Reviews & Analysis

Studies over the past two decades have shown that neurostimulation provides symptomatic benefit to patients with Parkinson disease (PD). However, surgical intervention is considered only for patients in late stages of disease. Now, results from the EARLYSTIM trial demonstrate that neurostimulation in early PD can markedly improve quality of life.

Oligoclonal IgG bands are present in the cerebrospinal fluid of most patients with multiple sclerosis (MS) and constitute a useful tool to enable accurate diagnosis. A recent meta-analysis has explored the precise prevalence of these antibodies in MS and their possible relationship with geographical location and patient outcome.

In patients with Parkinson disease (PD), the motor response to dopamine replacement therapy comprises an acute improvement in motor function, followed by the 'long-duration response' (LDR), in which motor improvements develop over weeks. Kang and colleagues review evidence to suggest that the LDR involves dopamine-dependent changes in corticostriatal plasticity, and discuss the implications of this framework for clinical management of PD. The authors argue that aberrant plasticity contributes to motor fluctuations during chronic dopamine replacement, and could be a novel therapeutic target for patients with PD or other basal ganglia disorders.

MicroRNAs (miRNAs) are short, single-stranded RNA molecules that inhibit translation of target mRNAs, and are key regulators of molecular and cellular responses in development, health and disease. A role for miRNAs in the regulation of pathology of CNS injuries has recently emerged, and in this Review, Bhalala et al. discuss findings from miRNA microarray studies in stroke, traumatic brain injury and spinal cord injury. They highlight how improved understanding of miRNA changes following CNS injuries can inform novel treatment strategies for these pathologies.

Traumatic brain injury (TBI) can occur as a single severe cranial impact or as repetitive concussions, and commonly affects professional athletes in contact sports and soldiers exposed to explosions. DeKosky and colleagues describe the distinct pathological changes accompanying each type of TBI, and characteristics of the resultant neuropathology, which frequently involves amyloid-β and tau aggregates. Potential biomarkers of TBI-induced damage are also outlined.

The aim of palliative care is to improve the quality of life for patients with terminal illness, and also their families. In this Perspectives article, the author discusses the challenges specific to palliative care for patients with neurological disorders, and outlines new approaches to the care of these patients.

At least 10% of diagnoses of Parkinson disease that are made while the patient is alive are not confirmed at autopsy. To help address this issue, the European Federation of Neurology and the Movement Disorder Society European Section have provided evidence-based guidelines and recommendations for clinical diagnosis of Parkinson disease.

Tumours of the spinal cord are associated with high morbidity but, owing to the rarity of such tumours, our understanding of the biology of these lesions is limited. In this Review, Zadnik et al. summarize current knowledge on the demographics, genetics and treatment of the most common spinal cord tumours—namely, ependymomas, astrocytomas, haemangioblastomas and meningiomas—and highlight how recent advances in genetic studies are informing research to develop novel therapeutic approaches.

Cerebrospinal fluid (CSF) investigation should be routinely performed in patients with a first clinical event that is suggestive of multiple sclerosis (MS). This Review highlights the value of existing CSF biomarkers in eliminating potential differential diagnoses for MS and understanding the underlying pathophysiology of this condition. The authors also discuss the potential for novel biomarkers that could be used in prognosis.

In multiple sclerosis (MS), a clinicoradiological paradox exists whereby clinical and MRI measures show poor correlation. New findings suggest that quantitative imaging to assess microstructural changes in the spinal cords of patient with MS could overcome this paradox, and provide novel markers to monitor disease progression.

A large epidemiological study of traumatic brain injury (TBI) in New Zealand has contributed to filling the knowledge gap on TBI incidence and severity. To improve health outcomes, however, public health practice must translate such findings into policies and intervention strategies.

A randomized study has indicated that continuous monitoring of intracranial pressure (ICP) in patients with traumatic brain injury does not improve outcome compared with care based on imaging and clinical examination. The results do not, however, justify elimination of continuous ICP measurement from standard care in patients with head injury.

Traumatic brain injuries (TBIs) sustained by athletes in contact–collision sports can cause long-term neurological complications. In recent years, cases of chronic traumatic encephalopathy—a neurodegenerative sequela of repetitive TBI—in retired boxers and American football players have been highly publicized. Here, Barry Jordan reviews the spectrum of sport-related brain injuries, and outlines the need for appropriate detection and management of both acute and chronic TBIs in athletes.

Treatment of anti-NMDA receptor encephalitis—a recently identified cause of autoimmune encephalitis—with aggressive immunosuppressive therapies has been a subject of debate. Now, a large observational cohort study suggests that most patients respond to immunotherapy, and that second-line therapies such as rituximab and cyclophosphamide may be beneficial.

The link between traumatic brain injury and dementia has long been recognized, and has gained additional prominence through recent high-profile reports of chronic traumatic encephalopathy (CTE) in athletes exposed to repetitive head injury. In this Review, Smith et al. outline the neuropathological features of CTE that are thought to contribute to cognitive impairment, and discuss the work that remains to be done to define CTE as a distinct disease entity.

In this Perspectives article, Roozenbeek et al. discuss issues with epidemiological studies in traumatic brain injury (TBI) and variability in the definition of such injuries. They describe how changing epidemiological patterns have influenced mortality and outcomes following brain injury, and identify the need for standardized epidemiological monitoring in TBI.

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.

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.

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.

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.