The editorial advisory board of Neurology Today, an official publication of the American Academy of Neurology, has picked a list of what they consider to be the most important papers of 2011. I’ve summarized their picks below. While others may have a different opinion of 2011’s most important research, this does allow for a quick review of recent progress in the rapidly advancing field of neurology.
1) In November, the British medical journal Lancet published evidence that electroencephalogram (EEG) studies done on patients considered to be in a vegetative state actually demonstrated some degree of awareness. This supplemented studies done using functional MRI, but uses a technique that is much more portable and wide-spread. These findings may have both major ethical and practical implications.
2) A new genetic abnormality on chromosome 9 was found in patients with familial frontotemporal dementia and amyotrophic lateral sclerosis. While it could be years before this finding translates into new treatments for these diseases, this paper provides an important new direction for further research.
3) An article in the Journal of the American Medical Association explored a new computerized method of analyzing electronic medical records to prevent complications from surgery. This demonstrates the growing importance and possibilities of electronic health databases.
4) The brain contains both gray matter and white matter. Gray matter predominantly consists of the nerve cells themselves, whereas white matter involves glial cells that wrap around the nerve cells with a substance called myelin. Multiple sclerosis (MS) has been traditionally thought of as only affecting white matter, though evidence has been accumulating that gray matter is also involved. A paper published in the New England Journal of Medicine gives even more evidence that MS involves gray matter even early in the disease, which will lead to further reconsideration of how this disease works.
5) The seizures of epilepsy are problematic enough, but epilepsy can also be life-threatening in cases of Sudden Unexplained Death in Epilepsy (SUDEP). Researchers discovered that even in patients whose seizures continue despite already being on multiple medications, adding further anti-epileptic medication can significantly reduce the risk of SUDEP. This may change how neurologists manage these so-called "refractory" seizures.
6) When the arteries in the brain narrow due to atherosclerosis, the resulting loss of blood flow can cause a stroke. Stenting involves placing a kind of tube, called a stent, into the artery to open it and allow blood to flow. Sounds like a good idea, right? The problem is that a study has now shown that it doesn't work as well as medical therapies such as aspirin and plavix, perhaps due to risks involved with the procedure. In fact, the study was stopped early due to the dangers in the group receiving stents!
7) Atrial fibrillation is an abnormal heart rhythm that can cause clots to form in the heart. These clots can then travel up through the neck and lodge in the arteries of the brain, leading to stroke. For this reason, many patients with atrial fibrillation are placed on strong blood thinners such as warfarin (also called Coumadin) or dabigitran (also called Pradaxa). A new medication named apixaban has also joined the ranks of these medications, with lower risks of bleeding than warfarin. How apixiban compares to some of its competitors, including dabigitran, is still under hot debate in a pharmacological race for the best anti-coagulant.
8) One of the most important reasons people go to the doctor is for help with pain. If this pain is due to a problem with the nerves, it is called neuropathic. Understanding how nerves signal painful messages to the brain can help lead to better pain control in the future. New ion channels have been described which are involved with neuropathic pain: mice without these ion channels do not develop the hypersensitivity to normal touch, heat and cold that is seen with neuropathic pain, although their normal sensation was preserved. If this is found to be true in humans as well, a new target will have been discovered for drugs that can help people with debilitating neuropathic pain.
9) Intracranial hypertension is a feared complication in patients who suffer from severe traumatic brain injury (TBI). When pressure in the skull gets too high as a result of swelling in the brain, brain tissue can be severely damaged with often-lethal results. To relieve this pressure, neurosurgeons will sometimes perform a craniectomy, in which part of the skull is removed to allow room for the brain to swell. A recent study showed that aggressive craniectomy involving both sides of the head in patients with severe TBI improved the pressure measurements, but did not improve survival or neurological function in six months. This study does not mean that there are not situations in which craniectomy is called for. Only one type of craniectomy was evaluated, and none of the cases of intracranial hypertension were due to blood accumulating under the skull. In these cases, and perhaps others, the procedure may still be indicated. Further studies are required to see when craniectomy is helpful in severe TBI.
This list by no means gives a full listing of all the interesting discoveries in neurology within the last year. Furthermore, it's hard to say what will become considered truly important in the future. Some of the research above may come to nothing, while other findings not mentioned may lead to great leaps of innovation in years to come.
Bernat, JL, T Bird, NA Busis, J Corboy, AS Feigen, JA French, JC Grotta, V Hachinski, DJ Iverson, AL Oaklander, KN Sheth. Best Papers of 2011: Picks from the Neurology Today Editorial Advisory Board. Neurology Today 2012 12(1):1-9
Cruse, D, S Chennu, C Chatelle, et al. Bedside detection of awareness in the vegetative state: A cohort study. Lancet 2011; E-pub 2011 Nov. 9.
Renton AE, E Majounie, A Waite, et al. A hexanucleotide repeat expansion in C9ORF72 is the cause of chromosome 9p21-linked ALS-FTD. Neuron 2011;72(2): 257-68. E-pub 2011 Sep 21.
DeJesus-Hernandez M, Mackenzie IR, Boeve BF, et al. Expanded GGGGCC hexanucleotide repeat in noncoding region of C9ORF72 causes chromosome 9p-linked FTD and ALS. Neuron 2011;72(2):245-256. E-pub 2011 Sep 21.
Murff HJ, F FitzHenry, T Speroff, et al. Automated identification of postoperative complications within an electronic medical record using natural language processing. JAMA 2011;306(8):848-855.
Lucchinetti CF, BFG Popescu, RM Ransohoff, et al. Inflammatory cortical demyelination in early multiple sclerosis. New England Journal of Medicine 2011; 365:2188-2197.
Ryvlin P, M Cucherat, S Rheims. Risk of sudden unexpected death in epilepsy in patients given adjunctive antiepileptic treatment for refractory seizures: A meta-analysis of placebo-controlled randomised trials. Lancet Neurology 2011;10(11):961-968.
Chimowitz MI, MJ Lynn, CP Derdeyn, et al. Stenting versus aggressive medical therapy for intracranial arterial stenosis. New England Journal of Medicine 2011;365:993-1003.
Granger CB, Alexander JH, Wallentin L, et al, for the ARISTOTLE Committees and Investigators. Apixaban versus warfarin in patients with atrial fibrillation. New England Journal of Medicine 2011;365:981-992.
Connolly SJ, Eikelboom J, Yusuf S, et al, for the AVERROES Sterring Committee and Investigators. Apixaban in patients with atrial fibrillation. New England Journal of Medicine 2011; 364(9): 806-817.
Emery EC, Young GT, McNaughton PA, et al. HCN2 ion channels play a central role in inflammatory and neuropathic pain. Science 2011; 333(6048):1462-1466.
Cooper DJ, Rosenfeld JV, Wolfe R, et al, for the DECRA Trial Investigators and the Australian and New Zealand Intensive Care Society Clinical Trials Group. New England Journal of Medicine 2011; 364: 1493-1502.