Basal Vein Research Articles

MRI venous architecture of the thalamus

PurposeOur purpose is to describe the thalamic veins using a novel approach named venous gliography in cases with primary or secondary gliomas of the thalamus. Venous gliography is defined by authors as a method to visualize veins on MRI Brain T1-weighted post contrast scans containing gliomas which have induced regional venous congestion. MethodsRoutine clinical MR Imaging studies were reviewed to assess the presence of thalamic veins in 29 glioma cases. In addition, confocal reconstruction techniques (Anatom-e and Osirix) were used in cases that had thin sections (1.0–1.5mm) post contrast T1 weighted sequences. Multiplanar MIP and confocal volume rendered images were generated to evaluate the thalamic veins in those cases. ResultsUsing venous gliography and confocal reconstruction techniques, two patterns in the venous architecture of the thalamus were documented. First, the branching pattern created by the tributaries of the internal cerebral vein, namely the superior thalamic vein and the anterior thalamic vein, which together formed the superior group of thalamic veins. Second, the pattern created by the un-branched vertically oriented veins, namely the inferior thalamic veins and the posterior thalamic veins, which joined the basal vein of Rosenthal and constituted the inferior group of thalamic veins. ConclusionsVenous gliography combined with the use of confocal reconstruction techniques provided a novel approach to display the thalamic veins that are usually not seen. The understanding of the venous architecture is mandated by the recent research where veins have taken on an important role in the perivenular spread of gliomas.

The Analysis of the Petrosal Vein to Prevent Venous Complications During the Anterior Transpetrosal Approach in the Resection of Petroclival Meningioma

The anterior transpetrosal approach (ATPA) has been used in the resection of petroclival meningioma (PCM) for more than 20 years. Although PCM sometimes involves the petrosal vein and its preservation has been an important issue, the precise risk of petrosal vein sacrifice and subsequent venous complications associated with the use of the ATPA in patients with PCM has not yet been elucidated. We used computed tomographic (CT) digital subtraction venography (DSV) in the retrospective analysis of the petrosal vein and its tributaries in patients with PCM before and after surgery. We also examined the incidence of postoperative venous complications in each of the patients. The detection rate of the petrosal vein and some of its tributaries on CT-DSV in patients with PCM was significantly lower than that in controls. Preoperatively, CT-DSV detected the petrosal vein in 71.8% of patients with PCM. The detected petrosal veins were preserved after the operation in 64.3% of these patients. No venous complications involving petrosal vein were observed in any of the patients. Anastomosis between the petrosal vein and the basal vein via the pontotrigeminal vein was found to be significantly more developed in the patients with PCM compared with the controls. Our study demonstrated that the ATPA could be performed safely on patients with PCM from the viewpoint of venous preservation. Preoperative CT-DSV is important for assessing the petrosal vein and its tributaries to facilitate a safer operation.

Clinical and Anatomic Insights From a Series of Ethmoidal Dural Arteriovenous Fistulas at Barrow Neurological Institute

Ethmoidal dural arteriovenous fistulas (dAVFs) have a malignant natural history and an anatomy that make endovascular therapy challenging. Their uniqueness begs for stratified analyses, but this has largely been precluded by their rarity. We sought to summarize the anatomic, presentation, treatment approaches, and clinical outcomes of patients with these lesions. We reviewed our prospectively maintained institutional database to identify patients diagnosed with ethmoidal dAVFs from January 1, 2000, to December 31, 2015. We evaluated demographic, presentation, angiographic, treatment, and follow-up data. In total, 27 patients with ethmoidal dAVFs underwent endovascular and/or surgical treatment. Mean patient age was 62 years old and there was a male sex predilection (67% men; 2:1 male-female ratio). All dAVFs exhibited direct cortical venous drainage; venous ectasia was present in 59% of cases. Of the dAVFs, 30% drained posteriorly into the basal vein of Rosenthal or the sylvian veins. Embolization with casting of the draining vein was successful in 2 of 9 cases (22%), including 1 successful transvenous case. There were no clinical or permanent complications from embolization; specifically, no patients experienced visual loss after treatment. Surgical treatment with successful dAVF obliteration was carried out in 24 of 24 patients (100%). One patient declined surgical treatment after attempted endovascular embolization. There were no permanent complications after surgical treatment and no cases of wound infection or cerebrospinal fluid leakage. Surgical disconnection remains the gold standard in the treatment of ethmoidal dAVFs. Embolization is a consideration for well-selected cases with favorable arterial or venous access anatomy.

Nonaneurysmal Perimesencephalic Hemorrhage Is Associated with Deep Cerebral Venous Drainage Anomalies: A Systematic Literature Review and Meta-Analysis.

Mechanisms underlying bleeding in nonaneurysmal perimesencephalic SAH remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic SAH and primitive venous drainage of the basal vein of Rosenthal. We performed a meta-analysis to evaluate the relation between primitive basal vein of Rosenthal drainage and nonaneurysmal perimesencephalic SAH. We performed a comprehensive literature search of all studies examining the prevalence of primitive basal vein of Rosenthal drainage in patients with aneurysmal SAH and nonaneurysmal perimesencephalic SAH. Data collected were primitive basal vein of Rosenthal drainage (direct connection of perimesencephalic veins into the dural sinuses instead of the Galenic system) in at least 1 cerebral hemisphere, normal bilateral basal vein of Rosenthal drainage systems, and the number of overall primitive venous systems in the nonaneurysmal perimesencephalic SAH and aneurysmal SAH groups. Statistical analysis was performed by using a random-effects meta-analysis. Eight studies with 888 patients (334 with nonaneurysmal perimesencephalic SAH and 554 with aneurysmal SAH) and 1657 individual venous systems were included. Patients with nonaneurysmal perimesencephalic SAH were more likely to have a primitive basal vein of Rosenthal drainage in at least 1 hemisphere (47.7% versus 22.1%; OR, 3.31; 95% CI, 2.15-5.08; P < .01) and were less likely to have bilateral normal basal vein of Rosenthal drainage systems than patients with aneurysmal SAH (18.3% versus 37.4%; OR, 0.27; 95% CI, 0.14-0.52; P < .01). When we considered individual venous systems, there were higher rates of primitive venous systems in patients with nonaneurysmal perimesencephalic SAH than in patients with aneurysmal SAH (34.9% versus 15.3%; OR, 3.90; 95% CI, 2.37-6.43; P < .01). Patients with nonaneurysmal perimesencephalic SAH have a higher prevalence of primitive basal vein of Rosenthal drainage in at least 1 hemisphere than patients with aneurysmal SAH. This finding suggests a venous origin of some nonaneurysmal perimesencephalic SAHs. A primitive basal vein of Rosenthal pattern is an imaging finding that has the potential to facilitate the diagnosis of nonaneurysmal perimesencephalic SAH.

Basal vein in the posterior incisural space: An anatomical comparison based on autopsy, digital subtraction angiography and computed tomographic venography.

During surgical procedures, the basal vein in the posterior incisural space is susceptible to obstruction. In such circumstances, venous infarction can occur along with venous damage. The aim of this study was to correlate the microanatomy of the basal vein in the posterior incisural space with the digital subtraction angiography (DSA) and computed tomographic venography (CTV). Twenty cadavers and 42 patients were examined in this study. The head of each cadaver was injected with blue-colored gelatin via the internal jugular veins. Venograms for each patient were obtained from the venous phases of DSA or CTV. Compared to the cadavers, in the patients, DSA and CTV revealed 90% and 95% of the basal vein, respectively. According to difference of entrance, three types of basal veins were identified. No statistical difference of typing was found among the cadavers, DSA images and CTV images. On three sides of the cadavers and one side of the CTV images, the basal vein entered the straight sinus through the meningeal vein in the tentorium cerebelli. Preoperative DSA and CTV are useful in the design of individualized surgical approaches and the preservation of the basal vein in the posterior incisural space.

The Role of Endoscopic Assistance in Ambient Cistern Surgery: Analysis of Four Surgical Approaches

We used microscopy with endoscopic assistance to conduct an objective analysis of 4 surgical approaches commonly used in the surgery of the ambient cistern: infratentorial supracerebellar (SC), occipital interhemispheric (OI), subtemporal (ST), and transchoroideal (TC). In addition, we performed a parahippocampalis gyrus resection in the ST context. Each approach (SC, OI, ST, TC) was performed on 3 cadaveric heads (6 sides). After the microscopic anatomic dissection, the 30-degree endoscope was used to explore the exposure. The parahippocampalis gyrus was resected through an ST approach and the exposure was evaluated. The quantitative analysis was based on linear exposure of the vascular structures (linear exposure), such as the posterior choroidal artery (PChA), the P2 and P3 segments of the posterior cerebral artery (PCA) with their branches, the basal vein of Rosenthal, and the area of exposure of the ambient cistern region (area of exposure) limited by points on its superior, mesial, and anterior walls. In all cases, a P value of less than 0.05 was considered significant. There was a significant difference (P < 0.05) in linear exposure of the PCA and medial PChA between microsurgery and endoscopic assistance using the ST approach. This approach also improved the medial, superior, and total exposure of the ambient cistern region. This study demonstrates that endoscope assistance improved exposure of the ambient cistern region when using the ST approach. Endoscopic assistance provided similar surgical exposure compared with ST associated with parahippocampalis resection.

The Lateral Mesencephalic Vein: Surgical Anatomy and Its Role in the Drainage of Tentorial Dural Arteriovenous Fistulae

The lateral mesencephalic vein (LMV) represents an important connection between the infratentorial and supratentorial compartments. It joins the basal vein of Rosenthal and the petrosal system. In our experience with management of tentorial dural arteriovenous fistulas (DAVFs) we have often noted involvement of the lateral mesencephalic vein (LMV) in the venous drainage of these fistulas. We reviewed the clinical and angiographic findings of 26 patients with tentorial DAVFs to study the incidence and pattern of drainage through the LMV. In addition, we reviewed the pertinent literature on the anatomy of the LMV. The LMV was involved in the venous drainage of 31% (8/26) of patients with tentorial DAVFs. The direction of venous drainage through the LMV is more commonly from the infratentorial to the supratentorial compartment. There were no specific clinical symptoms/signs associated with tentorial DAVFs involving the LMV compared with those without LMV involvement. When involved in DAVF drainage, the LMV could be invariably identified on noninvasive imaging studies. We present illustrative clinical/angiographic cases and provide a detailed review of the pertinent clinical anatomy of this important but often neglected intracranial vein. The LMV is a constant venous anastomosis between the supratentorial and infratentorial compartments. Detailed knowledge of the most common variations of the LMV surgical and radiological anatomy has important clinical implications. The vein is an important anatomic landmark during surgery of midbrain lesions. It is often involved in the tentorial DAVF drainage, and it is critical in understanding some "unexpected" venous complications during surgery for posterior fossa lesions.

A Rare Presentation of Bilateral Papilledema in a Patient with Cerebral Arteriovenous Malformation

A 40 year old lady presented with complete loss of vision in one eye and loss of perception of light in other eye since a year. Initially it was associated with constant headache without vomiting for around 3 months. Indirect ophthalmoscopy revealed chronic pale disc edema and dilated and severe tortuous blood vessels. MRI of the brain showed abnormal dilated tortuous vessels in the left temporal region communicating between basal vein and straight sinus. There was absence of flow voids in both sigmoid sinuses. MRI angiography revealed a small feeding artery to the right transverse sinus from posterior branch of middle meningeal artery. Findings suggestive of chronic raised Intra Cranial Tension were very evident. MRI and MRI angiography revealed a rare occurrence of dural arteriovenous malformation with isolated ocular symptoms and thus cerebral AV malformations with bilateral post papilloedemic optic atrophy was diagnosed. Key-words: Papilloedema, Cerebral AV malformation, Optic atrophy, Dural AV Malformation (DAVM)

Radiographic Evaluation and Clinical Implications of Venous Connections Between Dural Arteriovenous Fistula of the Cavernous Sinus and Cerebellum and the Pontomedullary Venous System

The types of cortical venous reflux channels, posterior fossa and pontomesencephalic venous reflux or their connections with the cavernous sinus (CS) are inadequately described in the literature. This study uses angiography, magnetic resonance imaging, and X-ray computed tomography to clarify the possible route of cavernous dural arteriovenous fistulae (CVDAVF) that causes posterior fossa and pontomedullary venous reflux and documents the clinical presentations associated with the reflux. Eighty-six patients with CSDAVF treated at Ramathibodi Hospital, Bangkok, Thailand, during 2009 to 2013 were studied retrospectively. Sixteen cases with posterior fossa and pontomedullary venous reflux were included for analysis. Bridging veins serve as an important pathway for venous reflux from CS to the posterior fossa and brainstem. The uncal vein directly terminates at the CS and has several connecting routes, ranging from the inferior frontal lobes and insula to the posterior fossa through the basal vein of Rosenthal. The petrosal vein was most frequently and easily detected angiographically. It plays a major role in the cerebellar hemispheric venous reflux. Only 1 patient developed brainstem and cerebellar venous congestion, which returned to normal after endovascular treatment. Connections of CS are not limited to intercavernous, ophthalmic veins, sphenoparietal sinuses, and inferior and superior petrosal sinuses. They also occur with complex venous drainages at the base of the frontotemporal lobes, insula, brainstem, and cerebellum. Knowledge of the venous connection of CS is key to understanding the possible locations of venous congestion/hemorrhage and the clinical presentation of patients with CSDAVF.

Adrenal Vein Sampling in Primary Aldosteronism: Sensitivity and Specificity of Basal Adrenal Vein to Peripheral Vein Cortisol and Aldosterone Ratios to Confirm Catheterization of the Adrenal Vein.

To assess the sensitivity and specificity for ratios of adrenal vein cortisol level (Ca) to peripheral vein cortisol level (Cp), adrenal vein aldosterone level (Aa) to peripheral vein aldosterone level (Ap), and combined cortisol and aldosterone levels ("combined ratio") for the detection of successful adrenal vein catheterization ("selectivity") in adrenal vein sampling (AVS) without adrenocorticotropic hormone (ACTH) injection at different cutoff values. This retrospective study was approved by the institutional review board, and informed consent was waived. AVS was performed in 160 consecutive patients (49 women and 111 men; mean age, 53.6 years) between December 1989 and January 2014. Cortisol and aldosterone levels were measured in samples from the adrenal veins and left iliac vein every 5 minutes, two times before (basal) and three times after intravenous cosyntropin (ACTH 1-24) injection. Selectivity was defined by Ca/Cp or Aa/Ap ratio of at least 5 in at least one sampling after ACTH administration. Sensitivity and specificity for the detection of selective adrenal vein catheterization were calculated for basal Ca/Cp ratio, Aa/Ap ratio, and combined ratios for three cutoff values reported in the literature. The McNemar test was used to assess differences in sensitivity and specificity to detect selective adrenal vein catheterization. The sensitivity and specificity for the cutoff values of at least 3, at least 2, and at least 1.1 for the detection of AVS selectivity were respectively 50.4% and 100%, 70.8% and 100%, and 98.5% and 76.9% for Ca/Cp ratio; 61.3% and 100%, 70.8% and 100%, and 94.2% and 53.8% for Aa/Ap ratio; and 75.2% and 100%, 88.3% and 100%, and 99.3% and 46.2% for combined ratios (sensitivity at the ≥2 cutoff value: P < .0001 for combined ratio vs Ca/Cp ratio and for combined ratio vs Aa/Ap ratio). Basal combined ratio has the best sensitivity for the detection of AVS selectivity at all cutoff values, and for all ratios, the cutoff value of at least 2 has the best sensitivity for 100% specificity.

Susceptibility Weighted Imaging and Mapping of Micro-Hemorrhages and Major Deep Veins after Traumatic Brain Injury.

Micro-hemorrhages are a common result of traumatic brain injury (TBI), which can be quantified with susceptibility weighted imaging and mapping (SWIM), a quantitative susceptibility mapping approach. A total of 23 TBI patients (five women, 18 men; median age, 41.25 years old; range, 21.69-67.75 years) with an average Glasgow Coma Scale score of 7 (range, 3-15) at admission were recruited at mean 149 d (range, 57-366) after injury. Susceptibility-weighted imaging data were collected and post-processed to create SWIM images. The susceptibility value of small hemorrhages (diameter ≤10 mm) and major deep veins (right septal, left septal, central septal, right thalamostriate, left thalamostriate, internal cerebral, right basal vein of Rosenthal, left basal vein of Rosenthal, and pial veins) were evaluated. Different susceptibility thresholds were tested to determine SWIM's sensitivity and specificity for differentiating hemorrhages from the veins. A total of 253 deep veins and 173 small hemorrhages were identified and evaluated. The mean susceptibility of hemorrhages was 435±206 parts per billion (ppb) and the mean susceptibility of deep veins was 108±56 ppb. Hemorrhages showed a significantly higher susceptibility than all deep veins (p<0.001). With different thresholds (250, 227 and 200 ppb), the specificity was 97%, 95%, and 92%, and the sensitivity was 84%, 90%, and 92%, respectively. These results show that SWIM could be used to differentiate hemorrhages from veins in TBI patients in a semi-automated manner with reasonable sensitivity and specificity. A larger cohort will be needed to validate these findings.

Angiographic assessment of variants of basal vein of Rosenthal in idiopathic subarachnoid hemorrhage

Previous studies have reported the possible contribution of a primitive variant of the basal vein of Rosenthal (BVR) in the cause of idiopathic subarachnoid hemorrhage (ISAH). The purpose of this study was to assess the drainage patterns of the BVR among ISAH patients. The venous phase at cerebral angiography was retrospectively analyzed in 19 patients with ISAH and then compared with patients with unruptured aneurysms as controls. A relationship was found between ISAH and the presence of a primitive variant. However, the venous configuration effect on bleeding is still unknown.

FMRI measurements of amygdala activation are confounded by stimulus correlated signal fluctuation in nearby veins draining distant brain regions.

Imaging the amygdala with functional MRI is confounded by multiple averse factors, notably signal dropouts due to magnetic inhomogeneity and low signal-to-noise ratio, making it difficult to obtain consistent activation patterns in this region. However, even when consistent signal changes are identified, they are likely to be due to nearby vessels, most notably the basal vein of rosenthal (BVR). Using an accelerated fMRI sequence with a high temporal resolution (TR = 333 ms) combined with susceptibility-weighted imaging, we show how signal changes in the amygdala region can be related to a venous origin. This finding is confirmed here in both a conventional fMRI dataset (TR = 2000 ms) as well as in information of meta-analyses, implying that “amygdala activations” reported in typical fMRI studies are likely confounded by signals originating in the BVR rather than in the amygdala itself, thus raising concerns about many conclusions on the functioning of the amygdala that rely on fMRI evidence alone.

Cerebral Hemodynamic Changes of Mild Traumatic Brain Injury at the Acute Stage

Mild traumatic brain injury (mTBI) is a significant public health care burden in the United States. However, we lack a detailed understanding of the pathophysiology following mTBI and its relation to symptoms and recovery. With advanced magnetic resonance imaging (MRI), we can investigate brain perfusion and oxygenation in regions known to be implicated in symptoms, including cortical gray matter and subcortical structures. In this study, we assessed 14 mTBI patients and 18 controls with susceptibility weighted imaging and mapping (SWIM) for blood oxygenation quantification. In addition to SWIM, 7 patients and 12 controls had cerebral perfusion measured with arterial spin labeling (ASL). We found increases in regional cerebral blood flow (CBF) in the left striatum, and in frontal and occipital lobes in patients as compared to controls (p = 0.01, 0.03, 0.03 respectively). We also found decreases in venous susceptibility, indicating increases in venous oxygenation, in the left thalamostriate vein and right basal vein of Rosenthal (p = 0.04 in both). mTBI patients had significantly lower delayed recall scores on the standardized assessment of concussion, but neither susceptibility nor CBF measures were found to correlate with symptoms as assessed by neuropsychological testing. The increased CBF combined with increased venous oxygenation suggests an increase in cerebral blood flow that exceeds the oxygen demand of the tissue, in contrast to the regional hypoxia seen in more severe TBI. This may represent a neuroprotective response following mTBI, which warrants further investigation.

Changes in glucose and fat metabolism in response to the administration of a hepato-preferential insulin analog.

Endogenous insulin secretion exposes the liver to three times higher insulin concentrations than the rest of the body. Because subcutaneous insulin delivery eliminates this gradient and is associated with metabolic abnormalities, functionally restoring the physiologic gradient may provide therapeutic benefits. The effects of recombinant human insulin (HI) delivered intraportally or peripherally were compared with an acylated insulin model compound (insulin-327) in dogs. During somatostatin and basal portal vein glucagon infusion, insulin was infused portally (PoHI; 1.8 pmol/kg/min; n = 7) or peripherally (PeHI; 1.8 pmol/kg/min; n = 8) and insulin-327 (Pe327; 7.2 pmol/kg/min; n = 5) was infused peripherally. Euglycemia was maintained by glucose infusion. While the effects on liver glucose metabolism were greatest in the PoHI and Pe327 groups, nonhepatic glucose uptake increased most in the PeHI group. Suppression of lipolysis was greater during PeHI than PoHI and was delayed in Pe327 infusion. Thus small increments in portal vein insulin have major consequences on the liver, with little effect on nonhepatic glucose metabolism, whereas insulin delivered peripherally cannot act on the liver without also affecting nonhepatic tissues. Pe327 functionally restored the physiologic portal–arterial gradient and thereby produced hepato-preferential effects.

What is the risk of venous infarction to intra-operative sacrifice of either the superficial or deep cerebral bridging veins?

Dear Editor: In the article entitled “The intracranial bridging veins: a comprehensive review of their history, anatomy, histology, pathology, and neurosurgical implications” by Mortazavi et al [1], the authors state in the section entitled Surgical significance of the bridging veins, “Furthermore, identification of the bridging veins during surgery makes the neurosurgeon aware of avoiding damage to them in order to prevent venous infarction secondary to iatrogenic occlusion of these veins.” Although this is a concept that is widely accepted, one could question what evidence exists to support this conclusion. The most direct route to many midline cerebral lesions is often barred by the presence of superficial or deep bridging veins. Because of the perceived consequence of surgically occluding and dividing these veins, imaging studies are frequently obtained to map a corridor that may be less direct and/or restricted so as to avoid these veins in order to reach the desired destination. This can result in a less than optimal exposure and ability to achieve the ideal outcome be it greater or complete tumor resection or reduced collateral involvement of structures adjacent to the target location. Conventional wisdom predicts venous infarction is likely to occur with obstruction to either the superficial or deep bridging veins [2]. Extensive connections exist between the superficial and deep venous systems with a significant degree of overlap and bidirectional flow as the cerebral veins have no valves [3]. The extensive anastomotic nature of the cerebral venous system allows venous drainage to be altered as needed through the numerous collateral pathways. We have reported on our own experience in a pediatric population of occluding one or more middle-third superior sagittal sinus cortical bridging veins in 63 patients as the initial intracranial step in a transcallosal approach to deep midline tumors without a single incidence of venous infarction [4]. This study was followed by a second publication investigating a retrocallosal approach to pineal lesions wherein superficial bridging veins were sacrificed in seven patients and deep bridging veins (basal vein of Rosenthal, internal cerebral vein, and precentral cerebellar vein) in another three patients with no evidence of venous infarction [5]. In a third publication, we reviewed the clinical and experimental literature regarding the effects of sacrificing the deep cerebral veins and did not find evidence of the dire consequences of venous infarction that conventional wisdom espouses [6]. It is highly suspected that the sequelae attributed to occluding the superficial and deep bridging cerebral veins result from brain retraction, especially against gravity (Fig. 1) [7] and can be avoided by positioning the patient and using an approach wherein gravity is an ally and not an enemy. Using the most direct approach to the region of interest without regard to the location of the bridging cerebral veins is of significant advantage. J. G. McComb Division of Neurosurgery, Children’s Hospital of Los Angeles, 1300 N. Vermont Ave, Doctor’s Tower, Suite 1006, Los Angeles, CA 90027, USA

Extensive basal ganglia edema caused by a traumatic carotid-cavernous fistula: a rare presentation related to a basal vein of Rosenthal anatomical variation

The authors report a very rare presentation of traumatic carotid-cavernous fistula (CCF) with extensive edema of the basal ganglia and brainstem because of an anatomical variation of the basal vein of Rosenthal (BVR). A 45-year-old woman was admitted to the authors' institution for left hemiparesis, dysarthria, and a comatose state caused by right orbital trauma from a thin metal rod. Brain MRI showed a right CCF and vasogenic edema of the right side of the brainstem, right temporal lobe, and basal ganglia. Digital subtraction angiography confirmed a high-flow direct CCF and revealed a hypoplastic second segment of the BVR responsible for the hypertension in inferior striate veins and venous congestion. Endovascular treatment was performed on an emergency basis. One month after treatment, the patient's symptoms and MRI signal abnormalities almost totally disappeared. Basal ganglia and brainstem venous congestion may occur in traumatic CCF in cases of a hypoplastic or agenetic second segment of the BVR and may provoke emergency treatment.

First Report of Myiasis Caused by Cochliomyia hominivorax (Diptera: Calliphoridae) in a Diabetic Foot Ulcer Patient in Argentina

Myiasis is usually caused by flies of the Calliphoridae family, and Cochliomyia hominivorax is the etiological agent most frequently found in myiasis. The first case of myiasis in a diabetic foot of a 54-year-old male patient in Argentina is reported. The patient attended the hospital of the capital city of Tucumán Province for a consultation concerning an ulcer in his right foot, where the larval specimens were found. The identification of the immature larvae was based on their morphological characters, such as the cylindrical, segmented, white yellow-coloured body and tracheas with strong pigmentation. The larvae were removed, and the patient was treated with antibiotics. The larvae were reared until the adults were obtained. The adults were identified by the setose basal vein in the upper surface of the wing, denuded lower surface of the wing, short and reduced palps, and parafrontalia with black hairs outside the front row of setae. The main factor that favoured the development of myiasis is due to diabetes, which caused a loss of sensibility in the limb that resulted in late consultation. Moreover, the poor personal hygiene attracted the flies, and the foul-smelling discharge from the wound favoured the female's oviposition. There is a need to implement a program for prevention of myiasis, in which the population is made aware not only of the importance of good personal hygiene and home sanitation but also of the degree of implication of flies in the occurrence and development of this disease.

The relationship between perimesencephalic subarachnoid hemorrhage and deep venous system drainage pattern and calibrations

Background and purposeThe purpose of this study is to investigate the relationship between Rosenthal basal vein (BVR) type and diameter and perimesencephalic nonaneurysmal subarachnoid hemorrhage (P-SAH). Materials and methodsAneurysmal subarachnoid hemorrhage (A-SAH), P-SAH, and control groups were evaluated, and BVRs were classified by type. BVR diameters in patients were measured. ResultsThere was a statistically significant difference of BVR drainage types between groups (P=.002). BVR diameters of patients with normal drainage pattern in P-SAH group were significantly smaller than those in both other groups (P<.001). ConclusionThere is a relationship between P-SAH and BVR primitive drainage type. P-SAH risk increases in parallel with decreasing caliber of BVR in patients with normal drainage pattern.

Duplex sonography of cerebral blood flow after cardiac arrest—A prospective observational study

AimDespite successful resuscitation, cardiac arrest (CA) often has a poor clinical prognosis. Different diagnostic tools have been established to predict patients’ outcome. However, their sensitivity remains low. Assessment of cerebral perfusion by duplex ultrasound might provide additional information regarding the extent of neuronal damage. The aim of the present study was to analyse the changes of global cerebral blood flow (CBF) and intracranial blood flow parameters in the acute stage after CA and its correlation with patients’ outcome. MethodsWe investigated 54 patients (17–85 years, mean age: 63±17 years) after CA with return of spontaneous circulation on an intensive care unit. All patients received therapeutic hypothermia (TH) for 24h after CA and reanimation. Serial measurements of CBF as well as intracranial blood flow velocities and pulsatility indices of the middle cerebral artery and the basal vein of Rosenthal were performed within the first 10 days using duplex ultrasound. Clinical outcome was measured using the Cerebral Performance Category. ResultsMeasurements were successful in 53 patients. CBF values differed between 210 and 1100ml/min. 24 patients (45%) attained a good outcome. No correlation between CBF or intracranial blood flow characteristics and outcome was found. Neither cerebral hypo- nor hyperperfusion was associated with a fatal outcome. ConclusionCerebral perfusion varies widely after CA. Neither hypo- nor hyperperfusion seems to be an independent risk factor for poor outcome. Duplex ultrasound of cerebral haemodynamics after CA is suitable but probably of limited prognostic value.