Review Articles in 2013

Parkinson disease (PD) begins with a long preclinical phase, which represents both a diagnostic challenge and a potential therapeutic opportunity for early intervention. Parnetti and colleagues discuss growing evidence to support the utility of cerebrospinal fluid levels of various proteins, such as α-synuclein, amyloid-β and tau, as accessible biomarkers for PD diagnosis. The authors emphasise the importance of measuring multiple biomarkers in combination to improve diagnostic accuracy.

Since the development of life support technology, the precise definition of death has been challenging. James Bernat outlines the brain criteria and the circulatory–respiratory criteria of death, and discusses controversial issues surrounding these definitions, such as a lack of standardization in the field. Ethical challenges in the context of organ donation are also considered.

Mild traumatic brain injury (TBI) is defined as a head trauma resulting in a brief loss of consciousness and/or alteration of mental state. Diagnostic methods to determine the extent of injury to the brain and potential long-term damage in patients are lacking. In this Review, the authors discuss the need for fluid biomarkers of mild TBI, and the potential validation of biomarkers before clinical implementation.

For patients with malignant glioma—a tumour that carries a very poor prognosis—resective surgery is the primary treatment approach. Whether the extent of resection affects prognosis, however, has been the subject of debate. Eyupoglu et al. describe advances in surgical imaging techniques that have enabled improvement in both assessment of resection extent and maximal feasible tumour removal. Preoperative and postsurgical factors that influence patient outcome are described, along with discussion of clinical data suggesting that maximal surgical resection is in the best interest of patients with malignant glioma.

Eye movement responses are altered in patients with age-related neurodegenerative diseases such as Huntington disease or Parkinson disease. In this Review, the authors describe the oculomotor features of various neurodegenerative diseases and discuss the potential utility of laboratory and clinical assessment of eye movements in monitoring of onset and progression in patients with these disorders.

Transient amnesic syndromes, such as transient global amnesia and transient epileptic amnesia, are often difficult to diagnose. Recent studies, however, have examined the structural and functional underpinnings of these disorders. In this Review, Bartsch and Butler discuss how these studies have improved our understanding of transient amnesic syndromes, summarizing the key clinical aspects of different amnesic disorders and providing recommendations for diagnosis and patient management.

The ε4 allele of the apolipoprotein E (APOE) gene is the strongest genetic risk factor for Alzheimer disease (AD). Guojun Bu and colleagues describe the pathogenic links between Apo-E4 and neurodegeneration, including amyloid-β-dependent mechanisms and impairment of neurovascular function. The authors suggest potential strategies to target Apo-E, which could provide important additions to therapeutic options for AD.