CONTRIBUTION OF THE CORPUS CALLOSUM TO THE SYMMETRICAL REPRESENTATION OF TASTE IN THE HUMAN BRAIN: AN fMRI STUDY OF CALLOSOTOMIZED PATIENTS

The present study was designed to establish the contribution of the corpus callosum (CC) to the cortical representation of unilateral taste stimuli in the human primary gustatory area (GI). Unilateral taste stimulation of the tongue was applied to eight patients with partial or total callosal resection by placing a small cotton pad soaked in a salty solution on either side of the tongue. Functional images were acquired with a 1.5 Tesla machine. Diffusion tensor imaging and tractography were also performed. Unilateral taste stimuli evoked bilateral activation of the GI area in all patients, including those with total resection of the CC, with a prevalence in the ipsilateral hemisphere to the stimulated tongue side. Bilateral activation was also observed in the primary somatic sensory cortex (SI) in most patients, which was more intense in the contralateral SI. This report confirms previous functional studies carried out in control subjects and neuropsychological findings in callosotomized patients, showing that gustatory pathways from tongue to cortex are bilaterally distributed, with an ipsilateral predominance. It has been shown that the CC does play a role, although not an exclusive one, in the bilateral symmetrical representation of gustatory sensitivity in the GI area, at least for afferents from one side of the tongue

Ultrasonography of salivary glands in primary Sjögren's syndrome: A comparison with contrast sialography and scintigraphy

Objective. To compare ultrasonography (US) of salivary glands with contrast sialography and scintigraphy, in order to evaluate the diagnostic value of this method in primary SS (pSS). Methods. The diagnostic value of parotid gland US was studied in 77 patients with pSS (male/female ratio 3/74; mean age 54 yrs) and in 79 with sicca symptoms but without SS. The two groups were matched for sex and age. Imaging findings of US were graded using an ultrasonographic score ranging from 0 to 16, which was obtained by the sum of the scores for each parotid and submandibular gland. The sialographic and scintigraphic patterns were classified in four different stages. The area under receiver operating characteristic curve (AUC-ROC) was employed to evaluate the screening methods performance. Results. Of the 77 patients with pSS, 66 had abnormal US findings. Mean US score in pSS patients was 9.0 (range from 3 to 16). Subjects without confirmed pSS had the mean US score 3.9 (range from 0 to 9) (P < 0.0001). Results of sialography showed that 59 pSS patients had abnormal findings at Stage 1 (n = 4), Stage 2 (n = 8), Stage 3 (n = 33) or Stage 4 (n = 14), and 58 patients had abnormal scintigraphic findings at Stage 1 (n = 11), Stage 2 (n = 18), Stage 3 (n = 25) or Stage 4 (n = 4). Through ROC curves US arose as the best performer (AUC = 0.863 +/- 0.030), followed by sialography (AUC = 0.804 +/- 0.035) and by salivary gland scintigraphy (AUC = 0.783 +/- 0.037). The difference between AUC-ROC curve of salivary gland US and scintigraphy was significant (P = 0.034). Setting the cut-off score 6 US resulted in the best ratio of sensitivity (75.3%) to specificity (83.5%), with a likelihood ratio of 4.58. If a threshold 8.0 was applied the test gained specificity, at the cost of a serious loss of sensitivity (sensitivity 54.5%, specificity 97.5%, likelihood ratio 21.5). Conclusions. Salivary gland US is a useful method in visualizing glandular structural changes in patients suspected of having pSS and it may represent a good option as a first-line imaging tool in the diagnostics of the disease

Dentinogenesis imperfecta in Osteogenesis imperfecta type XI in South Africa: a genotype–phenotype correlation

BACKGROUND: The maxillofacial and dental manifestations of Osteogenesis imperfecta (OI) have significant implications in terms of management. Although the occurrence of abnormal dentine in some forms of OI is well documented, there is scant information on the association of abnormal dentine in the Black African persons with phenotypic OI III and genotypic OI XI in South Africa. METHODS: This was a cross-sectional analytic study. A series of 64 Black South African individuals with a confirmed phenotypic diagnosis of OI III, ages ranging from 3 months to 29 years, were assessed clinically, radiographically, and at a molecular level. RESULTS: A total number of 64 saliva samples were analyzed and 3 DNA variations were identified in exon 5 of the FKBP10 gene. The homozygous mutation, c.[831dupC]; [831dupC], was identified in 23 affected persons who had no clinically obvious features of DI in their primary and secondary teeth. Radiologically, mild features of DI were evident in 10 persons in whom radiographic images were obtained and were given a Clinical–radiological score of 2. A compound heterozygous mutation, c. [831delC]; [831dupC], was identified in three siblings. An intraoral examination of these affected persons revealed no clinically apparent features of DI in their primary and secondary teeth. Due to the lack of radiological facilities, the presence or absence of DI could not be confirmed or negated. A second compound heterozygous mutation, c.[831dupC]; [1400-4C>G], was identified in a female of 29 years belonging to the Xhosa linguistic group. Her teeth appeared clinically normal but it was not possible to obtain radiographs. In 37 affected individuals, no disease-causing mutations were identified. CONCLUSION: Black African individuals in SA with the homozygous mutation in the FKBP10 gene have clinically unaffected teeth yet exhibited radiographic features of DI to varying degrees. This characterization is suggestive of a relationship between the genetic abnormality and the clinical manifestations of DI. The authors suggest that this diagnosis must include teeth that are clinically and/or radiologically aberrant, and should not exclude the presence of other, milder, dentinal aberrations associated with OI. There was no correlation between severity of OI and DI in this cohort of individuals