations, and in fact, when ICP monitoring is performed, baseline daytime measurements can be normal for age [11]. Pathologic ICP waveforms in these patients often present as intermittent spikes during periods of cerebral hyperemia (i.e. deep sleep) with a prolonged plateau before returning to normal baseline. These pathologic elevations are often referred to as Lundberg “A” waves and may repeat multiple times per night throughout the life of the child [9], [10], [12].

Since clinical presentation is often benign, often without any neurological signs or symptoms, and objective testing such as brain imaging demonstrates severe ventriculomegaly with paucity of subarachnoid spaces, arrested hydrocephalus patients may experience delayed diagnosis and treatment. Ultimately, such delays can lead to impaired neuropsychological and cognitive development [13]. Serial brain imaging with stable ventricle size can typically rule out the diagnosis of pressure-active hydrocephalus, for which CSF diversion is necessary. However, imaging studies alone are often insufficient for discerning between pressure-compensated hydrocephalus and isolated ventriculomegaly (Fig. 1). Furthermore, many of these patients are preverbal/nonverbal, making clinical assessments even more ambiguous. When the clinical and imaging pictures are discordant, diagnostic ambiguity combined with the lack of literature-guiding management, the role of continuous ICP monitoring in this patient population becomes very valuable [14], [15].

In this study, we retrospectively review our experience with children without traumatic pathologies who demonstrate severe non-progressive ventriculomegaly lacking overt signs and symptoms of elevated ICP for which no clearly defined management guidelines exist.