The Significance of the Intercarotid Distances for Transsphenoidal Pituitary Surgery: A Magnetic Resonance Imaging Study.

OBJECTIVE: We performed magnetic resonance imaging (MRI) to analyze the distance between the left and right internal carotid arteries (ICD) around pituitary tumors for transsphenoidal surgery (TSS). METHODS: Measurements were performed using thin slice T2-weighted MRI, and/or time-of-flight (TOI) MR angiography imaging for 64 nonfunctioning pituitary neuroendocrine tumors (NF-pitNETs), 22 growth hormone-producing pitNETs (GH producing pitNETs), and 46 normal controls. We measured the ICD at 3 anatomic levels: at the distal dural ring (ICD-A); at the most concave point of the C4-C5 bend (ICD-B); and at the most convex point of the C4 bend (ICD-C). Additionally, we measured the sagittal distance between the tuberculum selle and the junction of the sellar floor and clivus on the midsagittal MRI (TS-C). RESULTS: We found that ICD-B was the longest and that ICD-A was the shortest among the 3 distance parameters in all groups (P < 0.001). The comparison of the groups revealed that the NF-pitNET group had longer distances than the normal control group at all ICDs (P < 0.001). The GH producing pitNET group had longer distance than the normal control group at ICD-B (P < 0.001). Tumor volume was correlated with ICD-A and ICD-B in the NF-pitNET, and was correlated with ICD-C in the GH producing pitNET group. CONCLUSIONS: Among the distance parameters, ICD-B is the longest, and was approximately twice the width of the TS-C. The shape of the sella is an ellipse that is widest in the lateral dimension in TSS. A horizontal based dural incision may be more rational than a conventional X-shaped dural incision.

Preoperative Magnetic Resonance Imaging Localization of the Normal Pituitary Gland in Nonfunctioning Pituitary Adenoma Patients Using the Radiological Sign of "Internal Carotid Artery Notch".

OBJECTIVE: Asymmetric features of nonfunctioning pituitary adenoma (NFPA) are poorly understood. We investigated the asymmetry in NFPA on magnetic resonance imaging. METHODS: We reviewed preoperative magnetic resonance imaging findings of patients initially treated for NFPA. The internal carotid artery (ICA) often seemed to cause an indentation in the external shape of the tumor (i.e., the ICA notch). RESULTS: Two cases with a normal pituitary gland located at the midline were excluded. The remaining 66 cases were examined. The side where the normal gland was located was defined as the normal pituitary side and the opposite side as the cavernous sinus side. The Knosp grade was significantly higher on the cavernous sinus side (P < 0.001), and the vertical distance of the ICA was significantly greater on the cavernous sinus side (P < 0.001). The ICA notch was found in 87.9% of all cases on the normal pituitary side, but in only 45.5% on the cavernous sinus side (P < 0.001). In cases with a single-side ICA notch (34 of 68), the ICA notch was found in 91.2% of cases and on the cavernous sinus side in 8.8% (P < 0.001). CONCLUSIONS: Magnetic resonance imaging of NFPA frequently shows asymmetry. The tumor does not extend laterally on the normal pituitary side but extends laterally more freely on the cavernous sinus side. The ICA notch is often found on the normal pituitary side where the position of ICA does not move. This may be useful as a preoperative sign to indicate the normal pituitary side.

Single-Layer Fascia Patchwork Closure for the Extended Endoscopic Transsphenoidal Transtuberculum Transplanum Approach: Deep Suturing Technique and Preliminary Results.

OBJECTIVE: To describe a single-layer fascia patchwork closure (FPWC) without nasoseptal flap (NSF) and compare postoperative cerebrospinal fluid (CSF) leakage between FPWC using NSF and single-layer FPWC without NSF for the extended endoscopic transsphenoidal transtuberculum transplanum approach. METHODS: Forty-five cases of suprasellar tumor in 42 patients were treated with extended endoscopic transsphenoidal removal, resulting in extensive, high-flow CSF leakage. Following the intradural procedure for treatment of various suprasellar tumors, fascia lata was inlaid subdurally on the cranial base defect and patch-sutured around its entire circumference under endoscope visualization, using an average of 17 stitches. Septal bone or hydroxyapatite plate was used for the hard support material against pulsatile intracranial pressure. NSF was added in the earlier 17 cases. Closure was completed without NSF in the more recent 28 cases when the Valsalva maneuver confirmed watertight closure. Two recent cases required NSF after Valsalva maneuver and were included in the FPWC + NSF group. RESULTS: Postoperative CSF leakage did not occur in the FPWC + NSF group but occurred in 2 patients in the single-layer FPWC group (7.1%) (P = 0.52). There was no significant difference in CSF leakage between single-layer FPWC and FPWC + NSF. The mean suturing time for FPWC was 85.8 minutes, and the shortest was 39 minutes in a recent case (mean, 17 stitches; n = 35, video analysis). CONCLUSIONS: Single-layer FPWC may be a viable technical option for effective skull base reconstruction after the extended endoscopic transsphenoidal transtuberculum transplanum approach.

Combined supra-infrasellar approach to pituitary macroadenoma with oculomotor cistern extension: surgical strategy and experience.

BACKGROUND: Oculomotor cistern extension (OMCE) of pituitary adenoma through the oculomotor triangle may be one of the major characteristics of multi-lobulated adenoma. The OMCE may be hard to remove only through the endonasal approach. METHOD: We applied the simultaneous combined supra-infrasellar approach to remove pituitary adenoma with relatively large OMCE. Four (7.3%) of 55 consecutive patients with initially operated pituitary macroadenoma (> 10 mm) had OMCE. The combined supra-infrasellar approach was adopted in two cases with relatively large OMCE. RESULTS: The simultaneous combined supra-infrasellar approach was performed with the transcranial microscopic transsylvian anterior temporal approach and the nasal endoscopic approach. The medial main mass was removed through the nasal side. The lateral OMCE was also removed through the nasal side by pushing the tumor in the sellar direction from the transcranial side. The oculomotor nerve was confirmed with electrical nerve stimulation. The main medial mass and the OMCE were mostly removed in both cases. Remnant tumor in the cavernous sinus was treated by gamma knife radiosurgery. Endoscopic transsphenoidal removal was performed in the other two cases with relatively small OMCE. CONCLUSIONS: Pituitary macroadenomas with OMCE are a newly recognized form of progression with important implications for surgical strategy. The combined supra-infrasellar approach performed with the transcranial microscopic transsylvian anterior temporal approach using electrical nerve stimulation and the nasal endoscopic approach may be useful for this type of multi-lobulated pituitary adenoma.

Microanatomy Around the Facial Nerve Pathway for Microvascular Decompression Surgery Investigated with Correlative Light Microscopy and Block-Face Imaging.

BACKGROUND: Microvascular decompression for hemifacial spasm is performed at the root exit zone. More proximal segments of the facial nerve, defined as the root emerging zone (REmZ), may also be susceptible to neurovascular compression. Consequently, detailed knowledge of the microanatomy around facial nerve fibers at the pontomedullary junction is essential for consistent success of microvascular decompression. METHODS: Five human brainstems obtained from cadavers were investigated using correlative light microscopy and block-face imaging, which obtains arbitrary two-dimensional light microscopic and three-dimensional volume data from a single specimen. The entire facial nerve pathway, including the myelin transition, was evaluated inside and outside the brainstem. RESULTS: Correlative light microscopy and block-face imaging showed the intra-brainstem facial nerve fibers emerging at the brainstem surface deep at the pontomedullary sulcus (REmZ) and coursing along the pontine surface before detaching from the pons (root exit zone). An acute emerging angle significantly increased the surface area with central myelin. The facial nerve bundle formed 1 fasciculus in the portion covered by central myelin but divided into 2 fasciculi in the myelin transitional portion and then into multiple fasciculi more distally. Arteries around the REmZ were often anchored by perforating branches entangled with lower cranial nerves. CONCLUSIONS: Facial nerve fibers are susceptible to vascular compression on emerging onto the deep brainstem surface at the pontomedullary sulcus. The key procedure in microvascular decompression is full dissection of the lower cranial nerves down to the brainstem origin to explore both the root exit zone and the REmZ.

Sex- and Age-Related Differences in the Clinical and Neuroimaging Characteristics of Patients With Spontaneous Intracranial Hypotension: A Records Review.

BACKGROUND: The significance of sex- and age-related differences in the clinical course of spontaneous intracranial hypotension (SIH) was investigated. METHODS: We retrospectively studied 40 consecutive patients (female:male = 28:12, median age 41.5 years) treated under clinical diagnoses of SIH satisfying the International Classification of Headache Disorders 3rd edition criteria, including 37 patients (92.5%) with diffuse pachymeningeal enhancement. The patients were divided into two groups by age and sex, and the clinical and neuroimaging findings in each group were investigated. RESULTS: Acute onset (female:male = 82.1%:50.0%, P = .042), severe headache (75.0%:41.7%, P = .045) occurred with higher frequency in females than in males, and SDH occurred with lower frequency in females than in males (28.6%:75.0%, P = .006). Duration until the consultation (2:14 days, P = .022), SDH thickness (0:7.1 mm, P = .001), and iter displacement (1.6:7.1 mm, P = .004) was greater in males. Acute onset (Younger [≤40 years]: older [>40 years] = 94.1%:56.5%, P = .012), occurred with higher frequency in younger patients, and duration until the consultation (1:5 days, P = .001), frequency of SDH (17.7%:60.9%, P = .010), SDH thickness (0:5.9 mm, P = .003), in older patients. All nine patients with thunderclap headache were female, with median age of 37 years. CONCLUSIONS: More severe clinical symptoms with acute onset were observed in females and younger patients of SIH. Comparatively rare subdural hygroma/hematoma on magnetic resonance imaging might result from the shorter duration to diagnosis in females and younger patients. KEY WORDS: spontaneous intracranial hypotension, sex, age, magnetic resonance imaging, thunderclap headache.

Risk perception of unruptured intracranial aneurysms.

OBJECT: Recent prospective studies have shown that the rupture rate of small unruptured intracranial aneurysms is very low. However, awareness of harboring an aneurysm often provokes anxiety and depression, which may reduce the quality of life (QOL). METHODS: This cross-sectional study enrolled 52 patients who had previously been notified of the presence of untreated unruptured aneurysms. A Markov model was constructed to simulate the natural history over time, and the age- and size-specific loss of quality-adjusted life year (QALY) caused by the aneurysms was calculated. Preference-based subjective QALY losses (PSG and PTTO) were assessed using the standard gamble (SG) and time trade-off (TTO) according to patient's own perceptions. RESULTS: Calculated theoretical QALY losses were relatively small with median values of 0.4 years (interquartile range [IQR] 0.1-1.0 years) and 1.9 % (IQR 1.1-3.7 %) of expected lifetime. The median values of PSG and PTTO were 10.0 % (IQR 5.0-14.3 %) and 19.5 % (IQR 9.0-25.0 %), respectively. Although theoretical QALY losses were smaller in the patients with small aneurysms (<5 mm) than in patients with medium ∼ large aneurysms (≥5 mm), the PSG and PTTO were almost the same in both groups. The discrepancy between theoretical and subjective QALY losses was prominent in patients with small aneurysms. CONCLUSIONS: Notification of unruptured aneurysms exerts a significant psychological burden, and excessively reduces the QOL relative to the theoretical risks. The present study suggests that neurosurgeons should reconsider the method used to inform patients of small lesions with low risk of severe consequences.

Experimental model of lacunar infarction in the gyrencephalic brain of the miniature pig: neurological assessment and histological, immunohistochemical, and physiological evaluation of dynamic corticospinal tract deformation.

BACKGROUND AND PURPOSE: Lacunar infarction accounts for 25% of ischemic strokes, but the pathological characteristics have not been investigated systematically. A new experimental model of lacunar infarction in the miniature pig was developed to investigate the pathophysiological changes in the corticospinal tract from the acute to chronic phases. METHODS: Thirty-five miniature pigs underwent transcranial surgery for permanent anterior choroidal artery occlusion. Animals recovered for 24 hours (n=7), 2 (n=5), 3 (n=2), 4 (n=2), 6 (n=1), 7 (n=7), 8 (n=2), and 9 days (n=1), 2 weeks (n=2), 4 weeks (n=3), and more than 4 weeks (n=3). Neurology, electrophysiology, histology, and MRI were performed. Seven additional miniature pigs underwent transient anterior choroidal artery occlusion to study muscle motor-evoked potentials and evaluate corticospinal tract function during transient anterior choroidal artery occlusion. RESULTS: The protocol had a 91.4% success rate in induction of internal capsule infarction 286+/-153 mm(3) (mean+/-SD). Motor-evoked potentials revealed the presence of penumbral tissue in the internal capsule after 6 to 15 minutes anterior choroidal artery occlusion. Total neurological deficit scores of 15.0 (95% CI, 13.5 to 16.4) and 3.4 (0.3 to 6.4) were recorded for permanent anterior choroidal artery occlusion and sham groups, respectively (P<0.001, maximum score 25) with motor deficit scores of 3.4 (95% CI, 2.9 to 4.0) and 0.0 (CI, 0.0 to 0.0), respectively (P<0.001, maximum score 9). Histology revealed that the internal capsule lesion expands gradually from acute to chronic phases. CONCLUSIONS: This new model of lacunar infarction induces a reproducible infarct in subcortical white matter with a measurable functional deficit and evidence of penumbral tissue acutely.

A new model of focal cerebral ischemia in the miniature pig.

OBJECT: The purpose of this set of studies is to design a minimally invasive, reproducible stroke model in the gyrencephalic brain. This paper provides information on both surgical technique and methods of quantification of ischemic damage to both gray and white matter in the miniature pig. METHODS: Sixteen male miniature pigs were randomly divided into three groups and underwent transcranial surgery involving a frontotemporal approach with orbital rim osteotomy for permanent middle cerebral artery occlusion (MCAO; five animals), permanent internal carotid artery occlusion (ICAO; six animals), and a sham operation (five animals). Histological mapping and magnetic resonance (MR) imaging were used to delineate the areas of ischemic damage. The volumes of infarction measured directly from MR images were 16.2 +/- 1.1, 1.5 +/- 0.5, and 0.0 +/- 0.0 cm3 (mean +/- standard deviation [SD], p < 0.001) in the MCAO, ICAO, and sham-operated groups, respectively. The areas of ischemia identified through histological analysis and MR imaging showed a good correlation (r2 = 0.86, p < 0.0001). Immunohistochemical staining with an amyloid precursor protein (APP) antibody was used to evaluate axonal damage and calculate a total APP score for axonal damage of 44.8 +/- 2.9 in the MCAO, 13.2 +/- 6.6 in the ICAO, and 0.0 +/- 0.0 (mean +/- SD, p < 0.002) in the sham-operated animals. CONCLUSIONS: This new model of focal cerebral ischemia induces a reproducible amount of ischemic damage in both gray and white matter, and has significant utility for studies of the pathophysiology of ischemia in the gyrencephalic brain and for assessment of the therapeutic efficacy of drugs prior to the initiation of human clinical trials.

Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men.

BACKGROUND: Catechins, the major component of green tea extract, have various physiologic effects. There are few studies, however, on the effects of catechins on body fat reduction in humans. It has been reported that the body mass index (BMI) correlates with the amount of malondialdehyde and thiobarbituric acid-reactive substances in the blood. OBJECTIVE: We investigated the effect of catechins on body fat reduction and the relation between oxidized LDL and body fat variables. DESIGN: After a 2-wk diet run-in period, healthy Japanese men were divided into 2 groups with similar BMI and waist circumference distributions. A 12-wk double-blind study was performed in which the subjects ingested 1 bottle oolong tea/d containing 690 mg catechins (green tea extract group; n = 17) or 1 bottle oolong tea/d containing 22 mg catechins (control group; n = 18). RESULTS: Body weight, BMI, waist circumference, body fat mass, and subcutaneous fat area were significantly lower in the green tea extract group than in the control group. Changes in the concentrations of malondialdehyde-modified LDL were positively associated with changes in body fat mass and total fat area in the green tea extract group. CONCLUSION: Daily consumption of tea containing 690 mg catechins for 12 wk reduced body fat, which suggests that the ingestion of catechins might be useful in the prevention and improvement of lifestyle-related diseases, mainly obesity.

Cerebrospinal fluid leak demonstrated by three-dimensional computed tomographic myelography in patients with spontaneous intracranial hypotension.

BACKGROUND: Precise determination of the spinal level of a cerebrospinal fluid leak is important in the diagnosis and treatment of spontaneous intracranial hypotension. The authors report two cases of SIH in which a cerebrospinal fluid leak was demonstrated by three-dimensional computed tomographic (3D-CT) myelography. CASE DESCRIPTION: By overlaying 3D-CT images of contrast-enhanced CSF and the spine, the point of leakage was clearly depicted in the three-dimensional spinal structure, which assisted targeted epidural blood patch under the guidance of fluoroscopy. Although associated chronic subdural hematoma had to be treated by burr hole drainage, the patients' postural headaches subsided after treatment. CONCLUSION: Clear CSF images in relation to vertebral bones are obtainable with 3D-CT myelography, rendering this modality very useful for the diagnosis and treatment of spontaneous intracranial hypotension.