Re-defining the anatomical structures for blocking the nerves in adductor canal and sciatic nerve through the same injection site: an anatomical study.

PURPOSE: The aim of this study is to re-define the anatomical structures which are important for blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site. We also aimed to investigate the spread of the anesthetic toward the areas in which the mentioned nerves lie on cadavers. METHODS: This study was performed on 16 lower extremities of formaldehyde-embalmed eight adult cadavers. The anatomy of adductor canal, courses of the nerves within the canal and the relationships of the saphenous, medial femoral cutaneous, medial retinacular, posterior branch of the obturator and sciatic nerves with each other and with the fascial compartments were investigated. Transverse sections that crossed the superior border of vastoadductor membrane were taken to reach the sciatic nerve in the shortest way. Colored latex was injected to demonstrate the anesthetic blockage of the targeted nerves. The structures along the needle's way were investigated. RESULTS: The saphenous, medial femoral cutaneous and at its distal part posterior branch of the obturator nerve were colored with latex within the adductor canal. The nerve to vastus medialis (in other words, the medial retinacular nerve) lay beneath the fascia of vastus medialis and did not enter the adductor canal. There was a fascial plane which did not allow the passage of colored latex toward the sciatic nerve. To traverse this fascial structure, it was found out to be necessary to insert the needle perpendicular to both the vertical and transverse axes of the thigh and then advance it along 2/3 of diameter of the thigh. Thus, the colored latex was observed to fill the compartment where the sciatic nerve lay within. CONCLUSIONS: Blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site seems anatomically possible without injuring any neurovascular structures.

Arterial vascularisation of the anterior perforated substance.

INTRODUCTION: The arteries of the anterior perforated substance (APS) are important due to their role in supplying blood to important internal structures such as the internal capsule, putamen and caudate nucleus. The purpose of this study was to investigate in detail the arteries of the APS. METHODS: The arteries of the APS were investigated in 60 cerebral hemispheres from 30 adult cadaveric brains. The internal carotid arteries were cannulated and perfused with coloured latex. The branches of the middle cerebral artery (MCA) penetrating the APS were investigated. These arteries, known as the lateral lenticulostriate arteries and originating from the M1 segment, early temporal and early frontal branches of the MCA, were recorded. RESULTS: The branches of the anterior choroidal artery, which reached the APS, were seen in all specimens. We found one to three branches that arose from the A2 segment of the anterior cerebral artery (ACA) to the APS in all hemispheres, and one to three branches that originated from the A1 segment of the ACA in 48 hemispheres. In addition, two accessory MCAs that originated from the A2 segment of the ACA were recorded as variations, and perforating branches to the APS were observed. CONCLUSION: Serious complications like motor deficits can occur as a result of injury to the arteries of the APS. Hence, neurosurgeons performing operations such as aneurysm or insular tumour surgeries must be aware of the importance of preserving these arteries.

Lateral approach to the ankle and distal leg.

Fractures of the distal tibia are usually high-energy injuries and are well known for their soft tissue complications after surgery. Various factors have been studied regarding the possibility of them reducing the incidence of such damage, including timing of surgery, staged surgery, fixation method, and surgical approach. Less invasive surgical techniques with vascularity preserving approaches were proposed as reasonable solutions to this problem. The aim of this study was to investigate the presence of minor vascular structures, which can be preserved during anterolateral approach, possibly contributing to the success of the approach. Lateral approach for the distal tibia was performed in 22 cadaver feet. The mean distance between the lateral malleolus and the superficial peroneal nerve was 12.2 cm. Two different vascular pedicles, from peroneal vessels to muscles of the anterior compartment, were 4.3 and 8.2 cm away from the lateral malleolus, respectively. We conclude that preserving greater vascularity was possible in the lateral approach for the distal tibia, placing the plate in a completely submuscular plane.

Neurovascular relationship between abducens nerve and anterior inferior cerebellar artery.

We aimed to study the neurovascular relationships between the anterior inferior cerebellar artery (AICA) and the abducens nerve to help determine the pathogenesis of abducens nerve palsy which can be caused by arterial compression. Twenty-two cadaveric brains (44 hemispheres) were investigated after injected of coloured latex in to the arterial system. The anterior inferior cerebellar artery originated as a single branch in 75%, duplicate in 22.7%, and triplicate in 2.3% of the hemispheres. Abducens nerves were located between the AICAs in all hemispheres when the AICA duplicated or triplicated. Additionally, we noted that the AICA or its main branches pierced the abducens nerve in five hemispheres (11.4%). The anatomy of the AICA and its relationship with the abducens nerve is very important for diagnosis and treatment.

Callosal branches of the anterior cerebral artery: an anatomical report.

Although the morphology of the corpus callosum is well defined, the arterial supply of this structure has not been comprehensively studied. To elucidate this further, 40 cerebral hemispheres from 30 adult cadaveric brains were obtained. The anterior cerebral arteries were cannulated and injected with red latex. The following were observed and documented: (1) the number, diameter, and course of the arteries supplying the corpus callosum; (2) the territories vascularized by these arteries; (3) any variations of the callosal arteries. Short callosal arteries were present in 58 hemispheres (96.6%) and supplied the superficial surface of the corpus callosum along its midline and were a primary arterial source to this structure. Long callosal arteries were found in 28 hemispheres (46.6%) and contributed to the pial plexus. The cingulocallosal arteries were present in all hemispheres and supplied the corpus callosum, cingulate gyrus, and also contributed to the pericallosal pial plexus. The recurrent cingulocallosal arteries were present in 17 hemispheres (28.3%) and also contributed to the pericallosal pial plexus. The median callosal artery, an anatomical variation, was present in 10 brains (33.3%). This vessel supplied the corpus callosum and the cingulate gyrus. The aim of the present study was to provide a detailed description of the arteries supplying the corpus callosum for those who encounter these vessels radiologically or surgically.

Variations in anatomy at the suprascapular notch possibly causing suprascapular nerve entrapment: an anatomical study.

The purpose of the study was to determine anatomical variations at the suprascapular notch for better understanding of possible predisposing factors for suprascapular nerve entrapment. We dissected 32 shoulders of 16 cadavers between the ages of 39 and 74 years. We observed abnormally oriented superior fibers of the subscapularis muscle in five shoulders of the 16 cadavers, which were covering the entire anterior surface of the suprascapular notch and significantly reducing the available space for the suprascapular nerve. We also detected anterior coracoscapular ligament in six of the 32 shoulders, and calcified superior transverse scapular ligament in four of the shoulders. In this study, we classified the variations for the superior transverse scapular ligament. In conclusion, knowing the anatomical variations in detail along the course of the suprascapular nerve might be important for better understanding of location and source of the entrapment syndrome, especially for individuals who are involved in violent overhead sports activities such as volleyball and baseball. To our knowledge, close relationship of subscapularis muscle with the suprascapular nerve as a possible risk factor for suprascapular nerve entrapment has not been mentioned previously.

Bilateral paramedian thalamic infarct in the presence of an unpaired thalamic perforating artery.

Bilateral paramedian thalamic infarction is rare. The suggested mechanism is occlusion of a central unpaired thalamic perforating artery--an anatomic variant. In the few existing reports of this condition, the diagnosis was based on computed tomography (CT) or magnetic resonance imaging (MRI) findings alone. Other causes of thalamic lesions were not ruled out, and there was no angiographic demonstration of the presumed variant artery. We present a case of a 48-year-old man with a bilateral thalamic infarction seen on CT and MRI. Initial neurological examination revealed lethargy, severe combined motor and sensory aphasia, and a mild upward gaze limitation. The patient had no focal motor deficits. After 24 hours, the patient was more alert and his speech became more fluent, but Korsakoff-type amnesia with poor attention span became apparent. The patient improved slowly over 6 months of rehabilitation. Bilateral thalamic lesions can be caused by several conditions. Among those are thiamine deficiency, cerebral lupus, toxoplasmosis, cysticercosis, cerebral syphilitic gumma, and even tumors and fungal infections. All these were ruled out in our case. Superselective digital subtraction angiography (DSA) demonstrated a single unpaired thalamic perforator. To our knowledge, this is the first time this anatomical variant has been demonstrated in vivo in association with bilateral thalamic infarction.

Comprehensive microsurgical anatomy of the jugular foramen and review of terminology.

The microsurgical anatomy of the jugular foramen was studied in 12 formalin preserved cadavers (24 foramina) and 40 dry-skulls (80 foramina). The jugular foramen was exposed by microsurgical dissection with drilling from a superior to inferior direction. Observations regarding dural architecture of the jugular foramen and relationships between neurovascular structures passing through the foramen were noted in cadavers. Normal bony construction of the foramen and its variational anatomy were examined in dry-skull specimens. Using photographs and drawings, the anatomy of the jugular foramen is presented and related terminology is discussed in the light of a literature review.

Anatomical study of the lateral wall of the cavernous sinus, emphasizing dural construction and neural relations.

This study aims to determine the microscopic anatomy of the layers of the lateral wall of the cavernous sinus (CS) and, in particular, intends to examine the location and relations of the dural openings on the deep layer. Forty sides of 20 formalin-fixed and fresh cadavers were dissected and their CS examined. In 12 cases we found an opening on the deep dural layer; however, in four of them the inferolateral trunk of the internal carotid artery (ICA) was identified through these dural openings. We noticed the trochlear nerve making a curve (5% of cases) or lying close to the ophthalmic nerve (12.5%) on the lateral wall. In one case, the triangular area described by Parkinson could not be exposed surgically. Our findings indicate the importance of the heterogeneous courses of the cranial nerves lying on the lateral wall and point to the significance of the dural openings, which can influence the etiology of neoplastic invasions originating from the CS.

Radiological anatomy of the intratemporal course of facial nerve.

Preoperative evaluation of the facial nerve (FN) anatomy within the temporal bone by high-resolution computed tomography (HRCT) helps in minimizing surgical trauma to the nerve. In order to demonstrate the radiological correlation of the intratemporal FN, eight adult, formalin-preserved cadavers were studied by comparing the transaxial and coronal sections of HRCT with anatomic microdissection findings. It was possible to visualize all segments of the FN canal in its intratemporal course. The most difficult part of the FN to demonstrate was the pyramidal section. Anatomic microdissection findings were consistent with the HRCT images. It was concluded that adequate information on the FN anatomy could be obtained from standard HRCT scans.

Temporoparietal fascia: an anatomic and histologic reinvestigation with new potential clinical applications.

Temporoparietal fascia constitutes a very important structural unit from both an aesthetic and a reconstructive surgical point of view. A histologically supported anatomic study was conducted for the reappraisal of the anatomic relationships and clinical application potentials of the data obtained. Anatomy of the temporoparietal fascia was investigated on 20 sides from 10 cadavers. After dissections, necropsies were obtained to demonstrate histologic features of the temporoparietal fascia. The outer part of the temporoparietal fascia is continuous with the superficial musculoaponeurotic system (SMAS) in the inferior border and with orbicularis oculi and frontalis muscles in the anterior border. Therefore, plication of the temporoparietal fascia can increase tightness of the SMAS, orbicularis oculi, and frontalis muscle in rhytidectomy. The frontal branches of facial nerve were noted to course parallel to the frontal branch of the superficial temporal artery, lying deeper to the temporoparietal fascia within the innominate fascia. In the view of these findings, conventional subfascial dissection, which is performed to protect frontal branches of the facial nerve, is not reasonable during the temporal part of rhytidectomy. Careful subcutaneous dissection just under the hair follicles is more appropriate to avoid nerve injury and also provides excellent exposure of the temporoparietal fascia for plication in rhytidectomy with protection of the auriculotemporal nerve and the superficial temporal vessels. Furthermore, two layered structures of the temporoparietal fascia are very suitable to insert a framework into the temporoparietal fascia for ear reconstruction to eliminate some of the shortcomings of Brent's technique. A thin muscle layer was also noted within the outer part of the temporoparietal fascia below the temporal line; the term "temporoparietal myofascial flap" would, therefore, be more accurate than "temporoparietal fascial flap." Finally, the innominate fascia and the deep temporal fascia can be elevated with the two layers of the temporoparietal myofascial flap to obtain a well-vascularized, four-layered myofascial flap based on the superficial temporal vessels. This multilayered flap can be used to reconstruct all defects when fine, pliable, thin, multilayered flaps are required.

Surgical exposure in translabyrinthine approaches--an anatomical study.

OBJECTIVE: Translabyrinthine approach (TLA) is a procedure of choice for the removal of vestibular schwannomas in cases of profound hearing loss. There is a lack of anatomic studies reviewing the surgical anatomy of the cerebellopontine angle (CPA) as seen in the classical and enlarged TLAs. METHODS: Seven formalin-preserved cadavers were dissected. Structures, visualized in the CPA through the TLA, were scored according to the degree of their exposure (1, structure not seen; 2, partial exposure; 3, full exposure). RESULTS: The acousticofacial bundle, anterior inferior cerebellar artery and flocculus had the highest scores in both types of surgery. However. the fifth, ninth, and tenth cranial nerves, prepontine cistern, pons, superior cerebellar artery, and posterior inferior cerebellar artery had higher scores, i.e. better exposure, in the enlarged TLA than in the classical TLA. CONCLUSION: These findings suggest that the enlarged TLA be preferred in cases of larger tumors extending to either jugular foramen or middle fossa whereas the indications of the classical TLA should be limited to vestibular neurectomy and removal of smaller tumors.

The jugular foramen: a comparative radioanatomic study.

BACKGROUND: Advances in microsurgical techniques made possible the removal of advanced jugular foramen (JF) lesions, which once had been accepted as unoperable. However, successful surgery requires detailed knowledge of the JF anatomy. METHODS: Sixteen jugular foramina in eight formalin-preserved adult cadavers were scanned with axial and coronal high resolution computed tomography (HRCT) prior to dissection. After craniectomy and removal of brain tissue, the relationships of the neurovascular structures in the JF were determined by drilling the temporal bones from superior to inferior on planes parallel to the skull base. RESULTS: No bony partition of the JF was observed. A dural band consistently divided the JF into two parts. Anterior to it was the glossopharyngeal nerve (IX) while the vagus (X) and accessory (XI) nerves were located posteriorly. There was a notch in which the IX nerve entered the JF. It was also identified on the CT scans and defined as the glossopharyngeal recess. The IX nerve made a genu within the JF in all specimens. Then, it ran inferiorly through a bony canal in three specimens (18.75%), and through an incomplete bony canal in two (12.5%), which were also defined on the CT images. The inferior petrosal sinus ran through a sulcus anteromedial to the glossopharyngeal recess. The posterior meningeal artery was found to be located between the X and XI nerves within the JF. CONCLUSIONS: This study revealed a complex and highly variable pattern of the relationships of the neurovascular structures in the JF, and their HRCT images correlated well with the anatomic microdissections.

Branches of the intracavernous internal carotid artery and the blood supply of the intracavernous cranial nerves.

With the increasing frequency of surgical operations to the cavernous sinus greater knowledge of the microanatomy of the cavernous sinus has become necessary. The most frequently seen complications during cavernous sinus surgery involve impairment of cranial nerves. This can occur due to direct damage or ischemia. For these reasons, it is important to know the arterial supplies to the cranial nerves in the cavernous sinus and the anatomy of these branches as well. 15 formaline fixed adult cadavers were used in this study. Before the dissections, the internal carotid artery and vertebral artery were filled with coloured latex on both sides. In this report, the intracavernous branches of internal carotid artery (I.I.C.A.) were identified based on the principles of Nomina Anatomica (1989) and compared with others. In our study we found that the segment of the abducens nerve which lies in Dorello's channel was supplied by the meningeal branch; from the point at which it pierces the cerebellar tentorium, the trochlear nerve is supplied by the tentorial cerebellar artery; the posterior cerebellar artery supplies the proximal segment of the oculomotor nerve that proceeds to the oculomotor triangle. Except for these, all the cranial nerves that were located on the lateral wall of the sinus cavernosus are supplied by the tentorial marginal branch and the branches of the lateral trunk.

An anatomical study of the tympanic branch of the glossopharyngeal nerve (nerve of Jacobson).

Our study was aimed to examine the anatomic relationships of the tympanic branch of the glossopharyngeal nerve (GPN), namely the Jacobson's nerve (JN). The JN is the first branch of the GPN after having passed the jugular foramen. It contributes to the tympanic plexus on the promontory. It transmits secretory innervation to the parotid gland. Its possible role in the regulation of the middle ear pressure has also been hypothesized in terms of animal studies. Using microdissection techniques and high-resolution computed tomography (HRCT) scanning, the anatomic relationships and course of the JN were examined in eight formalin-preserved cadavers (16 sides). A morphometric analysis related to the JN was also performed both in the 16 cadavers and 40 dry-skull specimens. The JN emerged from the inferior ganglion of the GPN in all specimens. The mean distance between the ganglion and the genu of the GPN was 11.3 mm. The inferior 2/3 of the tympanic canal (TC) followed a vertical course, and then it ran anteromedially with an angle of 160 degrees to 170 degrees. The mean length of the TC was 9.5 mm. The TC was well-defined in all axial HRCT scans. In 2 cases the JN was entirely encased in a bony canal in the middle ear. A double JN was observed in one case. This study gives an additional information regarding the anatomy of the JN.

An assessment of fertility in boron-exposed Turkish subpopulations.

Relationships between elevated boron intake and fertility were sought by comparing reproduction in the residents of two Turkish villages with high levels of boron in their drinking water (one with 8.5 to 29 mg B/L and the other with 2.05 to 2.5 mg B/L), with three nearby villages with more typical low boron levels (0.03 to 0.40 mg B/L). The two high boron villages were designated as Region I, and the three villages with low boron in the drinking water were designated Region II. In addition to exposure to elevated boron in drinking water, 28.3% of the probands in Region I were employed in borate mining or processing, whereas in Region II, 11.7% were so employed. An observational study was carried out in which the authors compared the reproductive history of families living in Region I with families living in Region II by identifying married adults (referred to as probands) who were able to provide information about their and their spouses' family pedigrees covering three generations. Probands were identified by home visits and, if ever married, accepted for ascertainment. Evidence of fertility was birth of a living child, and data were obtained about the fertility of the proband generation, their parents' and also their childrens' generations. In high-boron villages (Region I), 159 three-generation kindreds containing 1068 families were ascertained and, in low-boron villages (Region II), 154 three-generation kindreds containing 610 families were ascertained. In Region 1, 96% of marriages produced at least one child, with primary infertility estimated at 2.34% compared with 96% and 2.62%, respectively, for Region II. There was no significant difference in fertility either between Region I and Region II or between the villages within the Regions. The fertility figures are not different from similar measures of fertility in other parts of Turkey. In Region I, the gender ratio (M:F) of offspring was 0.89, whereas in the Region II villages the gender ratio was 1.04 (NS, chi2 = 1.335, P > 0.05). It is concluded that at the elevated boron drinking water levels studied, a boron-related effect on reproduction was not found.

Comparison of infertility rates in communities from boron-rich and boron-poor territories.

As a part of a large-scale work aimed at studying the health effects of boron (B) in residents of a country with the world's largest supply, developmental effects of B are presented. Spontaneous abortions, stillbirths, and congenital malformations in addition to early infant mortality were questioned in the field by home visits. Although the number of families so far ascertained is rather small, the rates related to spontaneous abortions and stillbirths from high B exposure vs low B exposure subpopulations revealed no differences of significance, providing no evidence that B affects human development adversely.

Hirsutism due to the treatment with L-thyroxine in patients with thyroid pathology.

There are many factors involved in the aetiology of hirsutism. It is well known that some drugs may cause hirsutism as a side effect, such as phenytoin, diazoxide, minoxidil etc. In Turkey, where the endemic goiter constitutes an important health problem, the value of suppression therapy with thyroid hormone still carries a special importance. We established the increasing tendency of hirsutism in patients treated with L-thyroxine (L-T4) for various thyroid pathology. That is why we decided to evaluate the role of thyroid hormones in the aetiology of hirsutism observed in patients treated with L-T4. We determined the total and free T3, T4, TSH, TBG, Plasma Cortisol transcortin, delta-4-androstenedione, FSH, LH, prolactin, total and free testosterone, estradiol, progesterone, sex hormone-binding globulin (SHBG), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS) and 17 hydroxyprogesterone (17 OH Pg) levels in serum or plasma in a group of female patients who were taking L-T4 daily, regularly at least for 6 months and complaining of the occurrence of hirsutism. We demonstrated in these patients SHBG, transcortin and estradiol levels significantly lower than controls (p less than 0.001, p less than 0.05 and p less than 0.05, respectively) and DHEAS level significantly higher than controls (p less than 0.001). An important correlation was found between TBG and SHBG levels (r:0.536, p less than 0.05) and also between total and free testosterone levels (r:0.952, p less than 0.001).