Search

Montages are logical, orderly arrangements of electroencephalographic derivations or channels that are created to display activity over the entire head and to provide lateralizing and localizing information. Most often, bipolar and referential montages are used for routine electroencephalographic recordings. Common average and Laplacian montages can also be helpful in some situations. Because each type of montage has certain strengths and limitations, the ACNS guidelines recommend the use of multiple classes of montages for each electroencephalographic recording. A variety of factors need to be considered for localization by scalp electroencephalogram, but in clinical practice, a three-step approach can be used to localize an interictal epileptiform discharge by visual inspection using a standard set of scalp electrodes and conventional montages. The ACNS guideline provides a number of standard and suggested montages, but, depending on the clinical situation, additional montages can be designed using the electrodes within the 10-20 system or by placing additional electrodes.

To better understand head injuries, human head finite element (FE) models have been reported in the literature. In scenarios where the head is directly impacted and measurements of head accelerations are not available, a high-quality skull model, as well as a high-quality brain model, is needed to predict the effect of impact on the brain through the skull. Furthermore, predicting cranial bone fractures requires comprehensively validated skull models. Lastly, high-quality meshes for both the skull and brain are needed for accurate strain/stress predictions across the entire head. Hence, we adopted a multi-block approach to develop hexahedral meshes for the brain, skull, and scalp simultaneously, a first approach in its kind. We then validated our model against experimental data of brain pressures (Nahum et al., 1977 ) and comprehensive skull responses (Yoganandan et al., 1995 , Yoganandan et al., 2004 , and Raymond et al., 2009 ). We concluded that a human head FE model was developed with capabilities to predict blunt- and ballistic-impact-induced skull fractures and pressure-related brain injuries.

Background This study aims at identifying orthodontic activities with the highest frequency of unfavorable/awkward and static postures held over a period of more than 4 s based on kinematic analysis. Moreover, a separate analysis of static postures for orthodontic and non-orthodontic activities serves to evaluate the duration for which these particular postures are assumed. Methods In total, 21 (13f/8 m) orthodontists (age: 31.5 ± 3.8 years) participated in this study. CUELA, a personal measurement system, was used to collect kinematic data for all orthodontic activities in a working day. Angle values of the head and torso were evaluated in accordance with ergonomic standards. Only those postures that were held statically for 4 s and longer were selected for further analysis. Alongside the kinematic analysis, the activities performed on-site were also subject to a detailed computerized analysis. The synchronization of data collected from both measurements arranges the patterns of posture found chronologically and in conjunction with the orthodontic activities performed ((I) “treatment” (II) “office” and (III) “other activities”). Results For (I) we observed an anterior inclination of the head and torso area as well as a twist of the head and neck area to the right. We found anterior back inclination and lateral back torsion to the right for (II) and (III). If, furthermore, we differentiate the duration of static postures, there are primarily short to medium-term (4–30s) static postures identified for (I). Also, categories (II) and (III) predominantly demonstrate static back postures with a duration of up to 30 s. With regard to (II) we observed that the back is ventrally inclined for 10.1% of the total activity duration. Conclusions During treatment static strains are observed in the entire head and torso area. On the contrary, static postures prevalent in the torso area are essential for activities of the other categories, particularly office work. These findings allow for a careful selection of unfavorable and static postures for each of the activities performed and help to develop specific preventive measures.

Thalamocortical connections are altered following very preterm birth but it is unknown whether structural and functional alterations are linked and how they contribute to neurodevelopmental deficits. We used a multimodal approach in 27 very preterm and 35 term-born children and adolescents aged 10–16 years: Structural thalamocortical connectivity was quantified with two measures derived from probabilistic tractography of diffusion tensor data, namely the volume of thalamic segments with cortical connections and mean fractional anisotropy (FA) within the respective segments. High-density sleep EEG was recorded and sleep spindles were identified at each electrode. Sleep spindle density and integrated spindle activity (ISA) were calculated to quantify functional thalamocortical connectivity. In term-born participants, the volume of the global thalamic segment with cortical connections was strongly related to sleep spindles across the entire head (mean r = .53 ± .10; range = 0.35 to 0.78). Regionally, the volume of the thalamic segment connecting to frontal brain regions correlated with sleep spindle density in two clusters of electrodes over fronto-temporal brain regions (.42 ± .06; 0.35 to 0.51 and 0.43 ± .08; 0.35 to 0.62) and the volume of the thalamic segment connecting to parietal brain regions correlated with sleep spindle density over parietal brain regions (mean r = .43 ± .07; 0.35 to 0.61). In very preterm participants, the volume of the thalamic segments was not associated with sleep spindles. In the very preterm group, mean FA within the global thalamic segment was negatively correlated with ISA over a cluster of frontal and temporo-occipital brain regions (mean r = −.53 ± .07; −.41 to −.72). No association between mean FA and ISA was found in the term-born group. With this multimodal study protocol, we identified a potential misalignment between structural and functional thalamocortical connectivity in children and adolescents born very preterm. Eventually, this may shed further light on the neuronal mechanisms underlying neurodevelopmental sequelae of preterm birth., NeuroImage, 215, ISSN:1053-8119, ISSN:1095-9572

Detailed computational anatomical models of the entire head are needed for accurate in silico modeling in a variety of transcranial stimulation applications. Models from different subjects help to understand and account for population variability. To this end, we have developed a new library of head models of 20 individuals, segmented from co-aligned multi-modal medical image data. The acquired image modalities allow to accurately model tissues with different material properties, such as electrical conductivity or spatially varying acoustic properties. The usefulness of the models is illustrated for two example applications.

KEY POINTS A healthy 50-year-old woman presented with acute onset of the worst headache of her life. She characterized the headache as constant, pulsating and over her entire head. It was associated with photophobia and fever without visual changes and neck stiffness. On examination, the patient was

Background Manual paired‐point registration for navigated ENT‐surgery is prone to human errors; automatic surface registration is often caught in local minima. Methods Anatomical features of the human occiput are integrated into an algorithm for surface registration. A vector force field is defined between the patient and operating room datasets; registration is facilitated through gradient‐based vector field analysis optimization of an energy function. The method is validated exemplarily on patient surface data provided by a mechanically positioned A‐mode ultrasound sensor. Results Successful registrations were achieved within the entire parameter space, as well as from positions of local minima that were found by the Gaussian fields algorithm for surface registration. Sub‐millimetric registration error was measured in clinically relevant anatomical areas on the anterior skull and within the generally accepted margin of 1.5 mm for the entire head. Conclusion The satisfactory behavior of this approach potentially suggests a wider clinical integration.

OBJECTIVE The purpose of this study was to investigate the feasibility of a surface-based registration method based on a low-cost, hand-held Sense three-dimensional (3D) scanner in image-guided neurosurgery system. METHODS The scanner was calibrated prior and fixed on a tripod before registration. During registration, a part of the head surface was scanned at first and the spatial position of the adapter was recorded. Then the scanner was taken off from the tripod and the entire head surface was scanned by moving the scanner around the patient's head. All the scan points were aligned to the recorded spatial position to form a unique point cloud of the head by the automatic mosaic function of the scanner. The coordinates of the scan points were transformed from the device space to the adapter space by a calibration matrix, and then to the patient space. A 2-step patient-to-image registration method was then performed to register the patient space to the image space. RESULTS The experimental results showed that the mean target registration error of 15 targets on the surface of the phantom was 1.61±0.09 mm. In a clinical experiment, the mean target registration error of 7 targets on the patient's head surface was 2.50±0.31 mm, which was sufficient to meet clinical requirements. CONCLUSIONS It is feasible to use the Sense 3D scanner for patient-to-image registration, and the low-cost Sense 3D scanner can take the place of the current used scanner in the image-guided neurosurgery system.

The benefit of hyperthermia as a potent modifier of radiotherapy has been well established and more recently also the combination with chemotherapy was shown beneficial. Also for head and neck cancer, the impact of hyperthermia has been clinically demonstrated by a number of clinical trials. Unfortunately, the technology applied in these studies provided only limited thermal dose control, and the devices used only allowed treatment of target regions close to the skin. Over the last decade, we developed the technology for deep and controlled hyperthermia that allows treatment of the entire head and neck region. Our strategy involves focused microwave heating combined with 3D patient-specific electromagnetic and thermal simulations for conformal, reproducible and adaptive hyperthermia application. Validation of our strategy has been performed by 3D thermal dose assessment based on invasively placed temperature sensors combined with the 3D patient specific simulations. In this paper, we review the phase III clinical evidence for hyperthermia in head and neck tumors, as well as the heating and dosimetry technology applied in these studies. Next, we describe the development, clinical implementation and validation of 3D guided deep hyperthermia with the HYPERcollar, and its second generation, i.e. the HYPERcollar3D. Lastly, we discuss early clinical results and provide an outlook for this technology.

PRESENTATION A 62-year-old woman’s dermatologic difficulties were compounded when light treatment for psoriasis spurred pemphigus foliaceus; an occurrence very rarely noted in the medical literature. She presented with an erythematous, crusted eruption involving her entire head and neck and most of her trunk. The lesions developed several months after consecutive exposures to narrowband ultraviolet B (UVB) phototherapy for chronic plaque psoriasis (Figure 1).

Most jaw muscles are complex, multipennate with multiple components. The morphologic heterogeneity of masticatory muscles reflects their functions. We hypothesized that the volume of masticatory muscles changes between jaw closing and opening, and that there is a difference in the volume change among the muscles. Magnetic resonance images of the entire head were obtained in ten normal young adult subjects before and after maximum jaw opening. The volume changes of the masseter, medial, and lateral pterygoid muscles were measured. Only slight changes were seen in the masseter and medial pterygoid muscles. The lateral pterygoid muscle, however, significantly decreased its volume during jaw opening. The results provide normative values of muscle volume in living subjects, and suggest that the volume changes differ among jaw muscles.

The purpose of this study was threefold: to estimate the organ doses and effective doses (EDs) for seven neurovascular imaging protocols, to study the effect of beam collimation on ED, and to derive protocol-specific dose-area product (DAP)-to-ED conversion factors.A cone-beam CT system was used to measure the organ doses for seven neurovascular imaging protocols. Two datasets were obtained: seven protocols without beam collimation (FOV, entire head) and four with beam collimation (FOV, from the base to the top of the skull). Measurements were performed on an adult male anthropomorphic phantom with 20 metal oxide semiconductor field-effect transistor (MOSFET) detectors placed in selected organs. The DAP values were recorded from the console. The EDs of five protocols were also estimated using Monte Carlo simulations software. The ED values were computed by multiplying measured organ doses to corresponding International Commission on Radiological Protection tissue-weighting factors.Without collimation, the EDs ranged from 0.16 to 1.6 mSv, and the DAP-to-ED conversion factors ranged from 0.035 to 0.076 mSv/Gy·cm(2). For the four protocols investigated with beam collimation, the ED was reduced by a factor of approximately 2, and the DAP-to-ED conversion factors were reduced by approximately 30%. For the five protocols also estimated with the Monte Carlo method, the estimated EDs were in agreement (20% deviation) with those determined by the MOSFET method.We have estimated ED for standard adult neuroimaging protocols in a 3D rotational angiography system. Our results provide a simple means of ED estimation using DAP console readings.

The aims of the present study were, first to develop a new method for evaluating sperm hyperactivation (HA) based on sperm head axis angle deviation, and second to apply this method in scoring selected sperm populations during capacitation. This was made possible by improving our original superimposed image analysis system (SIAS). The new option on the system enables us to determine the real angular deviation of the entire head in successive superimposed frames. The entire procedure for each spermatozoon requires 10-20 sec, according to the frame/rate utilized. A clear cut-off between the values of hyperactivated, transitional and non-hyperactivated spermatozoa was found at 11 and 21 frames/sec. However, at 6 frames/sec, a partial overlap between the three classes was found. We defined sperm activity as follows. At 11 frames/sec, hyperactivated: angle sumor = 405 degrees; transitional: 200 degreesor = angle sum405 degrees. At 21 frames/sec, hyperactivated: angle sumor = 760 degrees; transitional: 350 degreesor = angle sum760 degrees. The results, in agreement with previous research, show the peaks of activity at 3 h, dropping to a minimum at 6 h. This phenomenon was significantly more evident in fertile compared with subfertile semen samples.

The myth of rachipagus twins is hereby exploded-the myth, not the rachipagus! In a review of over 1,200 cases of conjoined twins, one classic example of rachipagus was found-two complete infants with dorsal union of the entire head and trunk, with roentgenograms showing clearly visible bony union of the vertebral arches from T6 to L3. After the typical case was discovered, 20 dorsal parasitic twins were reevaluated and reclassified as rachipagus. Two had extensive vertebral fusion and 18 were united in the dorsal midline, all with a meningocele, vertebral anomaly, and/or bony or neural connection. A theory of the embryologic origin of these twins is proposed: two embryonic discs located on diametrically opposing aspects of a single amniotic cavity becoming united in the area of the closing neural folds. This again raises the controversy concerning "fission or fusion" in conjoined twins.

A new high-resolution MR protocol for the combined assessment of neurovascular arterial anatomy and subsequent evaluation of inflammatory disease in cranial vessels walls has been investigated. First-pass contrast-enhanced MR angiography (CE-MRA) in combination with parallel imaging at high field permits the depiction of the neurovascular geometry with large coverage, including the aortic arch, supraaortic vessels, and almost the entire head, with high, submillimeter detail. Utilizing the remaining contrast agent, postcontrast T1-weighted turbo spin-echo (TSE) imaging was used to generate late enhancement images of the vessel walls to assess the morphology and potential inflammatory changes in cranial arteries with high in-plane (195 × 260 μm2) spatial resolution. As a result, a combined analysis of neurovascular arterial anatomy as well as cranial vessel wall inflammations could be achieved in less than 45 minutes in all studies. The feasibility and clinical value for the diagnosis of rheumatologic diseases and simultaneous arteriosclerotic involvement was demonstrated in seven patients with suspected giant cell arteritis (GCA). Excellent CE-MRA image quality could be achieved and even vascular geometry of small superficial cranial arteries could be successfully visualized using single dose (0.1 mmol/kg) contrast agent administration and a dedicated phased-array head and neck coil at 3T. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.

We wish to thank Dr. Wierzbicka for the interesting comments to the paper ‘‘Open partial horizontal laryngectomies: a proposal for classification by the working committee on nomenclature of the European Laryngological Society’’ by Succo et al. [1]. Its declared aim, as well as that of the other ELS classifications on oncologic subjects published in the past years [2–4] is to create a common platform for sharing surgical data among the greatest number of institutions worldwide. In this sense, the specific intent of our working committee was to keep the classification as easy as possible, including only well-known, standardized, and widely accepted procedures, reproducible among the entire head and neck surgical community. Clearly, this is required to make choices among the dozens of types of open partial laryngectomies described in the literature, focusing on those that, in our opinion, still play a pivotal role between the two extremes of transoral microsurgery on one hand, and total laryngectomy on the other. Among the many less common types of open partial laryngectomies, horizontal glottectomy, described in 1978 by Calearo and Teatini [5] (who were both, by the way, strictly linked to our laryngological school), definitely represents a procedure that is nowadays quite limited in its application since it has been overshadowed, for the reported indications, by transoral laser microsurgery and radiotherapy. Nevertheless, we are perfectly aware of the fact that any classification of surgical procedures should be regarded as a temporary tool that is being continuously reshaped and modified whenever consistent limits in its application should become evident in the future among the head and neck cancer community.

P300 recordings were made from males at high risk (HR) for alcoholism and low-risk (LR) controls, participating in a visual go/no go reaction time paradigm. The go (button press) and no go (inhibit response) stimuli were large and small forms of the same letters. The LR group had significantly larger go than no go P300 amplitudes in the central, parietal, and temporal regions; the HR group manifested no response differences in any region. In the LR group compared to the HR group, both go and no go response amplitudes were larger over the entire head; no group differences in latencies were observed in any region. Surface energy magnitudes paralleled P300 amplitudes and were also larger in the LR group during both go and no go trials. Our findings indicate that HR individuals manifest widespread P300 amplitude deficits while performing a simple information-processing paradigm. These deficits, which may reflect genetic influences, preceded the onset of alcoholism and may function as a phenotypic marker for its development.

In 20 healthy subjects, auditory evoked magnetic fields were measured over the entire head, using a helmet-shaped 66-channel MEG system linked to MRI. When the left or right ear was stimulated by 60 msec 2 kHz tones, the prominent 100 msec response (N100m) appeared significantly earlier in the contralateral hemisphere than in the ipsilateral one. In 16 cases, the N100m dipolar field patterns were clear in both hemispheres, overlapping each other across the midline. The N100m sources were estimated using a 2-dipole model in a spherical conducting medium with the size and location of the sphere determined individually according to the MRI images. No differences were found between the contralateral and ipsilateral N100m dipole positions in one hemisphere. When superimposed on MRI, the N100m dipoles were located precisely on the upper surface of bilateral temporal lobes with a standard deviation of 2.2 mm in the superior-inferior direction. In 16 right handed males, the right hemispheric N100m dipoles were 6 mm anterior to the left hemispheric dipoles. The whole head MEG is suitable to see small but significant differences of bilateral cerebral function, with exceptionally high spatial resolution, confirmed by the MRI-linked system.

The survival of patients with glioblastoma multiforme is extremely poor, the 5-year survival rate being almost zero. The cause of failure is almost exclusively local progression of tumor, the remainder is due to complications of treatment. Although this tumor is clearly radiation resistant, there is evidence of a dose response relationship. Using a thin slice CT scan of the entire head of a patient with glioblastoma multiforme, 3-dimensional radiation treatment plans were developed for treatment to a dose of 90 cobalt-Gray-equivalent (CGE). Dose distributions using protons were compared to those using x-rays. The results showed advantages for the proton beam technique. Namely the proton plan irradiated less non-target brain than the x-ray plan; this was especially so in the decrease of coverage of deep-seated structures. The volume of non-target brain that received more than 70 CGE was 175 ml for the x-ray plan and 94 ml for the proton plan. This study indicates that for a subpopulation of patients with glioblastoma multiforme, at least 90 CGE could be delivered with proton beam techniques to the target with only small volumes of normal brain structures receiving more than 70 CGE.

Purpose To determine whether the size and configuration of the optic chiasm in humans with albinism is different from that in normal control subjects. Methods Seventeen patients and 15 control subjects underwent magnetic resonance imaging of the entire head. Images were reformatted to the chiasm region and analyzed with observer-independent morphometry and measurements by a blinded observer. Results The albino group showed significantly smaller chiasmatic widths, smaller optic nerves and tracts, and wider angles between nerves and tracts. Statistical morphometry showed a different configuration of the optic chiasm. Conclusions Size and configuration of the optic chiasm in humans with albinism are distinctly different from those in normal control subjects and reflect the atypical crossing of optic fibers.

• A totally implantable infusion pump (Infusaid) has been developed to achieve continuous drug delivery for long periods of time. The recent availability of a dualcatheter totally implantable infusion pump permits the infusion of both external carotid arteries simultaneously. This has obvious advantages for the treatment of extensive tumors of the head and neck that extend across the midline. Likewise, for the first time, unilateral local-regional disease that extends inferiorly beyond the nutrient field of the external carotid artery may be treated with intra-arterial infusion chemotherapy without the need to infuse the common carotid or innominate arteries. Unilateral infusion of the entire head and neck is accomplished by using the dual-catheter pump to infuse both the thyrocervical trunk and the external carotid artery. ( Arch Otolaryngol 1982;108:703-708)

Summary Man's knowledge of human head proportions was investigated by asking young adult Ss to judge the relative location of selected head landmarks. Ss placed “x”s along a “vertical” line in a “unidimensional” condition, and within an oval outline of a head in two “bidimensional” conditions. Ss displaced landmarks upwards in both unidimensional and bidimensional conditions, with distortions by males exceeding those by females. On the bidimensional stimulus displays, landmarks were also displaced inwards toward the sagittal plane. The upward displacements of eyes and bottom of nose were the most noteworthy of the various distortions. Psychophysical experiments related to the present study suggest that the observed head landmark distortions are not likely attributable to anchoring effects. The findings also cast doubt on the hypothesis that Ss overestimate landmark heights because they treat the stimulus display as though it represents the face alone, rather than the entire head. Other explanations of the...

F. N., a white man aged 66, was admitted to the Graduate Hospital of the University of Pennsylvania on July 11, 1950, because of swelling of the entire head, face, and neck. The patient stated that two months prior to admission he first noted that his lower eyelids were swollen in the morning. The swelling became progressively worse, so that his eyes were swollen shut in the morning, his neck veins became prominent, like cords, and his arms were swollen. He also began to notice distended veins on his chest and a sensation of being choked when he "stooped" over. All these symptoms were less severe after he was up and about. Physical examination revealed distended neck veins and numerous varices on the anterior chest wall, but no dependent edema. The rest of the examination revealed nothing significant. Laboratory studies showed a venous pressure of 310 mm. of water, a