Kuniki Eguchi

The Role of the Aryl Hydrocarbon Receptor-Interacting Protein Gene in Familial and Sporadic Pituitary Adenomas

CONTEXT Mutations have been identified in the aryl hydrocarbon receptor-interacting protein (AIP) gene in familial isolated pituitary adenomas (FIPA). It is not clear, however, how this molecular chaperone is involved in tumorigenesis. OBJECTIVE AIP sequence changes and expression were studied in FIPA and sporadic adenomas. The function of normal and mutated AIP molecules was studied on cell proliferation and protein-protein interaction. Cellular and ultrastructural AIP localization was determined in pituitary cells. PATIENTS Twenty-six FIPA kindreds and 85 sporadic pituitary adenoma patients were included in the study. RESULTS Nine families harbored AIP mutations. Overexpression of wild-type AIP in TIG3 and HEK293 human fibroblast and GH3 pituitary cell lines dramatically reduced cell proliferation, whereas mutant AIP lost this ability. All the mutations led to a disruption of the protein-protein interaction between AIP and phosphodiesterase-4A5. In normal pituitary, AIP colocalizes exclusively with GH and prolactin, and it is found in association with the secretory vesicle, as shown by double-immunofluorescence and electron microscopy staining. In sporadic pituitary adenomas, however, AIP is expressed in all tumor types. In addition, whereas AIP is expressed in the secretory vesicle in GH-secreting tumors, similar to normal GH-secreting cells, in lactotroph, corticotroph, and nonfunctioning adenomas, it is localized to the cytoplasm and not in the secretory vesicles. CONCLUSIONS Our functional evaluation of AIP mutations is consistent with a tumor-suppressor role for AIP and its involvement in familial acromegaly. The abnormal expression and subcellular localization of AIP in sporadic pituitary adenomas indicate deranged regulation of this protein during tumorigenesis.

CT perfusion imaging in the syndrome of the sinking skin flap before and after cranioplasty

The syndrome of the sinking skin flap (SSSF) has been described as one of the causes of neurological deficits after decompressive craniectomy We report a case of a 57-year-old woman with SSSF. Two years earlier, this patient, with no neurological deficits, underwent removal of the bone flap during treatment of an epidural abscess due to wound infection after a clipping operation for a ruptured aneurysm. The patient, who subsequently developed a sinking skin flap, gradually presented with gait disturbance and poor activity around 1 year before she came to our facility. On admission, neurological examination showed left hemiparesis and mild confusion. Cranioplasty with titanium mesh plate was performed. The cerebral blood flow (CBF) value in CT perfusion imaging in the symptomatic hemisphere increased from 23 to 31 cm3/100 g/min, and the value in the contralateral side increased from 37 to 41 cm3/100 g/min after cranioplasty. CT perfusion imaging after cranioplasty revealed the improvement of cerebral blood flow not only on the symptomatic side but also on the contralateral side. The patient recovered well and was discharged without hemiparesis and confusion 2 weeks after cranioplasty. As far as we know, this is the first reported case of SSSF examined with CT perfusion imaging before and after cranioplasty.

Incidence of intracranial aneurysm associated with pituitary adenoma

The incidence of in tracranial aneurysm associated with pituitary adenoma is not definitely established although reported higher than in general population. This study was designed to find the existence of such association in a large series of pituitary adenoma cases.A retrospective study of 467 cases of pituitary adenoma (mean age: 41 ± 15 years) was done. All patients underwent cerebral angiography at least of anterior circulation, detailed hormonal study, and 155 cases had additional magnetic resonance (MR) angiography. Twenty-five cases (5.4%) of pituitary adenoma (mean age 52 years) had intracranial aneurysm, 97% on anterior circulation, and 12% had multiple aneurysms. Two cases presented with aneurysmal rupture and the rest were incidental. Aneurysm was more frequently seen with increasing age (p < 0.001) and the age distribution resembled that of aneurysm among general population. Although the combination was most frequent among nonfuctioning adenoma (8.8%), and least frequent among prolactinoma (2.4%), this association was again due to age factor. There was no association between hormone secretion, size and invasive nature of the tumor. The results showed no association between intracranial aneurysm and pituitary adenoma. Our speculation is that such occurrence is merely a chance factor and the risk is no greater than that among general population.

Dissecting aneurysm of the peripheral posterior inferior cerebellar artery

Summary¶ Dissecting aneurysms of intracranial posterior circulation have recently been shown to be less uncommon than previously thought. However, those involving the posterior inferior cerebellar artery (PICA) and not vertebral artery at all are extremely rare. We report here a case of a patient with a dissecting aneurysm of the lateral medullary segment of PICA which presented as subarachnoid haemorrhage. The aneurysm was treated by trapping surgery and the distant PICA was anastomosed to the occipital artery. The patient showed a slight ataxia immediately after surgery but recovered fully. Recovery from immediately postoperative cerebellar symptoms due to intra-operative ischemia seemed to be due largely to recovery of flow in the region of cortical branches of PICA.

Multi-detector-row CT angiography as a preoperative evaluation for spinal arteriovenous fistulae

The role of multi-detector-row computed tomographic angiography (MDCTA) in spinal vascular malformations has not yet been determined. We present a report on a short series of spinal arteriovenous fistulae (AVF) evaluated by MDCTA. With 4-row and 16-row MDCTA, three cases of spinal dural AVF and one case of perimedullary AVF were examined. Each case was also examined by magnetic resonance (MR) imaging and spinal catheter angiography. In two patients with spinal dural AVF, including one patient with angiographically occult AVF, MDCTA successfully located the site of the AVF in a multi-planar reformation image. MDCTA failed to locate the remaining case of spinal dural AVF, probably due to the small amount of shunting blood volume at the fistula. In a patient with perimedullary AVF, MDCTA visualized the broad range of the lesion, including the anterior spinal artery as a single feeder, the fistulous point, and the single perimedullary draining vein. In conclusion, although conventional spinal angiography might be still essential, MDCTA provides useful information for the surgeon in treatment of the spinal dural AVF. Further accumulation of clinical cases is required to determine the potential of MDCTA for perimedullary AVF. MDCTA should be considered as a choice of investigation in the evaluation of spinal AVFs.

Churg-Strauss syndrome presenting with subarachnoid hemorrhage from ruptured dissecting aneurysm of the intracranial vertebral artery

Churg-Strauss syndrome (CSS) represents a rare systemic vasculitis that is almost invariably accompanied by bronchial asthma and eosinophilia. We report a case of a 36-year-old woman with previously diagnosed CSS presented with subarachnoid hemorrhage (SAH) from dissecting aneurysm in a vertebral artery (VA). Two months before onset of SAH, the patient had presented with numbness on her right lower leg due to peripheral neuropathy. On admission, angiography revealed dissecting aneurysm of the right intracranial VA and stenosis of the basilar artery. Hematological examination revealed an increased percentage of eosinophils. Ruptured dissecting aneurysm of the intracranial VA was diagnosed. Emergent coil embolization of the dissecting aneurysm and occlusion of the parent artery was performed to prevent repeated hemorrhage from the dissecting aneurysm. Then pharmacotherapy with prednisone was initiated for CSS. The patient recovered well and was discharged without any neurological deficit. As far as we know, this is the first reported case of CSS presented with SAH from dissecting aneurysm on posterior circulation.

Accuracy and pitfalls of multidetector-row computed tomography in detecting spinal dural arteriovenous fistulas.

OBJECT The purpose of this study was to evaluate the accuracy of multidetector-row CT angiography (MDCTA) in demonstrating spinal dural arteriovenous fistulas (SDAVFs). METHODS The authors studied 10 patients with SDAVFs, including 2 with spinal epidural AVFs, who underwent preoperative MR imaging, MDCTA, and digital subtraction angiography (DSA). In the evaluation of coronal sections of multiplanar reformation MDCTA images, inspection was focused on the presence of the following findings: 1) dilated perimedullary veins in the spinal canal; 2) focal enhancement of the nerve root, suggesting the location of the AVF, around the dural sleeve; and 3) a radicular vein that drains the AVF into perimedullary veins. The utility of MDCTA was assessed by comparing its findings with those of DSA in each case. RESULTS Digital subtraction angiography confirmed that the AVFs were located in the thoracic spine in 4 patients and in the lumbar spine in 6 patients, and MDCTA detected dilated perimedullary veins in all 10 patients. In 8 patients, there was focal enhancement of the nerve root. The radicular vein that drains the AVF into the perimedullary veins was found in 8 cases. In 8 cases, the MDCTA-derived level and side of the AVF and its feeder corresponded with those shown by DSA. In 2 patients, however, the MDCTA-derived side of the feeder was on the side contralateral to the feeding artery confirmed by DSA. These lesions were interpreted as spinal epidural AVFs with perimedullary drainage. In 2 cases, MDCTA could not detect the multiplicity of their feeders. CONCLUSIONS The use of MDCTA preceding DSA can be helpful to focus the selective catheter angiography on certain spinal levels. However, one should keep in mind that epidural AVFs with perimedullary drainage may resemble SDAVFs and also that MDCTA cannot exclude the possibility of multiple feeders. Further research should elucidate how broadly selective angiography should explore around the MDCTA-suggested target.

Interhemispheric arachnoid cyst in the elderly: case report and review of the literature

BACKGROUND Preoperative differential diagnosis of interhemispheric cysts is sometimes difficult. CASE DESCRIPTION We recently experienced a case of symptomatic interhemispheric arachnoid cyst in a 62-year-old woman. We reviewed interhemispheric arachnoid cysts in the elderly and the management of symptomatic interhemispheric arachnoid cysts in elderly patients. Symptomatic interhemispheric arachnoid cysts in the elderly are predominantly located on the right side, have a long history of progressive symptomology, occur predominantly in females, and have no communication with the subarachnoid space. Interhemispheric arachnoid cysts are usually not associated with agenesis of the corpus callosum in elderly patients, whereas interhemispheric nonarachnoid cysts are usually associated with agenesis of the corpus callosum, which will be clearly demonstrated on magnetic resonance imaging. CONCLUSIONS It is highly possible that an interhemispheric cyst without agenesis of the corpus callosum in an adult is an arachnoid cyst.

Expression of epithelial cadherin and cavernous sinus invasion in human pituitary adenomas

Pituitary adenomas generally are regarded as benign tumors,although some invade the cavernous sinus and recur.We examined the epithelial cadherin (E-CD) expression in30 pituitary adenomas (6 with cavernous sinus invasionand 24 without). Immunoreactivity of E-CD were foundin all pituitary adenomas but they were veryvarious. The presence of an association between E-CDexpression and cavernous sinus invasion was assessed. Therewere no significant differences in E-CD expression betweeninvasive and noninvasive adenomas. These results suggest thatE-CD expression is not associated with cavernous sinusinvasion in pituitary adenomas.

Posterolateral protrusion of the vertebral artery over the posterior arch of the atlas: quantitative anatomical study using three-dimensional computed tomography angiography

OBJECT The vertebral artery (VA) often takes a protrusive course posterolaterally over the posterior arch of the atlas. In this study, the authors attempted to quantify this posterolateral protrusion of the VA. METHODS Three-dimensional CT angiography images obtained for various cranial or cervical diseases in 140 patients were reviewed and evaluated. Seven patients were excluded for various reasons. To quantify the protrusive course of the VA, the diameter of the VA and 4 parameters were measured in images of the C1-VA complex obtained in the remaining 133 patients. The authors also checked for anomalies and anatomical variations. RESULTS When there was no dominant side, mean distances from the most protrusive part of the VA to the posterior arch of the atlas were 6.73 +/- 2.35 mm (right) and 6.8 +/- 2.15 mm (left). When the left side of the VA was dominant, the distance on the left side (8.46 +/- 2.00 mm) was significantly larger than that of the right side (6.64 +/- 2.0 mm). When compared by age group (< or = 30 years, 31-60 years, and > or = 61 years), there were no significant differences in the extent of the protrusion. When there was no dominant side, the mean distances from the most protrusive part of the VA to the midline were 30.73 +/- 2.51 mm (right side) and 30.79 +/- 2.47 mm (left side). When the left side of the VA was dominant, the distance on the left side (32.68 +/- 2.03 mm) was significantly larger than that on the right side (29.87 +/- 2.53 mm). The distance from the midline to the intersection of the VA and inner cortex of the posterior arch of the atlas was approximately 12 mm, irrespective of the side of VA dominance. The distance from the midline to the intersection of the VA and outer cortex of the posterior arch was approximately 20 mm on both sides. Anatomical variations and anomalies were found as follows: bony bridge formation over the groove for the VA on the posterior arch of C-1 (9.3%), an extracranial origin of the posterior inferior cerebellar artery (8.2%), and a VA passing beneath the posterior arch of the atlas (1.8%). Conclusions There may be significant variation in the location and branches of the VA that may place the vessel at risk during surgical intervention. If concern is noted about the vulnerability of the VA or its branches during surgery, preoperative evaluation by CT angiography should be considered.