Reviews & Analysis

The largest ever study of cognitive function in progressive supranuclear palsy and multiple system atrophy, investigating almost 700 patients, confirms that cognitive dysfunction in these conditions is common and often severe, and can occur early in the course of the disease. Detection, however, depends on an appropriate choice of tests.

Poststroke depression (PSD) shows an association with long-term disability and quality of life in stroke survivors, two new reports confirm. Effective treatments for PSD exist and should be standards of care. More research is required to investigate a causal relationship between PSD and functional outcomes after stroke.

Ischemic stroke diagnosis and optimal patient management begin with neuroimaging. In an evidence-based guideline, the American Academy of Neurology recently published a systematic review to evaluate the diagnostic and prognostic roles of diffusion-weighted and perfusion-weighted imaging techniques in patients with acute ischemic stroke.

Alzheimer disease (AD) biomarkers reflect specific features of AD pathology. These biomarkers may be used in the diagnosis and staging of AD, or may act as surrogate end points in clinical trials. Thus, a thorough understanding of the diagnostic accuracy of and longitudinal change in cerebrospinal fluid and MRI AD biomarkers is important.

Natural history studies have identified numerous features of disability progression in patients with multiple sclerosis (MS), and have provided valuable insight into the underlying pathology of the disease that could assist the development of new treatment strategies. A new study indicates that disability progression occurs in two stages in patients with MS.

Thromboembolism resulting from complex atheromatous plaque formation at the origin of the internal carotid artery is a common cause of ischemic stroke. In appropriately selected patients, plaque removal by carotid endarterectomy is of substantial net benefit. Endovascular stenting appears less 'invasive' than endarterectomy, but is the former as safe and effective as the latter?

Two new studies suggest that pediatric medulloblastomas and high-grade gliomas are genetically different from the same tumors in adults. Age-dependent gene expression might affect tumor biology; therefore, therapies for adult medulloblastomas or gliomas might not produce the same clinical outcomes in pediatric patients, and vice versa.

Lesion location might turn out to be an important factor in long-term disability prediction in patients with primary progressive multiple sclerosis (MS). Using a lesion probability mapping approach, researchers have identified brain regions where the presence of MS lesions predicts an early need for bilateral walking support.

Antiepileptic drugs (AEDs) are receiving increasing attention for a possible association with suicidal thoughts and behaviors. Several recent studies examining this association, however, have yielded inconsistent findings, particularly in terms of the risk of suicidal behavior conferred by specific AEDs. In patients with epilepsy, heightened suicide risk is also attributable to comorbid psychiatric conditions.

Oligoclonal bands are present in the cerebrospinal fluid of most patients with multiple sclerosis (MS) and represent a useful diagnostic measure. Two recent studies indicate that the identification of such bands might provide insight into the underlying mechanism of disease in MS and guide the treatment of individuals with this disorder.

Levodopa treatment alleviates the motor symptoms that characterize Parkinson disease, but is associated with motor complications. Treatments that prolong the action of levodopa could potentially reduce the risk of these adverse events, but a new study reports that one such approach—entacapone as an adjunct to levodopa–carbidopa—is associated with earlier dyskinesia onset than with levodopa–carbidopa alone.

The growing literature on comorbidity in multiple sclerosis (MS)—in particular, the association of MS with other autoimmune diseases—provides interesting clues to the complex pathogenesis of this disease, but also raises awareness of the important issues that need to be considered in its management.

A direct role for large tau aggregates in neurodegeneration has been challenged by new data indicating that, in relation to degeneration of neurons, caspase activation precedes tangle formation. The findings suggest that any toxic tau moiety related to neurodegeneration is likely to be soluble rather than aggregated.

A new study indicates that deep brain stimulation (DBS) plus best medical therapy markedly improves quality of life of patients with advanced Parkinson disease compared with best medical therapy alone. The frequency of serious adverse events related to DBS was similar to that reported in other DBS trials, underscoring the need for careful patient selection and counseling for this invasive therapy.

Bacterial meningitis causes substantial neurological morbidity and mortality worldwide. The use of corticosteroids as adjunctive therapy to antibiotics has been studied in clinical trials and debated for decades. A new meta-analysis attempts to reconcile some of the disparate findings from trials in this field.

After a stroke, seizures and later development of epilepsy can have a devastating impact on patient outcome and quality of life. Predicting the risk of developing poststroke epilepsy is currently an inexact science, and improving the accuracy of this process could lead to more-targeted use of prophylactic antiepileptic drugs for a defined period of time.

Malignant gliomas are aggressive tumors that often progress despite multimodality therapy. At recurrence, treatment approaches must balance the potential morbidity of a given therapy against the survival benefit that might be achieved. A new study reports that irradiation in this setting is well tolerated and could prolong survival.

Deep brain stimulation of the subthalamic nucleus or the internal pallidum can be an effective treatment for the disabling motor complications arising from dopaminergic treatment for Parkinson disease. The subthalamic nucleus has emerged as the preferred target for such treatment; however, no data exist to guide the choice between these two sites.

A 2009 study found that cerebral venous drainage was impaired in all patients with multiple sclerosis examined, but was not affected in control individuals. The study's investigators suggested that venous obstruction in the neck—a treatable condition—caused perivenous inflammation and demyelination. A comprehensive ultrasound study has now challenged this hypothesis.

A large, retrospective study indicates that in patients with acute ischemic stroke, endovascular interventions performed under conscious sedation carry a lower risk of poor neurological outcome and mortality than those performed under general anesthetic. Owing to a number of potential confounding factors, however, the results must be interpreted with caution.