Bilateral Tolosa-Hunt syndrome mimicking pituitary adenoma

The authors report a rare case of bilateral Tolosa-Hunt syndrome, which occurred in a 80-year-old female and remitted spontaneously. Inflammatory lesions were found not only in typical locations, i.e. superior orbital fissures and cavernous sinuses, but also in the pituitary; these imitated gland's macroadenoma in imaging studies.

Moyamoya Disease Associated with Tuberculum Sellae Meningioma and Cavernous Sinus Hemangioma

BACKGROUND

Primary moyamoya disease associated with skull base tumors has been reported only rarely in the literature. Surgical treatment can be complicated due to the compensatory collateral circulation through meningeal and leptomeningeal anastomosis. A standard frontotemporal craniotomy may interrupt critical transdural anastomoses.

CASE DESCRIPTION

We report a case of primary moyamoya disease coexisting with tuberculum sellae meningioma and left cavernous sinus hemangioma. Simultaneous management of tuberculum sellae meningioma and moyamoya disease was performed using a left modified pterional incision. Two separate bone windows were opened to protect the transdural anastomosis via the middle meningeal artery. The tuberculum sellae meningioma was successfully removed through a small frontal craniotomy, and encephaloduromyosynangiosis was used to treat moyamoya disease through a temporoparietal craniotomy. Finally, CyberKnife radiotherapy was used to treat the left cavernous sinus hemangioma at 6 weeks after the initial operation. The patient recovered well without complications. This is the first report of moyamoya disease associated with tuberculum sellae meningioma and cavernous sinus hemangioma.

CONCLUSIONS

With careful bone flap design, moyamoya disease and skull base tumors can be treated simultaneously. Care should be taken to avoid interruption of critical dural-pial collaterals and injury to fragile moyamoya vessels.

Evaluation of Sella Turcica Shape and Dimensions in Cleft Subjects Using Cone-Beam Computed Tomography

OBJECTIVE

The aim of this study was to assess the morphology of the sella turcica and measure its size in cleft and noncleft subjects.

MATERIAL AND METHODS

Cone-beam computed tomography (CBCT) images of 54 individuals (29 males; 25 females) with cleft and 85 (22 males; 63 females) without cleft were used for this study. Syndromic patients with cleft(s) were not included because of possible additional endocrinological and/or morphological disorders. Linear measurements included length, depth, and diameter. The shape of the sella turcica was analyzed in the cleft and noncleft groups. An independent t test was conducted to evaluate differences between genders and groups. One-way ANOVA was used to compare age groups.

RESULTS

The length (p < 0.001) of the sella turcica was smaller in noncleft subjects than in cleft subjects. Diameter (p = 0.014) and depth (p = 0.005) showed as constantly increasing from an age <15 to >25 years in the overall assessment. The distribution of the shape of the sella turcica differed significantly between groups (p < 0.001).

CONCLUSIONS

In this study, CBCT was used to assess the morphology of the sella turcica. A majority of the subjects with cleft had a flattened sella turcica compared to that of the control group. A shorter length of the sella turcica was more evident in the cleft subjects than in the control group.

Rare presentation of Ewing sarcoma metastasis to the sella and suprasellar cistern

We present an exceedingly rare case of a Ewing sarcoma metastasis manifesting as a sellar mass mimicking a pituitary adenoma. The differential diagnosis of the young adult with a sellar mass is presented and correlated with a review of available literature, demonstrating this case's unique potential for clinical teaching. More specifically, this case illustrates that in a patient with a clinical history of Ewing sarcoma, a metastasis may involve the sella and suprasellar cistern without apparent osseous involvement.

Invagination of the Sphenoid Sinus Mucosa after Endoscopic Endonasal Transsphenoidal Approach and Its Significance

Objective

To describe the clinical features of invagination of the sphenoid sinus mucosa (ISM) and compare them with other similar cases using a visual analog scale (VAS) to assess the various nasal symptoms and to discuss its clinical significance and means of prevention.

Study Design

Retrospective chart review at a tertiary referral center.

Methods

Between 2010 and 2015, 8 patients who had undergone EETSA surgery displayed postoperative ISM. The comparison group consisted of 147 patients who underwent the same surgical procedures and were diagnosed with the same diseases. Pre- or postoperative paranasal sinus computed tomography (PNS CT) and VAS were performed and subsequently analyzed.

Results

The clinical features of ISM of the sphenoid sinus showed sellar floor invagination and regenerated inverted ingrowing sphenoid mucosa on endoscopic imaging. PNS CT also showed a bony defect and invaginated air densities at the sellar turcica. Pre- and postoperative VAS scores revealed that the ISM group had much less of an improvement in headaches after surgery than that of the comparison group (p = 0.049).

Conclusion

ISM may occur because of a change in pressure, sphenoid mucosal status, or arachnoid membrane status. Moreover, ISM is related to improvements in headaches. Therefore, EETSA patients should avoid activities that cause rapid pressure changes during the healing process. In addition, sellar reconstruction that is resistant to physical pressure changes should be mandated despite the absence of an intraoperative CSF leak.

Postnatal sellar spine growth: A case report and literature review

BACKGROUND

A sellar spine is a bony spur protruding anteriorly from the central portion of the dorsum sellae. Its etiology is an ossified notochordal remnant of the cephalic end of the notochord. It is presumed to be a congenital malformation based on magnetic resonance imaging (MRI) findings of sellar spine in a 4-year-old boy. A sellar spine should therefore be detectable at birth with or without ossification, and the posterior pituitary lobe should be displaced.

METHODS AND RESULTS

Here we review the literature and report the first case of typical sellar spine in an 8-year-old girl who presented with precocious puberty, but her MRI taken at age 4 months for a febrile convulsion did not show a sellar spine or posterior pituitary lobe deformation. T1-weighted sagittal images at 8 years old showed a bony structure protruding anteriorly from the central portion of the dorsum sellae. The length of this lesion was 3.8 mm on computed tomography (CT) scanning at 9 years old, and it elongated to 4.7 mm on CT at 12 years old.

CONCLUSIONS

Based on the present case, we speculate that the sellar spine would be too small to detect early in development and would grow in size after birth. In this case, a sellar spine and precocious puberty were potentially associated due to deformation of the growing pituitary gland.

Management of Cushing's disease: a single-center experience

The purpose of this study was to review therapeutic outcomes and comorbidities of patients with Cushing's disease (CD) in a single center. We conducted a retrospective study of 33 patients with CD undergoing transsphenoidal surgery from January 2007 to February 2014 (27 females and 6 males, median age 38 years, range 18-71 years). The diagnosis of Cushing's syndrome was established on the basis of the patient's history, characteristic clinical features, and laboratory data including an elevated 24-h urinary free cortisol level, lack of serum cortisol suppression after dexamethasone suppression tests and an elevated midnight cortisol level. In 28/33 patients, the tumor was visualized on MR of the sellar region, while in 5 it was diagnosed using an inferior petrosal sinus sampling. Out of the 33 patients, 10 had macroadenoma and the remaining 23 had microadenoma. Twenty-one patients (63.6%) had hypertension, 17 (51.5%) dyslipidemia, and 7 (21.2%) had type 2 diabetes or impaired glucose tolerance. The median follow-up period was 28 months. Remission after transsphenoidal surgery was achieved in 78.8% of patients, while 7 patients failed to achieve disease remission. Those patients were treated with second-line treatment modalities (second operation, radiotherapy, bilateral adrenalectomy, and/or ketoconazole). One patient rejected all the treatment modalities after surgery. Cumulative remission after all the treatment modalities was achieved in 87.9% patients. Patients with Cushing's disease should be managed in centers with much experience due to high patient load. In our Center, the remission of the disease has been achieved in 78.8% of the patients following transsphenoidal surgery. Multimodal treatment which included radiotherapy and medical treatment led to biochemical remission of the disease in 87.9% of patients.

Chondroid chordoma of the sella turcica mimicking a pituitary adenoma

We report an unusual case of a chondroid chordoma of the sella turcica that mimicked the clinical and radiologic presentation of the more common pituitary adenoma. A 50-year-old man presented with bitemporal visual field deficits. Magnetic resonance imaging (MRI) detected a sellar mass that was suggestive of a pituitary adenoma. However, the intraoperative appearance of the mass was not consistent with an adenoma, and frozen-section pathology was obtained. Pathology identified the mass as a malignant lesion. Based on this finding, the mass was treated more aggressively. Chondroid chordomas are rare and slowly growing but locally aggressive tumors. The prognosis depends on the ability to totally resect the mass, so differentiating this tumor from a benign lesion is critical. An intrasellar chordoma can be confused clinically and radiologically with a pituitary adenoma. These two lesions are nearly identical on MRI, although T2-weighted imaging sometimes demonstrates higher intensity with a chondroid chordoma. Computed tomography may be helpful in demonstrating bony destruction by these lesions, as can the presence of intralesional calcifications. Intraoperative findings of bony invasion or a purple-red color may also lead the surgeon to suspect a diagnosis other than pituitary adenoma.

Extra-Pituitary Birth Defects May Predict Diagnosis of Congenital Hypopituitarism in a Short Child

BACKGROUND

Extra-pituitary birth defect (EPBD) in children with congenital hypopituitarism is largely unknown.

OBJECTIVE

The study aims to evaluate the incidence and pattern of EPBD in children with congenital hypopituitarism and to evaluate whether it can serve as a clue to diagnose this condition.

PATIENTS AND METHODS

Retrospective analysis of hospital record of patients of short stature due to various etiology from which patients with congenital hypopituitarism with age ≥18 years were recruited for the analysis. Clinical, hormonal, radiological and ocular electrophysiological studies were done in all patients and all EPBD were noted.

RESULTS

Twenty seven patients (79%) had multiple pituitary hormone deficiency (MPHD) of which growth hormone was universal followed by gonadotropin (62%), TSH (59%), ACTH (44%) and prolactin (12%). Nineteen patients (56%) had multiple EPBD in various combinations. Twenty three ocular abnormalities were present in 12 patients (35%). Nine patients (26%) had other associated EPBD along with ocular abnormalities while 3 had ocular abnormalities without any other associated birth defect. Skeletal defects were present in 10 patients (29.5%). On the contrary, 5 patients in the EPBD group had total 15 visual defects. The most common abnormality of the visual system were abnormal visual evoke response (VER, 18%), followed by strabismus (15%), visual acuity (VA, 12%), electroretinogram (ERG) and electrooculogram (EOG) 8% each and visual field defect 6%. There was a trend towards early age at presentation with EPBD.

CONCLUSIONS

Presence of EPBD in a short child is a sensitive marker to diagnose congenital hypopituitarism. Subtle abnormalities of visual pathway without absent septum pellucidum or midline brain defects were common.

Sphenoid and subdural hemorrhage as a presenting sign of ruptured clinoid aneurysm

BACKGROUND

Aneurysm rupture presenting as an isolated or pure subdural hematoma (SDH) without subarachnoid hemorrhage is an extremely rare radiographic presentation. We present a case of a ruptured internal carotid artery aneurysm with a pure SDH and concurrent sphenoid sinus hemorrhage.

METHODS

Case report and review of the literature.

RESULTS

We describe a case of a 48-year-old right-handed woman found comatose brought by emergency medical services to an outside hospital. A non-contrast head CT scan demonstrated bilateral acute SDHs without evidence of intraparenchymal or subarachnoid hemorrhage. A CT angiogram of the head showed a focal hyperdensity in the distal left internal carotid artery (ICA) and was confirmed by conventional cerebral angiography to be a 7-mm left supraclinoid ICA aneurysm. On repeat CT scan a new hemorrhage was seen in the sphenoid sinus indicating a re-bleeding. The aneurysm was treated with coil embolization and complete occlusion was confirmed with subsequent angiograms. The patient had an eventful hospital course complicated by a Takotsubo cardiomyopathy and pulmonary edema. She was medically treated with successful recovery of her cardiopulmonary function. She remained markedly disabled and was transferred to an inpatient rehabilitation center for continued convalescence.

CONCLUSIONS

Acute subdural hematoma may be due to a ruptured clinoid carotid aneurysm. Acute hemorrhage into the sphenoid sinus can be an important clue.

Extensive investigation of 114 patients with Sheehan's syndrome: a continuing disorder

OBJECTIVE

Sheehan's syndrome (SS) is a well-known cause of hypopituitarism resulting from postpartum pituitary necrosis. Because of its rarity in Western society, its diagnosis is often overlooked. We aimed to investigate the clinical, laboratory, and radiological aspects of SS in a large number of patients.

STUDY DESIGN

A retrospective assessment of the medical records of 114 patients with SS was conducted. In addition, sella turcica volumes of 29 healthy women were compared with those of patients by magnetic resonance imaging examinations.

RESULTS

The mean period of diagnostic delay was 19.7 years in patients with SS. It was found that 52.6% of patients had nonspecific complaints, 30.7% had complaints related to adrenal insufficiency, and 9.6% had complaints related to hypogonadism when diagnosed. At the time of diagnosis, 55.3% of the patients had panhypopituitarism, while 44.7% had partial hypopituitarism. The number of deficient hormones was found to be increased over the years. None of the patients whose basal prolactin was below 4.0 ng/ml had adequate prolactin responses to TRH test, while all patients whose basal prolactin was above 7.8 ng/ml had adequate responses. Mean sella volume was found to be significantly lower in the SS group (340.5±214 mm(3)) than that in the healthy group (602.5±192 mm(3)).

CONCLUSIONS

SS is a common cause of hypopituitarism in underdeveloped and developing countries. The main reasons for diagnostic delay seem to be the high frequency of patients with nonspecific complaints and neglect of SS. In addition, the TRH stimulation test was found to have a high sensitivity and specificity to recognize PRL deficiency. Furthermore, small sella size may have an important contributing role in the etiopathogenesis of SS.

Comparison of pharyngeal airway volume among different vertical skeletal patterns: a cone-beam computed tomography study

OBJECTIVE

To test the null hypothesis that there are no significant differences in pharyngeal airway volumes among adult patients with different vertical skeletal patterns and a clinically normal sagittal skeletal pattern using cone-beam computed tomography (CBCT).

MATERIAL AND METHODS

The study sample consisted of 100 adult patients (45 men and 55 women; mean age  =  24.0 ± 5.3 years) with a normal sagittal skeletal pattern divided into three groups according to the vertical skeletal patterns: high angle (32 patients: 15 women and 17 men), low angle (34 patients: 14 women and 20 men), and normal angle (34 patients: 16 women and 18 men) groups. Nasopharyngeal, oropharyngeal, and total airway volumes of patients in all vertical groups were calculated. Group differences were analyzed using one-way analysis of variance and post hoc Tukey tests.

RESULTS

Nasopharyngeal airway volume in the high-angle group (mean  =  6067.9 ± 1693.9 mm(3)) was significantly lower than that of the low- and normal-angle groups (P < .01). Oropharyngeal airway volume was highest in the low-angle group (mean  =  15,957.6 ± 6817.2 mm(3)) and significantly decreased in the control (mean  =  11,826.1 ± 4831.9 mm(3); P  =  .008) and high angle (mean  =  10,869.1 ± 4084.1 mm(3); P  =  .001) groups. Total airway volume was highest in the low-angle group (mean  =  24,261.6 ± 8470.1 mm(3)) and lowest in the high-angle group (mean  =  16,937.0 ± 5027.4 mm(3); P < .001).

CONCLUSION

The null hypothesis was rejected. Significant differences were found in pharyngeal airway volumes among different skeletal vertical patterns.

Upper airway changes after Xbow appliance therapy evaluated with cone beam computed tomography

OBJECTIVE

To determine the treatment effects of the Xbow appliance on the upper airway dimensions and volume using cone-beam computed tomography (CBCT); to evaluate the cephalometric changes in the skeletal and dental structures of the skeletal Class II patients.

MATERIALS AND METHODS

The sample consisted of 25 Class II patients (11 male, 14 female) with a mean age of 11.1 ± 1.1 years. CBCT images were obtained at the beginning of the treatment (T0) and after the debonding of the Xbow (T1).

RESULTS

Changes in superior, middle, and inferior parts of the oropharynx in the retroglossal region and changes in the oropharyngeal airway volume were statistically significant (P < .05, P < .01). The differences favoring the Xbow for the changes in the direction of Class II correction included SNA, SNB, ANB, maxillary depth angles, and point A-NPg and Co-B distances. Data of the dental parameters showed palatal tipping and extrusion of the maxillary incisors, labial tipping of the mandibular incisors, and mesial movement and extrusion of the mandibular molars.

CONCLUSIONS

Treatment with the Xbow appliance in Class II patients resulted in favorable increase in the oropharyngeal airway dimensions and volume. Further studies with larger study samples and with control groups are needed.

An evaluation of condylar and ramal vertical asymmetry in adolescents with unilateral and bilateral posterior crossbite using cone beam computed tomography (CBCT)

AIMS

The primary purpose was to evaluate condylar and ramal vertical asymmetry in adolescent patients displaying unilateral posterior (UCB) and bilateral posterior crossbite (BCB) malocclusions. A secondary aim was to compare the findings with a matched control group exhibiting normal occlusion (CG) using cone beam computed tomography (CBCT).

MATERIAL AND METHODS

The study groups consisted of (1) 30 patients (Mean age: 14.49 +/- 1.91 years) with a UCB, (2) 29 patients (Mean age: 14.57 +/- 1.84 years) with a BCB, and (3) 36 patients (Mean age: 14.24 +/- 2.42 years) as a matched control group (CG). Condylar, ramal, condylar-plus-ramal height and index measurements were performed using CBCT images following the method of Habets et al. A paired t-test was performed for side comparison in each group. Oneway ANOVA (Analysis of Variance) was used to determine statistically-significant differences between the groups for asymmetry index measurements and Tukey's HSD test was employed for individual group differences.

RESULTS

There was no statistically significant difference in condylar height (CH), ramal height (RH), and condylar plus ramal height (CH + RH) measurements between the right and left sides of the UCB group and CG, except for the RH in the BCB group (p = 0.045). Tukey's HSD test showed that the ramal asymmetry index (RAI) and the condylar plus the ramal asymmetry index (CRAI) were statistically significantly different between the UCB and BCB groups (p = 0.035 and p = 0.015, respectively).

CONCLUSIONS

Although the condylar asymmetry index (CAI) values were found to be high in the groups of UCB (13.84 +/- 11.33), BCB (9.38 +/- 8.56), and CG (10.58 +/- 9.48), the comparisons amongst the groups were not statistically significant. The asymmetry between the UCB and BCB groups was observed for RAI and CRAI values, rather than CAI values.

Morphometry of the cranial base and the cranial-cervical-mandibular system in young patients with type II, division 1 malocclusion, using tomographic cone beam

AIMS

Traditionally, diagnosis and treatment planning of structural and three-dimensional anomalies have been performed using two-dimensional X-rays. Cone beam computed tomography (CBCT), the technology utilized in this study, allows creation of specialized images from the craniofacial region that provide more precise and reliable results. The growth of the cranial base, position and size of the cervical system, and the hyoid bone has an influence upon the morphogenesis and the growth of the maxillofacial complex. The data obtained through this current study offer a better understanding of the origin and manifestation of malocclusions, and will, therefore, offer a better therapeutic approach. The objective of the current study is to describe the measurements of the cranial base and the cranial-cervical-mandibular system in young patients with type II, division 1 malocclusion, using CBCT.

METHODOLOGY

Twenty-four CBCT images were obtained for young patients with type II, division 1 malocclusion. The i-CAT Vision (Imaging Sciences International, Hatfield, PA, USA) was used to view the images. Linear and angular measurements were obtained in the mid-sagittal plane. Univariate and bivariate analyses, as well as a multivariate analysis of principal components, were conducted.

RESULTS

The only metric with a statistically significant difference regarding gender was S-N major in the male participants. The metrics SNA-SNB and SNPg are positively related and inversely proportional to the angles BA-S-N and PO-P McGregor. The inclination of the upper incisor showed an inverse relationship with the angles SNA-SNB and SNpg. The craniovertebral angle was diminished in the entire sample, and the variable that vertically relates the hyoid was independent of the other variables.

CONCLUSIONS

After evaluating 24 images of young patients with type II, division 1 malocclusion using helical spiral CBCT, it was concluded that relationships exist between the cranial base structures, the structures that determine the sagittal position of the maxilla, mandible and chin, and the cervical vertebrae complex and hyoid bone.

Imaging of the pituitary and sella turcica

The pituitary gland is housed in the sella turcica and has vital endocrinologic functions. It lies in close proximity to numerous vital structures, including the optic chiasm, sphenoid sinus, cavernous sinus and hypothalamus. An understanding of the function, anatomy and embryology of the pituitary gland and its surrounding structures is vital to understanding its normal appearance, as well as in evaluating the broad spectrum of pathology that can involve the pituitary gland. Imaging of pathology in the sellar region, including pituitary adenomas, meningiomas, craniopharyngiomas and aneurysms, plays an important role in guiding treatment decisions. Modern imaging techniques are also important in evaluating the pituitary gland after surgery.

Validation of anatomically shaped cranial collimation (ACC) in orthodontic lateral cephalography

The use of an anatomically shaped cranial collimator (ACC) to reduce patient dose in orthodontic lateral cephalography was investigated in this study. The aim was to evaluate the potential interference of the ACC on landmark identification for orthodontic cephalometry. Consecutive orthodontic patients underwent a total of 100 cephalograms using an ACC mounted on a Veraviewepocs(®) 3D X550 (J. Morita Co., Kyoto, Japan) X-ray unit. 10 observers were asked whether the identification of 5 landmarks close to the collimated area was hindered or rendered impossible by the presence of the collimator. Of the 500 landmarks that were judged by the 10 observers, 496 (99.2%) were reported to lack hindrance. In three landmarks, a minority of the observers reported hindrance. In 1 landmark, 8 of the 10 observers reported hindrance by the collimator. In no instance did the observers state that the identification of landmarks was impossible as a result of the collimation. Application of the ACC on the cephalostat of the X-ray unit is a viable way of reducing patient dose, as it only marginally interferes with the diagnostic yield of the exposure. The need to retake images when the ACC is applied was found to be extremely low.

Sella turcica metastasis from follicular carcinoma of thyroid

A case of metastasis to the sella turcica from a follicular adenocarcinoma of the thyroid gland is presented. Metastasis to this site is rare and review of the literature reveals only 12 cases of metastatic thyroid carcinoma involving the sella turcica and pituitary gland. The optimal treatment strategy is still to be determined. A 43-year-old woman presented with headache, nausea, visual impairment and galactorrhea. An MRI scan of the cranium revealed an enhancing destructive sellar lesion. The patient underwent transsphenoidal removal of the lesion to alleviate visual loss. The histological features of the sellar tumor were identical to those of a follicular adenocarcinoma partially removed from the thyroid gland 22 months earlier. Total thyroidectomy followed by three courses of iodine-131 ablation enhanced with synthetic thyrotropin and thyroid hormone suppression therapy was instituted. The post-operative course was satisfactory with improved vision and ceased galactorrhea. This case was successfully treated with a combination of surgical removal, iodine-131 ablation and hormone suppression therapy, which resulted in disease control duration of four years. Sella turcica metastases of thyroid carcinoma are exceedingly rare and currently there are no established therapeutic guidelines.

Primary empty sella (PES): a review of 175 cases

The term primary empty sella (PES) makes reference to the herniation of the subarachnoid space within the sella turcica in patients with no history of pituitary tumor, surgery or radiotherapy. To retrospectively assess clinical features, radiological findings and the biochemical endocrine function from the records of 175 patients with a diagnosis of PES. One hundred seventy-five patients (150 females) were studied. The mean age at diagnosis was 48.2 ± 14 year. Most diagnoses were made by magnetic resonance imaging (n = 172). In most patients, the pituitary function was assessed by basal pituitary hormones measurements. Pituitary scans were ordered for different reasons: headache (33.1 %), endocrine disorders (30.6 %), neurological symptoms (12.5 %), visual disturbances (8.75 %), abnormalities on sella turcica radiograph (8.75 %) and others (6.25 %). Multiple pregnancies were observed in 58.3 % of women; headaches, obesity, and hypertension were found in 59.4, 49.5, and 27.3 % of the studied population, respectively. Mild hyperprolactinemia (<50 ng/ml) was present in 11.6 % of women and 17.3 % of men. Twenty-eight percent of our patients had some degree of hypopituitarism. In the male population, hypopituitarism represented 64 % of cases, whereas it accounted for 22 % of all females. PES seems to be more commonly found in middle-aged women, with a history of multiple pregnancies. In most patients, PES was discovered as an incidental finding on imaging studies, while in almost a quarter of patients PES was found during the diagnostic evaluation of anterior pituitary deficiency, which was more common in men.

Cephalometric assessment of effect of head rotation toward focal spot on lateral cephalometric radiographs

INTRODUCTION

The patient's head can be slightly rotated sagittally vertically or transversely with the head holding device. Because of such improper positions due to head rotation, an error can occur in cephalometric measurements. The purpose of this study was to identify the projection errors of lateral cephalometric radiograph due to head rotation in the vertical Z-axis toward the focal spot.

MATERIALS AND METHODS

Ten human dry skulls with permanent dentition were collected. Each dry skull was rotated from 0° to +20° at 5° intervals. A vertical axis, the Z-axis, was used as a rotational axis to have 50 lateral cephalometric radiographs exposed. Four linear (S-N, Go-Me, N-Me, S-Go) and six angular measurements (SNA, SNB, N-S-Ar, S-Ar-Go, Ar-Go-Me, AB-mandibular plane angle) were calculated manually.

RESULTS

The findings were that: (1) Angular measurements have fewer projection errors than linear measurements. (2) The greater the number of landmarks on the midsagittal plane that are included in angular measurements, the fewer the projection errors occurring. (3) Horizontal linear measurements have more projection errors than vertical linear measurements.

CONCLUSION

The angular measurements of lateral cephalometric radiographs are more useful than linear measurements in minimizing the projection errors associated with head rotation on a vertical axis toward the focal spot.

Comparison of landmark identification and linear and angular measurements in conventional and digital cephalometry

The purpose was to compare the reliability of landmark identification and linear and angular measurements in conventional versus digital cephalometry. Using 50 cephalometric radiographs, four orthodontic residents identified 19 cephalometric landmarks followed by 18 linear and angular measurements of the same radiographs. The values of 18 measurements were compared to quantify the measurement difference and interobserver errors between these two methods. Multivariate analysis of variance showed that the "cephalometric radiograph" and "landmark" variation had greater influence than that of "method" (landmark identification on original radiograph/on digital). A statistically significant difference for interobserver errors between the two methods was noted only for 5 out of 19 cephalometric landmarks. The most accurately identified landmark in conventional and digitized method was Sella (S), followed by Nasion (N). Landmarks requiring further scrutiny in digital images were Porion (P) Articulare, ANS, UM, and LM. The advantages of digital cephalometry were also substantiated.

Measurements from conventional, digital and CT-derived cephalograms: a comparative study

OBJECTIVE

The purpose of this retrospective radiographic study was to determine the reliability and reproducibility of skeletal and dental measurements of lateral cephalograms created from a computerised tomography (CT) scan compared with conventional and digital lateral cephalograms.

METHODS

CT and conventional lateral cephalograms of the same patients were obtained from university archives. The lateral cephalometric radiographs of 30 patients were manually traced. The radiographs were subsequently scanned and traced using Dolphin Imaging software version 11 (Dolphin Imaging, Chatsworth, CA, USA). The CT-created lateral cephalograms were also traced using the same software. Sixteen (10 angular and 6 linear) measurements were performed. Cephalometric measurements obtained from conventional, digital and CT-created cephalograms were statistically compared using repeated measures analysis of variance (ANOVA). Statistical significance was set at the p < 0.05 level of confidence.

RESULTS

The intra-rater reliability test for each method showed high values (r > 0.90) except for mandibular length which had a correlation of 0.82 for the CT-created cephalogram. Five measurements (N-A-Pog, N-S, ANS-PNS, Co-ANS and CoGn) were found to be significantly different between the CT-created and conventional cephalograms and three measurements (SNB, ANB, and/1-MP) were found to be significantly different between the CT-created and digital cephalograms.

CONCLUSIONS

There are statistically-significant differences in measurements produced using a traditional manual analysis, a direct digital analysis or a 3D CT-derived cephalometric analysis of orthodontic patients. These differences are, on average, small but because of individual variation, may be of considerable clinical significance in some patients.

Approach to the patient with persistent hyperprolactinemia and negative sellar imaging

Hyperprolactinemia is a common cause of menstrual disturbances affecting young women. There is a diversity of causes, from physiological, such as pregnancy, to pharmacological and pathological, such as hypothyroidism. Renal and hepatic failure, intercostal nerve stimulation by trauma or surgery, prolactinomas, other tumors in the hypothalamus-pituitary region, as well as macroprolactinemia can also be considered. Identifying the correct cause is important to establish the correct treatment. Should all these causes be ruled out and pituitary imaging revealed as negative, idiopathic hyperprolactinemia is therefore diagnosed. In symptomatic patients, treatment with dopaminergic agonists is indicated. As for the asymptomatic hyperprolactinemic individuals, macroprolactinemia should be screened, and once it is detected, there is no need for pituitary imaging study or for dopaminergic agonist use.

Sellar plasmacytomas: a concise review

The diagnosis of a sellar plasmacytoma is often missed and is mistaken for a non functioning pituitary adenoma. We reviewed the literature on reported cases of sellar plasmacytoma in order to identify its clinical presentation, laboratory, radiological and pathological characteristics. We describe the management of these cases after the correct diagnosis was made and provide insight to preoperative diagnosis of this entity. Preoperative diagnosis may help avoid unnecessary surgical resection of an otherwise radiosensitive tumor. We also report and describe in detail a new case of sellar plasmacytoma that we have recently evaluated.

Neuronavigation used for the transsphenoidal resection of a pituitary adenoma accompanied by a concha sphenoid sinus

A concha non-pneumatized sphenoid is considered to be a contraindication for the transsphenoidal resection of a pituitary adenoma. Specifically, this anatomical variation makes it difficult to approach the sella turcica. However, in this report, an intra-operative navigational system was used as a guide to access the sella through the sphenoid sinus. This procedure was found to be both reasonable and safe.

Comparison of pharyngeal airway changes on plain radiography and cone-beam computed tomography after orthognathic surgery

PURPOSE

The purpose of the present prospective study was to develop a 3-dimensional analysis of the airway using cone-beam computed tomography (CBCT) and to determine whether changes in the airway before and after orthognathic surgery correlate on 2-dimensional lateral cephalogram and 3-dimensional CBCT images.

MATERIALS AND METHODS

Patients requiring orthognathic surgery during 2004 to 2005 were recruited for the present study. Lateral cephalograms and CBCT scans were obtained at 3 points: preoperatively, within 1 month postoperatively, and after 6 months postoperatively. The nasopharynx, oropharynx, and hypopharynx were segmented on both the radiograph and the CBCT scan for each patient in a repeatable manner at each point. For the lateral cephalogram, linear measurements in the middle of each of the 3 segments were obtained. For the CBCT, volumetric measurements of each of the 3 segments were obtained. The intrarater variability was assessed, and Pearson's correlation was used to compare the 2 imaging modalities.

RESULTS

A total of 20 patients scheduled for orthognathic surgery were recruited for the present study. Of the 20 patients, 13 were female and 7 were male. The mean age at surgery was 23.85 years (range 14 to 43). Of the 20 patients, 6 underwent maxillary advancement only, 8 underwent mandibular advancement with or without genioplasty, and 6 underwent 2-jaw surgery or mandibular setback. We examined the entire cohort without separation into procedure or examination point and found a weak, but statistically significant, correlation between the linear and volume measurements in the nasopharyngeal and oropharyngeal regions but not in the hypopharyngeal region (r = 0.43, P < .002; r = 0.49, P < .0002; r = 0.16, P = .26, respectively). The maxillary advancement group (n = 6) demonstrated a correlation between the linear and volume measurements in the nasopharyngeal region (r = 0.53, P = .03). The mandibular advancement with or without genioplasty group (n = 8) showed a correlation in the nasopharyngeal and oropharyngeal regions (r = 0.55, P < .02, and r = 0.46, P = .05, respectively). For the combination/setback procedures (n = 6), a correlation was found in the oropharyngeal region (r = 0.64, P < .01). All other comparisons between the linear and volume measurements did not correlate. Additionally, no correlations were found between the linear and volumetric change in airway size between 6 months postoperatively and preoperatively, except for the oropharyngeal region (r = 0.67, P < .01).

CONCLUSION

We present a method of measuring the airway that could be used for both 2-dimensional and 3-dimensional images. It includes segmentation of the pharyngeal airway into its nasopharyngeal, oropharyngeal, and hypopharyngeal components. Correlations were found between the linear and volumetric measurements of the segmented airway in patients who had undergone orthognathic surgery; however, the correlations were generally weak.

Dimensions, septation, and pattern of pneumatization of the sphenoidal sinus

The endoscopic endonasal transsphenoidal approach (EEA) to treat sellar, parasellar, and suprasellar tumours continues to gain increased significance. Due to the close proximity of the sphenoid sinus to the carotid artery and the optic canal, it is very important for surgeons to know the anatomical features and variations of the sphenoid sinus as relevant to EEA. A prospective study of the sphenoid sinus morphology was carried out on the cranial tomographic (CT) scan images of 60 Nigerian adult patients. The CTs were reviewed regarding the different anatomical variations of the sphenoid sinus: dimensions, septation, and pattern of pneumatisation. There were 37 males and 23 females. The patients' ages ranged from 18 years to 85 years, with a mean of 47.2 years. There was a main single intersphenoid septum in most patients (95%). The insertion of the septum was usually to the right posteriorly (38%) and in the midline anterior (65%). Although there is usually a main septum, the septa present were multiple in 29 of the sinuses studied. There was no gender difference with respect to the attachment of the main sphenoid sinus septum. The sphenoid anterior, posterior, and transverse dimensions were not significantly dependent on age, but they were longer in males than in females. Sellar pneumatization was present in the majority of the patients (83%), with 4 patients having postsellar pneumatization (6.7%) and 3 patients having presellar pneumatization (5%). There were no cases with conchal pneumatization or lateral pneumatization of the greater wing of the sphenoid. The present study provides anatomical information about the sphenoid sinus dimensions morphology that is essential for avoiding complications in performing an endoscopic sphenoidotomy.

Precision of cephalometric landmark identification: cone-beam computed tomography vs conventional cephalometric views

INTRODUCTION

In this study, we compared the precision of landmark identification using displays of multi-planar cone-beam computed tomographic (CBCT) volumes and conventional lateral cephalograms (Ceph).

METHODS

Twenty presurgical orthodontic patients were radiographed with conventional Ceph and CBCT techniques. Five observers plotted 24 landmarks using computer displays of multi-planer reconstruction (MPR) CBCT and Ceph views during separate sessions. Absolute differences between each observer's plot and the mean of all observers were averaged as 1 measure of variability (ODM). The absolute difference of each observer from any other observer was averaged as a second measure of variability (DEO). ANOVA and paired t tests were used to analyze variability differences.

RESULTS

Radiographic modality and landmark were significant at P <0.0001 for DEO and ODM calculations. DEO calculations of observer variability were consistently greater than ODM. The overall correlation of 1920 paired ODM and DEO measurements was excellent at 0.972. All bilateral landmarks had increased precision when identified in the MPR views. Mediolateral variability was statistically greater than anteroposterior or caudal-cranial variability for 5 landmarks in the MPR views.

CONCLUSIONS

The MPR displays of CBCT volume images provide generally more precise identification of traditional cephalometric landmarks. More precise location of condylion, gonion, and orbitale overcomes the problem of superimposition of these bilateral landmarks seen in Ceph. Greater variability of certain landmarks in the mediolateral direction is probably related to inadequate definition of the landmarks in the third dimension.

Microscope and endoscopic pituitary surgery

Having just celebrated the centenary of the first transsphenoidal pituitary operation by (Schloffer in Austria in Beitr Klin Chir 50:767-817, 1906), and this year the quarter centenary of the first published report of a therapeutic use of the neuroendoscope (for colloid cysts of the third ventricle) (Powell et al. in Neurosurgery 13:234-237, 1983), it is time to consider the relative merits of microscopic and endoscopic approaches for pituitary surgery. Although transsphenoidal endoscopic surgery has only been utilised by pioneers such as Jho since the mid-1990s (Jho et al., 1996), there is no doubt that it has already gained an important place in the neurosurgical armamentarium, but there is both confusion and propaganda about which method of surgery has most to offer, and indeed whether or not there is any real difference at all.

Prolactinomas in men: clinical characteristics and the effect of bromocriptine treatment

Thirty-seven men with prolactin (PRL) producing pituitary adenomas were studied to elucidate if patient's delay might cause the predominance of large tumours in men as compared to women in whom microadenomas predominate. We found two clinical subgroups; one presented with short duration of symptoms, dominated by local signs from the growth of notably large tumours, the other exhibited a long history of disease with hypogonadism as the dominating symptom. There was a correlation between tumour size and PRL levels. The age at the time of diagnosis showed no correlation to duration of symptoms, size of adenoma or PRL levels. Four patients with small adenomas, moderate hyperprolactinemia and short duration of symptoms showed signs of hypergonadotropic hypogonadism. Surgery or irradiation, performed in 14 patients, did not normalize PRL levels. Bromocriptine was equally beneficial in the two clinical subgroups, improving clinical symptoms and normalizing PRL levels in all but three patients. The study shows that the predominance of large tumours in men does not depend on patient's or doctor's delay, but on a high frequency of presumably rapidly growing PRL producing tumours. In the majority of patients, these tumours do not give signs of hypogonadism before the tumour is revealed by local signs of tumour growth.

Incidence of bridging and dimensions of sella turcica in Class I and III Turkish adult female patients

Mineralization of the interclinoid ligament of the sella turcica, or sella turcica bridging, has been associated with severe craniofacial deviations. The aim of this study was to evaluate the incidence of sella turcica bridging, sella turcica dimensions, and skeletal variables in 57 Class I (mean age, 27.2 ± 5.3 years) and 61 Class III (mean age, 25.8 ± 4.6 years) Turkish adult females. Sella bridging was found in three (5%) of the Class I and 11 (18%) of the Class III individuals (P<.010). The association between sella turcica bridging and manifest skeletal Class III malocclusions was statistically significant according to the chi-square test (P<.050). No significant differences in sella turcica dimensions were found between the Class I and Class III patients. Skeletal variables that differed significantly were SNB (P=.004), ANB (P=.002), and NAPg (P=.000) angles and N-B (P=.030), N-Pg (P=.003), Go-Pg (P=.007), and TM-Pg (P=.002) dimensions.

A rare case of pituitary adenoma with calcification: a case report

Though craniopharyngioma remains the most common sellar suprasellar tumor with calcification, it can be seen very rarely in pituitary adenomas and Rathke's cleft cysts. Appreciation of the pattern of calcification in a sellar suprasellar lesion can give a clue to the nature of the lesion. The authors describe a 53-yearold male with a cystic sellar suprasellar lesion and curvilinear calcification that was managed by successful transsphenoidal surgery. The present case highlights the occurrence of calcification in a pituitary adenoma and the importance of recognizing the calcification pattern for pre-operative diagnosis of sellar suprasellar lesions that can help plan the surgical strategy and management.

Plain radiographic cephalometry of the sella turcica: an overview

BACKGROUND

The simplest of the parameters in anthropometry, including, height, weight, length, thickness and widths of various parts of the body vary from tribe to tribe and from one race to the other, and measurements of these parameters also differ amongst different age groups and between the two sexes as well.

METHOD

A review composed via Medline Internet search, literature search and contributions from our experiences as well as experiences from colleagues.

RESULTS

Studies on measurements of the sella turcica have revealed variations in the size of the fossa with certain parameters such as age, sex e.t.c.

CONCLUSION

It is concluded that complete study of the sella turcica requires multidirectional tomography.

Outcome of surgical intrasellar growth hormone tumor performed by a pituitary specialist surgeon in a developing country

BACKGROUND

Acromegaly is an excessive GH secretion, which in most cases, is caused by a pituitary GH-secreting adenoma. Traditional treatment of acromegaly consists of surgery, drug therapy, and eventually radiotherapy. The aim of this retrospective study is to evaluate the results of transsphenoidal endoscopic surgery in a group of patients with intrasellar GH adenoma who were operated by a pituitary specialist surgeon. We shall then argue about the economical advantages, for the NHS of a developing country, between surgical and medical treatment.

METHODS

We have analyzed data from 33 patients with intrasellar GH tumor who had been referred to the neuroendocrine department of the HGF, Brazil. The patients underwent a transsphenoidal endoscopic adenomectomy for acromegaly between 2000 and 2005. Their ages were between 20 and 67 years (mean, 44 years) at the moment of surgery. No cavernous sinus invasion was present. Follow-up was a median of 2 years (range, 12 months-6 years).

RESULTS

All 33 patients had intrasellar adenoma, 84.84% of patients achieved remission by surgery. One patient was operated twice and reached hormonal normalization. Five patients still had the disease and refused a second surgery. A treatment with octreotide was started for these 5 patients and resulted in an adequate control of GH and IGF-1 levels. No patients had radiotherapy.

CONCLUSION

Our patients, with intrasellar GH tumor, operated by a pituitary specialist neurosurgeon had remission rates approaching those obtained by most specialized neurosurgical centers worldwide. For equal results, our study shows that the surgical treatment is the best issue for the patient and for the NHS.

Sphenoid sinus osteoma at the sella turcica associated with empty sella: CT and MR imaging findings

SUMMARY

A 50-year-old woman presented with intermittent headache for the past few years. A paranasal sinus CT scan showed a diffusely calcified lesion at the roof of the sphenoid sinus and sella turcica, with the sellar floor bony cortex involved. Empty sella was noted. MR imaging revealed a soft-tissue lesion with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and heterogeneous enhancement on postgadolinium images. Histologic examination revealed an osteoma composed of mature lamellar bone.

[Sellar tumors]

Because of the complex anatomy, examination of the sella turcica and hypophysis needs a dedicated MR sequence protocol. Not every sellar lesion is a pituitary adenoma. Thus, this review article summarizes the most frequently encountered intra-, supra-, and parasellar tumors and lesions. Differential diagnoses comprise besides adenoma among others craniopharyngioma, meningioma, glioma, germinoma, hamartoma, aneurysm, trigeminal schwannoma, pituitary carcinoma, chordoma, metastasis, infection, and empty sella. Characteristic imaging findings are presented and correlated to micro- and macro-pathology.

INTRASELLAR ARACHNOID CYSTS

OBJECTIVE

To evaluate the clinical, endocrinological, and radiological presentation of nine cases of surgically verified intrasellar arachnoid cysts and to discuss the physiopathological mechanisms of formation of these cysts.

METHODS

Among 1540 patients presenting with pituitary lesions, nine presented with an intrasellar arachnoid cyst. Their charts were retrospectively reviewed.

RESULTS

Presenting symptoms included headache (n = 2), visual symptoms (n = 3), menstrual irregularities (n = 2), rapid weight gain (n = 1), vertigo (n = 1), and/or confusion (n = 1). Two cysts were discovered incidentally. T1-weighted magnetic resonance imaging scans showed an intrasellar cystic lesion in all cases, with a huge suprasellar extension in six cases. The cyst was of the same intensity as the cerebrospinal fluid (CSF) in only two patients. A transsphenoidal approach allowed the transdural aspiration of fluid and injection of a water-soluble contrast agent under mild pressure. In three patients, the contrast infiltrated along the pituitary stalk toward the subarachnoid spaces; in the other patients, it remained in the intrasellar compartment. Cyst membranes were removed as completely as possible with fenestration toward the subarachnoid spaces in communicating cysts. In spite of tight packing of the sella and sphenoid sinus, CSF fistulae requiring reoperation developed in two patients.

CONCLUSION

The clinical picture of an intrasellar arachnoid cyst resembles that of a nonfunctional pituitary adenoma. Magnetic resonance imaging scans typically show a cystic intrasellar lesion with suprasellar extension, containing isointense or, more often, hyperintense fluid on T1-weighted sequences. In spite of the risk of CSF fistulae, the preferred surgical approach is transsphenoidal. A physiopathological mechanism is proposed according to anatomic variations of the sellar diaphragma allowing penetration of subarachnoid spaces into the sellar compartment and their enlargement by a ball-valve mechanism.

[Randomly discovered enlargement in the region of sella turcica]

Computer tomography (CT) and magnetic resonance imaging (MRI) quite often detect unexpected cases of enlargement in the hypothalamus-hypophysial region, without the above methods being indicated for clinical manifested symptomatology provoked by the tumour. This is not surprising if we consider that autopsies show the presence of hypophysial adenomas of 10-15% of population on an average. X ray, CT or MRI are indicated in the case of head traumas, lateral nasal cavity inflammations, headaches, strokes, neurological diseases and other disorders. A number of tumours of diverse etiology occur in the hypothalamus-hypophysial region, but hypophysial adenomas are by far the most frequent among all (above 90 %). Among other primary enlargements, the most frequent are craniopharyngeomas and meningeomas, while other enlargements are by fare less common. Such randomly detected tumours are mostly asymptomatic, but targeted anamnesis may show some of the symptoms quite clearly. The symptomatology can be linked with possible slight hormonal overproduction of hypophysial adenomas, a deficit of hypophysial hormones or local manifestations of expansion. Exact assessment of MRI results, of hormonal activity of the enlargement, of the relation to surrounding structures, especially the optic nerves, and the assessment of hypophysial functions are important for the therapeutic decision. Depending on the type and extension of the tumour the options considered are pharmacotherapy (the treatment of choice in the case of prolactinomas), surgery, radiotherapy (today prevailingly using the gamma knife), and if no intervention is necessary, follow up with regular MRI examinations. Tumorous growth is more often observed in "macroadenomas" than in "microadenomas" (up to 10 mm).

Resection of extensive sellar tumors with extended endoscopic transseptal transsphenoidal approach

The endoscope has recently been used to extensive sellar lesions, but the extended areas of the lesions and operative techniques vary from each study. Here we present our experience with extended endoscopic transseptal transsphenoidal (EETT) approach to 16 patients with extensive sellar lesion and evaluate the feasibility of EETT in different extensive sellar tumor resection. Sixteen patients with extensive sellar lesion were operated by EETT approach in this study. The approach included unilateral posterior septum mucosa resection, posterior septectomy, extended ethmoidectomy and sphenoidoctomy, four tumoral circumferences (bilateral, superior, inferior aspects) isolated and subsequently tumoral removal from outside to inside of the tumors obtained. This surgical procedure is satisfactory for sellar lesion with different juxtasellar extension. After surgery, CT scan and MR image showed that total removal of the tumor was achieved in 10 patients. Six patients who received subtotal resection were treated with postoperative radiation therapy or gamma knife surgery. Two patients developed postoperative cerebrospinal fluid leak that was successfully managed by conservative treatment within 6 days after surgery. No other new postoperative endocrinological or neurological defects occurred. Six months to 5 years follow up indicated that all 16 patients with the visual disturbances and 4 patients with endocrine impairments have recovered or improved. One patient with malignant meningioma died due to recurrence of the tumor 2 years postoperation. Another one patient with malignant inverted papilloma recurred 1 year postoperation and underwent operation and radiation therapy again. The EETT approach might better facilitate the removal of different extensive sellar lesions with maximal preservation of important anatomical structures and nasal function.

Validity and reproducibility of cephalometric measurements obtained from digital photographs of analogue headfilms

The emerging market of digital cephalographs and computerized cephalometry is overwhelming the need to examine the advantages and drawbacks of manual cephalometry, meanwhile, small offices continue to benefit from the economic efficacy and ease of use of analogue cephalograms. The use of modern cephalometric software requires import of digital cephalograms or digital capture of analogue data: scanning and digital photography. The validity of digital photographs of analogue headfilms rather than original headfilms in clinical practice has not been well established. Digital photography could be a fast and inexpensive method of digital capture of analogue cephalograms for use in digital cephalometry.

AIM

The objective of this study was to determine the validity and reproducibility of measurements obtained from digital photographs of analogue headfilms in lateral cephalometry.

MATERIAL AND METHODS

Analogue cephalometric radiographs were performed on 15 human dry skulls. Each of them was traced on acetate paper and photographed three times independently. Acetate tracings and digital photographs were digitized and analyzed in cephalometric software. Linear regression model, paired t-test intergroup analysis and coefficient of repeatability were used to assess validity and reproducibility for 63 angular, linear and derivative measurements.

RESULTS AND CONCLUSIONS

54 out of 63 measurements were determined to have clinically acceptable reproducibility in the acetate tracing group as well as 46 out of 63 in the digital photography group. The worst reproducibility was determined for measurements dependent on landmarks of incisors and poorly defined outlines, majority of them being angular measurements. Validity was acceptable for all measurements, and although statistically significant differences between methods existed for as many as 15 parameters, they appeared to be clinically insignificant being smaller than 1 unit of measurement. Validity was acceptable for 59 of 63 measurements obtained from digital photographs, substantiating the use of digital photography for headfilm capture and computer-aided cephalometric analysis.

Evaluation of platybasia in patients with idiopathic trigeminal neuralgia

BACKGROUND

Vascular compression of the trigeminal nerve is generally accepted as the primary source causing TN. To date, skull base bone deformity associated with ITN has been reported in only a number of case reports. The aim of the present study was to investigate one such skull base deformity, platybasia, in ITN patients in comparison with a randomized control population.

METHODS

Basal angle values reflecting the development of platybasia were measured in 25 patients with ITN and compared with the measurements in 25 control subjects.

RESULTS

Basal angle measured to investigate the existence of platybasia was found significantly wider in the ITN group (t = 3.90; P < .001), although platybasia was present in only 10 patients. Moreover, the average angle was also greater in the study group than in the control group, and the difference was statistically significant. Platybasia was found in 10 patients, whereas it was detected in only 2 control individuals; difference in platybasia incidence between the 2 groups was also statistically significant (chi(2) = 7.01; P < .01).

CONCLUSION

Our data demonstrated that platybasia affecting the bony walls of the posterior fossa may play an important role in the pathogenesis if vascular abnormalities causing TN.