Ophthalmic rete mirabile: the first angiographic documentation of embryonic ophthalmic collaterals in a patient with moyamoya disease. A case report

SUMMARY

Plexiform vascular networks of the rete mirabile in humans are rare but can be observed in some vertebrates such as cobaye, cat, cow and sheep. Each set of embryonic arteries can be a potential source of these vascular networks which reconstitute the distal flows in segmental agenesis of internal carotid or vertebral arteries especially in patients with PHACE (posterior fossa malformation of the brain, facial hemangiomas, arterial anomalies, cardiac anomalies with coarctation of aorta, and eye abnormalities) syndrome. Ophthalmic rete mirabile has been found in some mammals such as camel, deer and avian species of pigeon, Hawaiian seabirds and deep-water fish of the cod other than human. We describe the first human case of ophthalmic rete mirabile confirmed on angiography in a patient with moyamoya disease. These findings are the first description in the English literature as far as we know. The clinical implications with moyamoya disease will be briefly discussed according to the embryologic development of cranial arteries.

Anatomic variations of the superficial middle cerebral vein: embryologic aspects of the regressed embryonic tentorial sinus

SUMMARY

The embryonic tentorial sinus usually regressses during postnatal development, but its typical prenatal drainage patterns and intradural anastomoses can be depicted as various developmental phenotypic representations. Here, we tried to clarify the variant types of the superficial middle cerebral vein (SMCV) associated with the embryonic tentorial sinus. Total 41 patients and 82 hemispheres were included in this study. CT angiography was performed in all patients as screening for cerebrovascular disease or other intracranial disorders. A separate workstation and 3D software were used to evaluate the cranial venous systems with 3D volume rendering techniques, thin-slice MIP images, and MPR techniques for the analysis of its complicated angioarchitecture. Variations of the SMCV were classified according to the developmental alterations of the embryonic tentorial sinus, including sphenoparietal sinus (cranial remnant of tentorial sinus), basal sinus (floor of middle cranial fossa), petrosal and caudal remnant of the tentorial sinus. Secondary intradural anastomoses of cavernous and superior petrosal sinuses were also evaluated for the efferent pathways. The most frequent type of remnant tentorial sinus, sphenoparietal sinus was present in 49% (40/82) of hemispheres examined. Other regressed patterns of embryonic tentorial sinus were also identified in 38% (31/82): nine caudal remnant type around the transverse sinus, 12 petrosal type, one basal type, five unclassified cases, and mixed type were found in four cases. Secondary intradural cavernous sinus anastomosis was seen in 44% (36/82), however the most prevalent pattern was no anastomosis (46/82) with cavernous sinus. Only one case of superior petrosal sinus anastomosis was found in this series associated with basal sinus type. Anatomic variations of SMCV can be clearly demonstrated with embryologic aspects of the tentorial sinus according to its developmental regression and postnatal secondary adaptations of cerebral venous drainage.

Anatomic variations of the deep cerebral veins,tributaries of Basal vein of rosenthal: embryologic aspects of the regressed embryonic tentorial sinus

SUMMARY

The embryonic tentorial sinus regresses at the 60-80 mm embryologic stage and most of the deep venous channels constitute the basal vein of Rosenthal (BVR). Persisting remnants of the embryonic tentorial sinus can be seen in the adult configuration of the BVR.We tried to explain the anatomic representations of the BVR associated with the remnant embryonic tentorial sinus. A total 41 patients and 82 hemispheres were included in this study. CT angiography was performed in all patients as screening for cerebrovascular disease or other intracranial disorders. A separate workstation and 3D software were used to evaluate the cranial deep venous systems with 3D volume rendering techniques, thin-slice MIP images, and MPR techniques for the analysis of complicated angioarchitecture. Variations of the BVR were classified according to the developmental alterations of efferent pathways into four groups: telencephalic group (A) including tributaries of the uncal vein, inferior frontal vein, anterior communicating vein, and inferior striatal vein; diencephalic group (B) of the interior ventricular vein and peduncular vein; tegmental bridging group (C) of the longitudinal LMV anastomosis; tectal group (D) of the superior vermian vein and internal occipital vein in relation to the Galenic connection. The BVR constituted from the embryonic tentorial sinus was also assessed and the developmental aspects reviewed. Remnant embryonic tentorial sinus was visualized in 12% (10/82) of hemispheres, all of them invariably connected with the telencephalic (A) and diencephalic (B) groups. Most of those connections (9/10) to basal venous tributaries originated from the medial tentorial sinus except one case from the lateral tentorial sinus. No Galenic connections of the BVR were identified in 10% (8/82). Various tributaries of the BVR were classified as: Telencephalic group (A) 43% (35/82), Diencephalic group (B) 35% (29/82), Bridging group (C) 11% (9/82), and Tectal group (D) 6% (5/82). Four cases (5%) were unclassified and revealed only small basal tributaries of the BVR without connection to the great vein of Galen. Anatomic variations of the BVR connected with persistent embryonic tentorial sinus could often be demonstrated in adult configurations considering the embryologic aspects of developmental regression and secondary cerebral venous adaptations.

Combined spinal intramedullary arteriovenous malformation and lipomyelomeningocele

Combined spinal arteriovenous malformation and lipomyelomeningocele are extremely rare. We present a rare combined case of a lipomyelomeningocele with an intramedullary arteriovenous malformation (AVM) occurred at the L3-L4 level in a 30-year-old man who suffered from low back pain radiating to the lower extremities, dysuria, and frequency for 5 years. The MR studies showed an intradural mass with high-signal intensity on both T1-weighted and T2-weighted images, intermingled with multiple signal-void structures. The mass extended extradurally toward a subcutaneously forming fatty mass on the patient's back. Spinal angiography showed an AVM supplied by the radiculopial branches of the lumbar arteries and drained by tortuous, dilated, perimedullary veins. Endovascular embolization and surgical resection were performed.

Multifocal cerebral venous malformations and associated developmental venous anomalies in a case of blue rubber bleb nevus syndrome

SUMMARY

We report a sporadic case of probable BRBN (blue rubber bleb nevus syndrome) with multiple CNS (central nervous system) involvement. These features consisted of multiple VMs (venous malformations) and DVAs (developmental venous anomalies) in supratentorial brain, cerebellum, and diencephalon. Since its first description by Bean, there have been many cases of BRBN manifesting with gastrointestinal bleeding with or without associated hemorrhage. Cases with CNS involvement were rarely reported and many of the descriptions were confusing with different terminologies used to describe them such as capillary venous malformation, hemangiomas, and vascular malformations. The lesions illustrated are venous malformations similar to our case. The association of DVA was recognized in some cases; they are likely to be underestimated when revisiting the published case illustrations.Although our case is sporadic, the link with HHT1 is unlikely despite the involvement of the same chromosome (Ch 9).

Transient MR signal changes in patients with generalized tonicoclonic seizure or status epilepticus: periictal diffusion-weighted imaging

BACKGROUND AND PURPOSE

Our purpose was to investigate transient MR signal changes on periictal MR images of patients with generalized tonicoclonic seizure or status epilepticus and to evaluate the clinical significance of these findings for differential diagnosis and understanding of the pathophysiology of seizure-induced brain changes.

METHODS

Eight patients with MR images that were obtained within 3 days after the onset of generalized tonicoclonic seizure or status epilepticus and that showed seizure-related MR signal changes had their records retrospectively reviewed. T1- and T2-weighted images were obtained of all eight patients. Additional diffusion-weighted images were obtained of five patients during initial examination. After adequate control of the seizure was achieved, follow-up MR imaging was performed. We evaluated the signal changes, location of the lesions, and degree of contrast enhancement on T1- and T2-weighted images and the signal change and apparent diffusion coefficient (ADC) on diffusion-weighted images. We also compared the signal changes of the initial MR images to those of the follow-up MR images.

RESULTS

The initial MR images revealed focally increased T2 signal intensity, swelling, and increased volume of the involved cortical gyrus in all eight patients. The lesions were located in the cortical gray matter or subcortical white matter in seven patients and at the right hippocampus in one. T1-weighted images showed decreased signal intensity at exactly the same location (n = 6) and gyral contrast enhancement (n = 4). Diffusion-weighted images revealed increased signal intensity at the same location and focally reduced ADC. The ADC values were reduced by 6% to 28% compared with either the normal structure opposite the lesion or normal control. Follow-up MR imaging revealed the complete resolution of the abnormal T2 signal change and swelling in five patients, whereas resolution of the swelling with residual increased T2 signal intensity at the ipsilateral hippocampus was observed in the other two patients. For one of the two patients, hippocampal sclerosis was diagnosed. For the remaining one patient, newly developed increased T2 signal intensity was shown.

CONCLUSION

The MR signal changes that occur after generalized tonicoclonic seizure or status epilepticus are transient increase of signal intensity and swelling at the cortical gray matter, subcortical white matter, or hippocampus on periictal T2-weighted and diffusion-weighted images. These findings reflect transient cytotoxic and vasogenic edema induced by seizure. The reversibility and typical location of lesions can help exclude the epileptogenic structural lesions.

The usefulness of the new "double-catheter technique" in the treatment of parent artery incorporated wide-necked aneurysm with guglielmi detachable coils. Technical notes

SUMMARY

We describe a technique used to treat a widenecked aneurysm in which the neck is incorporated with the parent artery. The patient was a 54-year-old woman who had suffered a grade III subarachnoid haemorrhage. Angiogram and three-dimensional CT showed a large, widenecked aneurysm of the basilar bifurcation area with the right posterior cerebral artery incorporated in the aneurysm sac. A microcatheter was placed in the right posterior cerebral artery (PCA). Another catheter was placed within the aneurysm lumen. When making a first frame with a GDC, we made sure that the frame of the coil did not overlap the PCA positioned microcatheter. Then, with the microcatheter positioned at the PCA, the angiogram was done. The flow pattern and dye-disappearance time were checked. Subsequent coils were introduced, but not beyond the frame of the first coil to maintain PCA flow. This new "double-catheter technique" represents a viable option for treating wide-necked aneurysms, especially when the parent artery is incorporated in a wide-necked aneurysm and the delineation of the parent artery is impossible.

Posterior interosseous free flap: various types

The posterior interosseous artery is located in the intermuscular septum between the extensor carpi ulnaris and extensor digiti minimi muscles. The posterior interosseous artery is anatomically united through two main anastomoses: one proximal (at the level of the distal border of the supinator muscle) and one distal (at the most distal part of the interosseous space). In the distal part, the posterior interosseous artery joins the anterior interosseous artery to form the distal anastomosis between them. The posterior interosseous flap can be widely used as a reverse flow island flap because it is perfused by anastomoses between the anterior and the posterior interosseous arteries at the level of the wrist. The flap is not reliable whenever there is injury to the distal forearm or the wrist. To circumvent this limitation and to increase the versatility of this flap, we have refined its use as a direct flow free flap. The three types of free flaps used were (1) fasciocutaneous, (2) fasciocutaneous-fascia, and (3) fascia only. Described are 23 posterior interosseous free flaps: 13 fasciocutaneous flaps, 6 fasciocutaneous-fascial flaps, and 4 fascial flaps. There were 13 sensory flaps using the posterior antebrachial cutaneous nerve. The length and external diameter of the pedicle were measured in 35 cases. The length of the pedicle was on average 3.5 cm (range, 3.0 to 4.0 cm) and the external diameter of the artery averaged 2.2 mm (range, 2.0 to 2.5 mm). The hand was the recipient in 21 patients, and the foot in 2. All 23 flaps covered the defect successfully.

Evaluation of embolization effect of hepatocellular carcinoma by hepatic arterial flow study with Tc-99m MAA SPECT

The degree of hepatocellular carcinoma vascularity in eight patients was assessed with Tc-99m MAA radionuclide angiography before and after treatment. For chemoembolization therapy, lipiodol and doxorubicin hydrochloride were administered intraarterially along with Gelfoam particles. The ratio of radioactivity in the hepatocellular carcinoma compared to that in the surrounding uninvolved tissue before therapy was 6.5-19.0 with a mean of 12.0. After therapy, the ratio dropped to 0.5-1.3. Because survival improved significantly after the therapeutic regimen used in these patients, radionuclide Tc-99m MAA angiography appears to be an accurate method for demonstrating successful embolization of the vascular supply in hepatocellular carcinoma.