Small Skull Research Articles

Craniofacial birth defects: The role of neural crest cells in the etiology and pathogenesis of Treacher Collins syndrome and the potential for prevention

Of all the babies born with birth defects, approximately one-third display anomalies of the head and face [Gorlin et al., 1990] including cleft lip, cleft palate, small or absent facial and skull bones and improperly formed nose, eyes, ears, and teeth. Craniofacial disorders are a primary cause of infant mortality and have serious lifetime functional, esthetic, and social consequences that are devastating to both children and parents alike. Comprehensive surgery, dental care, psychological counseling, and rehabilitation can help ameliorate-specific problems but at great cost over many years which dramatically affects national health care budgets. For example, the Center for Disease Control and Prevention estimates that the lifetime cost of treating the children born each year with cleft lip and/or cleft palate alone to be US$697 million. Treating craniofacial malformations, of which in excess of 700 distinct syndromes have been described, through comprehensive, well-coordinated and integrated strategies can provide satisfactory management of individual conditions, however, the results are often variable and rarely fully corrective. Therefore, better techniques for tissue repair and regeneration need to be developed and therapeutic avenues of prevention need to be explored in order to eliminate the devastating consequences of head and facial birth defects. To do this requires a thorough understanding of the normal events that control craniofacial development during embryogenesis. This review therefore focuses on recent advances in our understanding of the basic etiology and pathogenesis of a rare craniofacial disorder known as Treacher Collins syndrome and emerging prospects for prevention that may have broad application to congenital craniofacial birth defects.

Leg length, skull circumference, and the prevalence of dementia in low and middle income countries: a 10/66 population-based cross sectional survey.

Adult leg length is influenced by nutrition in the first few years of life. Adult head circumference is an indicator of brain growth. There is a limited literature linking short legs and small skulls to an increased risk for cognitive impairment and dementia in late life. One phase cross-sectional surveys were carried out of all residents aged over 65 years in 11 catchment areas in China, India, Cuba, Dominican Republic, Venezuela, Mexico and Peru (n = 14,960). The cross-culturally validated 10/66 dementia diagnosis, and a sociodemographic and risk factor questionnaire were administered to all participants, and anthropometric measures taken. Poisson regression was used to calculate prevalence ratios for the effect of leg length and skull circumference upon 10/66 dementia, controlling for age, gender, education and family history of dementia. The pooled meta-analyzed fixed effect for leg length (highest vs. lowest quarter) was 0.82 (95% CI, 0.68-0.98) and for skull circumference 0.75 (95% CI, 0.63-0.89). While point estimates varied between sites, the proportion of the variability attributable to heterogeneity between studies as opposed to sampling error (I2) was 0% for leg length and 22% for skull circumference. The effects were independent and not mediated by family history of dementia. The effect of skull circumference was not modified by educational level or gender, and the effect of leg length was not modified by gender. Since leg length and skull circumference are said to remain stable throughout adulthood into old age, reverse causality is an unlikely explanation for the findings. Early life nutritional programming, as well as neurodevelopment may protect against neurodegeneration.

Radiotelemetry Applied to Field Studies of Shrews

Abstract: Radiotelemetry is a widely used method to study ecology, behavior, and physiology of different animals but has rarely been used on shrews. Small body size, wide neck and narrow skull, high mobility, and fragility of shrews cause problems for both transmitter attachment and the safety of the animals. We developed a method for nonpermanent attachment of transmitters, which allowed us to track such small mammals as the Eurasian water shrews (Neomys fodiens; n = 39, mean body mass 14.9 g), Mediterranean water shrews (Neomys anomalus; n = 32, 10.9 g), and common shrews (Sorex araneus; n = 51, 8.1 g). We used microtransmitters weighing 0.47 g, but those we applied to the larger Neomys species were heavier (0.67 g) because we fortified them with a layer of hard material to prevent damage from biting. We glued a transmitter directly to the skin on a shrew's back, with the anterior edges particularly well sealed. We tracked shrews in the wild and in outdoor enclosures. Transmitters usually dropped off together with peeled skin (on average, after 56.0 hr, n = 92 observations), but if not dropped and if the signal was not lost, mean duration of monitoring was 96.7 hours (n = 37) and in 2 cases exceeded 194 hours. Other advantages of our attachment method were 1) it was less invasive and easier to apply than implantation of transmitters into the body cavity, and 2) we could find dropped transmitters and reuse them. We give suggestions on how to minimize the risk of injury to animals by correct handling, manipulation, and gluing. In conclusion, we recommend radiotelemetry as a useful technique for studying shrew behavior in both free‐living populations and experimental enclosures.

Radiotelemetry Applied to Field Studies of Shrews

Radiotelemetry is a widely used method to study ecology, behavior, and physiology of different animals but has rarely been used on shrews. Small body size, wide neck and narrow skull, high mobility, and fragility of shrews cause problems for both transmitter attachment and the safety of the animals. We developed a method for nonpermanent attachment of transmitters, which allowed us to track such small mammals as the Eurasian water shrews (Neomys fodiens; n = 39, mean body mass 14.9 g), Mediterranean water shrews (Neomys anomalus; n = 32, 10.9 g), and common shrews (Sorex araneus; n = 51, 8.1 g). We used microtransmitters weighing 0.47 g, but those we applied to the larger Neomys species were heavier (0.67 g) because we fortified them with a layer of hard material to prevent damage from biting. We glued a transmitter directly to the skin on a shrew's back, with the anterior edges particularly well sealed. We tracked shrews in the wild and in outdoor enclosures. Transmitters usually dropped off together with peeled skin (on average, after 56.0 hr, n = 92 observations), but if not dropped and if the signal was not lost, mean duration of monitoring was 96.7 hours (n = 37) and in 2 cases exceeded 194 hours. Other advantages of our attachment method were 1) it was less invasive and easier to apply than implantation of transmitters into the body cavity, and 2) we could find dropped transmitters and reuse them. We give suggestions on how to minimize the risk of injury to animals by correct handling, manipulation, and gluing. In conclusion, we recommend radiotelemetry as a useful technique for studying shrew behavior in both free-living populations and experimental enclosures.

MRI and X-ray scanning images of the brain of 3-, 6- and 9-month-old rats with bilateral neonatal ventral hippocampus lesions

Rats with bilateral neonatal ventral hippocampus lesions (NVHL) are commonly used for modeling developmental aspects of the pathophysiology of schizophrenia. Given that functional changes become significant only after puberty, NVHL as well as sham-operated rats were analyzed at the ages of 21, 42 and 63days (i.e. as pups, adolescents and adults), using MRI to examine the damage caused by surgery over time. Morphometric evaluations were considered and lesions were classified as small, medium and large. The volume of lesions increased regularly with age, to a greater extent than increases in overall brain size. This was relatively linear, corresponding to a gradually shrinking forebrain, and these observations held true for each class of lesions considered. Following the observation that the lesion procedure elicited calcifications in the brain, the same rats were subjected to 3D X-ray scanning the day after each MRI session, allowing precise measurements of skull size to be carried out. The NVHL rats had smaller skulls; however, the dimensions of the calcifications did not grow more than the skull size over time. The mechanisms underlying the progressive anatomical changes following surgery are discussed, and we propose this in vivo follow-up method to investigate therapeutic strategies aimed at countering or limiting the post-lesion consequences of a neonatal brain damage.

A new and unusual procolophonid parareptile from the Lower Triassic Katberg Formation of South Africa

ABSTRACT A small skull collected from the base of the Katberg Formation of South Africa represents a new Early Triassic procolophonid parareptile. Phonodus dutoitorum, gen. et sp. nov., is diagnosed by a roughly straight ventral temporal margin, prefrontals that contact each other along the dorsal midline, presence of a large posterior maxillary tooth, an edentulous pterygoid, a reduced transverse flange of the pterygoid, and other autapomorphies. A cladistic analysis identifies P. dutoitorum as a basal member of the procolophonid clade Leptopleuroninae. The presence of large maxillary teeth, their positioning ventral to strongly developed antorbital buttresses, and the loss of the ventral temporal emargination are suggestive of a durophagous diet. Phonodus dutoitorum is recognized as the oldest known leptopleuronine. Optimization of geographic distributions onto procolophonid phylogeny indicates that the presence of P. dutoitorum in the Karoo Basin of South Africa is explained most parsimoniously as the result of migration from Laurasia. Phonodus dutoitorum is the fifth procolophonoid species to be described from the Induan of the Karoo Basin, providing further support for the hypothesis that procolophonoid evolution was not greatly perturbed by the end-Permian extinction event.

The braincase and skull roof of Gryposaurus notabilis (Dinosauria, Hadrosauridae), with a taxonomic revision of the genus

ABSTRACT The facial and neurocranial anatomy of AMNH 5350, containing the most complete braincase available for Gryposaurus, is described in detail. The specimen, collected from Late Campanian outcrops of the Dinosaur Park Formation of southern Canada, is referred to G. notabilis because of the combination of a preorbital nasal protuberance positioned above the level of the frontals, narrow U-shaped posterior margin of the narial fenestra, dorsal margin of the infratemporal fenestra being wider than that of the orbit, and posterodorsal margin of the squamosal located dorsal to the skull roof. The flat nasal protuberance of AMNH 5350 differs from the arcuate lateral profile displayed in other specimens of G. notabilis, indicating that substantial intraspecific variation existed in this feature. The taxonomy of Gryposaurus is revised in light of the newly garnered anatomical data. Thus, G. incurvimanus is regarded as a junior synonym of G. notabilis, composed of subadult specimens of the latter. Characters thought to be diagnostic of G. incurvimanus are either present in G. notabilis (e.g., slightly excavated ventral surface of the nasal protuberance) or probably indicative of sub-adulthood (e.g., less developed and more anteriorly positioned nasal protuberance correlated with smaller skull size). A number of characters previously used to distinguish among Gryposaurus sepecies are shown to be intraspecifically variable (e.g., curvature of the lateroventral margin of the maxilla or ventral deflection of the dentary symphyseal process).

Neil Harrison Cox

Neil Cox was a precocious student at Leeds Grammar School, taking A levels two years early. He went on to qualify in medicine at Liverpool University, having taken 1st class...

Lycalopex vetulus (Carnivora: Canidae)

Lycalopex vetulus (Lund, 1842), commonly called the hoary fox, is Brazil's smallest canid. It has a slender body and limbs and a small skull composed of relative fragile bones. Its size and skull characteristics combined with its peculiar dentition make it more suitable for an insectivorous diet rather than one of large vertebrates. L. vetulus is endemic to Brazil and occurs primarily in the south-central cerrados at low elevations. There is some evidence to indicate its presence in Bolivia. L. vetulus is widespread and abundant in Brazil and presently there are no known threats that would result in declines in its occurrence in the core area of its distribution.

The Superior Turbinate Osteoplastic Flap: A New Vascularized Flap for Repair of the Anterior Skull Base

Introduction: Traditionally, repairs of spontaneous skull base defects have relied on local or free mucosal and free bone grafts for closure. Free grafting is highly successful for small skull base defects, with a low incidence of postoperative cerebrospinal fluid (CSF) leaks. With larger defects, a vascularized flap has been shown to be more effective in reducing CSF leak rates to those similar to open repair. Previously described techniques include a nasoseptal flap, a pedicled inferior turbinate flap, and a middle turbinate mucosal flap. The use of the superior turbinate for repair of defects has limited description in otolaryngology and neurosurgery literature. We describe the use of the superior turbinate as an osteoplastic flap for repair of an anterior skull base defect after endoscopic endonasal resection of a cribriform encephalocele.

A new species of Haborophocoena, an Early Pliocene phocoenid cetacean from Hokkaido, Japan

AbstractA new species of phocoenid cetacean Haborophocoena, collected from the Early Pliocene Embetsu Formation, in the close vicinity to the site where the holotype of the type species of the genus Haborophocoena was retrieved, improves our knowledge of the anatomy of this cetacean. The new species, represented by a skull, lacking distal half of the rostrum, ear bones, and teeth, is significantly smaller than, but morphologically similar to, the type species Haborophocoena toyoshimaiIchishima and Kimura 2005. This new record of Haborophocoena confirms the veracity of the genus Haborophocoena as a biological entity, contributes to understanding the interspecific variation, and suggests that the genus diversified in the northwestern Pacific of early Pliocene time. The adult‐like degree of ossification in this small skull precludes it from being a juvenile of Haborophocoena toyoshimai. Autapomorphies of Haborophocoena minutus include narrow premaxilla on the dorsal surface of the rostrum, the anterior position of the premaxillary foramen, and a distinct ridge dividing a fossa on the lateral face of the base of the zygomatic process into the dorsal and the ventral halves, the zygomatic process rectangular in lateral profile, and its small size, which is the most compelling feature, making it a distinct species.

Cranial variation in the European badgerMeles meles(Carnivora, Mustelidae) in Scandinavia

Morphometric variation in 30 craniometric characters of 465 skulls of the European badgers (Meles meles) from across Europe was analysed. Multivariate analyses revealed that the populations from Norway, Sweden, and Finland differ from other European populations in having smaller skulls. The analyses also revealed significant differences between the ‘south-western Norwegian’ and ‘main Fennoscandian’ forms. On average, badgers from south-west Norway were smaller than those of the remaining Fennoscandia. Morphological differences between the ‘south-western Norwegian’ and ‘main Fennoscandian’ populations of M. meles suggest a possible in situ semisympatric divergence since the beginning of the Holocene warming, or a complex history of two groups involving at least two colonization routes. The small-sized Scandinavian badgers may be close to the ancestral form that used to be widespread in Denmark and throughout Europe. The animals from south-west Norway may instead be descendants of ancestors that were the first to penetrate the southern parts of the Scandinavian Peninsula. The ‘main Fennoscandian’ badgers are likely to have been the descendants of the second wave of recolonization of Scandinavia. Specifically, they might have colonized the Scandinavian Peninsula from the east after the last glaciation.

Comparison of the effects of two different surgical treatments for hypertensive cerebral hemorrhage

Objective To compare the effect of microsurgical treatment through a small skull window with that of computed tomographic guided aspiration for hypertensive cerebral hemorrhage.Methods The clinical manifestation,operation and prognosis of 95 cases of hypertensive cerebral hemorrhage were analyzed retrospectively.Results The number of microsurgical treatment though a sulall skull window and computed tomographic-guided aspiration were 51 and 44 respectively1 There were no differences in age,blood pressure before operation,size of hematonm,GCS score and time interval before operation of the two groups(P＞0.05).Hematoina was evacuated more thoroughly with the operation of microsurgical treatment through a small skull window than that with computed tomographic-guided aspiration (P＜0.05).The consciousness state elevated for 76.47% patients with the operation of microsurgical treatment through a small skull window and 63.64% patients with computed tomographic-guided aspiration 48 hours after operation(P＜0.05).The rehemorrhage rate of the patients with microsurgical treatment through a small skull window was lower than that of the patients with computed tomographic-guided aspkation(P＜0.05).Conclusion The effect of microsurgery through a small skull window is more satisfactory than that of computed tomographic-guided aspiration.Hematoma could be enough evacuated and exact hemostasis could be achieved with microsurgery through a small skull window. Key words: Hypertension cerebral hemorrhage; Small skull window; Computed tomographic-guided aspiration

Distribution of the Southern birch mouse (Sicista subtilis) in East-Poland: Morphometric variations in discrete European populations of superspecies S. subtilis

We report new records for the inadequately known Southern birch mouse Sicista subtilis in Poland. This species was found in Poland in 1994 by catching a live specimen by hand and to date there has been no other data on this species. The Polish population is most likely an isolated population of S. subtilis but its taxonomic status has not been studied yet. According to our results, it is a morphometric variation or a new subspecies of S. subtilis. Its craniometrical size is in general smaller than that of the Ukrainian “core” population. Morphometrically, it is similar to the S. subtilistrizona living in Hungary. It is probable that the size reduction and the microevolutionary divergence in morphometry most likely result from a long isolation in the case of trizona or a shorter isolation of the Polish population. However, the geographic isolation of the Polish subpopulations in the Lublin region has not been adequate to produce significant morphologic variation in the crania. Hypothetically, the Polish specimens with smaller skulls may also be affected by differences in prey base, which is reflected in the different habitats. The craniometrical characteristics of the geographically most isolated Hungarian trizona population are the smallest in the superspecies S. subtilis.

A new Lower Permian amphibamid (Dissorophoidea, Temnospondyli) from the fissure fill deposits near Richards Spur, Oklahoma

ABSTRACT The fissure fills of Richards Spur, Oklahoma, together constitute the most productive Paleozoic continental fossil locality in the world, having produced a wealth of terrestrial vertebrates, including occasional articulated skeletons. A new dissorophoid amphibian is represented by two skulls: an exquisitely preserved, complete small skull and the posterior part of a second skull, almost twice the size of the holotype. The specimens provide detailed information about the skull roof, palate, braincase, and mandible, showing that this new taxon is characterized by a relatively elongate skull with large tabulars and postparietals, and monocuspid, recurved teeth that show no sign of pedicelly. The large, laterally expanded interpterygoid vacuities are covered by a mosaic of small dermal plates, each carrying more than a dozen strongly recurved teeth. A phylogenetic analysis of 17 ingroup taxa and 62 cranial and postcranial characters yielded a single most-parsimonious tree with the new taxon in a monophyletic Amphibamidae as the sister taxon to the Lower Triassic Micropholis from South Africa. In addition, the new analysis supports a basal split of Amphibamidae into two distinct clades, one containing the new taxon, Micropholis, along with Tersomius, and the other comprising Amphibamus, Gerobatrachus, Doleserpeton, Platyrhinops, Plemmyradytes, Eoscopus, and Georgenthalia. The data retrieved from this new taxon provides insights into the evolution and diversity of the Amphibamidae.

Cranial Auto Graft Expansion (CAGE) Technique for Cranial Vault Expansion

We present a method for cranial vault expansion that provides a strong construct, leaves small skull defects, and provides bony coverage of the sagittal sinus. The resultant small defects optimize the possibility for spontaneous reossification while avoiding large calvarial defects. This method has been used in 2 children who developed clinical evidence of total cranial growth restriction.

A phylogeny of Plesiosauria (Sauropterygia) and its bearing on the systematic status of Leptocleidus Andrews, 1922

Leptocleidus Andrews, 1922 is a poorly known plesiosaur genus from Lower Cretaceous successions of the UK, South Africa, and Australia. Historically, there has been little consensus regarding its phylogenetic position within Plesiosauria, largely because of its seemingly aberrant combination of a relatively small skull and short neck. As a result, a diverse array of potential sister groups have been posited for Leptocleidus, including long-necked Cretaceous elasmosaurids, Early Jurassic “rhomaleosaurs”, and Middle to Late Jurassic pliosaurids. A cladistic analysis including Leptocleidus, and a new, apparently morphologically similar specimen from Alberta, TMP 94.122.01, was undertaken to assess their phylogenetic position within Plesiosauria. A character-taxon matrix was assembled afresh, consisting of 33 operational taxonomic units sampled broadly among plesiosaurs. 185 cranial and postcranial characters used in plesiosaur phylogenetics were critically reanalyzed, of which 152 were employed in the parsimony analysis. The results indicate a basal dichotomous split into the traditionally recognized pliosauroid and plesiosauroid clades. Nested within Pliosauroidea, a monophyletic Leptocleididae was recovered, consisting of L. superstes Andrews, 1922 and L. capensis (Andrews, 1911a). In contrast to earlier suggestions, Leptocleidus neither clusters with Rhomaleosaurus, which was found to be paraphyletic, nor with large-skulled pliosaurid taxa, such as Simolestes. Rather, a sister group relationship between Cretaceous Polycotylidae and Leptocleididae was recovered, which is here named Leptocleidoidea. Although TMP 94.122.01 is superficially similar to Leptocleidus, several discrete characters of the skull nest this new taxon within Polycotylidae. Compared to other phylogenetic hypotheses of plesiosaurs, these results are more congruent with respect to the stratigraphic distribution of leptocleidoids. A classification for Plesiosauria is presented.

Long-Term Outcome of Endonasal Endoscopic Skull Base Reconstruction with Nasal Turbinate Graft

To study the long-term outcome of endonasal endoscopic skull base reconstruction with nasal turbinate tissue free graft. This study included 55 consecutive patients who underwent endonasal endoscopic skull base reconstruction with nasal turbinate graft and were available for follow-up. They were 30 patients with pituitary adenomas, 20 with cerebrospinal fluid (CSF) rhinorrhea of different etiologies, three with meningoencephalocele, and two with skull base meningiomas. Autologous nasal turbinate tissue materials were used in reconstructing the skull base defect. Clinical follow-up with endoscopic nasal examination was done routinely 1, 3, 6, and 12 months after surgery. Computed tomography and magnetic resonance imaging were performed when indicated. The follow-up period ranged from 6 months to 8 years. There were no major operative or postoperative complications. Nasal turbinate graft was effective in sealing of intraoperative CSF leak, obliteration of dead space, and anatomic reconstruction of the skull base. There was no evidence of graft migration or inflammatory changes. Starting from 3 months after surgery to the rest of the follow-up period, endonasal endoscopic view of the site of duraplasty showed that: with small skull base defect (less than 5 mm), there was neither dural pulsation nor prolapse; with moderate-sized defect (5 to 10 mm), there was dural pulsation without prolapse; with larger defect (> 10 mm), there was dural pulsation and prolapse. These finding were constant regardless of the etiology of the lesion and the reconstruction material used. This long-term study demonstrated the efficacy of nasal turbinate graft in sealing of CSF leak without any delayed complications. Other rigid materials may be considered in reconstruction of large skull base defect (more than 10 mm) to prevent dural prolapse and herniation. For any future endonasal procedure for those patients, who had previous endonasal endoscopic duraplasty, the surgeons should be fully aware of the state of duraplasty (e.g., dural prolapse) to avoid any intraoperative complication (e.g., penetration of the prolapsed dura during nasal packing).

P4-001: Skull circumference, leg length and handedness as developmental indicators and their association with dementia in low- and middle-income countries: Evidence from the 10/66 population-based studies

Adult head circumference is to some extent a proxy for neurodevelopment. Adult leg length is a recognised marker of nutritional adequacy in the first few years of life. There is a limited literature linking small skulls and short legs to an increased risk for cognitive impairment and dementia in late life. Left handedness may be associated with increased mortality, and both higher and lower intelligence; findings regarding association with late-onset dementia are inconsistent. We set out to estimate the association between skull circumference, leg length, handedness and dementia prevalence in seven low- and middle-income countries surveyed in the 10/66 Dementia Research Group population-based study baseline phase. One phase cross-sectional surveys of all over 65 year old residents (n=15,075) in 11 catchment areas in seven low- and middle-income countries (China, India, Cuba, Dominican Republic, Venezuela, Mexico and Peru). In each centre the core minimum data set included cross-culturally validated assessments of dementia diagnosis (10/66 dementia), anthropometry, and an extensive sociodemographic and risk factor questionnaire. Poisson regression (STATA 9.2) was used to calculate prevalence ratios (PRs) controlling for age, gender, education and family history of dementia. The effects of secular improvement in nutrition (larger skulls and longer legs in younger people) were evident in Latin America, but not in China or India. After adjusting for relevant confounders, we found fairly consistent and independent associations between smaller skulls (pooled PR 1.23, 95% CI 1.05–1.43) and shorter legs (pooled PR 1.54, 95% CI 1.32–1.85) and risk for dementia. Contrary to previous reports, the effect of skull circumference was not modified by educational level, and the effect of leg length is not modified by gender. Neither of the effects seemed to be mediated via family history of dementia. There was no clear or consistent pattern of association between handedness and dementia risk. Since skull circumference and leg length remain stable throughout adulthood into old age, reverse causality cannot explain the findings. Selective mortality is also unlikely. General early life nutritional programming may be relevant to lifetime dementia risk, in addition to neurodevelopment and brain maturation.

Utility of Preoperative High-Resolution CT and Intraoperative Image Guidance in Identification of Cerebrospinal Fluid Leaks for Endoscopic Repair

Endoscopic repair of cerebrospinal fluid (CSF) leaks is a well-established procedure. The radiological workup and use of intraoperative image guidance (IGS), lumbar drain (LD), and intrathecal fluorescein (IF) are less universally accepted. This study examines endoscopic repair of CSF leaks using preoperative high-resolution CT (HRCT) and intraoperative IGS without IF or LD. Retrospective review was performed of a single surgeon experience between September 2002 and January 2007. Forty-two anterior skull base defects in 40 patients were repaired endoscopically. The etiology of CSF leaks was traumatic in 5, spontaneous in 12, and iatrogenic in 25 defects (15 from endoscopic sinus surgeries and 10 from neurosurgical procedures). Fifty-two percent of defects presented with a meningoencephalocele. Defect location was sphenoid sinus (17 defects), ethmoid roof (14 defects), cribriform plate (9 defects), and frontal sinus (2 defects). Defect size ranged from 1x1 mm to 2x2 cm. Follow-up ranged from 8 to 46 months. All defects were identified preoperatively on HRCT with successful intraoperative IGS localization. No patients required IF for identification of CSF leak. Overall successful repair was achieved in 40 (95%) defects after initial repair, and 100% after revision. Seven patients had LD, 6 patients were early in the series. Twenty-three patients were discharged the day after surgery and 6 patients were discharged on day 2. Using preoperative HRCT for diagnosis and intraoperative IGS for localization, even small skull base defects can be definitively identified. High success rates and early discharges are achieved without additional procedures such as IF or LD. This is a less invasive and more cost-efficient method of repairing CSF leaks.