Posterior clinoid process in children: morphometric analysis, pneumatization ratio, and surgical implications.

PURPOSE: To describe pneumatization and topographic position of the posterior clinoid process (PCP) in healthy children when approaching the anterior and middle fossae. METHODS: The study consisted of computed tomography images of 180 pediatric patients (90 males / 90 females), aged 1-18 years. The presence or absence of PCP pneumatization was noted, and the distances of certain landmarks to PCP were measured. RESULTS: The distances of the foramen ovale, foramen rotundum, superior orbital fissure, anterior clinoid process (ACP), foramen magnum and crista galli to PCP were measured as 18.59 ± 3.36 mm, 15.37 ± 3.45 mm, 14.60 ± 3.05 mm, 5.27 ± 3.24 mm, 32.03 ± 3.27 mm, and 30.45 ± 3.93 mm, respectively. These parameters increased with growth (between 1-18 years), but the distance between PCP and ACP decreased with an irregular pattern. In 11 sides (3.10%), a fusion between PCP and ACP was determined. PCP pneumatization was identified in 32 sides (8.9%). Its pneumatization correlated with pediatric ages (p < 0.001), but not gender (p = 0.459) or side (p = 0.711). Most of PCP pneumatization appeared after late childhood period (i.e., between 10-18 years). CONCLUSION: Our study provides beneficial data for neurosurgeons to use PCP as a reference point for creating a skull base map in children, because of the incomparable position of PCP in the skull base center.

Anatomical features of the sphenoid ridge in the pediatric population.

PURPOSE: To describe the relation of the sphenoid ridge (SR) with the surrounding anatomical structures in healthy children when approaching the anterior and middle fossae. METHODS: Computed tomography of 180 pediatric patients (90 males / 90 females), aged 1-18 years were included the study. The size of the lesser wing (LW) and the distances of the LW to certain landmarks were measured. RESULTS: The LW length was 28.48 ± 8.15 mm. The LW widths at the midline and the midpoint and lateral point of the SR were 7.78 ± 1.74 mm, 2.84 ± 0.81 mm, and 1.91 ± 0.64 mm, respectively. The distance between the midpoint of the SR and the crista galli was 28.22 ± 5.56 mm, and the distance between the crista alaris and internal auditory meatus was 51.73 ± 5.79 mm. The linear function was calculated as y = 18.748 + 1.024 × age for SR length, y = 6.046 + 0.182 × age for the midline width of SR, y = 2.367 + 0.050 × age for the midpoint width of SR, y = 1.249 + 0.069 × age for the crista alaris width, y = 21.727 + 0.683 × age for the distance between the SR midpoint and the crista galli, and y = 43.614 + 0.855 × age for the distance between the crista alaris and internal auditory meatus. CONCLUSION: All measured parameters increased irregularly with advancing age. Furthermore, our regression equations representing the growth dynamics of SR may be used to estimate these parameters.

Pediatric Anatomy of the Sternocleidomastoid Muscle on Magnetic Resonance Imaging Views.

OBJECTIVE: This study aimed to investigate morphologic features of the sternocleidomastoid muscle (SCM) in children for pediatric head-neck surgeries. METHODS: Magnetic resonance imaging images of 84 (46 males/38 females) pediatric patients aged ages 1 to 18 years (mean age: 9.38 ± 4.46 y) constituted the study universe. The size of SCM (including its height, width, and angulation) was measured, and the origin types of SCM were noted. RESULTS: All patients had SCM bilaterally. The origin variation of SCM was observed in 22 sides (13.10%). The authors observed type 1 in 146 sides (86.90%), type 2a in 15 sides (8.90%), type 3 in 2 sides (1.20%), type 4 in 1 side (0.60%), and type 5 in 4 sides (2.40%). The absence and presence of SCM variation were not affected by sex (P = 0.370) and side (P = 0.360). All measured parameters were similar in right and left sides, and also in males and females, except from the angle between the junction of the sternal and clavicular heads of SCM. The angle was greater in males than females (P = 0.004). All measured parameters increased with advancing age (between 1 and 18 y; P < 0.05). CONCLUSION: The authors' SCM-related data may be useful for clinicians to estimate the size origin variations of SCM in children.

Precise Localization of the Posterior Clinoid Process in the Fetal Skull Base.

OBJECTIVE: To determine the precise position of the posterior clinoid process (PCP) in fetuses. MATERIALS AND METHODS: Skull bases of 32 fetuses (11 males/21 females) aged 17 to 32 weeks in utero were included in the study. The distances of PCP to certain reference points were measured. RESULTS: The distances of PCP to the foramen ovale, foramen rotundum, superior orbital fissure, anterior clinoid process, foramen magnum, and crista galli were measured as 7.70±1.86 mm, 6.99±1.65 mm, 6.07±1.85 mm, 3.85±1.10 mm, 15.34±3.38 mm, and 14.49±2.65 mm, respectively. All parameters were similar for both sides (P>0.05). Apart from the distance of PCP to the foramen magnum, the remaining parameters were similar for both genders. This parameter was greater in males than females (P=0.001). All parameters were greater in the third-trimester fetuses than the second-trimester fetuses. All parameters increased with advancing gestational weeks (P<0.001). Linear functions were calculated for the distances of PCP to the crista galli (y = 1.311 + 0.551 × age), to the foramen magnum (y = 0.086 + 0.638 × age), to the anterior clinoid process (y = -0.303 + 0.174 × age), to the superior orbital fissure (y = - 2.013 + 0.338 × age), to the foramen rotundum (y = 1.803 + 0.217 × age), and to the foramen ovale (y = 0.760 + 0.290 × age). CONCLUSION: The measured distances increased with growth. The linear functions displaying the growth dynamics of PCP-related parameters may be used to estimate the distances.

Vidian Canal in Chiari Type I Malformation: A Computed Tomography Study.

OBJECTIVE: To evaluate the position and dimension of the Vidian canal (VC) in Chiari type I malformation (CIM). MATERIALS AND METHODS: Radiologic views of 49 CIM (mean age: 23.58±15.62 y, sex: 23 males/26 females) and 51 healthy subjects (mean age: 42.50±20.12 y, sex: 21 males/30 females) were included in this computed tomography study. RESULTS: In comparison with controls, the VC angle and the distance of the round foramen to VC were greater in CIM, but VC length and the distances of the superior wall of the bony sphenoidal sinus, midsagittal plane, and vomerine crest to VC were smaller in CIM. Relative to the sphenoid bone, the position of VC in CIM was determined as type 1 (59.2%) >type 2 (28.6%) >type 3 (12.2%), whereas in controls as type 1 (54.9%) >type 3 (25.5%) >type 2 (19.6%). Relative to the medial pterygoid plate, the position of VC in CIM was determined as type A (63.3%) >type B (20.4%) >type C (16.3%), while in controls as type B (43.1%) >type A (40.2%) >type C (16.7%). CONCLUSION: VC size and position correlated with CIM. Compared with controls, CIM patients had more partially protruded VC into the bony sphenoidal sinus and more medially located VC according to the medial pterygoid plate.

Crista Galli Morphology in Fetuses.

OBJECTIVE: To determine alterations in the crista galli (CG) size in fetuses with advancing weeks. METHODS: Skull bases of 32 fetuses (11 males/21 females) aged 17 to 32 weeks in utero were included in the study. The width (width of CG), height (height of CG), and length (length of CG) of CG were measured, and also olfactory fossa depth (OFD) was measured to determine the relation of CG with OFD. RESULTS: Width of CG, height of CG, length of CG, and OFD were measured as 1.77 ± 0.59 mm, 5.10 ± 1.70 mm, 12.32 ± 2.25 mm, and 1.56 ± 0.56 mm, respectively. No significant difference was observed between the measurements in terms of sex and side (P> 0.05). Apart from OFD, the parameters were greater in the third-trimester fetuses than in the second-trimester fetuses (P< 0.001). Olfactory fossa depth was similar in both trimester fetuses (P= 0.798). Olfactory fossa depth did not alter with advancing gestational weeks (P= 0.077), but the others increased (P< 0.01). Only one configuration regarding Keros types was observed. Type 1 was detected in all fetuses (100%). A linear function was calculated as y=1.442+0.455×age for the length of CG, y=-2.566+0.321×age for the height of CG, y=0.641+0.039×age for OFD, and y=-1.088+0.119×age for the width of CG. CONCLUSIONS: Crista galli size increased with advancing fetal weeks. The authors detected Keros type 1 in all fetuses. The authors' linear functions representing the growth pattern of CG and OFD in fetuses may be useful in estimating their dimensions.

Age-dependent changes in the hyoid bone morphology in children.

PURPOSE: This radiologic work aimed to display the alteration in the hyoid bone (HB) morphology in the pediatric population with advancing age. METHODS: This pediatric examination consisted of computed tomography images of 129 subjects (49 males / 80 females) aged 1-17 years. RESULTS: The anterior-posterior length of HB, the lengths of right and left greater horns, the width and height of HB's body, and the distance between the midpoints of the posterior ends of the greater horns increased with advancing age (p < 0.001), but the angle of the right and left greater horns (p = 0.022) decreased. Four configurations regarding HB shape were observed: Type A (U-shaped HB) in 8.5% (11 HBs) out of 129 children, Type B (B-shaped HB) in 33.3% (43 HBs), Type C (D-shaped HB) in 45% (58 HBs), and Type D (V-shaped HB) in 13.2% (17 HBs). HB shape types correlated with the pediatric age (p < 0.001), but not gender (p = 0.153). CONCLUSIONS: Most of the parameters increased until the postpubescent period, but the angle of the right and left greater horns decreased after the late childhood. Our linear functions representing the growth pattern of HB in children may be useful to estimate HB size.

Pneumatization types of the dorsum sellae: a computed tomography study.

PURPOSE: The present work aimed to classify the pneumatization of the dorsum sellae (DS) in subjects aged 1-90 years. METHODS: The study consisted of computed tomography images of 1080 subjects (582 males / 498 females), aged 1-90 years (mean age: 45.51 ± 26.06 years). Four different types regarding DS pneumatization were defined as follows: Type 0: no pneumatization, Type 1: pneumatization < 50%, Type 2: pneumatization > 50%, and Type 3: total pneumatization. RESULTS: DS pneumatization was identified in 354 (32.8%) subjects (189 males and 165 females). Its pneumatization was identified in 51 (21.2%) out of 241 children, and 303 (36.1%) out of 839 adults. The frequency of DS pneumatization types was found as follows: Type 0 (no pneumatization in 726 subjects, 67.2%) > Type 1 (pneumatization < 50% in 234 subjects, 21.6%) > Type 2 (pneumatization > 50% in 87 subjects, 8.1%) > Type 3 (total pneumatization in 33 subjects, 3.1%). DS pneumatization incidence was affected by ages (p < 0.001), but not sex (p = 0.818). The pneumatization degrees of DS (i.e., the distributions of Types 1-3) were not affected by ages (p = 0.637) or sex (p = 0.391). CONCLUSION: The pneumatization incidence of DS increased significantly with advancing adult ages (especially in elderly people). DS pneumatization should be taken into account by neurosurgeons and neuroradiologists to decrease the risk of complications such as cerebrospinal fluid fistula during surgeries such as posterior clinoidectomy.

Topographic anatomy of the endolymphatic sac: a pilot cadaveric dissection study.

PURPOSE: The precise location of the endolymphatic sac (ES) may be difficult during surgical approaches. This morphometric study aimed to determine the exact location of ES in adult human cadavers for the management of pathologies such as Meniere's disease. METHODS: Twenty temporal bones of 10 adult cadavers (mean age: 70 ± 13.40 years, range: 45-92 years; sex: 4 males and 6 females) fixed with 10% formalin were bilaterally dissected to obtain numeric data about the location of ES. RESULTS: Distances of ES to the posterior semicircular canal (PSC), Donaldson line (DL), sigmoid sinus (SS) and sinodural angle (SA) were found as 2.76 ± 1.18 (0.96-5.58) mm, 1.74 ± 1.13 (0.58-5.07) mm, 2.30 ± 1.09 (0.54-4.91) mm and 16.04 ± 3.15 (9.82-22.18) mm, respectively. In addition, the angle between the tangents passing through the cortical bone (CB) and SS was determined as 35.37°±11.32° (21.30°-60.58°). No statistical difference was found between right-left or male-female measurements (p > 0.05). CONCLUSION: DL, SS, and PSC are essential anatomical landmarks for determining the location of ES. The spatial location of SS, including its depth to the cortical bone and the distance to anteriorly located anatomical structures of the mastoid cavity consisting of the facial nerve and PSC, is believed to be underlined for ES surgery. Our data may be used as a database to further define the relationship between ES and adjacent anatomical structures (SS, PSC, etc.) during the application of surgical approaches.

Radiologic evaluation of the Vidian canal in the pediatric population.

PURPOSE: This examination aimed to display the size and topographic position of the Vidian canal (VC) in normal children. METHODS: 180 pediatric subjects aged 1-18 years were included this computed tomography examination. The distances of VC to certain landmarks, and VC length were measured. The locations of VC according to the sphenoid sinus, and the medial plate of pterygoid process were classified as three types, separately. RESULTS: The distances of VC to the vomerine crest, midsagittal plane, round foramen, and the superior wall of sphenoid sinus were measured as 12.68 ± 3.17 mm, 10.76 ± 2.52 mm, 8.62 ± 2.35 mm, and 14.16 ± 5.00 mm, respectively. The length and angle of VC were measured as 12.00 ± 2.52 mm, and 16.60 ± 9.76°, respectively. According to the sphenoid bone, VC location was identified as Type 1 in 113 sides (47.5%), as Type 2 in 70 sides (29.4%), and as Type 3 in 55 sides (23.1%). According to the medial plate of pterygoid process, VC location was identified as Type A in 274 sides (76.1%), as Type B in 55 sides (15.3%), and as Type C in 31 sides (8.6%). VC location types correlated with pediatric ages, but not sex or side. CONCLUSION: With advancing pediatric age, the protrusion of VC into the sphenoid sinus increases, and VC shifts from medial to lateral side of the medial plate of pterygoid process.

Massa intermedia in adults: incidence, dimension, location and clinical importance.

PURPOSE: This retrospective magnetic resonance imaging investigation aimed to obtain information related to the anatomy of the massa intermedia (MI) in an adult population. METHODS: The work conducted on MRI views of 1058 (539 males and 519 females) healthy adult samples aged with 48.93 ± 17.63 years. Initially, the presence or absence of MI was noted, and then if present, its numbers and location in the third ventricle were recorded. Its horizontal (HDMI) and vertical (VDMI) diameters were measured on MRI views, while the cross-sectional area (CSAMI) was calculated using its diameters. RESULTS: MI was missing in 2.6% (27 cases) of 1058 adult samples. Six subjects (0.6%) had a double MI. HDMI, VDMI and CSAMI were measured as 4.83 ± 1.01 mm, 4.86 ± 0.98 mm, and 19.11 ± 7.23 mm2, respectively. MI size did not show a significant alteration from 19 up to 49 years, but then its size distinctly decreased between 50 and 60 years. After age 60, MI dimension did not display an important change. MI was settled in the antero-superior quadrant in 929 cases (90.63% of 1025 subjects), in the postero-superior quadrant in 22 cases (2.15%), in the antero-inferior quadrant in 32 cases (3.12%), in the postero-inferior quadrant in 8 cases (0.78%), and in the central part in 34 cases (3.32%). CONCLUSIONS: The size, position and incidence of MI were not affected by sex, and its position and incidence were not affected by adult age periods. In adults, MI size demonstrated a significant decrease in the middle age.

Sternocleidomastoid Muscle in Fetuses: Classification, Morphometric Analysis, and Clinical Significance.

PURPOSE: This study aimed to examine variations and morphometric properties of the sternocleidomastoid muscle (SCM) in fetuses in terms of infancy and early childhood surgeries. MATERIALS AND METHODS: Neck regions of 27 fetuses (mean age: 23.30±3.40 wk, sex: 11 boys and 16 girls) fixed with 10% formalin were dissected bilaterally. Photographs of the dissected fetuses were taken in the standard position. Morphometric measurements, such as length, width, and angle, were performed on the photographs using the ImageJ software. In addition, the origin and insertion of SCM were detected. Taking into account the studies in the literature, a classification consisting of 10 types associated with the origin of SCM was carried out. RESULTS: No statistically significant difference was observed in the parameters in terms of side and sex ( P >0.05), except from the linear distance between the clavicle and motor point where the accessory nerve enters SCM (20.10±3.76 for male, 17.53±4.05 for female, P =0.022). Two-headed SCM (Type 1) was detected in 42 out of 54 sides. Two-headed clavicular head (Type 2a) was detected on 9 sides, and 3-headed (Type 2b) on 1 side. A 2-headed sternal head (Type 3) was detected on 1 side. A single-headed SCM (Type 5) was also detected on 1 side. CONCLUSION: Knowledge related to variations of the origin and insertion of fetal SCM may be helpful in preventing complications during treatments of pathologies such as congenital muscular torticollis in early period of life. Moreover, the calculated formulas may be useful to estimate the size of SCM in newborns.

Ischiofemoral space dimensions for ischiofemoral impingement: is it different in children?

OBJECTIVE: This study intended to analyze alterations in ischiofemoral space (IFS) dimensions in normal children between the ages of 1 and 18 years for the ischiofemoral impingement. MATERIALS AND METHODS: This study retrospectively focused on computed tomography images of 360 hips of 180 (90 boys and 90 girls) pediatric subjects (mean age: 9.50 ± 5.20 years, range: 1-18 years) without any hip disorders to measure IFS, femoral neck angle (FNA), and ischial angle (IA). RESULTS: Mean IFS, FNA, and IA were measured as 14.64 ± 7.24 mm, 34.61 ± 11.47°, and 131.52 ± 4.22°, respectively. IFS increased in children aged between 1 and 18 years, whereas FNA and IA decreased. IFS was similar in infancy and early childhood periods but then increased up to postpubescent period. FNA decreased proportionally from birth, whereas IA decreased in an irregular pattern. Linear functions were detected as y = 3.451 + 1.178 × years for IFS, as y = 48.555 - 1.468 × years for FNA, and as y = 132.535 - 0.107 × years for IA. CONCLUSION: Our findings indicate that IFS tends to increase in size with age during childhood but decreases with further aging. Therefore, age-specific values for IFS, FNA, and IA may be beneficial for clinicians and radiologists for the diagnosis of ischiofemoral impingement.

Cochleo-facial corridor to the vestibule and fundus of the internal auditory canal through oval window: a minimal invasive and cochlea sparing approach.

PURPOSE: This cadaveric work aimed to test the effectiveness of a modified surgical corridor (ExpTSA: expanded transcanal supracochlear approach) developed for anatomic cochlear preservation in selected vestibular schwannoma patients necessitating to perform cochlear implantation for appropriate cases to achieve the best outcome. METHODS: The ears of 10 cadavers (at mean age 75.70 ± 13.75 years, range 45-92 years) were dissected from the external auditory canal (EAC) to the internal auditory canal by ExpTSA under the guidance of a microscope and endoscope. All stages of the surgical process were recorded step by step and evaluated morphometrically. RESULTS: The vestibular base was successfully reached in all ears without damaging the cochlear morphology and facial nerve. The vestibular base was 23.33 ± 2.02 mm away from the entrance (external orifice) and 10.26 ± 1.33 mm from the exit (internal orifice) of EAC. The oval window and vestibular base were measured to be 2.94 ± 1.05 mm and 5.87 ± 1.24 mm deep from the facial nerve, respectively. The normal areas of the oval window, the exit and entrance of EAC were found as 2.90 ± 0.81 mm2, 42.52 ± 13.66 mm2, and 110.73 ± 25.32 mm2, respectively. After ExpTSA procedure, the areas of the oval window (11.04 ± 2.83 mm2), the exit (122.45 ± 20.41 mm2) and entrance (167.49 ± 30.94 mm2) of EAC were expanded approximately 280%, 188%, and 50%, respectively. CONCLUSION: The ExpTSA may be performed for accessing to the vestibule and fundus of IAC for tumor removal of intravestibular schwannoma patients (with or without fundus involvement) with unserviceable hearing, preserving the cochlear morphology.

Evaluation of the Cranial Aperture of the Optic Canal on Cone-Beam Computed Tomography Images and its Clinical Implications for the Transcranial Approaches.

OBJECTIVE: This study aimed to investigate morphometric properties of the cranial aperture (CA) of the optic canal. METHODS: Cone-beam computed tomography images of 400 individuals (200 males and 200 females) aged 37.32 ± 15.87 years were retrospectively examined to assess the morphometry and morphology of the CA. RESULTS: The height and width of CA were found as 4.22 ± 0.74 mm and 7.27 ± 1.15 mm, respectively. The distances between the CA and the midsagittal line, the anterior and lateral boundaries of the anterior skull base were measured as 5.77 ± 1.32 mm, 64.97 ± 6.36 mm, and 41.00 ± 4.05, respectively. The angle of the optic canal in the sagittal plane was measured as 7.57° ± 3.95°, whereas in the horizontal plane as 38.96° ± 4.36°. The aperture shape was defined as the tear-drop (413 foramina, 51.62%), triangular (180 foramina, 22.50%), oval (158 foramina, 19.75%), round (30 foramina, 3.75%), and polygonal (19 foramina, 2.38%). CONCLUSIONS: The authors observed that the diameters, and angulations of the CA may change relative to gender and the shape. The anatomic features of CA are important for the positioning of the patient's head, the choice of the appropriate surgical approach or equipment, and the detection of anatomical landmarks during interventions. In this context, our dataset may be beneficial for surgeons helpful as a reference for radiological evaluations.

Change in the Location of the Optic Strut Relative to the Anterior Clinoid Process Pneumatization.

OBJECTIVE: This study aimed to peruse the alteration of the position of the optic strut (OS) according to the anterior clinoid process (ACP) pneumatization. METHODS: This retrospective study conducted on cone-beam computed tomography images of 400 patients with a mean age of 36.49±15.91 years. RESULTS: Anterior clinoid process length, width, and angle were measured as 10.56±2.42 mm, 5.46±1.31 mm, and 42.56±14.68 degrees, respectively. The tip of ACP was measured as 6.60±1.50 mm away from the posterior rim of OS. In the 631 sides (78.87%) did not have ACP pneumatization. In the cases with ACP pneumatization, three different configurations were identified as follows: Type 1 in 71 sides (8.87%), Type 2 in 56 sides (7%), and Type 3 in 42 sides (5.23%). Relative to ACP, the location of OS was determined as follows: Type A in 29 sides (3.64%), Type B in 105 sides (13.12%), Type C in 344 sides (43%), Type D in 289 sides (36.12%), and Type E in 33 sides (4.12%). The spread of data related to the attachment site of OS according to the presence or absence of ACP pneumatization showed that the location of OS was affected by ACP pneumatization ( P <0.001). In ACPs with pneumatization, the frequency of OS position relative to ACP was found as follows: Type A in none of sides (0%), Type B in 8 sides (7.6%), Type C in 53 sides (15.4%), Type D in 88 sides (30.4%), and Type E in 20 sides (60.6%). CONCLUSIONS: The main finding of this study was that the location of OS relative to ACP was affected by ACP pneumatization. In ACPs with pneumatization, OS was located more posteriorly compared with ACPs without pneumatization.

Arnold Kirkpatrick Henry (1886-1962) and his eponym (Master Knot of Henry): a narrative review.

PURPOSE: The aims of this review were to form a more precise description for Master Knot of Henry (MKH), and to modify classifications related to interconnections between flexor hallucis longus (FHL) and flexor digitorum longus (FDL) for showing all configurations in the literature. METHODS: A literature search was performed in main databases to obtain information related to anatomical definitions and variations of MKH. The search was carried out using the following keywords: "Master Knot of Henry", "Chiasma plantare", "Flexor hallucis longus" and "Flexor digitorum longus". Information extracted from the studies was: sample size, numerical values, classifications, variation types, incidence of types, anatomical definitions of MKH, year of publication, and type of study. RESULTS: This study proposes that MKH should be defined as the intersection territory where FDL crosses over FHL in the plantar foot. The postchiasmatic plantar area located at distal to MKH (the narrow space between MKH and the division of FDL) should be termed as the triangle of Henry. Moreover, the classification systems showing different configurations related to interconnections situated at Henry's triangle were updated as eight types to present all forms in the literature. CONCLUSION: Our definitions may assist in determining the precise anatomical boundaries of MKH, and thus facilitate the use of MKH as a surgical landmark. In addition, our modified classification systems covering all variations in the current literature may be helpful for surgeons and anatomists to understand formations of the triangle of Henry, and the long flexor tendons of the lesser toes.

Evaluation of Bell's palsy in the cerebellopontine angle: An MRI study.

BACKGROUND: Evaluation of cranial nerve morphology through measuring cross-sectional area (CSA) on magnetic resonance imaging (MRI) is increasing day-by-day in clinical diseases. In Bell's palsy (BP), the manifestation of the enlarged CSA of the facial nerve (FN) may be used for diagnosis. This study aims to evaluate whether there is an enlargement of the cisternal FN in BP. METHODS: This retrospective study included 43 patients diagnosed with BP. In the reconstructed MRI, the long (LD) and short (SD) diameters of the paralytic and normal sides of the FNs located in the cerebellopontine angle were measured, and the CSA was calculated using the Radinsky formula. Before the radiologic measurement, a preliminary experiment was carried out on the rat sciatic nerve to be able to determine the actual nerve boundary on MRI. FINDINGS: There was a statistically significant relationship between paralytic and normal sides in the measurements of LD, SD, and CSA. The paralytic side was larger than the normal side in the cisternal FN. According to the Receiver Operating Characteristic (ROC) curve, BP can be estimated with 60% sensitivity and 70% specificity by the CSA of the FN more than 1.04 mm2 . As a result of the preliminary experiment, it was found that the actual nerve boundary was at approximately 50% intensity between the minimum and maximum values. CONCLUSION: Although entrapment of FN in the labyrinthine segment in BP was known, this study showed that the cisternal FN, which could be evaluated more conveniently, enlarged in the paralytic side compared with the normal side, and revealed the necessity of performing the comparison amongst the MRI studies on BP patients by a standardised measurement method. This study will also help clinicians to make a decision in the diagnosis of BP by giving a cut-off value for the CSA.

Chiasmatic Ridge: Incidence, Classification, and Clinical Implications.

OBJECTIVE: The study aimed to identify the chiasmatic ridge (CR) morphology and to discuss its surgical significance. METHODS: The suprasellar region of 90 adult dry skulls with unknown ages, sexes, or nationalities was examined to record the shape and incidence of the CR. RESULTS: The CR was found in 14 (15.56%) of 90 dry skulls. The ridge was classified into 3 types, taking into account its shape, incidence (presence/absence), and the risk of residual tumor formation. The absence of the CR was named as Type 1 (76 cases, 84.44%). The bony extension without a hidden area was identified as Type 2 (8 cases, 8.89%), while the bony extension with a hidden area as Type 3 (6 cases, 6.67%). CONCLUSION: Type 3 CR (which has an evident hidden area beneath the ridge) should be taken into account by neurosurgeons to eliminate possible residual tumor risk during removal of tumors (eg, meningioma) with subfrontal or supraorbital approaches.

Morphological features of the chiasma tendinum and its relation with surface landmarks and pulleys: a cadaveric study.

AIM: Chiasma tendinum (Camper's chiasm) is of great importance in the delicate movements and stability of the fingers and takes place poorly in the literature. This study aims to reveal the morphometric details of the chiasma tendinum in relation with pulleys and other relevant structures. MATERIALS AND METHODS: Palm and 2nd to 5th fingers of 10 (6 male, 4 female) formalin fixed cadavers were used bilaterally. After determining the superficial reference points on the fingers, the skin and the tendon sheath were incised, and then measurements of chiasma tendinum and related tendons were performed. The measurements were analyzed with respect to fingers, genders, and sides. Finally, the types of chiasma tendinum were identified and then grouped as symmetrical, asymmetrical, and pseudo chiasm. RESULTS: Pulley and chiasma tendinum positions were correlated with finger length (p < 0.01). Pulley lengths were significantly less in females. Asymmetrical chiasma tendinum types were found in 45% of the fingers. In most comparisons, values for fifth finger were significantly different than that of other fingers and chiasma tendinum types differed according to fingers and gender. The case of no fiber exchange was observed only in the 5th finger in 15%. CONCLUSION: Findings related to the prediction of location of the pulleys and chiasma tendinum according to the superficial signs, awareness of cases where one of the two arms of the flexor digitorum superficialis is extremely thin and no fiber exchanges that may be risk factors for spontaneous tendon rupture may help provide more accurate approaches in relevant clinical applications.