Volume 9 Issue 3, March 2013

The amyloid cascade hypothesis, which posits that amyloid-β accumulation is the key event in Alzheimer disease neurodegeneration, has dominated the field for 20 years. Recent findings, however, show that neuronal-injury biomarkers are independent of amyloid-β, calling for reconsideration of the pathological cascade and assessment of alternative therapeutic strategies.

Results from two phase III trials show the potency of alemtuzumab—a T-cell and B-cell depleting antibody—in reducing clinical and paraclinical measures of disease activity in relapsing–remitting multiple sclerosis. The effects of this immunotherapeutic agent highlight the relevance of T lymphocytes in the early pathogenesis of disease.

A recent study has shown that infection in the first 2 weeks after stroke correlates with 3-year mortality, and that risk of infection is highest in patients with dysphagia, urinary catheterization, or intracerebral haemorrhage. Studies are needed to assess treatment strategies to prevent early infection in patients with acute stroke.

The treatment of Bell palsy remains a matter of debate. A recent update of the American Academy of Neurology practice parameter concluded that corticosteroids should be offered to increase the probability of facial nerve recovery. The benefits of antiviral treatment, however, have not been established.

In relapsing–remitting multiple sclerosis, conversion to the progressive stage is thought to be influenced by early relapses. Despite a new study suggesting that relapses do not drive long-term disability and proposing the latency period as an ideal target for therapeutic intervention, the relapsing phase remains a relevant treatment window.

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.

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.

Around 25% of patients with subarachnoid haemorrhage (SAH) experience deterioration in the days following stroke, often as a result of delayed cerebral ischaemia (DCI). These deficits have been principally attributed to cerebral vasospasm, but recent studies suggest a role for dysfunction of cerebral autoregulation in post-SAH DCI. Budohoski et al. discuss recent findings on cerebral autoregulation, and present an overview of the pathophysiology and stages of autoregulatory impairment that occur following SAH.

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.

Hypertension is highly prevalent, particularly in individuals over 60 years of age, and constitutes a major risk factor for stroke and dementia. Antihypertensive therapy in elderly individuals has, however, been limited owing to concerns over adverse effects of such therapies. In this Perspectives article, Sörös et al. emphasize that treatment of hypertension can markedly reduce stroke and dementia risk, and argue that antihypertensive therapy should be considered in all patients, irrespective of age.