Sinus Sigmoideus Thrombosis Secondary to Graves' Disease: A Case Description

Cerebral venous thrombosis (CVT) is a distinct cerebrovascular condition that represents 0.5-1% of all strokes in the general population. Because of its procoagulant and antifibrinolytic effects [Horne et al.: J Clin Endocrinol Metab 2004;89:4469-4473], hyperthyroidism has been proposed as a predisposing factor for CVT [Saposnik et al.: Stroke 2011;42:1158-1192]. For the first time, we describe a 22-year-old right-handed woman with a sinus sigmoideus thrombosis due to Graves' disease. Although subclinical hyperthyroidism had been detected 2 years before the onset of neurological symptoms, she did not receive any medical follow-up. Early recognition, diagnosis and treatment are of crucial importance, as Graves' disease is a risk factor for CVT and stroke

Identifying the speech production stages in early and late adulthood by using electroencephalography

Structural changes in the brain take place throughout one's life. Changes related to cognitive decline may delay the stages of the speech production process in the aging brain. For example, semantic memory decline and poor inhibition may delay the retrieval of a concept from the mental lexicon. Electroencephalography (EEG) is a valuable method for identifying the timing of speech production stages. So far, studies using EEG mainly focused on a particular speech production stage in a particular group of subjects. Differences between subject groups and between methodologies have complicated identifying time windows of the speech production stages. For the current study, the speech production stages lemma retrieval, lexeme retrieval, phonological encoding, and phonetic encoding were tracked using a 64-channel EEG in 20 younger adults and 20 older adults. Picture-naming tasks were used to identify lemma retrieval, using semantic interference through previously named pictures from the same semantic category, and lexeme retrieval, using words with varying age of acquisition. Non-word reading was used to target phonological encoding (using non-words with a variable number of phonemes) and phonetic encoding (using non-words that differed in spoken syllable frequency). Stimulus-locked and response-locked cluster-based permutation analyses were used to identify the timing of these stages in the full time course of speech production from stimulus presentation until 100 ms before response onset in both subject groups. It was found that the timing of each speech production stage could be identified. Even though older adults showed longer response times for every task, only the timing of the lexeme retrieval stage was later for the older adults compared to the younger adults, while no such delay was found for the timing of the other stages. The results of a second cluster-based permutation analysis indicated that clusters that were observed in the timing of the stages for one group were absent in the other subject group, which was mainly the case in stimulus-locked time windows. A z-score mapping analysis was used to compare the scalp distributions related to the stages between the older and younger adults. No differences between both groups were observed with respect to scalp distributions, suggesting that the same groups of neurons are involved in the four stages, regardless of the adults' age, even though the timing of the individual stages is different in both groups

Developmental Coordination Disorder: Disruption of the Cerebello-Cerebral Network evidenced by SPECT

Little is known about the neurobiological substrate of developmental coordination disorder (DCD), a neuro-developmental syndrome with significant, negative impact on the motor, cognitive and affective level throughout lifespan. This paper reports the clinical, neurocognitive and neuroradiological findings of a 19-year-old patient with typical DCD. As demonstrated by mild ataxia and a close semiological correspondence with the recently acknowledged ‘cerebellar cognitive affective syndrome’, clinical and neurocognitive investigations unambiguously indicated functional disruption of the cerebellum. Structural MRI of the brain confirmed cerebellar involvement revealing a slight anterior/superior asymmetry of vermal fissures consistent with rostral vermisdysplasia. Although this abnormality of vermal fissuration is generally considered an incidental neuroradiological finding without any clinical relevance, a potentially subtle impact on the developmental level has never been formally excluded. In addition to a generally decreased perfusion of the cerebellum, a quantified Tc-99m-ECD SPECT disclosed functional suppression of the anatomoclinically suspected supratentorial regions involved in the execution of planned actions, visuo-spatial processing and affective regulation. Based on these findings, it is hypothesised that the cerebellum is crucially implicated in the pathophysiologcial mechanisms of DCD, reflecting disruption of the cerebello-cerebral network involved in the execution of planned actions, visuo-spatial cognition and affective regulation

Mastication Dyspraxia: A Neurodevelopmental Disorder Reflecting Disruption of the Cerebellocerebral Network Involved in Planned Actions

This paper reports the longitudinal clinical, neurocognitive, and neuroradiological findings in an adolescent patient with nonprogressive motor and cognitive disturbances consistent with a diagnosis of developmental coordination disorder (DCD). In addition to prototypical DCD, the development of mastication was severely impaired, while no evidence of swallowing apraxia, dysphagia, sensorimotor disturbances, abnormal tone, or impaired general cognition was found. He suffered from bronchopulmonary dysplasia and was ventilated as a newborn for 1.5 months. At the age of 3 months, a ventriculoperitoneal shunt was surgically installed because of obstructive hydrocephalus secondary to perinatal intraventricular bleeding. At the age of 5 years, the patient’s attempts to masticate were characterized by rough, effortful, and laborious biting movements confined to the vertical plane. Solid food particles had a tendency to get struck in his mouth and there was constant spillage. As a substitute for mastication, he moved the unground food with his fingers in a lateral direction to the mandibular and maxillary vestibule to externally manipulate and squeeze the food between cheek and teeth with the palm of his hand. Once the food was sufficiently soft, the bolus was correctly transported by the tongue in posterior direction and normal deglutition took place. Repeat magnetic resonance imaging (MRI) during follow-up disclosed mild structural abnormalities as the sequelae of the perinatal intraventricular bleeding, but this could not explain impaired mastication behavior. Quantified Tc-99m-ethylcysteinate dimer single-photon emission computed tomography (Tc-99m-ECD SPECT), however, revealed decreased perfusion in the left cerebellar hemisphere, as well as in both inferior lateral frontal regions, both motor cortices, and the right anterior and lateral temporal areas. Anatomoclinical findings in this patient with DCD not only indicate that the functional integrity of the cerebellocerebral network is crucially important in the planning and execution of skilled actions, but also seem to show for the first time that mastication deficits may be of true apraxic origin. As a result, it is hypothesized that “mastication dyspraxia” may have to be considered as a distinct nosological entity within the group of the developmental dyspraxias following a disruption of the cerebellocerebral network involved in planned actions

Recombinational micro-evolution of functionally different metallothionein promoter alleles from Orchesella cincta

<p>Abstract</p> <p>Background</p> <p>Metallothionein (<it>mt</it>) transcription is elevated in heavy metal tolerant field populations of <it>Orchesella cincta </it>(Collembola). This suggests that natural selection acts on transcriptional regulation of <it>mt </it>in springtails at sites where cadmium (Cd) levels in soil reach toxic values This study investigates the nature and the evolutionary origin of polymorphisms in the metallothionein promoter (<it>pmt</it>) and their functional significance for <it>mt </it>expression.</p> <p>Results</p> <p>We sequenced approximately 1600 bp upstream the <it>mt </it>coding region by genome walking. Nine <it>pmt </it>alleles were discovered in NW-European populations. They differ in the number of some indels, consensus transcription factor binding sites and core promoter elements. Extensive recombination events between some of the alleles can be inferred from the alignment. A deviation from neutral expectations was detected in a cadmium tolerant population, pointing towards balancing selection on some promoter stretches. Luciferase constructs were made from the most abundant alleles, and responses to Cd, paraquat (oxidative stress inducer) and moulting hormone were studied in cell lines. By using paraquat we were able to dissect the effect of oxidative stress from the Cd specific effect, and extensive differences in <it>mt </it>induction levels between these two stressors were observed.</p> <p>Conclusion</p> <p>The <it>pmt </it>alleles evolved by a number of recombination events, and exhibited differential inducibilities by Cd, paraquat and molting hormone. In a tolerant population from a metal contaminated site, promoter allele frequencies differed significantly from a reference site and nucleotide polymorphisms in some promoter stretches deviated from neutral expectations, revealing a signature of balancing selection. Our results suggest that the structural differences in the <it>Orchesella cincta </it>metallothionein promoter alleles contribute to the metallothionein -over-expresser phenotype in cadmium tolerant populations.</p