Lucas Soares Bezerra

Global hippocampal atrophy in major depressive disorder: a meta-analysis of magnetic resonance imaging studies

INTRODUCTION Major depressive disorder (MDD), an incapacitating mental disorder, is characterized by episodes of at least 2 weeks of apparent changes in mood, cognition, and neurovegetative functions. Many neuroimaging studies using magnetic resonance imaging (MRI) have examined morphometric changes in patients with MDD, but the results are not conclusive. This study aims to review the literature and perform a meta-analysis on hippocampal volume (HcV) in patients with MDD. METHODS Studies on HcV in patients with MDD diagnosis were identified from major databases (MEDLINE, EMBASE, The Cochrane Library, Scopus, PsycINFO, and SciELO) using the search terms depression, major depressive disorder, MDD, unipolar, magnetic resonance imaging, MRI, and hippocampus. RESULTS A meta-analysis of 29 studies fulfilling specific criteria was performed. The sample included 1327 patients and 1004 healthy participants. The studies were highly heterogeneous with respect to age, sex, age of onset, and average illness duration. However, the pooled effect size of depression was significant in both hippocampi. MDD was associated with right (-0.43; 95% confidence interval [95%CI] -0.66 to -0.21) and left (-0.40; 95%CI -0.66 to -0.15) hippocampal atrophy. CONCLUSIONS MDD seems to be associated with global HcV atrophy. Larger longitudinal follow-up studies designed to analyze the influence of sociodemographic variables on this relationship are required to yield better evidence about this topic.

Hippocampal Volume Changes in Patients with Mood Disorders: A Systematic Review of MRI Studies

Background and objectives: due to the neurotoxic effect caused by high levels of cortisol, 13 studies suggest that stress and certain psychiatric disorders, such as mood disorders, have 14 influences under the hippocampus, causing a decrease in volume and consequent memory changes. 15 This study aims to evaluate the relationship between hippocampal volume in patients with mood 16 disorders under therapy. Materials and Methods: the PRISMA protocol for systematic reviews was 17 followed. Pubmed, Cochraine and Scielo databases were searched by terms “Hippocampus”, 18 “Mood Disorders” and “MRI”, and variants in other languages, in human, from January 2011 to 19 September 2016. The individual quality of the articles was analyzed using the Cochraine modified 20 scale for clinical trials and the Agency for Healthcare Research and Quality scale for observational 21 studies. Results: all studies showed reduction of hippocampal volume in depressive patients. 22 Change in hippocampal volume is not related to the use of antidepressant. Particularly the sub23 region of the subculum is more reduced, without lateralizations. Significant relationship between 24 stress and right hippocampal reduction. The findings seem to point out: a common pathway of 25 hippocampus reduction, mediated by stress, explaining memory deficits due to depression, where 26 the cortisol pathway seems to act; alteration in the prefrontal cortex; reduction in the subiculum 27 related to inhibition of the hypothalamic-pituitary-adrenal axis, corroborating the hypothesis of 28 cortisol. Conclusions: the papers suggest: association between global hippocampal atrophy with 29 mood disorders; reduction of hippocampal subiculum; refractoriness to clinical treatment among 30 patients with lower hippocampal volume. 31

Neuropsychiatric symptoms in vascular dementia: Epidemiologic and clinical aspects

ABSTRACT Dementia is a general term for a heterogeneous group of organic neurodegenerative diseases. Cerebrovascular causes account for 20% of cases. Objective: To describe the clinical and epidemiological features of individuals aged >60 years diagnosed with vascular dementia (VD) or mixed dementia (MxD) in a referral hospital for dementia. Methods: A descriptive, retrospective study was carried out from 2014 to 2017 involving elderly individuals (≥60 years) with VA or MxD. Patients presenting other forms of dementia or in use of medication that mimics cognitive disorders were excluded. The 12-item Neuropsychiatric Inventory was used to assess neuropsychiatric symptoms (NPS). Results: 81.1% of the patients presented NPS and only 15% had two or more symptoms. Apathy was the most frequent NPS (56.6%). There was an association between CDR score 1 or 2 and NPS (OR = 6.16, 95% CI: 1.36-27.9, p = 0.02). Conclusion: Most patients had a single symptom, predominantly apathy. There was an association between mild-to-moderate dementia and NPS.

Neuronal plasticity mechanisms induced by brain-machine interfaces: connecting brain to artificial neural network

Brain-machine interfaces, also known as Brain-Computer Interfaces (BCI), are devices that connect the brain to a computer. In the last decade it is been used to investigate the restore of sensorimotor function in patients with cortical damage. Some evidence supports that the results obtained in the research using BCIs in the treatment of these patients are directly dependent on plasticity mechanisms very similar to those observed in learning and memory tasks. Recent studies have been making use of Artificial Neural Networks (ANN) to classify signal patterns throughout neuronal circuits in order to command movements . In this review, we attempted to make a survey on the available data in the literature on this topic in order to gather the most relevant evidence of such mechanisms and the role of ANN on human brain neuronal input decoding compared to other data processing techniques.

Pharmacological approach for the management of patient with carpal tunnel syndrome associated to diabetic polyneuropathy. Case report

BACKGROUND AND OBJECTIVES: Peripheral neuropathy and carpal tunnel syndrome are debilitating diseases associated to diabetes mellitus in 12 to 21% of cases. There are no significant evidences of the clinical differentiation between such painful syndromes and their specific management. This study aimed at reporting the clinical presentation of a patient with peripheral polyneuropathy associated to carpal tunnel syndrome, focusing on therapeuthic approaches and discussing clinical differentiation between both diseases. CASE REPORT: Male patient, 68 years old, married, retired, who looked for medical assistance complaining of burning pain, especially in left upper limb. He also referred pain in lower limbs with night exacerbation, in addition to numbness in extremities and pain intensity of 6 in the visual analog scale. Presence of trigger- points in trapezius and levator scapulae muscles. Patient was submitted to decompression surgery due to carpal tunnel syndrome diagnosis two years ago, however without postoperative improvement. Patient refers pain in upper and lower limbs, with nocturnal exacerbation, numbness and pain in extremities. He has history of hypertension, diabetes mellitus type 2 and leprosy. At physical evaluation: painful boot and glove hypoesthesia and possible motor deficit in C6 and C7. Electromyography showed mixed peripheral polyneuropathy of lower limbs and median carpal syndrome to the left. There has been movement amplitude improvement in myotomes C6 and C7. Pain decreased to 3 in the visual analog scale after two weeks under gabapentin and duloxetine. CONCLUSION: It is difficult to clinically differentiate between neuropathy of different etiology and peripheral polyneuropathy. The proposed treatment has provided 50% improvement in the visual analog scale two weeks later. Lidocaine infusion at 5% has provided acute improvement of patient’s pain.