August was undeniably marked by the loss of Oliver Sacks. There is nothing I can say about him that hasn’t already been said. He was a wonderful example of how to engagingly communicate science and medicine. He was a wonderful example of many, many things.

Here is the best and worst news I came across in August.

THE BEST

A new therapeutic target for aging

Heterochronic parabiosis is an experimental method in which the circulatory systems of young and old animals are joined.

In a study published in Nature Medicine, this method was used to identify circulating pro-aging factors that may impact cognition and neuroregeneration. Data showed that the molecule beta2-microglobulin (B2M) was elevated in the blood and hippocampus of aged mice. The administration of B2M, either systemically or directly in the hippocampus, impaired cognitive function and neurogenesis in young mice. On the other hand, the absence of B2M expression decreased age-related cognitive decline and enhanced neurogenesis in aged mice. This work therefore indicates that B2M promotes age-related cognitive decline and impairs neuroregeneration, placing it as a potential therapeutic target in age-related diseases.

Dementia may be decreasing (slightly) in Western Europe

European researchers from Sweden, the Netherlands, the UK, and Spain joined forces to determine whether dementia occurrence has changed during the past 20–30 years in Western Europe. A significant reduction in overall dementia prevalence in the UK was observed. The study done in Spain also showed significant reduction in dementia prevalence, specifically in men. The studies from Sweden and the Netherlands also reported slight reductions, although they were not significant.

These reductions may be the outcome of an improved education and living conditions, and better prevention and treatment options, showing that these are worthy investments.

Serum BDNF as a prognostic tool for traumatic brain injury

Brain-derived neurotrophic factor (BDNF) is a key molecule for neuronal survival and regeneration. Therefore, a study published in the Journal of Neurotrauma aimed at determining if the values of serum BDNF could be used as a diagnostic and prognostic index in traumatic brain injury (TBI).

The authors determined that the concentrations of BDNF at the day of injury were lower among TBI cases than in controls. The BDNF concentrations decreased according to the severity of TBI. Subjects with very low BDNF values were shown to have higher risk of incomplete recovery. This study therefore shows that day-of-injury serum BDNF can be associated with TBI diagnosis and also provide prognostic information regarding recovery from TBI.

A new classification model for the diagnosis of Parkinson’s disease

Researchers from the Parkinson’s Disease Biomarkers Program and Parkinson’s Progression Marker Initiative got together to create a non-invasive, accurate classification model for the diagnosis of Parkinson’s disease. The main goal of this project was to devise a system for future disease prediction studies in longitudinal cohorts.

They developed a model for disease classification that includes olfactory function, genetic risk, family history of Parkinson’s disease, age, and gender. The model was then tested in patients and in controls. This model was able to correctly distinguish patients with Parkinson’s disease from controls with high sensitivity and specificity. Furthermore, it was able identify individuals with preclinical Parkinson’s disease.

A new neuroprotective therapy for brain injury

Hypoxia due to vascular damage occurs frequently at the injured brain. Among the effects of hypoxia are increased oxidative stress and neuronal death.

In a study published in the Journal of Cerebral Blood Flow & Metabolism, researchers were able to significantly decrease the adverse effects of hypoxia through noninvasive exposure of injured brain to low-level light. This technique was able to protect cells from oxidation and death. This effect of low-level light was reinforced by combination with metabolic substrates. The combinational therapy was able to protect the hippocampus from the deleterious effects of hypoxia, thereby retaining memory and learning abilities of injured mice.

THE WORST

The impact of long working hours on health

The Lancet published a huge systematic review and meta-analysis on the effect of long working hours as a risk factor for coronary heart disease (CHD) and stroke. The study used data from 25 studies from 24 cohorts in Europe, the USA, and Australia. The meta-analysis included data from 603,838 people with a mean follow-up of 8.5 years for CHD, and 528,908 people with a mean follow-up of 7.2 years for stoke. Data showed that working long hours (over 55h per week) was associated with an increased risk of incident CHD and stroke. This analysis shows that working long hours may have a clear negative impact on health.

Cerebrovascular atherosclerosis and Alzheimer’s disease go together

There is increasing evidence for a close association between cerebrovascular atherosclerosis and Alzheimer’s disease. It is hypothesized that these pathologies may interact to disrupt brain structure and function.

A review article published in Frontiers in Aging Neuroscience looked at this possible connection. There is evidence suggesting that impaired clearance of A-beta is a simultaneously occurring mechanism by which Alzheimer’s disease and cerebrovascular disease may be causally linked. Understanding this interaction may be an important step towards better diagnostic and therapeutic approaches for Alzheimer’s.

Migraine may be associated with oxidative stress

Migraine is a poorly understood disorder. Since increased levels of oxidative stress markers have been reported in migraine patients, it has been hypothesized that an impaired oxidative mitochondrial metabolism may play a role in the pathogenesis of migraine.

In a study published in Headache, this possible connection was again assessed. The plasmatic levels of markers related to oxidative stress was evaluated in a sample of chronic migraine patients and compared to healthy headache-free subjects. The analysis showed significantly lower levels of antioxidant power in patients with chronic migraine. This data reinforces the view that oxidative stress due to a decreased antioxidant capacity may contribute to the development of chronic migraine.

Epilepsy and pregnancy

Epilepsy and antiepileptic drugs have been associated with different pregnancy complications, from congenital malformations and cognitive deficits to miscarriage.

A systematic review published in The Lancet analyzed the association between epilepsy and reproductive outcomes, with or without exposure to antiepileptic drugs. The study found that women with epilepsy have increased odds of spontaneous miscarriage, hemorrhages, hypertensive disorders, induction of labor, caesarean section, preterm birth, and fetal growth restriction. This work reinforces the association of epilepsy and exposure to antiepileptic drugs to adverse outcomes in pregnancy.

Loss of gray matter associated with antipsychotic medication

Patients with schizophrenia often manifest progressive deficits in cortical gray matter. A meta-analysis published in Biological Psychiatry aimed at evaluating whether the amount and type of antipsychotic medication intake could be associated with those deficits. Imaging studies assessing the volume of cortical gray matter in patients with schizophrenia and in healthy controls, published between 1983 and 2014, were analyzed in this work.

Data showed that patients with schizophrenia showed a significantly higher loss of gray matter over time, and that it was associated with antipsychotic drug intake. However, progressive gray matter loss was higher in patients treated with at least one first-generation antipsychotic; patients treated only with second-generation antipsychotics showed a smaller deleterious effect.

References

Dong T, Zhang Q, Hamblin MR, & Wu MX (2015). Low-level light in combination with metabolic modulators for effective therapy of injured brain. Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 35 (9), 1435-44 PMID: 25966949

Gupta A, & Iadecola C (2015). Impaired A? clearance: a potential link between atherosclerosis and Alzheimer’s disease. Frontiers in aging neuroscience, 7 PMID: 26136682

Kivimäki M, Jokela M, Nyberg ST, Singh-Manoux A, Fransson EI, Alfredsson L, Bjorner JB, Borritz M, Burr H, Casini A, Clays E, De Bacquer D, Dragano N, Erbel R, Geuskens GA, Hamer M, Hooftman WE, Houtman IL, Jöckel KH, Kittel F, Knutsson A, Koskenvuo M, Lunau T, Madsen IE, Nielsen ML, Nordin M, Oksanen T, Pejtersen JH, Pentti J, Rugulies R, Salo P, Shipley MJ, Siegrist J, Steptoe A, Suominen SB, Theorell T, Vahtera J, Westerholm PJ, Westerlund H, O’Reilly D, Kumari M, Batty GD, Ferrie JE, Virtanen M, & IPD-Work Consortium (2015). Long working hours and risk of coronary heart disease and stroke: a systematic review and meta-analysis of published and unpublished data for 603?838 individuals. Lancet (London, England) PMID: 26298822

Korley FK, Diaz-Arrastia R, Wu AH, Yue JK, Manley GT M D Ph D, Sair HI, Van Eyk J, Everett AD, Okonkwo DO, Valadka A, Gordon WA, Maas A, Mukherjee P, Yuh EL, Lingsma H, Puccio AM, & Schnyer DM (2015). Circulating Brain Derived Neurotrophic Factor (BDNF) Has Diagnostic and Prognostic Value in Traumatic Brain Injury. Journal of neurotrauma PMID: 26159676

Lucchesi C, Baldacci F, Cafalli M, Chico L, Lo Gerfo A, Bonuccelli U, Siciliano G, & Gori S (2015). Evidences of Reduced Antioxidant Activity in Patients With Chronic Migraine and Medication-Overuse Headache. Headache, 55 (7), 984-91 PMID: 26129705

Nalls MA, McLean CY, Rick J, Eberly S, Hutten SJ, Gwinn K, Sutherland M, Martinez M, Heutink P, Williams NM, Hardy J, Gasser T, Brice A, Price TR, Nicolas A, Keller MF, Molony C, Gibbs JR, Chen-Plotkin A, Suh E, Letson C, Fiandaca MS, Mapstone M, Federoff HJ, Noyce AJ, Morris H, Van Deerlin VM, Weintraub D, Zabetian C, Hernandez DG, Lesage S, Mullins M, Conley ED, Northover CA, Frasier M, Marek K, Day-Williams AG, Stone DJ, Ioannidis JP, Singleton AB, & Parkinson’s Disease Biomarkers Program and Parkinson’s Progression Marker Initiative investigators* (2015). Diagnosis of Parkinson’s disease on the basis of clinical and genetic classification: a population-based modelling study. The Lancet. Neurology PMID: 26271532

Smith LK, He Y, Park JS, Bieri G, Snethlage CE, Lin K, Gontier G, Wabl R, Plambeck KE, Udeochu J, Wheatley EG, Bouchard J, Eggel A, Narasimha R, Grant JL, Luo J, Wyss-Coray T, & Villeda SA (2015). ?2-microglobulin is a systemic pro-aging factor that impairs cognitive function and neurogenesis. Nature medicine, 21 (8), 932-7 PMID: 26147761

Viale L, Allotey J, Cheong-See F, Arroyo-Manzano D, Mccorry D, Bagary M, Mignini L, Khan KS, Zamora J, Thangaratinam S, & EBM CONNECT Collaboration (2015). Epilepsy in pregnancy and reproductive outcomes: a systematic review and meta-analysis. Lancet (London, England) PMID: 26318519

Vita A, De Peri L, Deste G, Barlati S, & Sacchetti E (2015). The Effect of Antipsychotic Treatment on Cortical Gray Matter Changes in Schizophrenia: Does the Class Matter? A Meta-analysis and Meta-regression of Longitudinal Magnetic Resonance Imaging Studies. Biological psychiatry, 78 (6), 403-12 PMID: 25802081

Image via Halfpoint / Shutterstock.