Supraorbital Regions Research Articles

Effect of bihemispheric anodal transcranial direct current stimulation for dysphagia in chronic stroke patients: A randomized clinical trial.

To investigate whether bihemispheric anodal transcranial direct current stimulation (tDCS) with conventional dysphagia therapy could improve swallowing function in chronic stroke patients with dysphagia. Randomized controlled trial. Twenty-six patients with dysphagia for at least 6 months post-stroke were randomly assigned into: (i) bihemispheric anodal tDCS group; or (ii) sham group. All patients underwent 10 tDCS sessions with simultaneous conventional swallowing therapy for 2 weeks. Both anodal electrodes were attached bilaterally to the pharyngeal motor cortices, and cathodal electrodes were attached to both supraorbital regions. Swallowing function was evaluated with the Dysphagia Outcome and Severity Scale (DOSS) before and immediately after the last intervention session. The bihemispheric anodal tDCS group showed a mean significant improvement 0.62 points; standard deviation (SD) 0.77, in the DOSS immediately after all sessions (p = 0.02). However, there was no mean significant improvement in the sham group (0.38 points; SD 0.65(p = 0.06)). There was no significant difference between the 2 groups (p = 0.48). The bihemispheric anodal tDCS with conventional dysphagia therapy had additional helpful effects on the improvement in swallowing function in chronic stroke patients.

Hyaluronic acid in the rejuvenation of the upper third of the face: review and update. Part 2: temporal and supraorbital regions

Hyaluronic acid in the rejuvenation of the upper third of the face: review and update. Part 2: temporal and supraorbital regions

Morphological relationship between the cranial and supraorbital regions in Homo sapiens.

Although some hypotheses that attempt to explain the variation in supraorbital region morphology in modern humans have been proposed, this issue is still not well understood. In this study, the craniofacial size and spatial models were tested using a sample of modern human crania from geographically diverse populations, and the co-occurrence of the degrees of glabella (GL) and superciliary arch (ST) expression were analyzed. The two supraorbital structures were examined by visual assessment, and eight quantitative variables were included in the three-way ANOVA, canonical variates analysis and partial rank correlation. The influences of sex and the region of origin of the cranial samples on the relationships between the examined variables and the degrees of supraorbital structures expression were also considered. The results only partially supported the craniofacial size and spatial models and suggested that GL and ST experienced separate influences during development. In the sample of all crania, the neurocranial size more strongly influenced the morphological variation of the ST than of the GL, and sex influenced both of these structures the most. The results suggest that sex may be the main factor (having an influence independent of the other traits) on the morphological variation of the GL and ST.

Cluster-like headache attacks triggered by nitrofurantoin intake

Sir,A wide spectrum of drugs can induce headache, which is infact one of the most common adverse drug events [1, 2].Although headache is usually a nonserious, unwanted effect,itcould bedifficult toquickly and correctly diagnose, leadingto repeated medical consultations, prescription of laboratoryor instrumental examinations, and even hospitalization [1].The International Headache Classification (IHC), inChapter 8, includes these secondary headaches as adversereactions to drugs [3]. Whereas some drug-related headachesare well characterized, others lack specific and accuratedefinition [1]. We present a patient experiencing cluster-likeattacks after nitrofurantoin consumption.A previously healthy 42-year-old man with no personal orfamily history of migraine, tension, or cluster headachepresented to the emergency room (ER) complaining of asevere unilateral left-sided headache. The pain was describedas lancinating, centered on the left eye and extending toperiorbital, supraorbital, and temporal regions. It wasaccompanied by conjunctival injection, lacrimation, eyelidedema, facial swelling, nasal congestion, and rhinorrhea ontheaffectedside.Theattackquicklyworsened,peakingwithin5–10 min, with a duration of about 60 min; both pain and theaccompanying autonomic signs spontaneously resolved. Theheadache began about 1 h after he took a tablet ofnitrofurantoin (50 mg) for a urinary tract infection. The daybefore, just after the first-ever consumption of nitrofurantoin,he had a headache attack with the same clinical presentation,the same latency between drug consumption and pain onset,and the same duration. Physical and neurologicalexaminations were normal, as were routine hematologicaltests and brain magnetic resonance imaging. As both attacksfollowed the intake of nitrofurantoin, the patient was advisedto stop taking the drug, which was replaced with a differentantibiotic agent (ciprofloxacin 500 mg twice daily).Thereafter, he experienced no further headache attacks.During a 2-year follow-up, he remained headache free.Theclosetemporalassociationbetweenthedrugintakeandthe appearance of headache on two occasions suggests acausal relationship. Nitrofurantoin is a widely used drug fortreating and preventing urinary tract infections. Headache is awell-known and one of the most common adverse effects,occurring in about 4–6 % of users [4, 5]; others side effectsinclude immune-mediated liver and lung reactions andpulmonary fibrosis. Nitrofurantoin-induced headache isusually described as severe to moderate; no specific featureshave been reported, and the pathogenetic mechanisms are notfully elucidated. Some authors [1] have categorized thisheadache as type C reactions arising from chronic use [6].Nitrofurantoin is usually included in the list of drugs that caninducebenignintracranialhypertension[7]andthenheadacherelated to raised intracranial pressure [2]. Our patient,however, had cluster-like attacks in close association withdrug intake. Several studies have demonstrated thatnitrofurans can release nitric oxide (NO) [8, 9], which is animportant neurotransmitter and regulates the vascular tone,acting as a potent vasodilator by diffusing into vascularsmooth-muscle cells. Moreover, NO is thought to play a rolein processing sensory information and pain sensitization [10].NO donors induce an immediate headache in healthyindividuals and in headache sufferers, with a delayedheadache with the characteristics of migraine, tension-type,orclusterheadacheinpatientssufferingfromtheseheadaches[10, 11]. In particular, cluster headache sufferers develop

Aspectos clínicos, ultra-sonográficos e venográficos da tromboflebite jugular experimental em equinos

A tromboflebite jugular ocorre frequentemente em equinos, decorrendo geralmente de processos mórbidos associados à iatrogenia, podendo levar a perda de função, edema cefálico, diminuição do desempenho atlético e ainda causar o óbito. Esta enfermidade nos equinos apesar de frequente é pouco conhecida quanto à sua evolução e tratamentos. O objetivo deste trabalho foi avaliar a evolução da tromboflebite jugular experimental em equinos, quanto às alterações clínicas e estruturais envolvidas na enfermidade, observando-se os aspectos clínicos, ultra-sonográficos e venográficos no contexto do trombo e do vaso, quanto à possibilidade de recanalização do trombo produzido e da vascularização compensatória. A tromboflebite da veia jugular foi induzida, unilateralmente, em 05 equinos nos quais previamente à indução da tromboflebite e diariamente após foram observadas manifestações clínicas e realizados exames ultra-sonográficos. Venografias foram feitas nos momentos pré-indução, na indução e a cada seis dias após a indução da tromboflebite, verificando-se a recanalização do trombo oclusivo e a presença de vasos na drenagem sanguínea compensatória. Observou-se a ocorrência de edema moderado das regiões parotídea, massetérica e supra-orbitária e discreto edema submandibular que reduziram até o 6º dia, permanecendo apenas discreto aumento parotídeo. O ingurgitamento da jugular cranial a região da indução permaneceu durante todo o período de avaliação. A porção caudal à tromboflebite mostrou ingurgitamento frente ao garrote na entrada do tórax desde o primeiro dia após a indução. Os exames ultra-sonográficos mostraram formação de trombo oclusivo total durante todo o período de observação em 3 animais e o restabelecimento parcial do fluxo na jugular em 2 animais e a presença de vasos colaterais conduzindo o sangue da porção cranial para a porção caudal à obstrução. As venografias revelaram fluxo sanguíneo "linear" normal no momento pré-operatório, constatando nos momentos pós-operatórios a presença oclusiva do trombo, com o contraste preenchendo os vasos tributários compensatórios direcionados à porção caudal à oclusão da veia ou ainda estagnado cranialmente ao trombo. Conclui-se que a trombose oclusiva na tromboflebite jugular experimental e unilateral sofre recanalização e compensação vascular por vasos tributários de drenagem, com redução gradativa dos sinais decorrentes da estase sanguínea de retorno, especificamente as regiões cefálicas com edema. Estudos envolvendo a tromboflebite jugular nos equinos devem evoluir nos aspectos experimental e clínico.

Cutaneous innervation and trigeminal pathway function in a patient with facial pain associated with Parry-Romberg syndrome

Parry-Romberg syndrome (PRS) is a rare condition manifesting with progressive hemifacial atrophy. Although reported PRS clinical disturbances include facial pain and recent studies raised the possibility that PRS-related pain is a neuropathic pain condition due to the trigeminal nerve damage, no studies have directly investigated cutaneous innervation and trigeminal pathway function in patients with this rare condition. In a 50-year-old woman presenting with a 10-year history of slowly progressive hemifacial atrophy and facial pain, we investigated large myelinated fibres with masticatory muscle electromyography and trigeminal reflexes, and tested small myelinated and unmyelinated fibres with laser-evoked potentials. We also investigated cutaneous innervation by measuring the intraepidermal nerve fibre (IENF) density after skin biopsy of the supraorbital regions. We found that neurophysiological data and IENF density came within normal ranges, with no differences between normal and affected side. Our study showing that the standard reference techniques for assessing cutaneous innervation and trigeminal pathway function disclosed no abnormalities in this patient with PRS suggest that this rare and disabling condition is not associated with trigeminal system damage. These findings indicate that in this patient PRS-related pain is not a neuropathic pain condition, rather it probably arises from the musculoskeletal abnormalities.

Transciliary Supraorbital Approach

To the Editor: We read with interest the comments by Dr Balasubramanian.1 The pros and cons that Dr Balasubramanian mentioned are important aspects when neurosurgeons consider these transciliary methods. However, we think it is prudent to stress that the transciliary incision could be used not only for the supraorbital craniotomy but also for the mini-orbitozygomatic craniotomy. With the orbital rim removed, the latter provides increased space for instrument use, minimizes brain retraction, and improves the vertical angle of the corridor to common sites in the anterior circulation aneurysms and anterior skull base lesions (especially in frontobasal or suprasellar tumors).2,3 We find this mini-orbitozygomatic craniotomy especially useful when the endoscope-assisted method is considered (because the increased angle provides a better space to insert the endoscope, which avoids “sword fighting” with the other instruments). In our experience, the prominent frontal sinus is not a contraindication to these approaches. In our patients, the pericranial flap could be harvested and used for reconstruction of the frontal sinus, similar to traditional anterior skull base procedure. In our experience, the initial saline injection to the space above the periosteum is very critical (Figure, A). Immediately after the junction of the orbicularis and frontalis muscle is split, the underlying pericranial (periosteal) flap is harvested (Figure, B; the supraorbital nerve was isolated with a silk). The harvested flap is usually about 3.5 cm in height and 4.5 cm in width, depending on the length of transciliary incision (Figure, C, showing the bony exposure for supraorbital craniotomy [arrow indicates pericranial flap]). If a longer flap is needed (judging from preoperative sagittal imaging), the traction endoscopic method could be used to harvest the flap up to 10 cm. With this traction endoscopic method, the supraorbital nerve (Figure, D) could be preserved after it was isolated up to 5 cm and lateralized to the nasal side during surgery. In our experience, this technique minimizes the postoperative scalp numbness (in both the supraorbital and temporoparietal regions). A similar method is reported by Patel et al4 for repair of the dural defect from an extended endonasal approach. However, they used a median nasion incision and an additional incision behind the hairline to harvest the flap. During surgery, the frontal sinus was entered and the mucosa removed. After irrigation with gentamicin water, the frontal sinus was packed with beta-iodine-soaked gel foam, and the roof was covered with the pericranial flap. With such a method, none of the 23 supraorbital or mini-orbitozygomatic craniotomies that traverse the frontal sinus had postoperative central nervous system or wound infection. Therefore, we do not consider a prominent frontal sinus to be a contraindication to these approaches.FIGURE: The steps and technique used to harvest the pericranial flap in the transciliary approach.When a ventriculostomy is needed, mostly in aneurysm cases, the entry point could be created at the frontal basal region directly under the keyhole. The ventriculostomy catheter was directed at a 45° angle to the midline and a 20° angle up from an imaginary line parallel to the orbitomeatal line.5 The catheter will usually be inserted into the frontal horn at a point 5 cm from the pial surface and may be inserted to 6.5 cm. A subcutaneous tunnel is then created, and the catheter is pulled through another small incision near the pterion behind the hairline. We could not agree more with Dr Balasubramanian that patient selection is the most important step in choosing these minimally invasive techniques. In terms of aneurysmal surgery, traditional craniotomy or even hemicraniectomy was needed in patients with poor-grade subarachnoid hemorrhage or significant brain edema. These cases are apparently poor candidates for supraciliary approach. The approach selection for an anterior skull base tumor is further complicated by the additional option of the extended endonasal approach.6 The tumor size, relationship to optic nerve, surgical experience, and confidence in a watertight reconstruction of dural defect are all important factors to consider. In summary, when minimally invasive approaches are considered, the exposure and angle provided by these approaches are equally important.7 As most experts have mentioned, the most important point is to use the most suitable approach for a particular patient rather than using a one-size-fits-all approach for all patients. Abel Po-Hao Huang Chien-Lian Chen Taipei, Taiwan

Orbital Infantile Myofibroma: a Case Report and Clinicopathologic Review of 24 Cases from the Literature

Isolated orbital infantile myofibroma are rare tumors in the head and neck. The mass-like clinical presentation and variable histologic features result in frequent misdiagnosis and potentially inappropriate clinical management. There are only a few reported cases in the English literature. Twenty-four patients with orbital infantile myofibroma or myofibromatosis were compiled from the English literature (Medline 1960-2011) and integrated with this case report. The patients included 14 males and 10 females, aged newborn to 10years (mean, 34.8months), who presented with a painless mass in the infra- or supraorbital regions, usually increasing in size andassociated with exophthalmos (n=5). Females were on average older than their male counterparts (38.9 vs. 31.9months, respectively; P=0.71). The tumors were twice as frequent on the left (n=16) than right (n=8). Patients experienced symptoms for an average of 2.7months before clinical presentation. The tumors involved the bone (n=17) or the soft tissues (n=7) of the orbit, with extension into the nasal or oral cavity (n=3). The mean size was 3.0cm, with a statistically significant difference between males and females (mean: 3.9 vs. 1.82; P=0.0047), but without any differences based on age at presentation (P=0.25), duration of symptoms (P=0.66), or bone or soft tissue involvement (P=0.51). Grossly, all tumors were well-circumscribed, firm to rubbery, homogenous, and white-grey. Histologically, the tumors were biphasic, showing whorled and nodular areas of fusiform cells with extracellular collagen, mixed with a population of small, primitive-appearing, darkly staining cells. Necrosis was not present, but mitoses could be seen. Tumors with immunohistochemistry performed showed strong and diffuse smooth muscle actin and vimentin immunoreactivity, but were negative with muscle specific actin, desmin, MYOD1, myogenin, S100 protein, GFAP, keratin, CD31, 34, Factor VIIIR-Ag, and CD45RB. The principle histologic differential diagnosis includes juvenile hyaline fibromatosis, fibrous hamartoma of infancy, fibromatosis coli, leiomyoma, infantile hemangiopericytoma, infantile fibrosarcoma, Ewing sarcoma/primitive neuroectodermal tumor, and lymphoma. All patients were managed with surgery. Recurrences developed in two patients at 4 and 6months, respectively. Follow-up data was available on all but two patients (n=22). These patients were either alive without evidence of disease (n=18), alive but with disease (n=3), or had died unrelated to this disease (i.e., neuroblastoma, n=1). Orbital infantile myofibroma is a rare tumor, presenting in infancy as an enlarging mass of the orbit, with characteristic histomorphologic and immunophenotypic features. Orbital disease is usually isolated rather than part of systemic disease, and shows an excellent long-term prognosis, making appropriate separation from other conditions important.

Transient stabbing headache from an acute thalamic hemorrhage

Stabbing headache can be encountered in both primary and secondary forms, but has been infrequently reported among patients with stroke, and is not known to be associated with a small well-circumscribed brain lesion. A 95-year-old woman taking warfarin presented with the sudden onset of stabbing headache strictly in the right frontal and supraorbital regions, along with gait imbalance and dysarthria. Neuroimaging revealed a small left thalamic hematoma. This association of an acute thalamic lesion with stabbing headache in the contralateral trigeminal distribution is discussed, along with a brief review of stabbing headache occurring in cerebrovascular disease.

Correction of Large Facial Encephalocele With Bilateral Rare Craniofacial Clefts

Treatment of Tessier number 3, 11 craniofacial clefts represent a surgical challenge with complex bone and soft tissue deficits of the lip, cheek, medial orbit, and forehead. The severity of the presenting defect will ultimately determine the number of reconstructive stages required as well as the timing of each stage. Initial surgery in infancy is aimed at functional correction. We present the case of a patient with an expanding fronto-orbital encephalocele, a right number 3, 11 cleft and a left number 3, 10 cleft. The initial procedure repaired the encephalocele and reconstructed the supraorbital and forehead regions. Subsequent surgeries corrected the bilateral facial clefts with cleft lip repair, rotation of the forehead and nasal unit, cheek advancement, and a lower eyelid transposition flap.

Retinal origin of phosphenes to transcranial alternating current stimulation

To examine possible retinal contributions to cortically induced phosphenes by transcranial alternating current stimulation (tACS) involving the visual cortex. Self-reported phosphene ratings and voltage-related potentials from the canthus, supra-orbital and sub-orbital regions of the right eye were measured to 2, 10 and 20 Hz tACS at 250 and 1000 microA intensities in healthy volunteers. Qualitatively similar, but more intense phosphenes were reported during frontalis-vertex tACS as compared to occiput-vertex tACS. In addition, voltage-related potentials were recorded at the canthus and orbit regions of the eye during frontalis-vertex, occiput-vertex and occiput-right shoulder tACS. The experience of phosphenes during tACS involving the visual cortex is influenced by volume conductions effects of the scalp. Retinal effects should be taken into account when studying the cortical modulatory effects of tACS.

Infrared thermal imaging as a physiological access pathway: a study of the baseline characteristics of facial skin temperatures

In this study we examine the baseline characteristics of facial skin temperature, as measured by dynamic infrared thermal imaging, to gauge its potential as a physiological access pathway for non-verbal individuals with severe motor impairments. Frontal facial recordings were obtained from 12 asymptomatic adults in a resting state with a high-end infrared thermal imaging system. From the infrared thermal recordings, mean skin temperature time series were generated for regions of interest encompassing the nasal, periorbital and supraorbital areas. A 90% bandwidth for all regions of interest was found to be in the 1 Hz range. Over 70% of the time series were identified as nonstationary (p< 0.05), with the nonstationary mean as the greatest contributing source. Correlation coefficients between regions were significant (p< 0.05) and ranged from values of 0.30 (between periorbital and supraorbital regions) to 0.75 (between contralateral supraorbital regions). Using information measures, we concluded that the greatest degree of information existed in the nasal and periorbital regions. Mutual information existed across all regions but was especially prominent between the nasal and periorbital regions. Results from this study provide insight into appropriate analysis methods and potential discriminating features for the application of facial skin temperature as a physiological access pathway.

Trigeminal small-fibre function assessed with contact heat evoked potentials in humans

Contact heat stimuli have been reported to excite mechano-thermal nociceptors and to evoke brain potentials (CHEPs) from the limbs. We investigated whether contact heat evokes reproducible CHEPs from the trigeminal territory and may prove a reliable diagnostic tool in facial neuropathic pain. We applied contact heat stimuli to the perioral and supraorbital regions; CHEPs were recorded from the vertex in 20 controls and 2 patients with facial neuropathic pains, and reflex responses from the orbicularis oculi and masticatory muscles in 5 controls. We studied the correlation between CHEP data and perceptive ratings, site of stimulation, and age. Finally, we compared CHEPs with laser evoked potentials (LEPs). Contact heat stimuli at 51 °C evoked vertex potentials consisting of an NP complex similar to that elicited by laser pulses, though with a latency some 100-ms longer. Perioral stimulation yielded higher pain intensity ratings, shorter latency and larger amplitude CHEPs than supraorbital stimulation. CHEP data correlated significantly with age. Contact heat stimuli at 53 °C evoked a blink-like response in the relaxed orbicularis oculi muscle and a silent period in the contracted masseter muscle. In patients with facial neuropathic pain the CHEP abnormalities paralleled those seen with LEPs. We were unable to achieve reproducible signals related to C-receptor stimulation by contact heat stimuli at 41 °C in the ten subjects in whom they were tested. Contact heat stimulation, as well as laser stimulation, easily yields large-amplitude brain potentials and nociceptive reflexes, both related to the Aδ input. However CHEPs are not suitable for C-fibres potentials recording.

Spatial relations between avian craniofacial neural crest and paraxial mesoderm cells

Fate maps based on quail-chick grafting of avian cephalic neural crest precursors and paraxial mesoderm cells have identified the majority of derivatives from each population but have not unequivocally resolved the precise locations of and population dynamics at the interface between them. The relation between these two mesenchymal tissues is especially critical for the development of skeletal muscles, because crest cells play an essential role in their differentiation and subsequent spatial organization. It is not known whether myogenic mesoderm and skeletogenic neural crest cells establish permanent relations while en route to their final destinations, or later at the sites where musculoskeletal morphogenesis is completed. We applied beta-galactosidase-encoding, replication-incompetent retroviruses to paraxial mesoderm, to crest progenitors, or at the interface between mesodermal and overlying neural crest as both were en route to branchial or periocular regions in chick embryos. With respect to skeletal structures, the results identify the avian neural crest:mesoderm boundary at the junction of the supraorbital and calvarial regions of the frontal bone, lateral to the hypophyseal foramen, and rostral to laryngeal cartilages. Therefore, in the chick embryo, most of the frontal and the entire parietal bone are of mesodermal, not neural crest, origin. Within paraxial mesoderm, the progenitors of each lineage display different behaviors. Chondrogenic cells are relatively stationary and intramembranous osteogenic cells move only in transverse planes around the brain. Angioblasts migrate invasively in all directions. Extraocular muscle precursors form tightly aggregated masses that en masse cross the crest:mesoderm interface to enter periocular territories, while branchial myogenic lineages shift ventrally coincidental with the movements of corresponding neural crest cells. En route to the branchial arches, myogenic mesoderm cells do not maintain constant, nearest-neighbor relations with adjacent, overlying neural crest cells. Thus, progenitors of individual muscles do not establish stable, permanent relations with their connective tissues until both populations reach the sites of their morphogenesis within branchial arches or orbital regions.

Neurosensory changes in the infraorbital nerve following zygomatic fractures

To document the neurosensory changes in the infraorbital nerve following zygomatic fractures managed in various ways. Twenty-five patients were included in the study. Neurosensory function was assessed with calibrated nylon monofilaments, electrical stimulation, heat detection thresholds and response to pin prick in the infraorbital, supraorbital, and mental nerve regions. Patients were seen immediately post-trauma, then 1 and 6 months following surgery. Nine fractures were caused by traffic accidents (TAs), 8 by falls, and 8 by a local blow in a physical dispute. The fractures consisted of 15 displaced and 10 minimally or nondisplaced zygomatic complex fractures, and were left surgically untreated in 7 cases (None group), reduced but not fixed in 8 cases (Reduction group), and fixed with plates in 10 cases (Plates group). Plates were employed significantly more often in displaced fractures (chi-squared P = .0006). At 6 months significantly improved infraorbital nerve function was found in the Plate and None groups relative to the Reduction group (ANOVA P = .006). Only 1 case of chronic neuropathic pain was found. This study concurs with previous studies in finding that plate fixation allows for significantly better restoration of infraorbital nerve function. Chronic neuropathic pain following zygomatic fractures is rare.

Experimental facial augmentation with hydroxyapatite cement.

To study the results of implantation of preformed hydroxyapatite (HA) disks and HA cement in onlay augmentation. In this prospective study involving 16 adult New Zealand rabbits, HA disk and HA cement samples were implanted separately and together along the bony and cartilaginous nasal dorsum as well as over the supraorbital bone. Gross and histologic examinations of the implants were performed at intervals ranging from 3 to 24 months. There was no evidence of infection, adverse reaction, or implant extrusion in the 15 rabbits surviving the planned period. Grossly, all rabbits had prominent noses and supraorbital regions that were immobile on digital palpation. No measurable change in HA disk height and width was noted but there was a 15% decrease in height and width in the HA cement implant. Microscopically, preformed HA disks were found to be enclosed in a vascularized fibrous capsule. When disks were combined with HA cement, a vascular fibrous capsule was still noted around the implant but there was osteoconversion in the underlying cement layer. Used alone, HA cement underwent both osteoconversion and osteointegration. Neither the preformed HA disk with and without HA cement nor the HA cement alone elicited giant cell reaction or inflammatory changes. The HA cement alone was found to have microscopic fissures at the edges. This animal study suggests that preformed HA implants and HA cement, alone or in combination, can be used to augment the non-stress-bearing craniofacial skeleton.

Nociceptive quality of the laser-evoked blink reflex in humans.

Laser radiant-heat pulses selectively excite the free nerve endings in the superficial layers of the skin and activate mechano-thermal nociceptive afferents; when directed to the perioral or supraorbital skin, high-intensity laser pulses evoke a blink-like response in the orbicularis oculi muscle (the laser blink reflex, LBR). We investigated the functional properties (startle or nociceptive origin) of the LBR and sought to characterize its central pathways. Using high-intensity CO(2)-laser stimulation of the perioral or supraorbital regions and electromyographic (EMG) recordings from the orbicularis oculi muscles, we did five experiments in 20 healthy volunteers. First, to investigate whether the LBR is a startle response, we studied its habituation to expected rhythmic stimuli and to unexpected arrhythmic stimuli. To assess its possible nociceptive quality, we studied changes in the LBR and the R2 component of the electrical blink reflex after a lidocaine-induced supraorbital nerve block and after intramuscular injection of the opiate fentanyl and the opiate-antagonist naloxone. To characterize the central pathways for the LBR, we investigated the interaction between the LBR and the three components of the blink reflex (R1, R2, and R3) by delivering laser pulses to the perioral or supraorbital regions before or after electrical stimulation of the supraorbital nerve at various interstimulus intervals. Finally, to gain further information on the central LBR pathways, using two identical CO(2)-laser stimulators, we studied the LBR recovery curves with paired laser pulses delivered to adjacent forehead points at interstimulus intervals from 250 ms to 1.5 s. The LBR withstood relatively high-frequency rhythmic stimulations, and unexpected laser pulses failed to evoke larger responses. When lidocaine began to induce hypoalgesia (about 5 min after the injection), the LBR was abolished, whereas R2 was only partly suppressed 10 min after the injection. Fentanyl injection induced strong, naloxone-reversible, LBR suppression (the response decreased to 25.3% of predrug values at 10 min and to 4% at 20 min), whereas R2 remained appreciably unchanged. Whether directed to the perioral or supraorbital regions, preceding laser pulses strongly suppressed R2 and R3 though not R1. Conversely, preceding electrical stimuli to the supraorbital nerve suppressed the LBR. In response to paired stimuli, the LBR recovered significantly faster than R2. These findings indicate that the LBR is a nociceptive reflex, which shares part of the interneuron chain mediating the nonnociceptive R2 blink reflex, probably in the medullary reticular formation. The LBR may prove useful for studying the pathophysiology of orofacial pain syndromes.

The blink reflex and the corneal reflex are followed by cortical activity resembling the nociceptive potentials induced by trigeminal laser stimulation in man

Laser stimulation of the supraorbital regions evokes brain potentials (LEPs) related to trigeminal nociception. The aim of this study was to record the R2 component of the blink reflex and the corneal reflex in 20 normal subjects, comparing the scalp activity following these reflexes with the nociceptive potentials evoked by CO 2 laser stimulation of supraorbital regions. Cortical and muscular reflexes evoked by stimulation of the first trigeminal branch were recorded simultaneously. The R2 component of the blink reflex and the corneal reflex were followed by two cortical peaks, which resembled morphologically N-P waves of LEPs. The two peaks demonstrated a difference in latency of approximately 40 ms, which is consistent with activation time of nociception. This finding suggests that these reflexes are induced by activation of small pain-related fibers.

Small-fiber dysfunction in trigeminal neuralgia: carbamazepine effect on laser-evoked potentials.

In patients with trigeminal neuralgia, results of clinical examination of sensory function are normal. Reflex and evoked potential studies have already provided information on large-afferent (non-nociceptive) function. Using laser-evoked potentials (LEP), the authors sought information on small-afferent (nociceptive) function. The brain potentials evoked by CO(2)-laser pulses directed to the perioral and supraorbital regions were studied in 67 patients with idiopathic or symptomatic trigeminal neuralgia and 30 normal subjects. Of the 67 patients, 49 were receiving carbamazepine. All patients with symptomatic and 51% of those with idiopathic trigeminal neuralgia had frankly abnormal LEP on the painful side. The mean latency was significantly higher and mean amplitude lower on the painful than the nonpainful side. However, even on the nonpainful side, the mean latency was significantly longer than that of the age-matched controls. The nonpainful-side latency correlated significantly with the carbamazepine dose. LEP detect severe impairment of the nociceptive afferent system on the painful side of patients with idiopathic as well as symptomatic trigeminal neuralgia. A dysfunction of small-myelinated afferents may play an important role in the pathophysiology of neuralgic pain. Carbamazepine markedly dampens these brain potentials. The authors propose that this effect may result from inhibition of nociceptive transmission in the cingulate gyrus.

口腔内アプローチ法による頬骨骨折手術における術中超音波断層検査法の有用性

Generally, en bloc zygomatic fractures are treated by open reductionwith incisions of theinfraorbital rim and supraorbital eyebrow regions. However this method is associated with postoperativecomplications such as facial scars. An intraoral approach requiring only a maxillary vestibular incision, has been reported in several articles. This method is simple and results in adequate bone reduction and fixation. However, the position of bone fragments in the infraorbital rim cannot be observed. We used anintraoral approach, during intraoperative ultrasonic examination to confirm the condition of infraorbitalfragments in 17 patients who had simple en bloc fractures of the zygoma bone body. Ultrasonographyshowed dynamic bone reduction as distinct real-time images and bone fixation was performed exactly. Inselected patients the intaroral approach during ultrasonography, is recommended for en bloc zygomaticfractures.