Neurology March 2013 Volume 80 Issue 10

Objectives: Postinfectious neurologic syndromes (PINSs) of the CNS include heterogeneous disorders, sometimes relapsing. In this study, we aimed to a) describe the spectrum of PINSs; b) define predictors of outcome in PINSs; and c) assess the clinical/paraclinical features that help differentiate PINSs from multiple sclerosis (MS).Methods: In this prospective cohort study, adult inpatients with PINSs underwent extensive diagnostic assessment and therapeutic protocols at inclusion and during a minimum 2-year follow-up. We compared them with newly diagnosed, treatment-naive patients with MS, also prospectively recruited.Results: The study sample comprised 176 patients with PINSs aged 59.9 +/- 17.25 years (range: 18-80 years) divided into 2 groups: group 1 (CNS syndromes, 64%)-encephalitis, encephalomyelitis, or myelitis; and group 2 (CNS + peripheral nervous system [PNS] syndromes, 36%)-encephalomyeloradiculoneuritis or myeloradiculoneuritis. We observed the patients for 24 to 170 months (median 69 months). Relapses, almost invariably involving the spinal cord, occurred in 30.5%. PNS involvement was an independent risk factor for relapses (hazard ratio 2.8). The outcome was poor in 43% of patients; risk factors included older age, greater neurologic disability at onset, higher serum-CSF albumin percentage transfer, myelitis, and PNS involvement. Steroid resistance occurred in 30% of the patients, half of whom responded favorably to IV immunoglobulins. Compared with MS, PINSs were characterized by older age, lower tendency to relapse, and distinct CSF findings.Conclusions: The category of PINSs should be revised: most of the clinical variants have a poor prognosis and are not readily classifiable on the basis of current knowledge. PNS involvement has a critical role in relapses, which seem to affect the spine only.(C)2013 American Academy of Neurology

Objective: To track cognitive and language changes over time in patients with logopenic (lv-PPA) and semantic (sv-PPA) variants of primary progressive aphasia (PPA).Methods: Thirteen consecutive patients with lv-PPA and 11 patients with sv-PPA underwent yearly evaluation for a mean of 3 years. Nineteen patients (11 lv-PPA, 8 sv-PPA) had Pittsburgh compound B PET scans. Outcome variables included the Mini-Mental State Examination, Addenbrooke's Cognitive Examination-revised (ACE-R) with its 5 cognitive subscores, and 3 language tasks based on single word processing. Mixed-models regressions were used to estimate the differential rate of decline between cohorts.Results: Despite equivalent level of baseline impairment, the lv-PPA cohort showed more rapid and generalized cognitive decline that involved nonverbal domains, with the majority of cases meeting criteria for dementia within 12 months. By contrast, cognitive changes in the sv-PPA cohort were slower and remained confined to verbally mediated tasks.Conclusions: Patients with lv-PPA are on the cusp of global dementia that typically develops quite rapidly, contrasting with the long period of circumscribed semantic impairment seen in patients with sv-PPA. The ACE-R appears capable of monitoring decline, which is relevant to therapeutic trials.(C)2013 American Academy of Neurology

Objective: To determine the association of conventional cardiovascular risk factors, markers of platelet activation, and thrombogenic blood-borne microvesicles with white matter hyperintensity (WMH) load and progression in recently menopausal women.Methods: Women (n = 95) enrolled in the Mayo Clinic Kronos Early Estrogen Prevention Study underwent MRI at baseline and at 18, 36, and 48 months after randomization to hormone treatments. Conventional cardiovascular risk factors, carotid intima-medial thickness, coronary arterial calcification, plasma lipids, markers of platelet activation, and thrombogenic microvesicles were measured at baseline. WMH volumes were calculated using a semiautomated segmentation algorithm based on fluid-attenuated inversion recovery MRI. Correlations of those parameters with baseline WMH and longitudinal change in WMH were adjusted for age, months past menopause, and APOE [epsilon]4 status in linear regression analysis.Results: At baseline, WMH were present in all women. The WMH to white matter volume fraction at baseline was 0.88% (0.69%, 1.16%). WMH volume increased by 122.1 mm3 (95% confidence interval: -164.3, 539.5) at 36 months (p = 0.003) and 155.4 mm3 (95% confidence interval: -92.13, 599.4) at 48 months (p < 0.001). These increases correlated with numbers of platelet-derived and total thrombogenic microvesicles at baseline (p = 0.03).Conclusion: Associations of platelet-derived, thrombogenic microvesicles at baseline and increases in WMH suggest that in vivo platelet activation may contribute to a cascade of events leading to development of WMH in recently menopausal women.(C)2013 American Academy of Neurology

Objectives: To identify corticobulbar tract changes that may predict chronic dysarthria in young people who have sustained a traumatic brain injury (TBI) in childhood using diffusion MRI tractography.Methods: We collected diffusion-weighted MRI data from 49 participants. We compared 17 young people (mean age 17 years, 10 months; on average 8 years postinjury) with chronic dysarthria who sustained a TBI in childhood (range 3-16 years) with 2 control groups matched for age and sex: 1 group of young people who sustained a traumatic injury but had no subsequent dysarthria (n = 15), and 1 group of typically developing individuals (n = 17). We performed tractography from spherical seed regions within the precentral gyrus white matter to track: 1) the hand-related corticospinal tract; 2) the dorsal corticobulbar tract, thought to correspond to the lips/larynx motor representation; and 3) the ventral corticobulbar tract, corresponding to the tongue representation.Results: Despite widespread white matter damage, radial (perpendicular) diffusivity within the left dorsal corticobulbar tract was the best predictor of the presence of dysarthria after TBI. Diffusion metrics in this tract also predicted speech and oromotor performance across the whole group of TBI participants, with additional significant contributions from ventral speech tract volume in the right hemisphere.Conclusion: An intact left dorsal corticobulbar tract seems crucial to the normal execution of speech long term after acquired injury. Examining the speech-related motor pathways using diffusion-weighted MRI tractography offers a promising prognostic tool for people with acquired, developmental, or degenerative neurologic conditions likely to affect speech.(C)2013 American Academy of Neurology

Objectives: To prospectively assess 1) the incidence and duration of postdural puncture headache (PDPH) in migraineurs and healthy subjects; 2) the associated risk factors; and 3) the risk of getting a migraine attack shortly before or after lumbar puncture (LP).Methods: As part of an extensive biochemical migraine research program, we assessed the occurrence, duration, and characteristics of PDPH in 160 migraineurs and 53 age- and sex-matched healthy controls. In addition, we evaluated potential risk factors for PDPH as well as the risk of developing a migraine attack before or after LP.Results: In total, 64 of 199 subjects (32.2%) developed PDPH. Young age, low body mass index, severe headache immediately after LP, and sitting sampling position, but not being a migraineur, increased the risk of PDPH (all p < 0.05). Duration of PDPH was prolonged by history of depression, sitting sampling position, high perceived stress during the LP procedure, and multiple LP efforts (all p < 0.05). Migraine attacks were less likely to occur before or shortly after LP.Conclusions: Migraineurs are not at increased risk of developing PDPH. PDPH duration is similar in migraineurs and age- and sex-matched controls. LP does not trigger migraine attacks, and the stress of an upcoming LP might even have a protective effect against onset of migraine attacks.(C)2013 American Academy of Neurology

Objective: To review the discoveries underpinning the introduction of cerebral PET scanning and highlight its modern applications.Background: Important discoveries in neurophysiology, brain metabolism, and radiotracer development in the post-World War II period provided the necessary infrastructure for the first cerebral PET scan.Methods: A complete review of the literature was undertaken to search for primary and secondary sources on the history of PET imaging. Searches were performed in PubMed, Google Scholar, and select individual journal Web sites. Written autobiographies were obtained through the Society for Neuroscience Web site at www.sfn.org. A reference book on the history of radiology, Naked to the Bone, was reviewed to corroborate facts and to locate references. The references listed in all the articles and books obtained were reviewed.Results: The neurophysiologic sciences required to build cerebral PET imaging date back to 1878. The last 60 years have produced an evolution of technological advancements in brain metabolism and radiotracer development. These advancements facilitated the development of modern cerebral PET imaging. Several key scientists were involved in critical discoveries and among them were Angelo Mosso, Charles Roy, Charles Sherrington, John Fulton, Seymour Kety, Louis Sokoloff, David E. Kuhl, Gordon L. Brownell, Michael Ter-Pogossian, Michael Phelps, and Edward Hoffman.Conclusions: Neurophysiology, metabolism, and radiotracer development in the postwar era synergized the development of the technology necessary for cerebral PET scanning. Continued use of PET in clinical trials and current developments in PET-CT/MRI hybrids has led to advancement in diagnosis, management, and treatment of neurologic disorders.(C)2013 American Academy of Neurology