Volume 5 Issue 12, December 2009

Despite growing interest in both the clinical and scientific aspects of sudden unexpected death in epilepsy (SUDEP), knowledge about the disease mechanisms remains limited. The epileptic baboon—the first natural nonhuman primate model of SUDEP—offers a potential model to evaluate the genetic factors and pathophysiology underlying this mysterious condition.

Neurons that seem to be specifically involved in relaying pruritogenic sensory information to the brain have been identified in lamina I of the spinal cord. Are these neurons part of the long sought-after neural pathway for itch? The answer to this question could be important for the development of antipruritogenic drugs.

The International Classification of Headache Disorders II has undergone several revisions in attempts to meet the challenges of accurately diagnosing medication overuse headache and chronic migraine. Newly proposed revisions to the classification are likely to make diagnoses of all secondary headaches more straightforward than before.

Prospective research participants, patients and consumers are faced with a cacophony of information about the risks and benefits of brain scans. In light of new data on incidental findings, the professional community has a duty to explicitly and systematically encourage questions that promote rational decision-making and informed choice.

Collateral circulation is a potent predictor of revascularization and clinical outcomes after acute ischemic stroke, and various features of collateral flow may be seen with a variety of neuroimaging techniques. Maas et al. investigated assessment of collaterals on CT angiography source images as a predictive tool in ischemic stroke.

Radiotherapy is administered to most patients with low-grade glioma. A well-designed, retrospective study assessed neurocognitive function in patients who had received radiotherapy for low-grade gliomas versus those who had not. Cognitive function did not differ markedly between groups after 6 years, but by 12 years this feature was worse in the group that received radiotherapy.

The view of cognitive impairment in elderly individuals has evolved over the centuries, from a normal inevitable part of aging, through demonic possession and hardening of blood vessels, to Alzheimer disease. As Fotuhi et al. discuss in this article, individuals over 80 years of age rarely have 'pure Alzheimer disease' or 'pure vascular dementia'. The authors present a new framework, known as the dynamic polygon hypothesis, which reflects the complex interplay of factors that contribute to cognitive impairment in the oldest old.

Cavernous malformations (CMs) are vascular malformations that mainly occur in the brain. Many patients with such lesions are asymptomatic; however, individuals with CMs can present with seizures, focal neurological deficits or intracranial hemorrhage. In this Review, Batra and colleagues examine the pathology, natural history and imaging of CMs. Furthermore, the authors discuss the use of pharmacology, surgical resection and stereotactic radiosurgery in the management of such lesions.

In multiple sclerosis, the ability of clinicians to provide a prognosis for a patient and the design and interpretation of clinical trials both rely heavily on prognostic factors identified from systematic natural history studies. Degenhardt and colleagues outline their criteria for well-designed natural history studies in multiple sclerosis and review the prognostic factors identified from such investigations for the various forms of the disease.

Susac syndrome is characterized by a classic triad of symptoms-encephalopathy, branch retinal artery occlusions and hearing loss. Dörr and colleagues present a case of Susac syndrome that highlights how this condition can be easily missed when the triad of symptoms develops successively. Their findings suggest that optical coherence tomography, which detected axonal damage and a reduction of macular volume, could be a valuable complementary tool for the follow-up of patients.