Growth restriction of cranial sutures in the fetal lamb causes deformational changes, not craniosynostosis

Newborns with in utero cranial vault molding can present with severe forms of plagiocephaly. Intrauterine constraint has been proposed as one cause for craniosynostosis. The purpose of this experiment was to investigate whether rigid plate fixation across a fetal cranial suture, representing a severe form of growth restriction in utero, would lead to cranial suture fusion in a fetal lamb model. Six fetal lambs at 85 to 95 days gestation (term = 145 days) underwent laparotomy, hysterotomy, fetal coronal scalp incision, and miniplate screw fixation across the right coronal suture in utero. Two unoperated twins and four unoperated age-matched lambs were used as controls (n = 12). Animals were killed at both 4 and 8 weeks postoperatively. Fetal head analysis consisted of gross examination, photography, basilar and lateral radiographs, and three-dimensional computed tomographic scans. Cranial suture analysis consisted of imaging by computed tomographic scan (axial and sagittal cuts) and histology of experimentally plated coronal sutures, contralateral nonplated coronal sutures and twin control coronal sutures. Gross examination, radiographs, and three-dimensional computed tomographic analysis of heads with cranial suture plating showed ipsilateral forehead flattening, contralateral forehead bossing, superiorly displaced ipsilateral orbital rim, anterolateral projection of ipsilateral malar eminence, and anterior position of the ipsilateral ear point compared with the contralateral side of the same animal and normal controls. There was no change in nasal root, chin point, or predentition occlusal plane. Although analysis of the plated coronal sutures by computed tomographic scans showed diminished width or even stenosis, the histology revealed narrowed but patent experimental coronal sutures at 4 and 8 weeks. Contralateral, nonplated coronal sutures were not only patent, but widened compared with normal control sutures. This finding may have represented compensatory changes in the contralateral coronal suture caused by growth restriction at the plated suture. These data demonstrate that intrauterine growth restriction across a cranial suture caused by compression plate fixation resulted in deformational skull changes, not craniosynostosis. In addition, these data strongly support a role for in utero positional molding secondary to growth restriction in the maternal pelvis as a cause for nonsynostotic plagiocephaly seen in newborns.     

The role of tissue expansion in the management of large congenital pigmented nevi of the forehead in the pediatric patient

The authors present a cohort of 21 consecutive patients who had congenital pigmented nevi covering 15 to 65 percent of the forehead and adjacent scalp and who were treated at their institution within the last 12 years. All patients were treated with an expansion of the adjacent texture- and color-matched skin as the primary modality of treatment. The median age at presentation was approximately 1 year; mean postoperative follow-up was 4 years. Nevi were classified according to the predominant anatomic areas they occupied (temporal, hemiforehead, and midforehead/central); some of the lesions involved more than one aesthetic subunit.The authors propose the following guidelines: (1) Midforehead nevi are best treated using an expansion of bilateral normal forehead segments and advancement of the flaps medially, with scars placed along the brow and at or posterior to the hairline. (2) Hemiforehead nevi often require serial expansion of the uninvolved half of the forehead to minimize the need for a back-cut to release the advancing flap. (3) Nevi of the supraorbital and temporal forehead are preferentially treated with a transposition of a portion of the expanded normal skin medial to the nevus. (4) When the temporal scalp is minimally involved with nevus, the parietal scalp can be expanded and advanced to create the new hairline. When the temporoparietal scalp is also involved with nevus, a transposition flap (actually a combined advancement and transposition flap because the base of the pedicle moves forward as well) provides the optimal hair direction for the temporal hairline and allows significantly greater movement of the expanded flap, thereby minimizing the need for serial expansion. (5) Once the brow is significantly elevated on either the ipsilateral or contralateral side from the reconstruction, it can only be returned to the preoperative position with the interposition of additional, non-hair-bearing forehead skin. Expansion of the deficient area alone will not reliably lower the brow once a skin deficiency exists. (6) In general, one should always use the largest expander possible beneath the uninvolved forehead skin, occasionally even carrying the expander under the lesion. Expanders are often overexpanded.     

Evaluating rejuvenation of the forehead and brow: an algorithm for selecting the appropriate technique

The traditional reason for performing aesthetic surgery in the forehead and brow area has been to correct brow ptosis. However, there are several other conditions that may be improved by surgery in this area, including frown muscle imbalance, transverse forehead rhytids, and lateral brow laxity. Recently, a better understanding of the relevant anatomy and the evolving therapeutic modalities (including both open and closed techniques) have contributed to a renewed interest in aesthetic surgery in the forehead and brow area. One hundred consecutive patients were studied, each of whom underwent forehead rejuvenation for one of four indications-forehead rhytids, glabellar creases, lateral brow laxity, or brow ptosis. Thirty-eight percent of patients underwent open procedures, 30 percent underwent closed procedures, and 32 percent underwent limited procedures. Complications occurred in 4 percent of patients, including three patients who were dissatisfied with the surgery and one patient who required scar revision. Based on our findings, we formulated an algorithm that integrates the different indications and any concomitant procedures being performed. Our proposed treatment plan is based on this information. The algorithm may be used as a template when assessing a patient and adapting the recommended intervention to the individual patient.     

Selective myotomy in forehead endoscopy

Endoscopic forehead surgery in a subgaleal plane allows selective manipulation of the forehead and glabellar muscles in accordance with their influence in forehead and brow deformity. Myotomy begins by interrupting the blend of the fibers of the elevator and depressor muscles, thereby exposing the bone fixation and cutaneous insertions of the depressor muscles. Myotomy of the depressor group is performed by section of the muscle fibers as close as possible to their bone fixation, with release of the cutaneous insertions at the brow level. The involuntary frontalis contraction free from the active opposition of the depressor muscles and free from the restriction of the inelastic structure of the periosteum stabilizes the brow elevation and gives a natural, long-term result. No fixation methods are used to hold the forehead flap in position. Transverse section of the frontalis muscle is performed to restore brow symmetry or excessive lift of the brow.     

Endoscopic brow lift: a retrospective review of 628 consecutive cases over 5 years

Since its introduction in 1992, endoscopic brow lift has gained tremendous recognition because it has been promoted as a novel technique to correct brow ptosis as well as glabella rhytids in a minimally invasive manner with fewer complications than the classic coronal brow lift method. In this retrospective study, 628 endoscopic brow lift procedures performed over a 5-year period (1997-2001) at Manhattan Eye Ear and Throat Hospital were reviewed. The number of endoscopic brow lift procedures performed at this institution has declined 70 percent. The purpose of this study was to elucidate the causes of this striking trend by soliciting the opinions of 21 New York plastic surgeons on their current brow ptosis management. The response rate was 84 percent (21 of 25 surgeons contacted). Currently, 25 percent of the interviewed plastic surgeons perform endoscopic brow lift regularly, 50 percent of the plastic surgeons perform endoscopic brow lift occasionally, and 25 percent of the participants no longer perform endoscopic brow lift. While most patients (70 percent) were satisfied with their results, only 50 percent of the plastic surgeons were pleased with the long-term results (after more than 2 years of follow-up). Observed postsurgical complications of endoscopic brow lift included alopecia, hairline changes, infected hardware, brow asymmetry requiring surgical revision, prolonged forehead/brow paresthesia, frontal branch nerve paralysis, and scalp dysesthesia. These complications were similar to those resulting from open brow lifts. Seventy-one percent of the surveyed New York plastic surgeons routinely administered botulinum toxin type A (Botox) within 6 months of the endoscopic brow lift procedure. Possible explanations for the decline in the overall number of endoscopic brow lift procedures include the following: (1) the selection criteria for the ideal endoscopic brow lift patients are currently more limited; (2) other techniques equal or surpass endoscopic brow lift in effectiveness and predictability; and (3) endoscopic brow lift is ineffective in the majority of patients. There is no single superior surgical procedure for brow ptosis management available at this time.     

Ascending and descending projections to the inferior colliculus in the rat

The ascending and descending projections to the central nucleus of the inferior colliculus (IC) were studied with the aid of retrograde transport of horseradish peroxidase (HRP). HRP-labelled cells were found in contralateral cochlear nuclei, where the majority of different cell types was stained. Few labelled cells were observed in the ipsilateral cochlear nuclei. HRP-positive neurones were found in all nuclei of the superior olivary complex on the ipsilateral side with the exception of the medial nucleus of the trapezoid body, which was never labelled either ipsilaterally or contralaterally. The largest concentration of HRP-labelled cells was usually observed in the ipsilateral superior olivary nucleus. Smaller numbers of labelled cells were present in contralateral nuclei of the superior olivary complex. Massive projections to the inferior colliculus were found from the contralateral and ipsilateral dorsal nucleus of the lateral lemniscus and ipsilateral ventral nucleus of the lateral lemniscus. Many neurones of the central and external nuclei of the contralateral inferior colliculus were labelled with HRP. Topographic organisation of the pathways ascending to the colliculus was expressed in the cochlear nuclei, lateral superior olivary nucleus and in the dorsal nucleus of the lateral lemniscus. HRP--positive cells were found in layer V of the ipsilateral auditory cortex, however, the evidence for topographic organisation was lacking.     

The evolution of the brow lift in aesthetic plastic surgery

For nearly 100 years, aesthetic improvement of the aging face has included surgical elevation of the brow. Early attempts to correct brow ptosis were largely unsuccessful. Recognizing the need to modify the frown muscles heralded the achievement of results previously unobtainable. Within the past decade, the minimal incision approach to brow lifting afforded with the endoscope radically changed surgical options in forehead rejuvenation. Further advances have added to these options and have provided a palette of alternatives in aesthetic correction of the upper one-third of the aging face.     

Correlation between rotational behaviors and neurochemical changes associated with damage of rat striatum: Analysis using unilateral microinjection of kainic acid

The correlation between rotational behaviors and neurochemical changes associated with the striatal damage induced by an unilateral microinjection of kainic acid were investigated. Shortly after the unilateral striatal injection of kainic acid, rats exhibited contralateral rotational behaviors, and these changes were antagonized by the simultaneous striatal injection of haloperidol. On the other hand, systemic injection of methamphetamine to animals having the lesion on nigro-striatal dopaminergic neurons exhibited ipsilateral turnings. In addition, it was found that the release of [¹⁴C]dopamine from striatal slices was increased by the in vitro addition of kainic acid. Following 2 days after the striatal injection of kainic acid and thereafter, the rats exhibited ipsilateral rotational behaviors and microinjection of muscimol into the ipsilateral substantia nigra of these animals altered turning movements to a contralateral type. Simultaneous nigral injection of bicuculline antagonized to the muscimol-induced contralateral turnings. These results suggest that the increase of dopamine release from dopaminergic neurons in the striatum may be involved in the occurrence of contralateral turning behaviors observed shortly after the striatal kainic acid treatment. The present results also suggest that changes in the functional states of striatonigral GABA-ergic neurons may play an important role in the occurrence of ipsilateral rotational movements at a late stage following the striatal injection of this agent.     

Frontalis muscle advancement: a dynamic structure for the treatment of severe congenital eyelid ptosis

Forty-two consecutive patients have had severe eyelid ptosis corrected by intraorbital frontalis flap advancement as a motor unit to substitute for the function of the levator muscle. This technique has avoided the need for the linking structure necessary in the standard frontalis sling approach and has improved the direction of pull to more closely mimic that of a normal levator. This simple technique includes elevation of the innervated frontalis muscle flap and the creation of a pulley near the insertion of the orbital septum at the superior orbital rim, which redirects the lid movement along the surface of the globe rather than lifting it from the globe's surface toward the brow. This type of displacement is produced because the muscle is directed posteriorly by the pulley, so that it conforms to the plane of the levator aponeurosis all the way down to the tarsal plate. In addition, to improve the remaining function of the levator muscle (if any) and to facilitate voluntary positioning of the eyelid, the levator aponeurosis is shortened by plication. Symmetry is created by intervention on the contralateral eyelid to provide symmetrical supratarsal creases.     

Neurovascular free-muscle transfer for the treatment of established facial paralysis following ablative surgery in the parotid region

Neurovascular free-muscle transfer for facial reanimation was performed as a secondary reconstructive procedure for 45 patients with facial paralysis resulting from ablative surgery in the parotid region. This intervention differs from neurovascular free-muscle transfer for treatment of established facial paralysis resulting from conditions such as congenital dysfunction, unresolved Bell palsy, Hunt syndrome, or intracranial morbidity, with difficulties including selection of recipient vessels and nerves, and requirements for soft-tissue augmentation. This article describes the authors' operative procedure for neurovascular free-muscle transfer after ablative surgery in the parotid region. Gracilis muscle (n = 24) or latissimus dorsi muscle (n = 21) was used for transfer. With gracilis transfer, recipient vessels comprised the superficial temporal vessels in 12 patients and the facial vessels in 12. For latissimus dorsi transfer, recipient vessels comprised the facial vessels in 16 patients and the superior thyroid artery and superior thyroid or internal jugular vein in four. Facial vessels on the contralateral side were used with interpositional graft of radial vessels in the remaining patient with latissimus dorsi transfer. Cross-face nerve grafting was performed before muscle transfer in 22 patients undergoing gracilis transfer. In the remaining two gracilis patients, the ipsilateral facial nerve stump was used as the primary recipient nerve. Dermal fat flap overlying the gracilis muscle was used for cheek augmentation in one patient. In the other 23 patients, only the gracilis muscle was used. With latissimus dorsi transfer, the ipsilateral facial nerve stump was used as the recipient nerve in three patients, and a cross-face nerve graft was selected as the recipient nerve in six. The contralateral facial nerve was selected as the recipient nerve in 12 patients, and a thoracodorsal nerve from the latissimus dorsi muscle segment was crossed through the upper lip to the primary recipient branches. A soft-tissue flap was transferred simultaneously with the latissimus muscle segment in three patients. Contraction of grafted muscle was not observed in two patients with gracilis transfer and in three patients with latissimus dorsi transfer. In one patient with gracilis transfer and one patient with latissimus dorsi transfer, acquired muscle contraction was excessive, resulting in unnatural smile animation. The recipient nerves for both of these patients were the ipsilateral facial nerve stumps, which were dissected by opening the facial nerve canal in the mastoid process. From the standpoint of operative technique, the one-stage transfer for latissimus dorsi muscle appears superior. Namely, a combined soft-tissue flap can provide sufficient augmentation for depression of the parotid region following wide resection. A long vascular stalk of thoracodorsal vessels is also useful for anastomosis, with recipient vessels available after extensive ablation and neck dissection.     

Phencyclidine-induced ipsilateral rotation in rats with unilateral 6-hydroxydopamine-induced lesions of the substantia nigra

The effect of phencyclidine (PCP) on rotational behavior in rats with unilateral 6-hydroxydopamine (6-OHDA)-induced lesions of the substantia nigra was examined and compared to the effects of d-amphetamine and apomorphine. PCP, like d-amphetamine, induced ipsilateral rotation indicating a presynaptic effect on dopamine (DA) neurons whereas apomorphine, a direct acting agonist, caused contralateral rotation. Pretreatment with alpha-methyparatyrosine inhibited PCP-induced rotation approximately to the same extent as it inhibited d-amphetamine-induced rotation, but did not significantly reduce apomorphine-induced contralateral turning, further indicating that PCP has a presynaptic effect on DA neurons. Anti-cholinergic effects on PCP may also contribute to the ipsilateral rotation noted.     

Neuropeptide Y inhibits sympathetic neurotransmission in ipsilaterally innervated but not contralaterally reinnervated superior tarsal smooth muscle of the rat.

The superior tarsal smooth muscle (STM), which elevates the upper eyelid, normally is innervated by sympathetic neurons from the ipsilateral superior cervical ganglion that are not neuropeptide Y-immunoreactive (NPY-ir). Following neonatal ganglionectomy, this target is reinnervated by sympathetic nerves from the contralateral superior cervical ganglion that are strongly NPY-ir. We examined the effects of exogenously administered NPY on STM tone, response to norepinephrine, and sympathetic neurotransmission in ipsilaterally innervated and contralaterally reinnervated STMs. NPY (2-10 micrograms/kg iv) increased blood pressure but did not alter STM tone. Similarly, contractile responses to co-administered norepinephrine were not affected. These findings imply an absence of direct and indirect postjunctional actions of NPY on STM. Contractions elicited by stimulation of the cervical sympathetic nerve (1.5 Hz) were not affected by NPY on the contralaterally reinnervated side; however, ipsilateral contractions were decreased in a dose-dependent fashion, with an inhibition of about 40% at 10 micrograms/kg. We conclude that while the STM is unresponsive to exogenously administered NPY, this peptide exerts selective inhibitory effects on the ipsilateral NPY-ir-negative but not the contralateral NPY-ir-positive innervation. This suggests that the neonatally denervated STM is reinnervated by contralateral fibers that are functionally different from the normal ipsilateral innervation in being devoid of functional prejunctional NPY receptors.     

Mucosal afferents mediate laryngeal adductor responses in the cat.

Laryngeal adductor responses (LAR) close the airway in response to stimulation of peripheral afferents in the superior laryngeal nerve. Although both mucosal afferents and proprioceptive receptors are present in the larynx, their relative contribution for reflex elicitation is unknown. Our purpose was to determine which receptor types are of importance in eliciting the LAR. A servomotor with displacement feedback was used to deliver punctate displacements to the body of the arytenoid cartilage and overlying mucosa on each side of the larynx in eight anesthetized cats. The same displacements were delivered both before and after surgical excision of the overlying mucosa. With the mucosa intact, early short-latency component R1 LAR responses recorded from the thyroarytenoid muscles were frequent (ipsilateral > 92%, contralateral > 95%). After the mucosa was removed, the LAR became infrequent (<3%) and was reduced in amplitude in both the ipsilateral and contralateral thyroarytenoid muscle recording sites (P < 0.0005). These findings demonstrate that mucosal mechanoreceptors and not proprioceptive afferents contribute to the elicitation of LAR responses in the cat.     

Transient contralateral rotation following unilateral substantia nigra lesion reflects susceptibility of the nigrostriatal system to exhaustion by amphetamine

Following unilateral 6-OHDA induced SN lesion, a transient period of contralateral rotation has been reported to precede the predominant ipsilateral circling. In order to clarify the nature of this initial contralateral rotation we examined the effect of the duration of recovery period after the lesion, on amphetamine-induced rotational behavior. Three days post lesion, most rats circled predominantly contralaterally to the lesion. Such contralateral rotation may result from either degeneration-induced breakdown of the DA pool, or lesion-induced increase of DA turnover in the spared neurons. A substantial degree of contralateral preference was still evident when amphetamine was administered for the first time 24 days after lesioning, indicating involvement of spared cells in the contralateral rotation. However, regardless of the duration of recovery (and irrespective of either lesion volume, amphetamine dose, or post-lesion motor exercise), amphetamine-induced rotation tended to become gradually more ipsilateral as the observation session progressed, and all rats circled ipsilaterally to the lesion in response to further amphetamine injections. These findings suggest that amphetamine has an irreversible effect on the post-lesion DA pool contributing to contralateral rotation.     

Control of conduction of afferent impulses across the lateral geniculate body by the side of the superior colliculus in alert rabbits

On alert rabbits it was shown that the stimulation of the superior colliculus inhibit visual evoked potential both of the ipsi- and contralateral geniculate body. Besides, the suppression of amplitude of the contralateral geniculate body's evoked potential was more significant than amplitude of the ipsilateral geniculate body's evoked potential. On the basis of the obtained results the authors suppose that superior colliculus is involved in organization of the effect of saccadic suppression of lateral geniculate body's visual responses.     

Breast reconstruction with contralateral rectus abdominis myocutaneous flap

A transverse myocutaneous rectus abdominis flap from the contralateral side has been employed for breast reconstruction in 52 patients. This flap has the advantage of balancing the patient by utilizing skin from an area of relative excess. The blood supply to the flap is based on the superior epigastric vessel and its perforators. The scar of the donor area is acceptable because it falls in the submammary sulcus. The use of a silicone implant can be avoided in some patients because of the adequate bulk of skin, muscle, and fat that is available. Abdominoplasty of the superior abdomen can be obtained during the same operation and can enhance the overall aesthetic results. Breast reconstruction is now possible with either ipsilateral or contralateral upper-abdominal transfer flaps, and further refinement of operative technique using the contralateral upper-rectus abdominis myocutaneous island flap must await further experience.     

Ten-m3 Is Required for the Development of Topography in the Ipsilateral Retinocollicular Pathway

Background

The alignment of ipsilaterally and contralaterally projecting retinal axons that view the same part of visual space is fundamental to binocular vision. While much progress has been made regarding the mechanisms which regulate contralateral topography, very little is known of the mechanisms which regulate the mapping of ipsilateral axons such that they align with their contralateral counterparts.

Results

Using the advantageous model provided by the mouse retinocollicular pathway, we have performed anterograde tracing experiments which demonstrate that ipsilateral retinal axons begin to form terminal zones (TZs) in the superior colliculus (SC), within the first few postnatal days. These appear mature by postnatal day 11. Importantly, TZs formed by ipsilaterally-projecting retinal axons are spatially offset from those of contralaterally-projecting axons arising from the same retinotopic location from the outset. This pattern is consistent with that required for adult visuotopy. We further demonstrate that a member of the Ten-m/Odz/Teneurin family of homophilic transmembrane glycoproteins, Ten-m3, is an essential regulator of ipsilateral retinocollicular topography. Ten-m3 mRNA is expressed in a high-medial to low-lateral gradient in the developing SC. This corresponds topographically with its high-ventral to low-dorsal retinal gradient. In Ten-m3 knockout mice, contralateral ventrotemporal axons appropriately target rostromedial SC, whereas ipsilateral axons exhibit dramatic targeting errors along both the mediolateral and rostrocaudal axes of the SC, with a caudal shift of the primary TZ, as well as the formation of secondary, caudolaterally displaced TZs. In addition to these dramatic ipsilateral-specific mapping errors, both contralateral and ipsilateral retinocollicular TZs exhibit more subtle changes in morphology.

Conclusions

We conclude that important aspects of adult visuotopy are established via the differential sensitivity of ipsilateral and contralateral axons to intrinsic guidance cues. Further, we show that Ten-m3 plays a critical role in this process and is particularly important for the mapping of the ipsilateral retinocollicular pathway.     

Sprouting of aberrant neuropeptide Y-immunoreactive sympathetic nerves into neonatally denervated smooth muscle.

Sympathetic nerves normally project ipsilaterally to lateral cranial targets. Following unilateral superior cervical ganglionectomy in neonatal rats, however, neurons from the contralateral superior cervical ganglion sprout into the denervated region. In the present study we examined neuropeptide Y immunoreactivity (NPY-ir) of neurons comprising ipsilateral (control) and denervation-induced contralateral pathways to the superior tarsal smooth muscle of the eyelid. Fluoro-Gold injection of the control muscle retrogradely labelled 133 +/- 18 neurons in the ipsilateral superior cervical ganglion; of these, 21 +/- 3% displayed detectable NPY-ir. Fluoro-Gold injections of the reinnervated muscle labelled 20 +/- 4 neurons in the contralateral superior cervical ganglion, of which 85 +/- 3% contained detectable NPY-ir. Examination of the control tarsal muscle revealed DBH-ir noradrenergic nerves throughout the muscle and vasculature, while NPY-ir nerves were present primarily around blood vessels. In the reinnervated preparation, NPY-ir fibers innervated both blood vessels and tarsal muscle in a pattern similar to that of DBH-ir innervation. Acute excision of the remaining superior cervical ganglion eliminated all DBH-ir fibers bilaterally; NPY-ir was reduced markedly in the reinnervated preparations, though some fibers remained. We conclude that, following neonatal denervation, the tarsal muscle is reinnervated by a subpopulation of sympathetic neurons that differs in neuropeptide phenotype from that of the normal ipsilateral innervation.     

The vascular anatomy of the galeal flap in the interparietal and midline regions.

The potential extension of the galeal flap in the interparietal area was studied on 17 fresh human cadaver heads by intravascular dye injection technique. It was demonstrated that an ipsilateral superficial temporal artery that supplies the galeal flap does not cross the midline or anastomose with the contralateral superficial temporal artery but ensures the survival of a flap extended up to 1 cm proximal to the sagittal suture line. The width of the temporoparietal flap can be extended up to 15 cm, depending on the vascular pattern of the superficial temporal artery. When required, the lateral extension may provide the required soft-tissue bulk despite the reduced flap length.     

A new resorbable tack fixation technique for endoscopic brow lifts

The endoscopic brow lift is now widely accepted in aesthetic plastic surgery, and various fixation techniques have been described in the literature. New developments and technology have expanded the use of resorbable devices in different surgical specialties, including plastic surgery. The authors present a technique that offers simple, fast, and reliable forehead fixation for endoscopic brow lifts using resorbable tacks. Successful facial rejuvenation was obtained in the majority of the patients without complications, need for follow-up visits to tighten the flap fixation system, or secondary procedures to extract the fixation system.