Review of theories into the pathogenesis of normal pressure hydrocephalus.

Normal pressure hydrocephalus (NPH) represents a unique form of hydrocephalus characterised by the paradox of ventriculomegaly without significant elevations in intracranial pressure, with the clinical triad of gait instability, cognitive impairment, and urinary incontinence. A myriad of neurobiological correlates have been implicated in its pathophysiology. We review the literature to provide an up-to-date, narrative review of the proposed mechanisms underlying the pathophysiology of NPH, proposing a holistic framework through which to understand the condition.

A quantitative model of the cerebral windkessel and its relevance to disorders of intracranial dynamics.

Objective: Traditional models of intracranial dynamics fail to capture several important features of the intracranial pressure (ICP) pulse. Experiments show that, at a local amplitude minimum, the ICP pulse normally precedes the arterial blood pressure (ABP) pulse, and the cranium is a band-stop filter centered at the heart rate for the ICP pulse with respect to the ABP pulse, which is the cerebral windkessel mechanism. These observations are inconsistent with existing pressure-volume models.

Brain Circuitry of Consciousness: A Review of Current Models and a Novel Synergistic Model With Clinical Application.

How consciousness arises in the brain has important implications for clinical decision-making. We summarize recent findings in consciousness studies to provide a toolkit for clinicians to assess deficits in consciousness and predict outcomes after brain injury. Commonly encountered disorders of consciousness are highlighted, followed by the clinical scales currently used to diagnose them.

Why don't ventricles dilate in pseudotumor cerebri? A circuit model of the cerebral windkessel.

Objective: Pseudotumor cerebri is a disorder of intracranial dynamics characterized by elevated intracranial pressure (ICP) and chronic cerebral venous hypertension without structural abnormalities. A perplexing feature of pseudotumor is the absence of the ventriculomegaly found in obstructive hydrocephalus, although both diseases are associated with increased resistance to cerebrospinal fluid (CSF) resorption. Traditionally, the pathophysiology of ventricular dilation and obstructive hydrocephalus has been attributed to the backup of CSF due to impaired absorption, and it is unclear why backup of CSF with resulting ventriculomegaly would not occur in pseudotumor.

Bifrontal Biparietal Cruciate Decompressive Craniectomy in Pediatric Traumatic Brain Injury.

Background: We investigated a novel surgical approach to decompressive craniectomy (DC), the bifrontal biparietal, or "cruciate," craniectomy, in severe pediatric traumatic brain injury (TBI). Cruciate DC was designed with a fundamentally different approach to intracranial pressure (ICP) control compared to traditional DC. Cruciate DC involves craniectomies in all 4 skull quadrants.