Defining the Temporal and Occipital Lobes: Cadaveric Study with Application to Neurosurgery of the Inferior Brain.

BACKGROUND: For surgical interventions, a precise understanding of the anatomical variations of the brain and defined anatomical landmarks to demarcate the regions of the temporal lobe is essential. Many anatomical studies have facilitated important surgical approaches to the temporobasal region. Because there is considerable sulcal variability, morphological analysis of the brain is imperative. The aim of this study was to define the boundaries of the temporal and occipital lobes and to define the variations in sulci and gyri in the inferior aspect. METHODS: In 110 cerebral hemispheres variations were identified and the major landmarks of the gyral-sulcal pattern at the inferior aspect of the brain were defined. RESULTS: The anatomy of the inferior aspect of the brain is defined in detail by morphological analysis of formalin-fixed hemispheres with a view to informing important surgical approaches. CONCLUSIONS: Since the literature defines no clear separation between the temporal and occipital lobes, certain landmarks such as the preoccipital notch and a basal temporo-occipital line were suggested as ways of making the distinction. The parahippocampal ramus is a constant structure that can be used as a reliable landmark for the posterior end of the hippocampus.

Identification of Deep Cervical Fascial Layers During Anterior Cervical Spine Exposure.

BACKGROUND: Anterior approaches to the cervical spine are among the most common exposures by which neurosurgeons and orthopedic surgeons access the prevertebral space and ultimately the cervical disk and vertebral bodies. There is a paucity of literature describing the microanatomic fascial planes of the neck with respect to anterior cervical approaches. OBJECTIVE: To delineate the microanatomic connections of the cervical fascial planes pertinent to anterior cervical exposure. METHODS: Using a cadaveric model, original illustrations, the Visible Human Project, and an original surgical video, we demonstrate a stepwise method for identifying the correct planes for anterior cervical exposure. RESULTS: A step-by-step method for identifying the anterior cervical fascial planes intraoperatively is demonstrated. CONCLUSION: A comprehensive understanding of anterior cervical microsurgical anatomy is vital for performing a methodical yet efficient approach to the prevertebral space while minimizing retraction and iatrogenic injury to the surrounding neurovascular structures.

Congenital Anomalies of the Tracheobronchial Tree: A Meta-Analysis and Clinical Considerations.

BACKGROUND: The aim of this study was to determine the prevalence and anatomic features of major tracheobronchial anomalies. METHODS: Major electronic databases were systematically searched to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcome was the prevalence of major tracheobronchial anomalies, specifically tracheal bronchus (TB) and accessory cardiac bronchus (ACB). Secondary outcomes included the origin and types of TB and ACB. RESULTS: A total of 27 studies (n = 119,695 patients) were included. A TB was present in 0.99% (95% confidence interval, 0.67 to 1.37) of patients, and an ACB was present in 0.14% (95% confidence interval, 0.09 to 0.20). The overall prevalence of TB was higher in imaging than in operative studies (1.81% vs 0.82%). It was also higher in pediatric (2.55%) than in adult studies (0.50%). Patients with other congenital anomalies were 15 times more likely to have a TB (odds ratio 14.89; 95% confidence interval, 7.09 to 31.22). The most common origin of TBs was from the trachea (81.42%), primarily from the right side (96.43%). The most common origin of ACBs was from the intermediate bronchus (74.32%). The ACBs terminated as blind-ending diverticulum in two thirds of cases. CONCLUSIONS: Major tracheobronchial anomalies are present in approximately 1% of the population, although the prevalence is higher among pediatric patients and patients with accompanying congenital anomalies. Although rare, major tracheobronchial anomalies can be associated with significant respiratory morbidities and present challenges during airway management in surgical and critical care patients. Establishing a preoperative diagnosis of these variations is essential for planning and implementing an appropriate airway management strategy to minimize attendant complications.

The iliac pillar - Definition of an osseous fixation pathway for internal and external fixation.

BACKGROUND: Increasing numbers of unstable pelvic ring fractures, due to the ongoing demographic change and improvements in the rescue of high-energy traumatic events, are challenging trauma and orthopedic surgeons. While initial installation of an external fixation device is often necessary, placement of iliac crest pins can be difficult due to the complex osteology of the ilium. HYPOTHESIS: We aim to analyze (1) the length, localization and angulation of the iliac pillar and (2) to define the dimensions of the surgical corridor for a better understanding of pin entry point and trajectory, thus preventing shortcomings in anterior external fixation of pelvic ring injuries. METHODS: Twenty hemipelvises from 10 fresh-frozen cadaveric torsos (3 female, 7 males; mean age 80.2 years) were harvested. The following measurements were taken with digital calipers: Location of the iliac pillar in relation to the anterior superior iliac spine and to the acetabulum roof, mean length and diameter of the iliac pillar, maximum diameter of the iliac pillar. In addition we measured the width of the different bone layers. RESULTS: The mean length of the hourglass shaped iliac pillar was 107.04mm with a mean width of 17.0mm (min. 15.1; max. 19.2). The mean distance to the anterior superior iliac spine was 69.00mm (min. 64.8; max. 73.4). The mean maximum width of the iliac pillar was 12.16mm (min. 9.4; max. 13.8). Caudally the line describing the iliac pillar intercepts the cranial acetabular rim at 12 o'clock. The smallest mean diameter of the cancellous bone was 7.5mm±2.0. CONCLUSION: The iliac pillar is part of the complex osteology of the human pelvis. A cohesive description of its location and dimensions has been lacking. Successful treatment of pelvic fracture depends on an optimal preoperative planning, accurate overall reduction, and stable fixation. We described the origin and angulation to provide a good bone stock for external fixation pin and the width of the different bone layers. This study therefore contributes by facilitating a thorough understanding of pelvic osteology and describing the location and dimensions of an optimal osseous pathway. LEVEL OF EVIDENCE: Anatomical descriptive study.

Vaginal Extrusion of a Ventriculoperitoneal Shunt: A Case Report and Review of Literature.

BACKGROUND: Ventriculoperitoneal shunting is the most common treatment for hydrocephalus (excessive cerebrospinal fluid accumulation in the brain), but has the potential for serious complications such as shunt migration. Potential migration sites include the lateral ventricle mediastinum, gastrointestinal tract, abdominal wall, bladder, vagina, and scrotum. CASE: Here, we present a rare case of vaginal extrusion of a ventriculoperitoneal shunt. SUMMARY AND CONCLUSION: Neurosurgeons and gynecologists should be aware of the potential occurrence of this rare complication.

Classification and fascicular analysis of variant branching pattern of femoral nerve for microsurgical intervention: a series of thirteen cadavers / Clasificación y análisis fascicular de las variantes en el patrón de ramificación del nervio femoral en intervenciones microquirúrgicas: una serie de 13 cadáveres

Femoral neuropathy associated with lower limb is treated by surgical intervention through activation/regeneration/grafting of nerve fibers by a nerve cuff electrode implant or neuro-prosthesis. These procedures require detailed and precise knowledge of neuro-anatomical variants of the femoral nerve and its fascicular anatomy so that the nerve injury can be investigated and treated more efficiently. The aim of the study is to uncover the variations both in the femoral nerve and its branches, to classify them and to bring out corresponding fascicular anatomy using a hypothesis based on the principle of consistency, continuity and traceability of fascicles. The study was carried out in the Department of Anatomy AIIMS Rishikesh using 13 matched lower limbs (26 femoral nerves) from 13 cadavers. The femoral nerve was exposed in the femoral triangle and traced to the posterior abdominal wall. Variations in the shape, size and course of the femoral nerve and its branches were analyzed. The fascicular arrangement was also conceptualized based on the hypothesis. Seven classes, high division, trunk anomaly, semi-scattered, scattered branching pattern, pectocutaneous, lateral cutaneous nerve of thigh and nerve to sartorius anomalies were detected. The corresponding fascicular organizations were modeled. The seven classes along with corresponding fascicular pattern will be very useful for neurosurgeons, radiologists, anesthetists and anatomists in diagnosis and treatment of femoral neuropathy.

La neuropatía femoral asociada con el miembro inferior es tratada por intervención quirúrgica a través de activación, regeneración e injerto de fibras nerviosas mediante un implante de electrodo de manguito de nervios o neuro-prótesis. Estos procedimientos requieren un conocimiento detallado y preciso de las variantes neuro-anatómicas del nervio femoral y su anatomía fascicular de modo que la lesión del nervio pueda ser investigada y tratada de manera más eficiente. El objetivo del estudio fue descubrir las variaciones tanto en el nervio femoral y sus ramas y clasificarlos a partir de la anatomía fascicular utilizando una hipótesis basada en el principio de la continuidad y trazabilidad de los fascículos correspondientes. El estudio se llevó a cabo en el Departamento de Anatomía AIIMS Rishikesh utilizando 13 miembros inferiores pareados (26 nervios femorales) de 13 cadáveres. El nervio femoral se expuso en el triángulo femoral y fue trazado en la pared abdominal posterior. Se analizaron las variaciones en la forma, tamaño y trayecto del nervio femoral y sus ramas. El patrón fascicular fue conceptulizado de acuerdo a la hipótesis planteada. Se detectaron anomalías clasificadas en: siete clases, división alta, anomalías de tronco, semi-dispersos, patrón de ramificación dispersa, pectocutáneo, nervio cutáneo lateral y nervio del músculo sartorio. Las clasificaciones junto con el patrón fascicular correspondientes serán de gran utilidad para los neurocirujanos, radiólogos, anestesistas y anatomistas en el diagnóstico y tratamiento de la neuropatía femoral.

The cubital tunnel: a radiologic and histotopographic study.

Entrapment of the ulnar nerve at the elbow is the second most common compression neuropathy in the upper limb. The present study evaluates the anatomy of the cubital tunnel. Eighteen upper limbs were analysed in unembalmed cadavers using ultrasound examination in all cases, dissection in nine cases, and microscopic study in nine cases. In all cases, thickening of the fascia at the level of the tunnel was found at dissection. From the microscopic point of view, the ulnar nerve is a multifascicular trunk (mean area of 6.0 ± 1.5 mm(2) ). The roof of the cubital tunnel showed the presence of superimposed layers, corresponding to fascial, tendineous and muscular layers, giving rise to a tri-laminar structure (mean thickness 523 ± 235 µm). This multilayered tissue was hyperechoic (mean thickness 0.9 ± 0.3 mm) on ultrasound imaging. The roof of the cubital tunnel is elastic, formed by a myofascial trilaminar retinaculum. The pathological fusion of these three layers reduces gliding of the ulnar nerve during movements of the elbow joint. This may play a role in producing the symptoms typical of cubital tunnel syndrome. Independent from the surgical technique, decompression should span the ulnar nerve from the triceps brachii muscle to the flexor carpi ulnaris fascia.

Impact of fibular torsion and rotation on chronic ankle instability.

BACKGROUND: The fibula is known not to involve in transmission of weight but known simply as an ankle stabilizer. However, its main function in stabilizing the ankle remains obscure. Since the fibula has an impact on torsion and rotation of the ankle, its effect on lateral ankle instability should be investigated. MATERIALS AND METHODS: Twenty patients with lateral ankle instability (Group 1) and 19 healthy volunteers (Group 2) were included in the study. The tibiofibular and talofibular relationships were evaluated using MRI images. Fibular torsion and rotation angles were calculated using a new method. Range of motion of the ankle joint was investigated while the knee was at flexion (90°) and extension (0°). The comparisons performed between the 2 groups and independent from the groups were statistically evaluated and, the p value of <0.05 was considered as statistically significant. RESULTS: A significant difference was found between the two groups for age (p<0.05). There were no statistically significant differences between the right and left sides for all measurements in the group 1 and 2 (p>0.05). There was a statistically significant difference between the two groups in dorsal flexion when the knee is at flexion (90°) and extension (0°) position. There was also a statistically significant difference between the two groups in plantar flexion which was measured while the knee was at extension (0°) position. No statistically significant difference was found between both groups in terms of fibular torsion and rotation. However, independent from the groups when the patients were divided into 2 groups according to whether the fibula localized posteriorly or not, in patients with posteriorly localized fibula it was demonstrated that the fibular torsion and rotation was increased significantly. CONCLUSION: We did not detect any relationship between fibular torsion and rotation and ankle instability. However, independent from the groups when the patients were divided into 2 groups according to whether the fibula localized posteriorly or not, we realized that in patients with posteriorly localized fibula, fibular torsion and rotation significantly increased. This finding did not explain the cause of instability. However, it may gain significance with new further studies regarding ankle instability.

Hyperbaric oxygen therapy for chronic post-concussive syndrome.

In this editorial, the value of hyperbaric oxygen therapy in the management of chronic post-concussive syndrome following mild traumatic brain injury is discussed.

The neurologist's dilemma: a comprehensive clinical review of Bell's palsy, with emphasis on current management trends.

BACKGROUND: Recent advances in Bell's palsy (BP) were reviewed to assess the current trends in its management and prognosis. MATERIAL/METHODS: We retrieved the literature on BP using the Cochrane Database of Systematic Reviews, PubMed, and Google Scholar. Key words and phrases used during the search included 'Bell's palsy', 'Bell's phenomenon', 'facial palsy', and 'idiopathic facial paralysis'. Emphasis was placed on articles and randomized controlled trails (RCTs) published within the last 5 years. RESULTS: BP is currently considered the leading disorder affecting the facial nerve. The literature is replete with theories of its etiology, but the reactivation of herpes simplex virus isoform 1 (HSV-1) and/or herpes zoster virus (HZV) from the geniculate ganglia is now the most strongly suspected cause. Despite the advancements in neuroimaging techniques, the diagnosis of BP remains one of exclusion. In addition, most patients with BP recover spontaneously within 3 weeks. CONCLUSIONS: Corticosteroids are currently the drug of choice when medical therapy is needed. Antivirals, in contrast, are not superior to placebo according to most reliable studies. At the time of publication, there is no consensus as to the benefit of acupuncture or surgical decompression of the facial nerve. Long-term therapeutic agents and adjuvant medications for BP are necessary due to recurrence and intractable cases. In the future, large RCTs will be required to determine whether BP is associated with an increased risk of stroke.

Amyand's hernia: a review.

Abstract Amyand's hernia is defined as when the appendix is trapped within an inguinal hernia. While the incidence of this type of hernia is rare, the appendix may become incarcerated within Amyand's hernia and lead to further complications such as strangulation and perforation. Incarceration of the appendix most commonly occurs within inguinal and femoral hernias, but may arise to a lesser extent in incisional and umbilical hernias. Incarcerated appendix has been reported in a variety of ventral abdominal and inguinal locations, yet its indistinct clinical presentation represents a diagnostic challenge. This paper reviews the literature on incarceration of the appendix within inguinal hernias and discusses current approaches to diagnosis and treatment of Amyand's hernia and complications that may arise from incarceration of the appendix within the hernia.

Bathrocephaly: a case report of a head shape associated with a persistent mendosal suture.

Bathrocephaly is a posterior cranial deformity associated with failure of fusion of the mendosal suture. Infants are born with a prominent occipital bone. Here we discuss a case report of bathrocephaly in a newborn discussing management, imaging finding, differential diagnosis and relevant bony anatomy and development.

Lumbosacral intrathecal nerve roots: an anatomical study.

BACKGROUND: The lumbosacral intrathecal anatomy is complex because of the density of nerve roots in the cauda equina. Space-occupying lesions, including disc herniation, trauma and tumor, within the spinal canal may compromise the nerve roots, causing severe clinical syndromes. The goal of this study is to provide spinal surgeons with a detailed anatomical description of the intrathecal nerve roots and to emphasize their clinical importance. METHOD: Ten formalin-fixed male cadavers were studied. They were dissected with the aid of a surgical microscope, and measurements were performed. RESULTS: The number of dorsal and ventral roots ranged from one to three. The average diameter of roots increased from L1 to S1 (0.80 mm for L1 and 4.16 for S1), respectively. Then their diameter decreased from S1 to S5 (4.16 mm for S1, 0.46 mm for S5). The largest diameter was found at S1 and the smallest at S5. The average number of rootlets per nerve root increased from L1 to S1, then decreased (3.25 for L1, 12.6 for S1, and 1.2 for S5), respectively. The greatest rootlet number was seen at S1, and the fewest were observed at S5. The average diameter of the lateral recess gradually decreased from L1 to L4 (9.1 mm for L1; 5.96 mm for L4) and then increased at L5 level (6.06 mm); however, the diameter of the nerve root increased from L1 to L5. The midpoint of distance between the superior and inferior edge of the intradural exit nerve root was 3.47 mm below the inferior edge of the superior articular process at the L1 level, while the origin of the L5 exit root was 5.75 mm above the inferior edge. The root origin gradually ascended from L1 to L5. CONCLUSIONS: The findings of this study may be valuable for understanding lesions compressing intradural nerve roots and may be useful for intradural spinal procedures.

Regional anatomic structures of the elbow that may potentially compress the ulnar nerve.

HYPOTHESIS: Traumatic injuries to the ulnar nerve at the elbow are a frequent problem as it is vulnerable to stretching and compression with motion of the upper limb. The aim of the present study was to explore the course of the ulnar nerve at the elbow and forearm and to determine possible anatomical structures that may cause compression of this structure. MATERIALS AND METHODS: We examined 12 upper limbs from cadavers. The length of any fibrous bands, and if present, their distance to the medial epicondyle was recorded. RESULTS: On 5 sides a fibrous band originating from the medial intermuscular septum was observed to cross over the ulnar nerve. The average length of the fibrous band was 5.7 cm, and it attached to the medial epicondyle. The mean length of the ulnar nerve as it coursed in the cubital tunnel was 3.8 cm. In 4 of the cases, the ulnar nerve was covered by muscle fibers originating from the flexor digitorum superficialis and extending to the flexor carpi ulnaris. On 5 sides we observed fibrous thickenings, and on 8 sides vascular structures were found crossing over the ulnar nerve. DISCUSSION: The cubital tunnel is the most common site of compression of the ulnar nerve. Numerous surgical procedures are recommended for cubital tunnel syndrome. Simple decompression is used most commonly. Although surgical procedures are reported to provide efficient pain relief and functional recovery, residual or recurrent symptoms have been reported. Reasons for such recurrences may be more proximal or distal compression of the ulnar nerve as seen in our study. CONCLUSION: Knowledge of possible compression sites of the ulnar nerve is important to the surgeon so that complications are avoided and postoperative recurrence is decreased. LEVEL OF EVIDENCE: Basic science study.