Encephalization And Diversification Of The Cranial Base In Platyrrhine Primates.

The cranial base, composed of the midline and lateral basicranium, is a structurally important region of the skull associated with several key traits, which has been extensively studied in anthropology and primatology. In particular, most studies have focused on the association between midline cranial base flexion and relative brain size, or encephalization. However, variation in lateral basicranial morphology has been studied less thoroughly. Platyrrhines are a group of primates that experienced a major evolutionary radiation accompanied by extensive morphological diversification in Central and South America over a large temporal scale. Previous studies have also suggested that they underwent several evolutionarily independent processes of encephalization. Given these characteristics, platyrrhines present an excellent opportunity to study, on a large phylogenetic scale, the morphological correlates of primate diversification in brain size. In this study we explore the pattern of variation in basicranial morphology and its relationship with phylogenetic branching and with encephalization in platyrrhines. We quantify variation in the 3D shape of the midline and lateral basicranium and endocranial volumes in a large sample of platyrrhine species, employing high-resolution CT-scans and geometric morphometric techniques. We investigate the relationship between basicranial shape and encephalization using phylogenetic regression methods and calculate a measure of phylogenetic signal in the datasets. The results showed that phylogenetic structure is the most important dimension for understanding platyrrhine cranial base diversification; only Aotus species do not show concordance with our molecular phylogeny. Encephalization was only correlated with midline basicranial flexion, and species that exhibit convergence in their relative brain size do not display convergence in lateral basicranial shape. The evolution of basicranial variation in primates is probably more complex than previously believed, and understanding it will require further studies exploring the complex interactions between encephalization, brain shape, cranial base morphology, and ecological dimensions acting along the species divergence process.

Discovery Of A Rare Pterosaur Bone Bed In A Cretaceous Desert With Insights On Ontogeny And Behavior Of Flying Reptiles.

A pterosaur bone bed with at least 47 individuals (wing spans: 0.65-2.35 m) of a new species is reported from southern Brazil from an interdunal lake deposit of a Cretaceous desert, shedding new light on several biological aspects of those flying reptiles. The material represents a new pterosaur, Caiuajara dobruskii gen. et sp. nov., that is the southermost occurrence of the edentulous clade Tapejaridae (Tapejarinae, Pterodactyloidea) recovered so far. Caiuajara dobruskii differs from all other members of this clade in several cranial features, including the presence of a ventral sagittal bony expansion projected inside the nasoantorbital fenestra, which is formed by the premaxillae; and features of the lower jaw, like a marked rounded depression in the occlusal concavity of the dentary. Ontogenetic variation of Caiuajara dobruskii is mainly reflected in the size and inclination of the premaxillary crest, changing from small and inclined (∼ 115°) in juveniles to large and steep (∼ 90°) in adults. No particular ontogenetic features are observed in postcranial elements. The available information suggests that this species was gregarious, living in colonies, and most likely precocial, being able to fly at a very young age, which might have been a general trend for at least derived pterosaurs.

Cervical Spine Involvement In Rheumatoid Arthritis--a Systematic Review.

Rheumatoid arthritis (RA) is a systemic chronic inflammatory disorder that can compromise the cervical spine in up to 80% of the cases. The most common radiological presentations of cervical involvement are atlantoaxial subluxation (AAS), cranial settling and subaxial subluxation (SAS). We performed a systematic review in the PubMed Database of articles published later 2005 to evaluate the prevalence, progression and risk factors for cervical spine involvement in RA patients. Articles were classified according to their level of evidence. Our literature review reported a wide range in the prevalence of cervical spine disease, probably explained by the different studied populations and disease characteristics. Uncontrolled RA is probably the main risk factor for developing a spinal instability. Adequate treatment with DMARD and BA can prevent development of cervical instabilities but did not avoid progression of a pre-existing injury. MRI is the best radiological method for diagnosis cervical spine involvement. AAS is the most common form of RA. Long term radiological follow-up is necessary to diagnosis patients with late instabilities and monitoring progression of diagnosed injuries.

Behavioral Changes Caused By Austrodiplostomum Spp. In Hoplias Malabaricus From The São Francisco River, Brazil.

Traira (Hoplias malabaricus) is a neotropical fish that is widely distributed in freshwater environments in South America. In the present study, we documented the occurrence of metacercariae of Austrodiplostomum spp. (Diplostomidae) in the eyes and cranial cavity of H. malabaricus and described parasite-induced behavioral changes in the host. The fish were collected from the upper São Francisco River, in the Serra da Canastra mountain range, Minas Gerais, transported alive to the laboratory, observed for 2 weeks, and subsequently examined for parasites. Of the 35 fish examined, 28 (80 %) had free metacercariae in the vitreous humor (mean intensity=95.4; mean abundance=76.3), and 24 (68.57 %) had free metacercariae in the cranial cavity, mainly concentrated below the floor of the brain, at the height of the ophthalmic lobe (mean intensity=12.91; mean abundance=8.85). Specimens of H. malabaricus with a high intensity of infection in the brain displayed changes in swimming behavior.

Facial Changes After Early Treatment Of Unilateral Coronal Synostosis Question The Necessity Of Primary Nasal Osteotomy.

The premature fusion of unilateral coronal suture can cause a significant asymmetry of the craniofacial skeleton, with an oblique deviation of the cranial base that negatively impacts soft tissue facial symmetry. The purpose of this study was to assess facial symmetry obtained in patients with unilateral coronal synostosis (UCS) surgically treated by 2 different techniques. We hypothesized that nasal deviation should not be addressed in a primary surgical correction of UCS. Consecutive UCS patients were enrolled in a prospective study and randomly divided into 2 groups. In group 1, the patients underwent total frontal reconstruction and transferring of onlay bone grafts to the recessive superior orbital rim (n = 7), and in group 2, the patients underwent total frontal reconstruction and unilateral fronto-orbital advancement (n = 5). Computerized photogrammetric analysis measured vertical and horizontal axis of the nose and the orbital globe in the preoperative and postoperative periods. Intragroup and intergroup comparisons were performed. Intragroup preoperative and postoperative comparisons showed a significant (all P < 0.05) reduction of the nasal axis and the orbital-globe axis in the postoperative period in the 2 groups. Intergroup comparisons showed no significant difference (all P > 0.05). Facial symmetry was achieved in the patients with UCS who underwent surgery regardless of surgical approach evaluated here. Our data showed a significant improvement in nasal and orbital-globe deviation, leading us to question the necessity of primary nasal correction in these patients.

Neurological evaluation of neonates with intraventricular and periventricular hemorrhage

We studied the clinical aspects of 100 consecutive premature newborns with and without intraventricular and periventricular hemorrhage (IPVH).The diagnosis of IPVH was obtained by ultrasonic scans of the skull during the first week of life and at the age of one month. Forty eight percent of newborns with IPVH had abnormal results, and there was a significant correlation with the neurological evaluation in 85% of the infants. The probability of normality for a child with no associated brain abnormalities was 72%, whereas for a child of the same gestational age with associated brain abnormalities was 48.7%.

Estudo vídeo-polissonográfico em recém-nascidos de termo pequenos para a idade gestacional

Video-polygraphic-EEG studies were performed in the first 24 life-hours of 26 healthy full-term newborns without perinatal injuries. The neurological examination and cranial ultrasonography were normal. The newborns were divided into two groups: one, with full-term appropriate - birth weight 11 newborns (control group ) and the other with full-term low-birth weight 15 newborns. Thirteen newborns of the second group had video-polygraphic-EEG study abnormalities. The most frequent abnormalities were found in 11 cases, as far as sleep architecture is concerned. Also, when compared with the control group, 8 cases of an excessive amount of startles and 2 cases of low behavior activities were found. The results demonstrate the usefulness of video-polygraphic-EEG study in the full-term newborns with intra-uterine growth retard. This examination was sensitive to detect behavior, sleep architecture and EEG standard differences in the low birth-weight newborns as to the control group.

Semiologia neurológica numa população de escolares da primeira série do ensino fundamental

We evaluated children in the first grade of a elementary school using neurological examination. With no previous knowledgement of their educational performance, were invited all children attending five classes of the first grade of an elementary public school chosen randomly, in Itatiba / Sao Paulo / Brazil, whose parents assigned a Commitment Term for participation in this research. Children who missed three evaluations in different days or whose parents did not assigned the Commitment Term were excluded. The Traditional Neurological Examination (ENT) (Lefevre, 1972) was applied. It was considered for normal the measurement of the skull circumference, proposed by Diament & Rodrigues (1976), and the application of all ENT items. The data were stored in a database of the Epi6 Program (Epidemiologic Information), and analyzed by percentage calculation and by the c2 test. The significance level was 0.05. Children evaluated were 124. The ENT results were normal in 87 (70.16%) and altered in 37 (29.83%). Among the alterations, there were observed: light tremor, light muscular hypotonia, speech acquisition delay, macrocephaly, microcephaly, hyperactivity, cranial nerve syndrome, central facial paralysis. One child presented corticospinal tract impairment syndrome of the distal lower extremities.

Ocular masquerade syndrome associated with extranodal nasal natural killer/T-cell lymphoma: case report

A 33-year-old woman complained of unilateral eyelid edema and blurred vision. Initial ophthalmic examination disclosed anterior chamber reaction with keratic precipitates on the cornea, without posterior abnormalities. Anterior uveitis was treated. Despite that, patient showed rapidly progressive unilateral vision loss with optic nerve swelling. Systemic workup was inconclusive, as well as cranial magnetic resonance imaging and cerebrospinal fluid examination. Based on the hypothesis of optic neuritis, intravenous methylprednisolone pulse was performed with no success. During the following days, the patient presented pericardial effusion and cardiac tamponade, progressing to death. Necropsy was performed and diagnosis of extranodal natural killers/T-cell lymphoma, nasal type with ocular involvement was confirmed by immunohistochemistry.

Polirradiculoneurite e malária: relato de um caso

Case report of a patient who three weeks after a Plasmodium falciparum malaria presented the Guillain-Barré syndrome. There was a severe type of polyradiculoneuritis with tetraplegia and involvement of several cranial nerves (VI, VII, IX, X) evolving to death. The Guillain-Barré syndrome has been considered a immune disorder with several eliciting antigenic stimuli. The case suggests that protozoan may be one these antigenic factors.

Aspectos da tomografia computadorizada craniana na neurocisticercose na infância

The authors present the analysis of 27 computed tomography scans (CT) of 18 children which were divided in three groups according to clinical and tomographic criteria. Group 1 was characterized mainly by epilepsy and calcifications. Group 2 was characterized by intracranial hypertension and several tomographic aspects: edema, cysts and nodules were seen in three patients; hydrocephaly and calcifications were seen in two patients and CT was normal in one patient. Group 3 had patients with epilepsy or headache and variable tomographic patterns. The results are discussed based on the available literature.