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The Petrosquamosal Sinus: CT and MR Findings of a Rare Emissary Vein
K. Marsot-Dupucha, M. Gayet-Delacroixa, M. Elmaleh-Bergèsa, F. Bonnevillea and P. Lasjaunias a
+ Author Affiliations

aFrom Service de NeuroRadiologie (K.M-D., F.B., P.I.), Hôpital Bicêtre, Le Kremlin-Bicêtre, Service de Radiologie (M.G-D.), Hôtel Dieu, Nantes, and Service de Radiologie (M.E-B.), Hôpital Robert Debré, Paris, France.
Abstract

BACKGROUND AND PURPOSE: Morphologic changes in the dural sinuses and emissary veins of the posterior fossa relate closely to the development of the brain. We report characteristic findings of imaging in six patients with a rare and forgotten emissary vein called the petrosquamosal sinus (PSS).

METHODS: From a larger group of patients with ear abnormalities, we selected six patients from three ENT imaging centers, because they had CT features suggestive of a PPS. This was the criterion for inclusion in this retrospective study. They were explored by high-resolution CT (HRCT) of the temporal bone. MR venography was performed in three patients to determine the presence and patency of the emissary vein.

RESULTS: The PPS was bilateral in two patients and unilateral in the other four. It affected mainly the left side (left:right ratio, 5:3). Three patients had associated inner ear (n = 2) or middle ear malformations (n = 1). Five of six patients had jugular vein hypoplasia, with development of emissary mastoid veins in three patients.

CONCLUSION: Petrosquamosal sinus can be identified on HRCT in a typical location. It is encountered more frequently in patients referred for congenital abnormalities of the skull base. This rare anatomic variant should be assessed before surgical treatment, because proper identification of these large venous channels would be of interest to the surgeon.

Internal jugular vein (IJV) abnormalities are a newly identified risk factor for cerebral venous sinus thrombosis (CVST), a new study shows.

Dr. Jia studied 51 consecutive patients with CVST and 30 healthy control participants using color Doppler flow imaging to evaluate the diameter and maximum flow velocity (Vmax) at 3 points along the IJV — at its influx into the innominate vein (J1), at the point of the superior thyroid vein influx into the IJV (J2), and at the bifurcation level of the common carotid artery (J3).

Among the 51 patients, she identified 31 (60.8%) with IJV abnormalities. Nineteen (61.3%) patients had annulus stenoses, 9 (29.0%) had hypoplastic IJVs, 2 (6.5%) had a thrombosis in the IJV, and 1 (3.2%) had an anomalous valve within the vein. No anomalies were detected in the remaining 20 patients.

New Association

Session moderator Turgut Tatlisumak, MD, PhD, vice chairman of the Department of Neurology and director of the Acute Stroke Unit at Helsinki University Central Hospital in Helsinki, Finland, called the study "very interesting" and said no one had looked at the association of IJV abnormalities and CVST before.

However, because the central venous sinus can extend into the IJV and because patients were evaluated for IJV abnormalities only after a CVST, there is a question of whether the CVST could have caused some of the IJV anomalies. Therefore, Dr. Tatlisumak suggested a prospective study would be needed to resolve this point.

Variability in the Cross-Sectional Area and Narrowing of the Internal Jugular Vein in Patients Without Multiple Sclerosis
Karen Buch1, Raymond Groller1, Rohini N. Nadgir1, Akifumi Fujita1, Muhammad M. Qureshi1,2 and Osamu Sakai1,2,3

Affiliations: 1Department of Radiology, Boston Medical Center, Boston University School of Medicine, 820 Harrison Ave, FGH Bldg, 3rd Fl, Boston, MA 02118.
2Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA.
3Department of Otolaryngology–Head and Neck Surgery, Boston Medical Center, Boston University School of Medicine, Boston, MA.
Citation: American Journal of Roentgenology. 2016;206: 1082-1086. 10.2214/AJR.15.14689

ABSTRACT :
OBJECTIVE. Chronic cerebrospinal vascular insufficiency is a proposed condition of intraluminal stenosis of the internal jugular vein (IJV) that impedes venous flow from the brain. Calculations of IJV stenosis are vague and described in veins with at least a 50% reduction in IJV caliber at a specific level. The purpose of this study was to assess normal changes in anatomic caliber of the course of the IJV in a generalized population.

MATERIALS AND METHODS. Images from 500 consecutive contrast-enhanced neck CT studies performed in January–July 2011 were reviewed. Cross-sectional areas of the IJV were calculated at the jugular foramen, C1–C7 levels, and jugular angles bilaterally. Patients were excluded if they had severely motion-limited studies; limited clinical data; a history of multiple sclerosis, neck mass, or neck dissection; or known IJV occlusion. Normalized IJV cross-sectional areas at each level were compared with an averaged normalized cross-sectional area from all patients at each level.

RESULTS. Greater than 50% narrowing compared with a normalized average was found in 133 of 363 patients (36.6%) and was seen at all IJV levels. In 36.1% of patients this narrowing occurred at the C1 level. Most of the areas of narrowing greater than 50% occurred above the C4 level.

CONCLUSION. The IJV has marked variability in its course in the neck. Areas of narrowing greater than 50% occur most commonly in the upper cervical and skull base regions. Given the normal anatomic variations in IJV caliber, caution should be used when making the diagnosis of and treating IJV stenosis.



Read More: http://www.ajronline.org/doi/abs/10.2214/AJR.15.14689

Cerebral venous drainage and its impact on cerebrospinal fluid motion: a retrospective
review of the work of the ISNVD
Clive Beggs 1,2

1. Buffalo Neuroimaging Analysis Center, University at Buffalo, 100 High St., Buffalo, NY 14203, NY, USA;
2. Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, LS1 3HE, UK

Since the inception of the Society, members of the ISNVD have pioneered work on the interaction
between the cerebrospinal fluid (CSF) system and the cerebral venous drainage system, and its
possible involvement in neurological disease. Initial investigations by ISNVD members involved the
association between multiple sclerosis (MS) and increased CSF pulsatility in the Aqueduct of
Sylvius (AoS) [1,2]. This was followed by a study that reported a similar phenomenon in healthy
adults without neurologic disease [3], suggesting that increased aqueductal pulsatility might be
primarily due to altered intracranial biomechanics associated with constricted cerebral venous
drainage, rather than neuronal decay. This opinion was reinforced by Zivadinov et al., [4] who
performed venous angioplasty on MS patients diagnosed with chronic cerebrospinal venous
insufficiency (CCSVI) and found that the procedure normalized CSF pulsatility in the AoS.
Independent work by Zamboni and co-workers [5] had already shown a 63% increase in the
hydraulic resistance of the extracranial venous pathways in MS patients diagnosed with CCSVI [6].
As such, this body of work indicated a direct biomechanical link between cerebral venous outflow
and the motion of the CSF pulse in the AoS, a link that was later confirmed by Lagana, Beggs and
co-workers in a MRI study that demonstrated a strong positive correlation (r=0.966, P<0.001)
between the intracranial venous blood volume and the aqueductal CSF volume in healthy young
adults [7].

Although the clinical implications of this work are yet to be fully understood, increased CSF
pulsatility in the AoS has been associated with early stage white matter damage (WM) in healthy
individuals without neurologic disease [8]. As such, this appears to support the work of Chung et al
[9], who found jugular venous reflux (JVR) to be associated with more severe age-related WM
changes in the elderly. Collaborative work between Chung, Zivadinov, Beggs and there co-workers
also revealed JVR to be associated with intracranial structural changes in Alzheimer's disease
patients, which resulted in increased gray matter volume [10]. This unexpected finding, which has
since been mirrored in a subsequent study investigating aging in healthy individuals [11], suggests
that venous drainage anomalies may have far reaching neurological implications, leading to
increased venous blood retention in the cranium, something that has the potential to alter the
dynamics of the intracranial CSF system.