Extradural and intradural characteristics of the cervical nerve root anomalies.

The anomalous anatomical arrangement of the cervical spinal nerve roots within the spinal canal can complicate the surgical treatment of several pathologies. This work aimed to reveal intraspinal anatomical anomalies of the extradural and also intradural cervical spinal nerve roots courses. The anatomical study was realised in 43 cadavers with a mean age of 53.7 (32 men and 11 women). After opening the spinal canal and also the dural sac the intradural and extradural anomalies of the cervical spinal nerve roots (bilaterally) were explored and documented. We found completely 49 cases (56.98%) of intraspinal cervical nerve root anomalies. Extradural anomalies were found in 11 cases (12.79%) including atypical spacing, two roots exiting through one neuroforamen, extradural communications, aberrant root. Intradural anomalies observed in 28 cases (32.56%) comprised: communications between the dorsal roots and ventral roots separately or together and the multiple communications. Other anomalies (10 cases, 11.63%) included various types of atypical spacing of the roots and their asymmetry. All the results are differentiated according to the plexus type (pre-, postfixed, normotyped). This study describes intraspinal (extradural and intradural) anatomical anomalies of the cervical spinal nerve root courses. Knowledge of these variabilities should help to prevent the failure of several medical procedures.

Intraspinal characteristics of thoracic spinal nerve roots anomalies.

Purpose: The anomalous anatomical arrangement of the thoracic spinal nerve roots within the spinal canal can complicate the surgical treatment of several pathologies. The aim of this work was to reveal intraspinal anatomical variations of the thoracic spinal nerve roots.Methods: Anatomical study on 43 cadavers with a mean age of 53.7. After opening the spinal canal and dural sac, intradural and extradural anomalies of the thoracic spinal nerve roots were documented. Extradural communicating branches were excised, histologically processed and examined for the presence of nervous tissue.Results: We found 14 cases (32.6%) of intraspinal thoracic nerve root variations: intradural in 8 cases (18.6%), intradural communicating branches in 3 cases (6.97%), extradural anatomical variations occurred 6 cases (13.95%), 2 cases (4.65%) had extradural communicating branches between the nerve roots, 1 case had simultaneous occurrence of intradural and extradural communications (0.23%). All the results are differentiated according to the plexus type. In macroscopic extradural thoracic communicating branch had no nervous tissue on microscopy.Conclusions: This study describes intraspinal anatomical variations of thoracic spinal nerve roots. Knowledge of these variables should help prevent the failure of several medical procedures.

Extraordinary features of the intraspinal extradural and intradural nerve root courses.

OBJECTIVES: Very few studies have reported occasional intradural and extradural communications between adjacent nerve roots. These studies mostly focus on lumbosacral regions followed by cervical regions, and rarely in the thoracic region. DESIGN: The aim of this work is to point out some extraordinary extradural and intradural features of the intraspinal nerve root courses and their possible participation in radiculopathy. SUBJECTS AND METHODS: The anatomical study was performed in 43 cadavers. All intradural and extradural rami communicantes between nerve roots were examined histologically for the presence or absence of nervous tissue. RESULTS: Findings of the normotype of plexus formation occurred in 30 cases (69.8%). Variations in its formation were observed in 13 cases (30.2%). Anatomical preparations revealed intradural rami communicantes in all cases of the lumbosacral plexus; 28 times (65.1%) in cases of cervical roots and in the thoracic region 4 times (9.3%). Extradural anatomical variations occurred in 26 cases (60.5%). In 9 cases (20.9%) current occurence of intraspinal extradural and intradural communicating branches in the spinal canal were observed. Multiple extradural rami communicantes were observed in 6 cases (13.95%), including the simultaneous occurrence of multiple intradural and extradural ones in 5 cases (11.6%). CONCLUSIONS: This study allowed us to identify and describe current occurence of intraspinal extradural and intradural communicating branches in the spinal canal with their potential influence on the clinical picture. Anatomical preparations revealed a higher incidence of intraspinal intradural variations, particularly between sacral roots. The reliance of their incidence of the type of plexus was observed.

Extradural Characteristics of the Origins of Lumbosacral Nerve Roots.

BACKGROUND AND STUDY AIMS: A great number of unsuccessful intervertebral herniated disk surgeries in the lumbosacral region have highlighted the importance of a comprehensive knowledge of the different types of nerve root anomalies. That knowledge gained by anatomical studies (and intraoperative findings) might contribute to better results. In our study we focused on intraspinal extradural lumbosacral nerve root anomalies and their possible role in radiculopathy. MATERIAL AND METHODS: The study was performed on 43 cadavers within 24 hours after death (32 men and 11 women). Bodies were dissected in the prone position, and a laminectomy exposed the entire spinal canal for the bilateral examination of each spinal nerve root from its origin to its exit through the intervertebral foramen or sacral hiatus. Uncommon extradural features in the lumbosacral region were pursued and documented. The spinal dural sac was also opened, aimed at recognizing the normotyped, prefixed, or postfixed type of plexus. RESULTS: A total of 20.93% of anomalies of extradural lumbosacral nerve root origins were observed, with the normotyped plexus prevailing. We observed atypical spacing of exits of lumbosacral roots (four cases), two roots leaving one intervertebral foramen (one case), extradural anastomoses (two cases), and missing extradural nerve root courses (two cases). The results were differentiated according to the normotyped, prefixed, or postfixed plexus type. CONCLUSION: Results of similar studies dealing with anomalies of lumbosacral nerve roots were aimed at improving the results of herniated disk surgeries because ∼ 10% of misdiagnoses are related to ignorance of anatomical variability. Our observations may help explain the differences between the clinical picture and generally accepted anatomical standards.

Intraspinal intradural variations of nerve roots.

PURPOSE: The aim of this work is to point out the intraspinal anatomical variations of nerve roots and their possible participation in radiculopathy. METHODS: The anatomical study was performed in 33 cadavers. There were 25 male cadavers aged 30-75 years and 8 female cadavers aged 45-77 years, with a mean age of 46.5 years to 24 h from death. All intradural rami communicantes between nerve roots were excised and examined histologically for the presence or absence of nervous tissue. The type of the plexus was defined by subtracting from the root C2. RESULTS: Findings of the normotype of plexus formation occurred in 24 cases (72.7%). Variations in its formation were observed in nine cases (27.3%). The prefixed type was observed in six cases (18.2%), postfixed type in three cases (9.1%). The formation of isolated prefixed or postfixed type of the brachial and lumbosacral plexus was not observed. Anatomical preparations revealed intradural variations in all cases of the lumbosacral plexus, 22 times (66.7%) in cases of cervical roots, and in the thoracic region seven times (21.2%). Variations occurred more frequently in variations of plexus formation. CONCLUSIONS: This study allowed us to identify and describe unpublished intraspinal intradural anatomical variations of nerve roots, and their interrelationships throughout the spinal canal with their potential influence on the clinical picture. Anatomical preparations revealed a higher incidence of intraspinal intradural variations, particularly between sacral roots. Reliance of their incidence of the plexus type was observed.

Intraspinal extradural variations of nerve roots.

INTRODUCTION: The aim of this work is to point out the intraspinal extradural anatomical variations of nerve roots and their possible participation in radiculopathy. METHODS: The anatomical study was performed in 33 cadavers at a mean age of 46.5 and up to 24h from death. All extradural anastomoses between nerve roots were excised and examined histologically for the presence or absence of nervous tissue. The type of the plexus was defined by subtracting from the root C2. RESULTS: Findings with the normotype of plexus formation prevailed in 24 cases (72.7%). Variations in its formation were observed in 9 cases (27.3%). The prefixed type in 6 cases (18.2%), post-fixed type in 3 cases (9.1%). We did not observe the formation of the isolated prefixed or post-fixed types in the brachial or lumbosacral plexuses. Extradural anatomical variations occurred in 20 cases (60.6%). They were more frequent on the left, in 10 cases (30.3%), bilateral in 3 cases (9.1%). In 8 instances (24.2%), the atypical spacing, including four in the lumbosacral region, was observed. Variations occurred more frequently in variations of formation of the plexus. CONCLUSIONS: This study allowed us to identify and describe unpublished intraspinal extradural anatomical variations of nerve roots and their interrelationships throughout the spinal canal with their potential influence on the clinical picture. Anatomical preparations revealed a higher incidence of intraspinal extradural variations, mainly between sacral roots. The reliance of their incidence of the type of plexus was observed.

The variable origin of the recurrent artery of Heubner: an anatomical and morphometric study.

The recurrent artery of Heubner (RAH) is the largest vessel of the medial lenticulostriate arteries. It supplies many deep structures, mainly the corpus striatum, the globus pallidus, and the anterior crus of the internal capsule. The aim of the present paper was studying the morphological variations of the RAH and its diameter in relation to different areas of origin. The series contained the records from 183 formalin-fixed adult human brains. The calibrated digital images of the studied brains were evaluated and measured by Image J, which can calculate the number of pixels and convert them to metric measures. The RAH arose most often from the postcommunicating part of the anterior cerebral artery (47.81%). It originated from the precommunicating part of the anterior cerebral artery in 3.55% and at the level of the anterior communicating artery in 43.4% of cases. The RAH was missing in 5.19% and doubled in 6.28% of cases. The mean outer diameter of the RAH was 0.6 mm. The maximal measured diameter was 1.34 mm, and the minimal diameter was 0.19 mm. The awareness of the various anatomical and morphometric variations of the RAH is essential in planning the neurosurgical procedures to avoid unexpected neurological complications.

Expression of constitutive nitric oxide synthase isoforms in varicose vein wall; preliminary results.

There are conflicting findings in literature about the structural changes of the primary varicose veins. NO (a potent vasodilatator) is synthesized by nitric oxide synthase (NOS). From 3 known NOS isoforms the two are constitutional: eNOS (endothelial NOS) and nNOS (neuronal NOS). 10 varicose and 10 control vein samples were processed by standard light microscopy and immuno-histochemica techniques using rabbit polyclonal antibodies against eNOS and nNOS. Antibodies expression was evaluated semiquantitatively and proved morphometrically by 2D-image analysis. total area of NOS isoforms expressions was determined by color analysis and color digital subtraction. The results showed discontinuous and significantly lower expression of both NOS isoforms the in the tunica media of varicose veins compared with the control group. For the statistical analysis the unpaired t-test was used. Our results suppose lower NO levels in varicose vein wall, deducing that varicose dilatation is due to other mechanism, and they contradict the results of previously published similar works.

Variation of the median nerve course and its clinical importance.

AIMS AND METHODS: In our work we present and describe the variation of the course of the median nerve found in both upper limbs of one of the cadavers in our Institute of Anatomy (Medical Faculty, Comenius University, Bratislava, Slovakia) during the students' dissection of the peripheral nerves and vessels. RESULTS AND CONCLUSION: This non-standard course of the median nerve was compared with a standard course described in the anatomical literature and atlases, and confronted with the variations of the median nerve found and its course described in the available literature. We also provide some clinical implications of such peripheral nerve variability because understanding such anomalies is important in the diagnosis of unexplained clinical signs and symptoms as well as during nerve blocks and certain surgical procedures around the neck and proximal arm.

Mast cell infiltration in the wall of varicose veins.

Varicose veins of the lower extremities are abnormally dilated, tortuous and elongated. The exact cause of vein dilatation has still not been established. Mast cells produce, store and release various types of vasoactive compounds (histamine, tryptase, prostaglandins, leukotrienes, and cytokines). Histamine enhances local vasopermeability and smooth muscle cell proliferation, leading to thickening of the intima. Tryptase can contribute to local vascular injury and subsequent weakness of the vascular wall causing varix formation. The aim of the present study was the comparison of mast cell infiltration in the wall of varicose and non-varicose veins. The mean mast cell density in the wall of varicose veins was 0.86 mast cell per mm2 and in healthy non-dilated vein walls, density was 1.23 mast cell per mm2. This difference was not statistically significant, therefore we could not confirm our hypothesis. Nevertheless, we suggest that mast cells could play an important role in the development of varices and the factor released by the mast cells should be further examined.