Modeling Pathological Intracranial Pressure Waveforms In Idiopathic Intracranial Hypertension
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S. A. Stevens, W. D. Lakin, N. J. Thakore, P. L. Penar & J. Stimpson
Idiopathic intracranial hypertension (IIH) is a syndrome of unknown cause characterized by elevated intracranial pressure (ICP). By representing an abnormally collapsible sinus with a downstream Starling-like resistor, our previous modeling efforts have produced explanations for various phenomenon associated with IIH. Recent reports indicate that many patients with chronic daily headaches have been found to actually be suffering from IIH without papilledema (IIWOP). Moreover, these patients often demonstrate hypertensive B-waves and plateau-like waves upon continuous ICP monitoring. Our previous results did not produce such pathological wave-forms. The current model, described here, resolves this deficit by representing a semi-collapsible sinus by a refined resistor based on experimental data. With this revision the model exhibits low frequency, high amplitude ICP waves in milder cases of sinus collapsibility. As collapsibility increases further, so does the duration of the waves until they are replaced by two stable states, one of normal pressures and one of elevated pressures. In this domain the model behaves in much the same way as our previous work. Thus, the current model reproduces the results of previous versions and additionally exhibits the high amplitude spikes and wave-forms seen clinically in milder cases of IIH.