Subarachnoid hemorrhage from vertebral artery dissecting aneurysms involving the origin of the posteroinferior cerebellar artery: report of two cases and review of the literature

OBJECTIVE AND IMPORTANCE

Few reports have been published on ruptured vertebral artery dissecting aneurysms in which the posteroinferior cerebellar artery (PICA) arises from the aneurysm wall, and there is ongoing debate as to the proper management of this type of aneurysm. This article describes two patients.

CLINICAL PRESENTATION

Both patients presented with subarachnoid hemorrhage and were admitted to our institution on the day of rupture. Computed tomography revealed that the subarachnoid hemorrhage was located mainly in the posterior fossa. Cerebral angiography demonstrated a vertebral dissecting aneurysm involving the origin of the PICA. In one patient, the PICA was very large.

INTERVENTION

One patient was treated by trapping, with the PICA involved in the trapped segment. Postoperatively, the patient experienced transient mild hoarseness and dysphasia but recovered completely. The other patient, whose PICA was very large, was initially treated by endovascular proximal occlusion. This resulted in marked enlargement of the distal part of the aneurysm, indicating a need for surgical treatment. A clip was applied to the origin of the PICA after anastomosis of the occipital artery to the PICA. The patient recovered well and was discharged with no neurological deficits.

CONCLUSION

The ideal method of treatment for patients with dissecting aneurysms of the vertebral artery involving the PICA origin is complete isolation of the aneurysm by trapping, with revascularization of the PICA. However, trapping alone is one possible treatment option. If proximal clipping alone is carried out, follow-up angiography is mandatory to observe any changes in the aneurysm.

[Cervical pyogenic spondylodiscitis: 4 cases report and a review of the literature]

We report 4 cases of cervical spondylodiscitis presenting neurological and/or neuroradiological abnormalities. Such a lesion is rare in the cervical spine of adults, but should be suspected when the patient has radiculopathy and/or myelopathy associated with inflammatory signs. We discussed the clinical characteristics and the procedures of the diagnosis and treatment of cervical spondylodiscitis. Early and definitive diagnosis can be achieved by cervical X-ray, MR imaging and biopsy. It is very important to evaluate the pyogen for the lesion by needle biopsy. When the patient has the compression of the spinal cord and/or nerve roots and the neurological findings of radiculopathy and/or myelopathy, surgical exploration and decompression of the spinal cord and/or nerve roots should be carried out as soon as possible. Anterior debridement and fusion should be performed using the effective antibiotics. We were able to achieve good prognosis by treatment following this procedure of diagnosis in the four cases of cervical spondylodiscitis mentioned.

Marked regional heterogeneity in venous oxygen saturation in severe head injury studied by superselective intracranial venous sampling: case report

OBJECTIVE

Continuous monitoring of jugular venous oxygen saturation (SjvO2) is useful in the management of severe head injury. Abnormally high SjvO2 values can be caused by increased cerebral blood flow, decreased cerebral metabolism, brain death, contamination from extracerebral venous blood, or traumatic arteriovenous fistula.

CLINICAL PRESENTATION

A 20-year-old man with severe head injury was diagnosed to have a traumatic dural carotid-cavernous sinus fistula on the day of trauma. Continuous left SjvO2 monitoring from Days 4 to 12 revealed oxygen saturation ranging between 85 and 98%.

INTERVENTION

Superselective intracranial and extracranial venous sampling on Day 5 demonstrated marked regional heterogeneity in venous oxygen saturation as follows: superior sagittal sinus, 95 to 97%; straight sinus, 88%; right transverse sinus, 94%; left transverse sinus, 74%; right SjvO2, 95%; left SjvO2, 89%; the basilar plexus, 99%; right internal jugular vein, 98%; the left internal jugular vein, 94%. Extremely high oxygen saturation in the superior sagittal sinus and basilar plexus was attributed to severe brain damage and carotid-cavernous sinus fistula, respectively.

CONCLUSION

Although jugular bulb oximetry is useful in the management of severe head injury, high oxygen saturation values should be interpreted with caution because they cannot show the intracranial heterogeneity of venous oxygen saturation.

Dual origin of the vertebral artery--case report

A 27-year-old female presented with dual origin of the left vertebral artery. Twenty-six cases of this rare congenital vascular anomaly have been reported. In general, the medial leg of the dual origin of the vertebral artery enters a higher transverse foramen (usually the fifth or less frequently the fourth) than the lateral leg, which usually enters the sixth. Exceptions to this rule occur when the medial and lateral legs of the right vertebral artery enter the right seventh and sixth transverse foramina, respectively. This congenital vascular anomaly has diagnostic and therapeutic implications in any intervention involving the proximal vertebral artery.

Thin-filament-binding domains of cardiac and fast skeletal muscle troponin I isoforms as studied by epitope tagging

We examined the binding domains of cardiac and fast skeletal muscle troponin I (CTnI and FTnI, respectively) to myofibrils (MFs). Deletion mutants containing CTnI amino acid residues 1-79, 43-207 and 80-207 (CTnI-head, CTnI-tail-I and CTnI-tail-2, respectively) and FTnI amino acid residues 1-54 and 55-182 (FTnI-head and FTnI-tail, respectively) were transiently expressed in cardiac and fast skeletal muscle cells. To monitor the intracellular localization of these exogenously introduced truncated TnIs, epitope tagging was used. CTnI-tail-1 was incorporated into cardiac MFs specifically, but CTnI-tail-2 was not assembled onto any MFs examined. This suggests that there is no potent actin filament-binding site in CTnI-tail-2. Since CTnI-tail-1 has an amino acid extension (CTnI residues 43-79) whose sequence is longer than that of CTnI-head-2; it appears that this sequence extension is important in binding to cardiac MFs. FTnI-tail, containing the inhibitory domain of actomyosin ATPase, showed intensive and specific incorporation into fast MFs. FTnI-tail was a homologous fragment of CTnI-tail-2, but the binding patterns of these two domains differed greatly from each other. It is possible that the absence of potent binding affinity of CTnI-tail-2 corresponding to the inhibitory domain of actomyosin ATPase is advantageous for continuous cardiac muscle contraction, since a potent inhibitory activity is a serious obstacle to cardiac muscle contraction. It can be assumed that distinctive binding ability of functional domains of TnI-tails reflect unique adaptations to muscles with different physiological properties.

Variations of the extensor indicis muscle and tendon

Variations of the extensor indicis muscle were examined in 164 hands from 86 Japanese cadavers. Anomalous cases exhibiting supernumerary muscles or tendons were found in 22 hands. These variations were classified into four types: type 1, an additional tendon slip from the extensor indicis tendon; type 2, an extensor indicis radialis or extensor pollicis et indicis accessorius; type 3, an extensor medii proprius with or without extensor medii brevis; and type 4, an extensor indicis radialis and extensor medii proprius. The extensor medii proprius was the most common variation, followed by extensor indicis radialis. There were no clear differences in incidence of variations between men and women or between right and left hands. When variations were bilateral, both sides were identical or similar in type.

Brachial plexus and supraclavicular nerve injury caused by manual carotid compression for spontaneous carotid-cavernous sinus fistula

BACKGROUND

Manual carotid compression is an established treatment for a spontaneous carotid-cavernous sinus fistula unless emergency treatment is required for it.

CASE REPORT

A 63-year-old woman presented with a spontaneous carotid-cavernous sinus fistula. Manual carotid compression of 5 minutes duration, twice a day, for 10 days resulted in injury to the upper trunk (C 5-6) of the brachial plexus and the supraclavicular nerve (C 3-4), which subsequently resolved within a month after cessation of the procedure.

CONCLUSION

It is important to know the possible neurological complications of manual carotid compression.

Photoregulation of the Formation and Dissociation of a DNA Duplex by Using the cis-trans Isomerization of Azobenzene

The duplex-forming activity of an oligonucleotide has been photoregulated by making use of the isomerization of an azobenzene moiety in the side chain. When the azobenzene moiety is isomerized from the trans form to the cis form upon photoirradiation, the melting temperature of the duplex between the oligonucleotide and its complementary counterpart is significantly lowered, and the duplex is largely dissociated into two single-stranded oligonucleotides (shown schematically).

Fusiform vertebral artery aneurysms as a cause of dissecting aneurysms. Report of two autopsy cases and a review of the literature

Two autopsy cases of angiographically determined fusiform aneurysms of the vertebral arteries (VAs) are reported and the appropriate literature is reviewed to investigate the pathological characteristics of both fusiform and dissecting VA aneurysms and the pathogenesis of dissecting aneurysms. One patient had suffered a subarachnoid hemorrhage (SAH) due to dissection of a previously documented incidental fusiform aneurysm. The other patient had harbored incidental fusiform aneurysms coexistent with a ruptured aneurysm of the posterior inferior cerebellar artery. The location and pathological features of the aneurysms were similar in the two cases. The aneurysms in both cases displayed intimal thickening, disruption of the internal elastic lamina, and degeneration of the media. A mural hemorrhage and patchy calcification were also found in the case that included SAH. Based on their pathological investigation of these two cases and a review of reported cases, the authors propose that incidental fusiform aneurysms in the VAs are characterized by weakness in the internal elastic lamina and, therefore, have the potential to become dissecting aneurysms, resulting in a fatal prognosis. This suggests that long-term control of blood pressure is mandatory in patients with incidental fusiform aneurysms in the VAs.

Gamma knife surgery for skull base meningiomas. The effectiveness of low-dose treatment

BACKGROUND

The surgical removal of skull base meningiomas has a high morbidity rate, even by modern microsurgical standards. We evaluated the results of gamma knife surgery for skull base meningiomas using a relatively low radiation dose for the tumor margins.

METHODS

We reviewed 24 cases of skull base meningiomas during a 30-month period. The locations of the tumors were the petroclival region in 11 cases, the cavernous sinus region in 9 cases, and the cerebellopontine angle region in 4 cases. Eight patients (33%) had been operated on previously and fourteen patients (67%) had been treated by neuroimaging. The marginal doses for the tumors were 8 Gy to 15 Gy (median, 10.6 Gy). A large petroclival tumor 58 mm in diameter was treated with a staged treatment protocol with a 6-month interval between treatments.

RESULTS

Tumor regression was observed in 46% of the patients imaged during the follow-up period (median, 17.1 months). No patients revealed tumor growth in the follow-up period (100% tumor control rate). Eleven patients (46%) had improved clinically by the time of the follow-up examinations. Preexisting cranial nerve deficit in one patient worsened because of radiation injury.

CONCLUSION

Although a longer follow-up period is required, the relatively low minimum tumor radiation dose treatment for skull base meningiomas using a gamma knife seems to be an effective treatment with low morbidity.

High incidence of persistent primitive arteries in moyamoya and quasi-moyamoya diseases

This study investigated the incidences of persistent primitive arteries in patients with moyamoya disease, unilateral moyamoya disease, and quasi-moyamoya disease. Cerebral angiograms of 50 patients (39 moyamoya disease patients, 6 unilateral moyamoya disease patients, and 5 quasi-moyamoya disease patients) were retrospectively reviewed. There were 35 females and 15 males, aged from 3 to 63 years (mean 27.4 years). Persistent primitive carotid-basilar artery anastomoses were observed in three patients: primitive hypoglossal artery in one moyamoya disease patient, primitive trigeminal artery variant in one unilateral moyamoya disease patient, and an anastomosis between the accessory meningeal artery and the anterosuperior cerebellar artery in one quasi-moyamoya disease patient. The ophthalmic artery originated from the middle meningeal artery in three moyamoya and two quasi-moyamoya disease patients. The incidence of the persistent primitive arteries is significantly higher in patients with moyamoya disease (10.7%) and quasi-moyamoya disease (60%) than in patients with other disease (0.67%) (p < 0.001), so congenital factors may be important in the pathogenesis of moyamoya disease.

Myofibrillogenesis in the developing chicken heart: assembly of Z-disk, M-line and the thick filaments

Myofibrillogenesis in situ was investigated by confocal microscopy of immunofluorescently labelled whole mount preparations of early embryonic chicken heart rudiments. The time-course of incorporation of several components into myofibrils was compared in triple-stained specimens, taken around the time when beating starts. All sarcomeric proteins investigated so far were already expressed before the first contractions and myofibril assembly happened within a few hours. No typical stress fibre-like structures or premyofibrils, structures observed in cultured cardiomyocytes, could be detected during myofibrillogenesis in the heart. Sarcomeric proteins like (α)-actinin, titin and actin were found in a defined localisation pattern even in cardiomyocytes that did not yet contain myofibrils, making up dense body-like structures. As soon as the heart started to beat, all myofibrillar proteins were already located at their exact position in the sarcomere. The maturation of the sarcomeres was characterised by a short delay in the establishment of the pattern for M-line epitopes of titin with respect to Z-disk epitopes and the incorporation of the M-line component myomesin, which preceded that of myosin binding protein-C. Thus dense body-like structures, made up of titin, (α)-actinin and actin filaments serve as the first organised complexes also during myofibrillogenesis in situ and titin functions as a ruler for sarcomere assembly as soon as its C termini have become localised. We suggest that assembly of thin and thick filament occurs independently during myofibrillogenesis in situ and that myomesin might be important for integrating thick filaments with the M-line end of titin.

Transumbilical embolization of a congenital dural arteriovenous fistula at the torcular herophili in a neonate. Case report

A neonate, in whom a congenital cerebral vascular anomaly had been diagnosed prenatally, exhibited progressive high-output congestive heart failure soon after birth. Cerebral angiography revealed a congenital dural arteriovenous fistula (AVF) with a huge dural lake located at the torcular herophili. In addition to the meningeal blood supply, an unusual pial blood supply from all cerebellar arteries was observed to feed the fistula. The patient was treated by repeated transarterial and transvenous embolization through the umbilical venous route. To the authors' knowledge, neither the existence of a congenital dural AVF at the torcular herophili presenting with an enormous pial blood supply or the technique of trans-umbilical venous intervention has been reported in the literature.

An additional variant of the persistent primitive trigeminal artery: accessory meningeal artery--antero-superior cerebellar artery anastomosis associated with moyamoya disease

Persistent embryological carotid-basilar anastomoses are rare. There has been no report on persistent anastomosis between the accessory meningeal artery and the antero-superior cerebellar artery. We describe a 3-year-old boy with moyamoya disease manifesting such a congenital vascular anomaly, namely, a large anastomosis between the accessory meningeal artery and the antero-superior cerebellar artery associated with marked hypoplasia of the basilar artery. This persistent vascular anomaly is considered embryologically as an additional variant of the persistent primitive trigeminal artery, i.e., a "stapedo-trigemino-cerebellar" variant.

[Application of ultrafast 3D-CT in cervical spine injury]

The authors investigated the usefulness of the ultrafast three-dimensional computed tomography (UF-3D-CT) in cervical spine injury. At Osaka City General Hospital, between April 1995 and March 1998, the authors examined 38 patients with cervical spine injury using UF-3D-CT. The ultrafast CT reduces scanning time. There were no complications associated with the examination. We examined 12 patients with vertebral body fracture, 11 patients with lamina fracture, 8 cases with subluxation including locking facet, 2 patients with atlanto-axial dislocation and 8 patients without bony abnormality. Results suggested that UF-3D-CT was very useful for helping us to understand the bony deformity and the relationship between the bone and the important vessels. UF-3D-CT is very useful for preoperative evaluation and pathophysiological evaluation in cervical spin injury.

Serial MR observation of cortical laminar necrosis caused by brain infarction

To examine the chronological changes characteristic of cortical laminar necrosis caused by brain infarction, 16 patients were repeatedly examined using T1-, T2-weighted spin-echo, T2*-weighted gradient echo, fluid attenuated inversion recovery (FLAIR) images, and contrast enhanced T1-weighted images at 1.0 or 1.5 T. High intensity cortical lesions were visible on the T1-weighted images from 2 weeks after ictus and became prominent at 1 to 3 months, then became less apparent, but occasionally remained at high intensity for 2 years. High intensity cortical lesions on FLAIR images became prominent from 1 month, and then became less prominent from 1 year, but occasionally remained at high intensity for 2 years. Subcortical lesions did not display high intensity on T1-weighted images at any stage. On FLAIR images, subcortical lesions initially showed slightly high intensity and then low intensity from 6 months due to encephalomalacia. Cortical lesions showed prominent contrast enhancement from 2 weeks to 3 months, but subcortical lesions were prominent from 2 weeks only up to 1 month. T2*-weighted images disclosed haemosiderin in 3 of 7 patients, but there was no correlation with cortical short T1 lesions. Cortical laminar necrosis showed characteristic chronological signal changes on T1-weighted images and FLAIR images. Cortical short T1 lesions were found not to be caused by haemorrhagic infarction.

Progress towards synthetic enzymes for phosphoester hydrolysis

Synthesis of artificial enzymes for catalyzing phosphoester hydrolysis has been attracting interest for a long time. The remarkable discovery that lanthanide ions catalyze the hydrolysis of DNA and RNA spurred the trend. Currently, progress is being made, mainly in the preparation of homogeneous catalysts, the promotion of catalytic activity by using acid/base cooperation within catalysts, the detailed understanding of the reaction mechanisms involved, and the design of artificial enzymes expressing high specificity and catalytic turn-over.

Rupture mechanism of a thrombosed slow-growing giant aneurysm of the vertebral artery--case report

A 76-year-old male developed left hemiparesis in July 1991. The diagnosis was thrombosed giant vertebral artery aneurysm. He showed progressive symptoms and signs of brainstem compression, but refused surgery and was followed up without treatment. He died of rupture of the aneurysm and underwent autopsy in March 1995. Histological examination of the aneurysm revealed fresh clot in the aneurysmal lumen, old thrombus surrounding the aneurysmal lumen, and more recent hemorrhage between the old thrombus and the inner aneurysmal wall. The most important histological feature was the many clefts containing fresh blood clots in the old thrombus near the wall of the distal neck. These clefts were not lined with endothelial cells, and seemed to connect the lumen of the parent artery with the most peripheral fresh hemorrhage. However, the diameter of each of these clefts is apparently not large enough to transmit the blood pressure of the parent artery. Simple dissection of the aneurysmal wall by blood flow in the lumen through many clefts in the old thrombus of the distal neck may be involved in the growth and rupture of thrombosed giant aneurysms of the vertebral artery.

Traumatic carotid cavernous sinus fistula: serial angiographic studies from the day of trauma

BACKGROUND AND PURPOSE

The purpose of this study was to ascertain the early angiographic features characteristic of traumatic carotid cavernous sinus fistulas (CCFs).

METHODS

Eight patients with severe craniofacial injuries underwent emergency diagnostic and therapeutic angiography for intractable oronasal bleeding, starting on an average of 6.7 hours after trauma. Carotid angiograms and the clinical manifestation of traumatic CCFs were then reviewed retrospectively to determine characteristic angiographic features.

RESULTS

In four of the eight patients, no arteriovenous fistulas were found in the cavernous sinuses and symptomatic CCF did not occur during the follow-up period. In the remaining four patients, dural CCFs (Barrow type B) were observed, unilaterally in three patients and bilaterally in one. One of these four patients subsequently became symptomatic and required transarterial coil embolization.

CONCLUSION

Traumatic dural CCFs are frequently observed in the early stage of severe craniofacial trauma, if investigated. Although their spontaneous disappearance is known, some of these do become symptomatic and need treatment.