| In Focus |
spotlight on the may 14 issue.
- Gross, Robert, MD, PhD, Editor-in-Chief, Neurology. Pages: 1821
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| Editorial |
changes in brain organization after tbi: evidence from functional mri findings.
- Zhou, Yongxia, Lui, Yvonne. Pages: 1822-1823
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human culture and the future dementia epidemic: crisis or crossroads?.
- Whalley, Lawrence, Smyth, Kathleen. Pages: 1824-1825
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| Article |
traumatic brain injury impairs small-world topology.
- Pandit, Anand, Expert, Paul, Lambiotte, Renaud, Bonnelle, Valerie, Leech, Robert, Turkheimer, Federico, Sharp, David. Pages: 1826-1833
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Objective: We test the hypothesis that brain networks associated with cognitive function shift away from a "small-world" organization following traumatic brain injury (TBI).Methods: We investigated 20 TBI patients and 21 age-matched controls. Resting-state functional MRI was used to study functional connectivity. Graph theoretical analysis was then applied to partial correlation matrices derived from these data. The presence of white matter damage was quantified using diffusion tensor imaging.Results: Patients showed characteristic cognitive impairments as well as evidence of damage to white matter tracts. Compared to controls, the graph analysis showed reduced overall connectivity, longer average path lengths, and reduced network efficiency. A particular impact of TBI is seen on a major network hub, the posterior cingulate cortex. Taken together, these results confirm that a network critical to cognitive function shows a shift away from small-world characteristics.Conclusions: We provide evidence that key brain networks involved in supporting cognitive function become less small-world in their organization after TBI. This is likely to be the result of diffuse white matter damage, and may be an important factor in producing cognitive impairment after TBI.(C)2013 American Academy of Neurology
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newly diagnosed atrial fibrillation linked to wake-up stroke and tia: hypothetical implications.
- Riccio, Patricia, Klein, Francisco, Pagani Cassara, Fatima, Munoz Giacomelli, Francisco, Gonzalez Toledo, Maria, Racosta, Juan, Delfitto, Matias, Roberts, Eleanor, Bahit, M., Sposato, Luciano, MD, MBA. Pages: 1834-1840
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Background: Based on the higher frequency of paroxysmal atrial fibrillation during night and early morning hours, we sought to analyze the association between newly diagnosed atrial fibrillation and wake-up ischemic cerebrovascular events.Methods: We prospectively assessed every acute ischemic stroke and TIA patient admitted to our hospital between 2008 and 2011. We used a forward step-by-step multiple logistic regression analysis to assess the relationship between newly diagnosed atrial fibrillation and wake-up ischemic stroke or TIA, after adjusting for significant covariates.Results: The study population comprised 356 patients, 274 (77.0%) with a diagnosis of acute ischemic stroke and 82 (23.0%) with TIA. A total of 41 (11.5%) of these events occurred during night sleep. A newly diagnosed atrial fibrillation was detected in 27 patients of 272 without known atrial fibrillation (9.9%). We found an independent association between newly diagnosed atrial fibrillation and wake-up ischemic stroke and TIA (odds ratio 3.6, 95% confidence interval 1.2-7.7, p = 0.019).Conclusions: The odds of detecting a newly diagnosed atrial fibrillation were 3-fold higher among wake-up cerebrovascular events than among non-wake-up events. The significance of this independent association between newly diagnosed atrial fibrillation and wake-up ischemic stroke and TIA and the role of other comorbidities should be investigated in future studies.(C)2013 American Academy of Neurology
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white matter microstructure deteriorates across cognitive stages in parkinson disease.
- Melzer, Tracy, Watts, Richard, MacAskill, Michael, Pitcher, Toni, Livingston, Leslie, Keenan, Ross, Dalrymple-Alford, John, Anderson, Tim, FRACP, MD. Pages: 1841-1849
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Objectives: To characterize different stages of Parkinson disease (PD)-related cognitive decline using diffusion tensor imaging (DTI) and investigate potential relationships between cognition and microstructural integrity of primary white matter tracts.Methods: Movement Disorder Society criteria were used to classify 109 patients with PD as having normal cognition (PD-N, n = 63), mild cognitive impairment (PD-MCI, n = 28), or dementia (PD-D, n = 18), and were compared with 32 matched controls. DTI indices were assessed across groups using tract-based spatial statistics, and multiple regression was used to assess association with cognitive and clinical measures.Results: Relative to controls, PD-N showed some increased mean diffusivity (MD) in corpus callosum, but no significantly decreased fractional anisotropy (FA). Decreased FA and increased MD were identified in PD-MCI and PD-D relative to controls. Only small areas of difference were observed in PD-MCI and PD-D compared with PD-N, while DTI metrics did not differ significantly between PD-MCI and PD-D. Executive function, attention, memory, and a composite measure of global cognition were associated with MD, primarily in anterior white matter tracts; only attention was associated with FA. These differences were independent of white matter hyperintensity load, which was also associated with cognition in PD.Conclusions: PD is associated with spatially restricted loss of microstructural white matter integrity in patients with relatively normal cognition, and these alterations increase with cognitive dysfunction. Functional impairment in executive function, attention, and learning and memory appears associated with microstructural changes, suggesting that tract-based spatial statistics provides an early marker for clinically relevant cognitive impairment in PD.(C)2013 American Academy of Neurology
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serotonergic loss in motor circuitries correlates with severity of action-postural tremor in pd.
- Loane, Clare, BSc, MSc, Wu, Kit, Bain, Peter, MD, FRCP, Brooks, David, MD, DSc, FRCP, FMedSci, Piccini, Paola, MD, PhD, Politis, Marios, MD, MSc. Pages: 1850-1855
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Objective: The underlying pathophysiology of tremor in Parkinson disease (PD) is unclear; however, it is known that tremor does not appear to be as responsive to dopaminergic medication as bradykinesia or rigidity. It is suggested that serotonergic dysfunction could have a role in tremor development.Methods: Using 11C-DASB PET, a marker of serotonin transporter binding, and clinical observations, we have investigated function of serotonergic terminals in 12 patients with tremor-predominant and 12 with akinetic-rigid PD. Findings were compared with those of 12 healthy controls.Results: Reductions of 11C-DASB in caudate, putamen, and raphe nuclei significantly correlated with tremor severity on posture and action, but not with resting tremor. The tremor-predominant group also showed reductions of 11C-DASB in other regions involved in motor circuitry, including the thalamus and Brodmann areas 4 and 10.Conclusions: Our findings support a role for serotonergic dysfunction in motor circuitries in the generation of postural tremor in PD.(C)2013 American Academy of Neurology
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the midbrain to pons ratio: a simple and specific mri sign of progressive supranuclear palsy.
- Massey, Luke, Jager, Hans, MD, FRCR, Paviour, Dominic, O'Sullivan, Sean, PhD, MRCPI, Ling, Helen, BScMed, BMBS, Williams, David, Kallis, Constantinos, Holton, Janice, PhD, FRCPath, Revesz, Tamas, MD, FRCPath, Burn, David, MD, FRCP, Yousry, Tarek, Dr med Habil, FRCR, Lees, Andrew, MD, FRCP, Fox, Nick, MD, FRCP, Micallef, Caroline, MD, FRCR. Pages: 1856-1861
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Objectives: MRI-based measurements used to diagnose progressive supranuclear palsy (PSP) typically lack pathologic verification and are not easy to use routinely. We aimed to develop in histologically proven disease a simple measure of the midbrain and pons on sagittal MRI to identify PSP.Methods: Measurements of the midbrain and pontine base on midsagittal T1-weighted MRI were performed in confirmed PSP (n = 12), Parkinson disease (n = 2), and multiple system atrophy (MSA) (n = 7), and in controls (n = 8). Using receiver operating characteristic curve analysis, cutoff values were applied to a clinically diagnosed cohort of 62 subjects that included PSP (n = 21), Parkinson disease (n = 10), MSA (n = 10), and controls (n = 21).Results: The mean midbrain measurement of 8.1 mm was reduced in PSP (p < 0.001) with reduction in the midbrain to pons ratio (PSP smaller than MSA; p < 0.001). In controls, the mean midbrain ratio was approximately two-thirds of the pontine base, in PSP it was <52%, and in MSA the ratio was greater than two-thirds. A midbrain measurement of <9.35 mm and ratio of 0.52 had 100% specificity for PSP. In the clinically defined group, 19 of 21 PSP cases (90.5%) had a midbrain measurement of <9.35 mm.Conclusions: We have developed a simple and reliable measurement in pathologically confirmed disease based on the topography of atrophy in PSP with high sensitivity and specificity that may be a useful tool in the clinic.(C)2013 American Academy of Neurology
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effect of 4-aminopyridine on vision in multiple sclerosis patients with optic neuropathy.
- Horton, Lindsay, Conger, Amy, Conger, Darrel, Remington, Gina, Frohman, Teresa, Frohman, Elliot, MD, PhD, Greenberg, Benjamin, MD, MHS. Pages: 1862-1866
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Objective: The objective of this randomized, double-blind, placebo-controlled, crossover study was to examine if patients with optic neuropathy would derive a therapeutic benefit from 4-aminopyridine (4-AP) treatment. Furthermore, the study was intended to determine if patients with certain P100 latencies or retinal nerve fiber layer (RNFL) measures would be more likely to respond to therapy.Methods: Patients were enrolled in a randomized, placebo-controlled, double-blind, crossover study of 10 weeks duration. Patients underwent visual evoked potentials (VEP), optical coherence tomography (OCT), and visual acuity before starting 5 weeks of either placebo or 4-AP. After 5 weeks, they completed a second evaluation (VEP, OCT, and visual acuity) and were crossed over between treatment arms. Five weeks later, they had their final evaluation. All investigators were blinded to treatment arm until after data analysis.Results: On average, patients had faster P100s on 4-AP when compared to placebo. A subset of patients had distinct responses to 4-AP as measured by improvements in visual acuity. Finally, eyes with an RNFL measure between 60 and 80 [micro]m had the highest response rate.Conclusions: 4-Aminopyridine is useful for improving vision in patients with demyelinating optic neuropathy. Future clinical trials may be able to enrich a patient population for potential responders using OCT and VEP measures. Selecting patients for future trials should use RNFL measures as part of inclusion/exclusion criteria.Classification of evidence: This study provides Class IV evidence supporting the use of 4-AP in certain patients with optic neuropathy to improve visual function (patients with RNFL between 60 and 80 [micro]m).(C)2013 American Academy of Neurology
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cerebellar learning distinguishes inflammatory neuropathy with and without tremor.
- Schwingenschuh, Petra, Saifee, Tabish, Katschnig-Winter, Petra, Reilly, Mary, Lunn, Michael, Manji, Hadi, Aguirregomozcorta, Maria, Schmidt, Reinhold, Bhatia, Kailash, Rothwell, John, Edwards, Mark. Pages: 1867-1873
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Objectives: This study aims to investigate if patients with inflammatory neuropathies and tremor have evidence of dysfunction in the cerebellum and interactions in sensorimotor cortex compared to nontremulous patients and healthy controls.Methods: A prospective data collection study investigating patients with inflammatory neuropathy and tremor, patients with inflammatory neuropathy without tremor, and healthy controls on a test of cerebellar associative learning (eyeblink classical conditioning), a test of sensorimotor integration (short afferent inhibition), and a test of associative plasticity (paired associative stimulation). We also recorded tremor in the arms using accelerometry and surface EMG.Results: We found impaired responses to eyeblink classical conditioning and paired associative stimulation in patients with neuropathy and tremor compared with neuropathy patients without tremor and healthy controls. Short afferent inhibition was normal in all groups.Conclusions: Our data strongly suggest impairment of cerebellar function is linked to the production of tremor in patients with inflammatory neuropathy.(C)2013 American Academy of Neurology
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motor neuron involvement in multisystem proteinopathy: implications for als.
- Benatar, Michael, MBChB, DPhil, Wuu, Joanne, Fernandez, Catalina, Weihl, Conrad, MD, PhD, Katzen, Heather, Steele, Julie, Oskarsson, Bjorn, Taylor, J., Paul MD, PhD. Pages: 1874-1880
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Objective: To explore the putative connection between inclusion body myopathy, Paget disease, frontotemporal dementia (IBMPFD) and motor neuron disease (MND).Methods: Clinical, genetic, and EMG characterization of 17 patients from 8 IBMPFD families.Results: Limb weakness was the most common clinical manifestation (present in 15 patients, median onset age 38 years, range 25-52), with unequivocal evidence of upper motor neuron dysfunction in 3. EMG, abnormal in all 17, was purely neurogenic in 4, purely myopathic in 6, and mixed neurogenic/myopathic in 7. Cognitive/behavioral impairment was detected in at least 8. Mutations in VCP (R155H, R159G, R155C) were identified in 6 families, and in hnRNPA2B1 (D290V) in another family. The genetic cause in the eighth family has not yet been identified.Conclusion: Mutations in at least 4 genes may cause IBMPFD, and its phenotypic spectrum extends beyond IBM, Paget disease, and frontotemporal dementia (FTD). Weakness, the most common and disabling manifestation, may be caused by muscle disease or MND. The acronym IBMPFD is, therefore, insufficient to describe disorders due to VCP mutations or other recently identified IBMPFD-associated genes. Instead, we favor the descriptor multisystem proteinopathy (MSP), which encompasses both the extended clinical phenotype and the previously described prominent pathologic feature of protein aggregation in affected tissues. The nomenclature MSP1, MSP2, and MSP3 may be used for VCP-, HNRNPA2B1-, and HNRNPA1-associated disease, respectively. Genetic defects in MSP implicate a range of biological mechanisms including RNA processing and protein homeostasis, both with potential relevance to the pathobiology of more common MNDs such as amyotrophic lateral sclerosis (ALS) and providing an additional link between ALS and FTD.(C)2013 American Academy of Neurology
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sensitivity and specificity of ftdc criteria for behavioral variant frontotemporal dementia.
- Harris, Jennifer, Gall, Claire, MB, ChB, Thompson, Jennifer, Richardson, Anna, MB, ChB, Neary, David, du Plessis, Daniel, MB, ChB, Pal, Piyali, Mann, David, Snowden, Julie, Jones, Matthew. Pages: 1881-1887
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Objective: We aimed to assess sensitivity and specificity of the updated criteria for behavioral variant frontotemporal dementia (bvFTD) based on a large autopsy-confirmed cohort of patients with dementia.Methods: Two hundred thirty-nine consecutive pathologically confirmed dementia patients, clinically assessed in a specialist cognitive unit were identified. Patients with predominant aphasia, motor disorders, or insufficient clinical information were excluded. Frontotemporal Dementia Consensus criteria were applied to anonymized clinical data taken from patients' initial assessment by raters who were blinded to clinical and pathologic diagnosis.Results: The final study cohort comprised 156 patients with predominantly early-onset dementia. The updated criteria for possible bvFTD had a sensitivity of 95% and specificity of 82%. Probable bvFTD criteria had a sensitivity of 85% and specificity of 95%. False positives were predominantly patients with presenile Alzheimer disease.Conclusion: Revised diagnostic criteria show encouragingly high sensitivity and specificity when applied to patients with early-onset dementia. They therefore provide a useful tool both for specialist researchers and general clinicians. There is a need for further prospective studies of sensitivity and specificity involving a broader spectrum of patients with dementia.(C)2013 American Academy of Neurology
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twenty-year changes in dementia occurrence suggest decreasing incidence in central stockholm, sweden.
- Qiu, Chengxuan, von Strauss, Eva, Backman, Lars, Winblad, Bengt, MD, PhD, Fratiglioni, Laura, MD, PhD. Pages: 1888-1894
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Objective: To explore whether prevalence, survival, and incidence of dementia have changed from 1987-1994 to 2001-2008 in Stockholm, Sweden.Methods: This study is based on 2 cross-sectional surveys of people aged 75 years or over conducted in central Stockholm: the Kungsholmen Project (KP) (1987-1989, n = 1,700) and the Swedish National study on Aging and Care in Kungsholmen (SNAC-K) (2001-2004, n = 1,575). In both surveys we diagnosed dementia according to DSM-III-R criteria, following the identical diagnostic procedure. Death certificates were used to determine survival status of KP participants as of December 1994 and SNAC-K participants as of June 2008. We used logistic and Cox models to compare prevalence and survival, controlling for major confounders. We inferred incidence of dementia according to its relationship with prevalence and survival.Results: At baseline, 225 subjects in KP and 298 in SNAC-K were diagnosed with dementia. The age- and sex-standardized prevalence of dementia was 17.5% (12.8% in men; 19.2% in women) in KP and 17.9% (10.8% in men; 20.5% in women) in SNAC-K. The adjusted odds ratio of dementia in SNAC-K vs KP was 1.17 (95% confidence interval 0.95-1.46). The multiadjusted hazard ratio of death in SNAC-K vs KP was 0.71 (0.57-0.88) in subjects with dementia, 0.68 (0.59-0.79) in those without dementia, and 0.66 (0.59-0.74) in all participants.Conclusions: Prevalence of dementia was stable from the late 1980s to the early 2000s in central Stockholm, Sweden, whereas survival of patients with dementia increased. These results suggest that incidence of dementia may have decreased during this period.(C)2013 American Academy of Neurology
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sodium valproate use is associated with reduced parietal lobe thickness and brain volume.
- Pardoe, Heath, Berg, Anne, Jackson, Graeme. Pages: 1895-1900
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Objective: We hypothesized that total brain volume, white matter volume, and lobar cortical thickness would be different in epilepsy patients. We studied valproate relative to nonvalproate by using patients with epilepsy and healthy controls.Methods: Patients with focal intractable epilepsy from a tertiary epilepsy center were the primary group for analysis. A confirmatory analysis was carried out in an independent group of subjects imaged as part of a community-based study of childhood-onset epilepsy. Total brain volume; white matter volume; and frontal, parietal, occipital, and temporal lobe thickness were measured by processing whole-brain T1-weighted MRI using FreeSurfer 5.1.Results: Total brain volume, white matter volume, and parietal thickness were reduced in the valproate group relative to controls and nonvalproate users (valproate, n = 9; nonvalproate, n = 27; controls, n = 45; all male). These findings were confirmed in an independent group (valproate, n = 7; nonvalproate, n = 70; controls, n = 20; all male).Conclusions: Sodium valproate use in epilepsy is associated with parietal lobe thinning, reduced total brain volume, and reduced white matter volume.Level of evidence: This study provides Class IV evidence that use of valproate in epilepsy is associated with reduced parietal lobe thickness, total brain volume, and white matter volume.(C)2013 American Academy of Neurology
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| Views & Reviews |
subcortical epilepsy?.
- Badawy, Radwa, MBBCh, PhD, Lai, Alan, B Eng, PhD, Vogrin, Simon, Cook, Mark, FRACP, PhD. Pages: 1901-1907
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In the past, the cortex has for the most part been considered to be the site of seizure origin in the different forms of epilepsy. Findings from histopathologic, electrophysiologic, and brain imaging studies now provide ample evidence demonstrating that like normal cerebral function, epileptic seizures involve widespread network interactions between cortical and subcortical structures. These studies show that different forms of generalized and focal epileptiform discharges and seizures engage various subcortical structures in varying ways. This interaction has been the subject of many reviews and is not the focus of the current work. The aim of this review is to examine the evidence suggesting the possibility for some of the subcortical structures to initiate seizures independently and the clinical implications of this.(C)2013 American Academy of Neurology
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| Clinical/Scientific Notes |
recurrent myoglobinuria and deranged acylcarnitines due to a mutation in the mtdna mt-co2 gene.
- Vissing, Christoffer, Duno, Morten, Olesen, Jess, Rafiq, Jabin, Risom, Lotte, Christensen, Ernst, Wibrand, Flemming, Vissing, John, MD, PhD. Pages: 1908-1910
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| NeuroImages |
carotid dissection following a generalized tonic-clonic seizure.
- Child, Nicholas, Cascino, Gregory. Pages: 1911
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| Resident and Fellow Section |
child neurology: zellweger syndrome.
- Lee, Paul, MD, PhD, Raymond, Gerald. Pages: e207-e210
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clinical reasoning: a 25-year-old man with headaches and collapse.
- Syed, Sana, Westwood, Andrew, MD, MRCP. Pages: e211-e214
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teaching neuroimages: t2 hyperintensities in neurofibromatosis type 1.
- Ostendorf, Adam, McKinstry, Robert, MD, PhD, Shimony, Joshua, MD, PhD, Gutmann, David, MD, PhD. Pages: e215-e216
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teaching neuroimages: spontaneous tension pneumo-hydrocephalus may be related to otitis media and temporal bony defect.
- Yu, Shao-Hua, Peng, Chian-Ze, Cheng, Kuo-Wei, How, Chorng-Kuang. Pages: e217
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