A virtual assessment of the proposed suprainiac fossa on the early modern European calvaria from Cioclovina, Romania.

OBJECTIVES: The calvaria from Cioclovina (Romania) has been argued to possess some traits commonly ascribed to individuals belonging to the Neanderthal lineage, including a suprainiac fossa. However, its supranuchal morphology has only been evaluated with a qualitative analysis of the ectocranial surface. We evaluate whether the morphology of the supranuchal area of this specimen is homologous to the Neanderthal condition. MATERIALS AND METHODS: We described in detail the external morphology, and, using computed tomography, investigated the internal morphology of the Cioclovina supranuchal area. We took measurements of the internal structures and calculated their relative contributions to total cranial vault thickness, which were compared to published data and evaluated with a principal component analysis (PCA). RESULTS: The Cioclovina supranuchal region is characterized by superficial resorption present on the outer layer of the external table. Neither the diploic layer nor the external table decrease in relative thickness in the area above inion. In the PCA, Cioclovina falls within the convex hulls of recent modern Homo sapiens. DISCUSSION: Our results show that the morphology of the Cioclovina supranuchal region does not correspond to the external and internal morphology of the typical Neanderthal suprainiac fossa. It cannot be characterized as a depression but rather as an area presenting superficial bone turnover. Together with earlier results, there is little phenotypic evidence that Cioclovina has high levels of Neanderthal ancestry. Our study demonstrates the usefulness of this quantitative method in assessing proposed Neanderthal-like suprainiac depressions in Upper Paleolithic and other fossil specimens.

Stimulation of the greater occipital nerve: anatomical considerations and clinical implications.

BACKGROUND: Stimulation of the greater occipital nerve has been employed for various intractable headache conditions for more than a decade. Still, prospective studies that correlate stimulation of the greater occipital nerve with outcome of patients with respect to alleviation of headache are sparsely found in literature. OBJECTIVE: To identify anatomical landmarks for a reproducible stimulation of the greater occipital nerve. For the clinical implication, the individual response to therapy of patients with refractory chronic cluster headache undergoing occipital nerve stimulation was correlated with the postoperative localization of the electrodes and with the distribution of the stimulation field. STUDY DESIGN: Prospective observational study, approved by the local research ethics board (09-4143). SETTING: University hospital, departments of neurosurgery and neurology, institute of anatomy and radiology. METHODS: Ten formaldehyde fixed human cadavers were dissected to identify the passage of the greater occipital nerve through the trapezius muscle. The distance to the external occipital protuberance was triangulated measuring the distance of the nerve from the nuchal midline and the protuberance. Between December 2008 and December 2011, 21 consecutive patients suffering from chronic cluster headache underwent surgery in terms of bilateral occipital nerve stimulation, with electrodes placed horizontally at the level of C1. The postoperative x-rays were compared with the acquired landmarks from the anatomical study. The distribution of the stimulation field was correlated to the individual response of each patient to the therapy and prospectively analyzed with regard to reduction of daily cluster attacks and relief of pain intensity at 3 months and at last follow-up. RESULTS: The greater occipital nerve crosses the trapezius muscle at a mean distance of 31 mm below the occipital external protuberance and 14 mm lateral to the midline as found in the anatomical subjects. The electrodes were targeted at this level in all of our patients and stimulated the greater occipital nerve in all patients. Eighteen of the patients (85.7%) reported a significant reduction of the frequency of their cluster attacks and/or declined intensity of pain during the attacks. Yet, 3 of 21 patients (14.3%) did not benefit from the stimulation despite an adequate spread of the stimulation over the occiput. The spread of the stimulation-induced paraesthesias over the occiput was not correlated to a reduction of cluster attacks, to the intensity of attacks, or to the response to treatment at all. LIMITATIONS: Single center non-randomized non-blinded study. CONCLUSIONS: From our study we conclude that a reproducible stimulation of the greater occipital nerve can be achieved by placing the electrodes parallel to the atlas, at about 30 mm distance to the external occipital protuberance. The response to the stimulation is not correlated to the field width of the paraesthesia. We, therefore, consider stimulation of the main trunk of the greater occipital nerve to be more important than a large field of stimulation on the occiput. Still, an individual response to the occipital nerve stimulation cannot be predicted even by optimal electrode placement.

Occipital neurostimulation-induced muscle spasms: implications for lead placement.

BACKGROUND: For many headache types, occipital peripheral nerve stimulation (ONS) provides significant relief of chronic, frequent, and severe headaches. Though rarely reported, ONS may cause painful muscle spasms that make stimulator use impractical. The classic description of the technique advocates placement of the leads transversely at the level of the arch of C1 or at C1-2. At that level, the greater occipital nerve (GON) infrequently pierces the superficial fascia of the neck muscles to become superficial. However, important anatomic variability exists. OBJECTIVE: To report placement of leads higher at the nuchal line rather than the classically recommended C1 level to avoid ONS-induced muscle spasm. METHODS: Four interventional pain physicians independently revised ONS leads due to painful muscle stimulation. Five case reports of surgical ONS lead revision for management of ONS-induced muscle spasms are described and discussed. RESULTS: Placement of peripheral neurostimulator leads at or above the nuchal line in these 5 cases provided good paresthesiae without causing neck muscle spasm. CONCLUSION: Lead placement at the level of C1 or C1-2 may cause some patients to have intolerable neck/occipital spasm during neurostimulation. This is the first known published report of technical variation in the location of lead placement, at the nuchal line in a transverse fashion, for ONS. Placing ONS leads at the level of the occipital protuberance appears to eliminate ONS-induced muscle spasm while allowing good paresthesia coverage. LIMITATIONS: Stimulation parameters vary, thus posting parameters may be misleading as muscle spasms occurred despite multiple reprogramming attempts and were a function of lead position, not program settings.

Occipital nerve stimulation (ONS). Surgical technique and prevention of late electrode migration.

Occipital nerve stimulation (ONS) is an emerging procedure for the treatment of cranio-facial pain syndromes and headaches refractory to conservative treatments. The aim of this report is to describe in detail the surgical intervention and to introduce some useful tricks that help to avoid late displacement and migration of the suboccipital leads. The careful description of the surgical steps may contribute to a standardization of the procedure and make the interpretation of results easier even if obtained in series of patients operated on by different authors.

Identification of greater occipital nerve landmarks for the treatment of occipital neuralgia.

Important structures involved in the pathogenesis of occipital headache include the aponeurotic attachments of the trapezius and semispinalis capitis muscles to the occipital bone. The greater occipital nerve (GON) can become entrapped as it passes through these aponeuroses, causing symptoms of occipital neuralgia. The aim of this study was to identify topographic landmarks for accurate identification of GON, which might facilitate its anaesthetic blockade. The course and distribution of GON and its relation to the aponeuroses of the trapezius and semispinalis capitis were examined in 100 formalin-fixed adult cadavers. In addition, the relative position of the nerve on a horizontal line between the external occipital protuberance and the mastoid process, as well as between the mastoid processes was measured. The greater occipital nerve was found bilaterally in all specimens. It was located at a mean distance of 3.8 cm (range 1.5-7.5 cm) lateral to a vertical line through the external occipital protuberance and the spinous processes of the cervical vertebrae 2-7. It was also located approximately 41% of the distance along the intermastoid line (medial to a mastoid process) and 22% of the distance between the external occipital protuberance and the mastoid process. The location of GON for anaesthesia or any other neurosurgical procedure has been established as one thumb's breadth lateral to the external occipital protuberance (2 cm laterally) and approximately at the base of the thumb nail (2 cm inferior). This is the first study proposing the use of landmarks in relation to anthropometric measurements. On the basis of these observations we propose a target zone for local anaesthetic injection that is based on easily identifiable landmarks and suggest that injection at this target point could be of benefit in the relief of occipital neuralgia.

A fourth hominin skull from Dmanisi, Georgia.

Newly discovered Homo remains, stone artifacts, and animal fossils from Dmanisi, Republic of Georgia, provide a basis for better understanding patterns of hominin evolution and behavior in Eurasia ca. 1.77 million years ago. Here we describe a fourth skull that is nearly complete, lacking all but one of its teeth at the time of death. Both the maxillae and the mandible exhibit extensive bone loss due to resorption. This individual is similar to others from the site but supplies information about variation in brain size and craniofacial anatomy within the Dmanisi paleodeme. Although this assemblage presents numerous primitive characters, the Dmanisi skulls are best accommodated within the species H. erectus. On anatomical grounds, it is argued that the relatively small-brained and lightly built Dmanisi hominins may be ancestral to African and Far Eastern branches of H. erectus showing more derived morphology.

Attachments of the ligamentum nuchae to cervical posterior spinal dura and the lateral part of the occipital bone.

OBJECTIVE: To describe previously unrecorded attachments of the ligamentum nuchae to the cervical posterior spinal dura, and to posterolateral parts of the occipital bone in an anatomical study, with particular reference to the deep aspects of the suboccipital triangle and upper cervical region. DESIGN: Dissections of 10 heads and necks from embalmed cadavers were made in the suboccipital and upper cervical region, either in whole specimens or in parasagitally sectioned specimens. RESULTS: In parasagittally sectioned material, continuity was observed between the ligamentum nuchae and the posterior cervical spinal dura as the latter passed deeply from the midline toward the dura, but only at the first and second cervical vertebral levels. The ligamentum nuchae also passed bilaterally on to the occipital bone as far as the sutures between the occipital bone and the temporal bones, approaching the inferior nuchal line superiorly. CONCLUSION: The present study is the first to describe the full morphology of the relationship between the ligamentum nuchae and the cervical posterior spinal dura and the lateral aspects of the occipital bone. This is of significance for understanding the biomechanics of the cervical spine, particularly rotational movements of the head in the sagittal or transverse planes. This may have implications in manipulative therapy for conditions as cervicogenic headache and for various degenerative disorders affecting the cervical spine.

External cranioplasty: historical perspectives.

Selective external cranial vault remodeling has been practiced since antiquity. The variations, methods, and desired results of external cranioplasty are as pervasive as the practice is old.

Variations in form of the hypoglossal canal.

Variation in the nature and extent of division of the hypoglossal canal can be classified by a simple scoring scheme. Applied to three series of crania of differing provenance, the results indicate a continuity in expression of the trait rather than the dichotomous character utilized in previous studies. The similarity in results in these three populations, of widely differing environment, suggests fairly strict canalization of development.

Some notes on the Vértesszöllös occipital.

An examination of the Vértesszöllös occipital bone indicates the need for takings its condition and preservation as well as certain aspects of its morphology into account prior to a metric assessment of its features. This analysis confirms the presence of extrasutural bones on the lambdoidal suture as well as some distortion in the sagittal curvature of this region. The advisability of using the endocranial sutures as well as other data for defining lambda in cases such as this is discussed, and a procedure for determining the position of opisthion is indicated. A metric and morphological analysis is used to support the claim that the specimen can be considered a large late representative of Homo erectus in Europe.