Browsing by Author "Pereira, D"
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- Anatomical characteristics of the styloid process in internal carotid artery dissection: Case-control studyPublication . Amorim, JM; Pereira, D; Rodrigues, MG; Beato-Coelho, J; Lopes, M; Cunha, A; Figueiredo, S; Mendes-Pinto, M; Ferreira, C; Sargento-Freitas, J; Castro, S; Pinho, JIntroduction Pathophysiology of cervical artery dissection is complex and poorly understood. In addition to well-known causative and predisposing factors, including major trauma and monogenic connective tissue disorders, morphological characteristics of the styloid process have been recently recognized as a possible risk factor for cervical internal carotid artery dissection. Aims To study the association of the anatomical characteristics of styloid process with internal carotid artery dissection. Methods Retrospective, multicenter, case-control study of patients with internal carotid artery dissection and age- and sex-matched controls. Consecutive patients with internal carotid artery dissection and controls with ischemic stroke or transient ischemic attack of any etiology excluding internal carotid artery dissection, who had performed computed tomography angiography, diagnosed between January 2010 and September 2016. Two independent observers measured styloid process length and styloid process distance to internal carotid artery. Results Sixty-two patients with internal carotid artery dissection and 70 controls were included. Interobserver agreement was good for styloid process length and styloid process-internal carotid artery distance (interclass correlation coefficient = 0.89 and 0.76, respectively). Styloid process ipsilateral to dissection was longer than left and right styloid process in controls (35.8 ± 14.4 mm versus 30.4 ± 8.9 mm and 30.3 ± 8.2 mm, p = 0.011 and p = 0.008, respectively). Styloid process-internal carotid artery distance ipsilateral to dissection was shorter than left and right distance in controls (6.3 ± 1.9 mm versus 7.2 ± 2.1 mm and 7.0 ± 2.3 mm, p = 0.003 and p = 0.026, respectively). Internal carotid artery dissection was associated with styloid process length (odds ratio = 1.04 mm-1, 95% confidence interval = 1.01-1.08, p = 0.015) and styloid process-internal carotid artery distance (OR = 0.77 mm-1, 95% confidence interval = 0.64-0.92, p = 0.004). Conclusion Longer styloid process and shorter distance between styloid process and cervical internal carotid artery are associated with cervical internal carotid artery dissection.
- Downbeat nystagmus elicited by eyelid closurePublication . Lemos, J; Pereira, D; Amorim, M; Santiago, B; Paiva, A; Cunha, LWe describe a patient with downbeat nystagmus (DBN) evoked only by eye closure. Brain and spinal cord magnetic resonance imaging revealed a T2 paramedian lesion in the left lower basis pontis and other white matter lesions consistent with multiple sclerosis. One potential mechanism for DBN in this case involves transverse ephaptic spread of excitation from areas that subserve coordinated lid closure to the decussating ventral tegmental tract.
- Mitochondrial Alterations in Fibroblasts of Early Stage Bipolar Disorder PatientsPublication . Marques, AP; Resende, R; Silva, DF; Batista, M; Pereira, D; Wildenberg, B; Morais, S; Macedo, A; Pais, C; Melo, JB; Madeira, N; Pereira, CFThis study aims to evaluate whether mitochondrial changes occur in the early stages of bipolar disorder (BD). Using fibroblasts derived from BD patients and matched controls, the levels of proteins involved in mitochondrial biogenesis and dynamics (fission and fusion) were evaluated by Western Blot analysis. Mitochondrial membrane potential (MMP) was studied using the fluorescent probe TMRE. Mitochondrial morphology was analyzed with the probe Mitotracker Green and mitophagy was evaluated by quantifying the co-localization of HSP60 (mitochondria marker) and LC3B (autophagosome marker) by immunofluorescence. Furthermore, the activity of the mitochondrial respiratory chain and the glycolytic capacity of controls and BD patients-derived cells were also studied using the Seahorse technology. BD patient-derived fibroblasts exhibit fragmented mitochondria concomitantly with changes in mitochondrial dynamics and biogenesis in comparison with controls. Moreover, a decrease in the MMP and increased mitophagy was observed in fibroblasts obtained from BD patients when compared with control cells. Impaired energetic metabolism due to inhibition of the mitochondrial electron transport chain (ETC) and subsequent ATP depletion, associated with glycolysis stimulation, was also a feature of BD fibroblasts. Overall, these results support the fact that mitochondrial disturbance is an early event implicated in BD pathophysiology that might trigger neuronal changes and modification of brain circuitry.
- Risk Calculators in Bipolar Disorder: A Systematic ReviewPublication . Silva Ribeiro, J; Pereira, D; Salagre, E; Coroa, M; Santos Oliveira, P; Santos, V; Madeira, N; Grande, I; Vieta, EIntroduction: Early recognition of bipolar disorder improves the prognosis and decreases the burden of the disease. However, there is a significant delay in diagnosis. Multiple risk factors for bipolar disorder have been identified and a population at high-risk for the disorder has been more precisely defined. These advances have allowed the development of risk calculators to predict individual risk of conversion to bipolar disorder. This review aims to identify the risk calculators for bipolar disorder and assess their clinical applicability. Methods: A systematic review of original studies on the development of risk calculators in bipolar disorder was performed. The studies' quality was evaluated with the Newcastle-Ottawa Quality Assessment Form for Cohort Studies and according to recommendations of the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis Initiative. Results: Three studies met the inclusion criteria; one developed a risk calculator of conversion from major depressive episode to bipolar disorder; one of conversion to new-onset bipolar spectrum disorders in offspring of parents with bipolar disorder; and the last one of conversion in youths with bipolar disorder not-otherwise-specified. Conclusions: The calculators reviewed in this article present good discrimination power for bipolar disorder, although future replication and validation of the models is needed.
- Visual Cortex Plasticity Following Peripheral Damage To The Visual System: fMRI EvidencePublication . Lemos, J; Pereira, D; Castelo-Branco, MOver the last two decades, functional magnetic resonance imaging (fMRI) has become a powerful research method to investigate cortical visual plasticity. Abnormal fMRI response patterns have been occasionally detected in the visually deprived cortex of patients with bilateral retinal diseases. Controversy remains whether these observations indicate structural reorganization of the visual cortex or unmasking of previously silent cortico-cortical connections. In optic nerve diseases, there is weak evidence showing that early visual cortex seems to lack reorganization, while higher-order visual areas undergo plastic changes which may contribute to optimise visual function. There is however accumulating imaging evidence demonstrating trans-synaptic degeneration of the visual cortex in patients with disease of the anterior visual pathways. This may preclude the use of restorative treatments in these patients. Here, we review and update the body of fMRI evidence on visual cortical plasticity.