Tubbs Rs

Morphometric analysis of the foramen magnum: an anatomic study.

OBJECTIVETo further elucidate the importance of anatomic variations in morphology of the foramen magnum and associated clinical implications, we conducted a morphometric study. METHODSSeventy-two dry skulls were used for this study. Digital images were obtained of the foramen magnum from an inferior view. These images were studied using a computer-assisted image analysis system. Next, an image processor was used to calculate pixel differences between 2 selected points, which allowed accurate translation of pixel differences into metric measurements. RESULTSWe found that the mean surface area of the foramen magnum was 558 mm2, the mean anteroposterior diameter was 3.1 cm, and the mean horizontal diameter was 2.7 cm. For comparison, surface areas were classified into 3 types based on size. Type I foramina were identified in 20.8% of the dry skulls (15 skulls) and exhibited a surface area of less than 500 mm2. Type II (66.6%, 48 skulls) was applied to foramina of an intermediate size with surface areas ranging between 500 to 600 mm2. Type III (12.5%, 9 skulls) was applied to large foramina with surface areas of more than 600 mm2. CONCLUSIONThese data may be of use as a morphometric database for description of “normal” variants of foramen magnum morphology.

The arcade of Struthers: An anatomical study with potential neurosurgical significance.

Background: Significant controversy exists regarding the existence of the so-called arcade of Struthers and whether this structure is involved in some cases of proximal ulnar nerve entrapment. Therefore, the aim of the present study was to further elucidate this anatomy. Methods: Fifteen cadavers (30 sides) underwent dissection of the medial arm with special attention to the course of the ulnar nerve and its relationships to the soft tissues of this region. Results: We identified a thickening in the inferior medial arm that crosses the ulnar nerve and is consistent with the so-called arcade of Struthers in 86.7% of sides. On 57.7% of the sides, the arcade was found to be due to a thickening of the brachial fascia and was classified as a type I arcade. On 19.2% of the sides, the arcade was due to the internal brachial ligament and these were classified as type II arcades. On 23.1% of the sides, the arcade was due to a thickened medial intermuscular septum and these were classified as type III arcades. The mean length of the arcade was 4.3 cm and the distal end of the arcade was, on average, 6.8 cm above the medial epicondyle. Although the presence of an arcade of Struthers was slightly more common in female specimens, this did not reach statistical significance. However, arcades were found more often on right side (P < 0.001). Conclusions: Based on our findings, the arcade of Struthers is an anatomical band of connective tissue in the medial distal arm that crosses the ulnar nerve. This structure was found in the majority of our specimens and may need to be evaluated in proximal ulnar neuropathies. We believe that past studies that have not observed the arcade and past studies with varied findings are due to the various definitions used for this anatomical structure. Using the classification system as demonstrated in the present study may make future communications regarding the arcade of Struthers more exact.

Neural interconnections between the nerves of the upper limb and surgical implications.

The knowledge of neural interconnections between adjacent nerves of the upper limb is important to the surgeon as such variations may lead to issues with surgical identification and thus iatrogenic injury. Trauma or entrapment of these nerves may cause functional losses different from those expected and thus result in misdiagnosis. The authors review the literature regarding such nervous system derangements.

Anatomical features and clinical relevance of a persistent trigeminal artery

Background: Although persistent trigeminal artery (PTA) is uncommonly identified, knowledge of this structure is essential for clinicians who interpret cranial imaging, perform invasive studies of the cerebral vasculature, and operate this region. Methods: A review of the medical literature using standard search engines was performed to locate articles regarding the PTA, with special attention with anatomical descriptions. Results: Although anatomical reports of PTA anatomy are very scarce, those were analyzed to describe in detail the current knowledge about its anatomical relationships and variants. Additionally, the embryology, classification, clinical implications, and imaging modalities of this vessel are extensively discussed. Conclusions: Through a comprehensive review of isolated reports of the PTA, the clinician can better understand and treat patients with such an anatomical derailment.

Sports and pediatric cerebrospinal fluid shunts: who can play?

OBJECTIVE:The purpose of this study was to collect and review available data on the incidence of sport-related complications in children with cerebrospinal fluid (CSF) shunts. METHODS:After review of medical and legal literature revealed no reports on sports and shunts, an Internet-based survey was conducted of pediatric neurosurgeons. Observed complications, recommendations for sport participation, and shunt volume data were collected. RESULTS:Ninety-two providers (55% sample) responded. Seventy-seven percent had never observed a sport-related shunt complication in their practice. The remaining 23% witnessed an estimated total of 25 to 30 complications. Broken shunt catheters and shunt dysfunction were the most common complications observed. Only one acute intracranial hematoma was reported in the entire series. The incidence of sport-related CSF complications in children seems to be significantly less than 1%. Ninety percent of pediatric neurosurgeons do not restrict their patients’ participation in noncontact sports. For contact sports, approximately one-third of neurosurgeons preclude all participation, whereas another third restrict specific sports. The final third of neurosurgeons surveyed do not restrict participation in contact sports for children with CSF shunts. CONCLUSION:Sport-related complications in children with CSF shunts are very uncommon.

Are Doppler ultrasonography parameters symmetric between the right and left kidney

Background: Among numerous modalities applied for evaluation of kidney diseases, Doppler ultrasonography (DU) provides information about the hemodynamic status of the kidneys. Meanwhile, the variability in DU parameters of the right and left kidney is a matter of controversy. The aim of this study was to determine whether any difference exists between the DU indices of the right and left kidney. Methods: Retrospectively, we collected DU findings of 25 healthy potential renal transplant donors. All donors underwent renal DU and multidetector computed tomographic angiography before donor nephrectomy. DU indices, including peak systolic volume (PSV), resistive index (RI), pulsatility index (PI), end-diastolic volume (EDV), and acceleration time (AT), were recorded. Results: The median age of the donors was 27 (range 23–39) years. The median PSV, RI, EDV, and AT for the right kidney were 29 cm/sec, 0.59, 10.9 cm/sec, and 50 msec, respectively. For the left kidney, the median PSV, RI, EDV, and AT were, respectively, 26.8 cm/sec, 0.60, 10.6 cm/sec, and 43 msec. Among the DU indices, median PI of the right kidney was significantly different from that of the left kidney (1.02 versus 0.95, P = 0.01). Conclusion: In conclusion, the present study revealed that right kidney DU indices, except for PI, may not differ from those of the left kidney.

Proposal of Venous Drainage-Based Classification System for Carotid Cavernous Fistulae With Validity Assessment in a Multicenter Cohort.

BACKGROUND Carotid cavernous fistulae (CCFs) are most commonly classified based on arterial supply. Symptomatology and treatment approach, however, are largely influenced by venous drainage. OBJECTIVE To propose an updated classification system using venous drainage. METHODS CCFs with posterior/inferior drainage only, posterior/inferior and anterior drainage, anterior drainage only, and retrograde drainage into cortical veins with/without other drainage channels were designated as types 1, 2, 3, and 4, respectively. CCFs involving a direct connection between the internal carotid artery and cavernous sinus were designated as type 5. This system was retrospectively applied to 29 CCF patients. RESULTS Our proposed classification was significantly associated with symptomatology (P < .001). Type 2 was significantly associated with coexisting ocular/orbital and cavernous symptoms only (P < .001), type 3 with ocular/orbital symptoms only (P < .01), and type 4 demonstrated cortical symptoms with/without ocular/orbital and cavernous symptoms (P < .01), respectively. There was a significant association of our classification system with the endovascular treatment approach (P < .001). Types 1 and 2 were significantly associated with endovascular treatment through the inferior petrosal sinus (P < .01). Type 3 was significantly associated with endovascular treatment through the ophthalmic vein (P < .01) and type 5 with transarterial approach (P < .01), respectively. Types 2 (27.6%) and 3 (34.5%) were most prevalent in this series, whereas type 1 was rare (6.9%), suggesting that some degree of thrombosis is present, with implications for spontaneous resolution. Type 2 CCFs demonstrated a trend toward partial resolution after endovascular treatment (P = .07). CONCLUSION Our proposed classification system is easily applicable in clinical practice and demonstrates correlation with symptomatology, treatment approach, and outcome.

When lithium hurts: a look at Ebstein anomaly.

Ebstein anomaly (EA) is a congenital defect of the tricuspid valve (TV) and the right ventricle (RV) in which the attachments of the septal and posterior valve leaflets are apically displaced. The latter creates 3 morphologic components inside the right heart, namely the right atrium proper, the atrialized RV, and the functional RV. This rare anomaly accounts for <1.5% of all congenital heart diseases. The current opinion among authors is that it is a genetically heterogeneous condition caused by failure of delamination of the TV leaflets from the underlying myocardium and the interventricular septum. Its characteristic electrocardiographic findings include tall, broad, right atrial P waves, prolonged PR intervals, and deep Q waves in the right precordial leads. Echocardiography is currently the best technique for diagnosing this anomaly, although cardiac magnetic resonance imaging is also gaining traction as an alternative modality. The management strategies for EA correlate with the age of the patient, severity of the heart disease, and/or associated cardiac abnormalities. TV repair, rather than valve replacement, is preferred because of its favorable long-term prognosis. Nevertheless, a large, randomized study is still needed to compare the different valve repair techniques used in patients with EA.

Update on the Notochord Including its Embryology, Molecular Development, and Pathology: A Primer for the Clinician

The notochord is a rod-like embryological structure, which plays a vital role in the development of the vertebrate. Though embryological, remnants of this structure have been observed in the nucleus pulposus of the intervertebral discs of normal adults. Pathologically, these remnants can give rise to slow-growing and recurrent notochord-derived tumors called chordomas. Using standard search engines, the literature was reviewed regarding the anatomy, embryology, molecular development, and pathology of the human notochord. Clinicians who interpret imaging or treat patients with pathologies linked to the notochord should have a good working knowledge of its development and pathology.

Transsylvian selective amygdalohippocampectomy for treatment of medial temporal lobe epilepsy: Surgical technique and operative nuances to avoid complications

Background: A number of different surgical techniques are effective for treatment of drug-resistant medial temporal lobe epilepsy. Of these, transsylvian selective amygdalohippocampectomy (SA), which was originally developed to maximize temporal lobe preservation, is arguably the most technically demanding to perform. Recent studies have suggested that SA may result in better neuropsychological outcomes with similar postoperative seizure control as standard anterior temporal lobectomy, which involves removal of the lateral temporal neocortex. Methods: In this article, the authors describe technical nuances to improve the safety of SA. Results: Wide sylvian fissure opening and use of neuronavigation allows an adequate exposure of the amygdala and hippocampus through a corticotomy within the inferior insular sulcus. Avoidance of rigid retractors and careful manipulation and mobilization of middle cerebral vessels will minimize ischemic complications. Identification of important landmarks during amygdalohippocampectomy, such as the medial edge of the tentorium and the third nerve within the intact arachnoid membranes covering the brainstem, further avoids operator disorientation. Conclusion: SA is a safe technique for resection of medial temporal lobe epileptogenic foci leading to drug-resistant medial temporal lobe epilepsy.