Authors: Korley FK, Morton MJ, Hill PM, Mundangepfupfu T, Zhou T, Mohareb AM, Rothman RE.

OBJECTIVE: Emergency department (ED) computed tomography (CT) use has increased significantly during the past decade. It has been suggested that adherence to clinical decision support (CDS) may result in a safe decrease in CT ordering. In this study, the authors quantified the percentage agreement between routine and CDS-recommended care and the anticipated consequence of strict adherence to CDS on CT use in mild traumatic brain injury (mTBI).

Authors: Bartek J Jr, Abedi-Valugerdi G, Liska J, Nyström H, Andresen M, Mathiesen T.

We report a patient with intracranial hemorrhage secondary to venous hypertension as a result of a giant aortic pseudoaneurysm that compressed the superior vena cava and caused obstruction of the venous return from the brain. To our knowledge, this is the first patient reported to have an intracranial hemorrhage secondary to a superior vena cava syndrome. The condition appears to be caused by a reversible transient rise in intracranial pressure, as a result of compression of the venous return from the brain. Treatment consisted of surgery for the aortic pseudoaneurysm, which led to normalization of the intracranial pressure and resorption of the intracranial hemorrhage.

Authors: García M, Poza J, Santamarta D, Abásolo D, Barrio P, Hornero R.

Hydrocephalus includes a number of disorders characterised by clinical symptoms, enlarged ventricles (observable using neuroimaging techniques) and altered cerebrospinal fluid (CSF) dynamics. Infusion tests are one of the available procedures to study CSF circulation in patients with clinical and radiological features of hydrocephalus. In them, intracranial pressure (ICP) is deliberately raised and CSF circulation disorders evaluated through measurements of the resulting ICP. In this study, we analysed seventy-seven ICP signals recorded during infusion tests using four spectral-based parameters: median frequency (MF) and relative power (RP) in three frequency bands. These measures provide a novel perspective for the analysis of ICP signals in the frequency domain. Each signal was divided into four artefact-free epochs (corresponding to the basal, early infusion, plateau and recovery phases of the infusion study). The four spectral parameters were calculated for each epoch. We analysed differences between epochs of the infusion test and correlations between these epochs and patient data. Statistically significant differences (p<1.7×10-3, Bonferroni-corrected Wilcoxon signed-rank tests) were found between epochs of the infusion test using MF and RP. Furthermore, some spectral parameters (MF in the basal phase, RP for the first frequency band and in the early infusion phase, RP for the second frequency band and in all phases of the infusion study and RP in the third frequency band and in the basal phase) revealed significant correlations (p<0.01) between epochs of the infusion test and signal amplitude in the basal and plateau phases. Our results suggest that spectral analysis of ICP signals could be useful for understanding CSF dynamics in hydrocephalus.

Authors: Ferraro F, Marano E, Petruzzi J, Tedeschi E, Santulli L, Elefante A.

Spontaneous intracranial hypotension is a rare condition caused by spontaneous cerebrospinal fluid leak. It is characterised by orthostatic headache, diffuse pachymeningeal enhancement on brain imaging and low cerebrospinal fluid pressure. Seven patients with spontaneous intracranial hypotension were treated conservatively: of these, four responded to drug treatment and three underwent a lumbar autologous epidural blood patch (EBP). A complete response was obtained in two patients after a single EBP; one patient underwent a second EBP and then became asymptomatic. Clinical improvement coincided with a dramatic reduction of pachymeningeal enhancement. The aetiology and brain imaging findings, and the technique and effectiveness of EBP are discussed.

Authors: Kim JB, Kwon DY, Park MH, Kim BJ, Park KW.

Headache is the most common symptom of cerebral venous thrombosis (CVT); however, the detailed underlying mechanisms and characteristics of headache in CVT have not been well described. Here, we report two cases of CVT whose primary and lasting presentation was orthostatic headache, suggestive of decreased intracranial pressure. Contrary to our expectations, the headaches were associated with elevated cerebrospinal fluid (CSF) pressure. Magnetic resonance imaging and magnetic resonance venography showed characteristic voiding defects consistent with CVT. We suggest that orthostatic headache can be developed in a condition of decreased intracranial CSF volume in both intracranial hypotensive and intracranial hypertensive states. In these cases, orthostatic headache in CVT might be caused by decreased intracranial CSF volume that leads to the inferior displacement of the brain and traction on pain-sensitive intracranial vessels, despite increased CSF pressure on measurement. CVT should be considered in the differential diagnosis when a patient complains of orthostatic headache.

Authors: Kim MN, Edlow BL, Durduran T, Frangos S, Mesquita RC, Levine JM, Greenberg JH, Yodh AG, Detre JA.

INTRODUCTION: Head-of-bed manipulation is commonly performed in the neurocritical care unit to optimize cerebral blood flow (CBF), but its effects on CBF are rarely measured. This pilot study employs a novel, non-invasive instrument combining two techniques, diffuse correlation spectroscopy (DCS) for measurement of CBF and near-infrared spectroscopy (NIRS) for measurement of cerebral oxy- and deoxy-hemoglobin concentrations, to monitor patients during head-of-bed lowering.