Reviews & Analysis

Minimally invasive spine surgery (MISS) was developed to minimize the morbidity associated with large, open surgical approaches, but questions over its benefits and safety. Smith and Fessler review the evidence to support MISS over open approaches for decompression of lumbar stenosis, and highlight new applications of these minimally invasive techniques. Issues with the adoption of MISS, criteria for acceptance of these procedures, and the need for better training and education on MISS are also discussed.

Deep brain stimulation (DBS) is currently used as an effective treatment to reduce symptoms in chronic pain and movement disorders. An inadvertent and positive side effect of this therapy is the autonomic response to DBS in terms of changes to respiratory indices, lung function, and urinary and bladder function. This Review discusses the circuitry of the autonomic nervous system and its higher control centres, and the potential for DBS as a therapy for patients with dysautonomias.

A recent study to investigate the safety and efficacy of serotonin reuptake inhibitors suggests that these drugs are beneficial for the treatment of depressive disorders in Parkinson disease. Whether these treatments will offer such benefits in the long term compared with other pharmacological and nonpharmacological approaches remains to be determined.

The past two decades have witnessed the emergence of minimally invasive techniques in most surgical specialties, but their role in spinal surgery remains controversial. A recent study has compared outcomes in minimally invasive versus open spinal fusion surgery. Does the size of the surgical approach really matter?

The immune response is increasingly recognised as a complex modulator of outcome after acute stroke. Chamorro and colleagues review key players of the innate and adaptive immune systems that are activated following brain ischaemia, and discuss stroke-induced immunodepression and the associated increased risk of infection in patients with stroke.

As many causes can underlie small-fibre neuropathy (SFN)—a condition characterized by neuropathic pain symptoms and autonomic complaints—making a clinical diagnosis of this disorder is difficult. Hoeijmakers et al. review recent advances in the understanding of the pathophysiology of SFN, highlighting new diagnostic methods for this disorder and discussing how these advances will contribute to better patient management.

A new study suggests that lesion volume assessed within 72 h of stroke onset is an important independent predictor of 90-day functional outcome and neurological recovery. If used in stroke trials, outcome models including stroke volume, age and NIH Stroke Scale scores could increase power for detecting treatment effect.

Intracerebral haemorrhage continues to carry a poor prognosis despite several recent therapeutic clinical trials. A study has demonstrated that CT angiography of the brain on admission can predict haematoma expansion and clinical outcome. This CT 'spot sign' could, therefore, help physicians to select patients who are likely to benefit from treatment.

The American Academy of Neurology has published guidelines for intravenous immunoglobulin (IVIg) treatment of neuromuscular diseases. These guidelines differ from those in Europe owing to different conventions for grading of recommendations. Although IVIg is an effective treatment for inflammatory neuropathies and neuromuscular diseases, it is much more expensive than alternative therapies.

Depressive symptoms frequently accompany Parkinson disease. Screening instruments to detect depression in this patient group exist, but the relative performance of these tools had not been assessed. A recent study has compared the clinimetric properties of nine frequently used depression rating scales in an attempt to identify the best instrument.

Olfactory dysfunction is a common feature of Parkinson disease (PD) and precedes the onset of motor symptoms. Richard Doty provides a comprehensive overview of this phenomenon, including clinical and neurophysiological characteristics. Evidence that exposure to environmental substances could play a part in causing olfactory dysfunction in PD is also discussed.

Alzheimer disease features neurobiological changes long before the first symptoms of cognitive decline. Results from a new study to define the orderly changes of markers of amyloidosis and neurodegeneration over the disease course will assist the development of biomarker-based protocols for early diagnosis, and disease-modifying drugs.

Anticoagulant therapy aims to prevent recurrent ischaemic stroke and venous thromboembolism; however, anticoagulant drugs currently in use or in trials have limitations. In this article, Graeme Hankey provides an update of the clinical data on the safety and efficacy of anticoagulant therapies, and discusses the clinical implications and future directions.

Medulloblastoma, once thought to represent a single disease entity, is now recognized to comprise distinct subgroups that can be identified using histological, genetic and transcriptomic approaches. Northcott et al. present the evidence for the four recently defined subgroups of medulloblastoma, and highlight how stratification of tumours into these subgroups could have important clinical implications for patient prognosis, treatment and care.

Psychogenic nonepileptic seizures (PNES) resemble epileptic seizures, but are the result of underlying psychological processes. In a recent study characterizing seizure presentations in childhood PNES, a modified semiological categorization of the disorder was proposed. Does seizure semiology matter when determining the underlying psychological factors of PNES or predicting patient outcome?

Effective targeting of therapeutics to the CNS has been hampered by many biological obstacles, including the tight blood–brain barrier. In this Review, Srikanth and Kessler propose that the use of nanotechnology can overcome such issues. The authors discuss evidence for the efficacy of nanotechnology in CNS disorders, ranging from neurodegeneration to injury and brain tumours, and highlight the potential for the translation of nanotechnology-based therapeutics to the clinic.

Despite the proven favourable risk–benefit ratio, thrombolytic therapy for acute stroke is perceived to carry a grave risk. A simple risk-rating system, the SEDAN score, allows clinicians to quantify elevated risk. Whether effective thrombolytic therapy should be withheld from any particular patient requires further study, including randomized trials of patients with elevated risk scores.

Neurological morbidity is common in children who have undergone convulsive status epilepticus (CSE), so a recent study evaluating the utility of MRI in determining the extent of brain lesions following CSE is welcome. How might imaging results from children with CSE influence diagnostic, prognostic, and therapeutic decisions?

Psychiatric disorders in epilepsy have been considered a consequence of the seizure disorder. In recent years, however, a bidirectional relationship has been suggested. Two new studies have examined recent epidemiological data that further supports this hypothesis, highlighting common pathogenic mechanisms that operate in both conditions.

Pain is a nonmotor symptom that substantially affects the quality of life of many patients with Parkinson disease (PD). In this Review, the authors propose a taxonomy to distinguish between the different types of pain in PD. Following classification using this taxonomy, effective treatment strategies that are targeted at the specific type of pain can be established.