The Monro-Kellie doctrine in its own context.

In 1783, Alexander Monro secundus maintained that because the brain is enclosed in a case of bone and its substance is nearly incompressible, the quantity of blood within the head must be the same, or very nearly the same, at all times. Years later, this hypothesis was experimentally supported by George Kellie, and became known as the Monro-Kellie doctrine. However, this doctrine encountered resistance.

[Post-op paraspinal atrophy: Does the approach matter?].

Objective: To compare the level of post-op muscle atrophy related to the different approaches used in segmental lumbar fusion for degenerative disease (midline vs. Wiltse vs. MIS TLIF).

Using the "ligamentum flavum gap" to identify originally missed type B vertebral fractures.

Background: Spine fractures may involve the ligamentum flavum (LF). Here, we utilized the "ligamentum flavum gap," defined by the discontinuity of the LF at the level of a vertebral fracture, to document a vertebral fracture.

Methods: Utilizing X-rays, computed tomography (CT), and magnetic resonance (MR) studies, 10 patients with type B vertebral fractures were diagnosed with the ligamentum flavum gap (LFG: discontinuity of the LF) at the fracture levels.

Brain motion and volume transmission: Keeping the interstice flowing.

Human brain undergoes two different kinds of movements: subtle pulsatile ones associated with the cardiac cycle and others of a greater magnitude related to breathing activity. These motions constitute a pumping force for the circulation of cerebrospinal fluid (CSF). Moreover, brain motion (BM) plays a fundamental role as a driving force for the interstitial and CSF flow of tracers.

Brain motion in patients with skull defects: B-mode ultrasound observations on respiration-induced movements.

Background: Since ancient times, brain motion has captured the attention of human beings. However, there are no reports about morphological changes that occur below the cortex or skin flap when a patient, with an open skull breathes, coughs, or engages effort. Thus, the aim of this study was to characterize brain motion caused by breathing movements in adults with an open skull.