Neurology May 2012 Volume 78 Issue 19

Objective: To investigate whether dementia incidence has changed over the last 2 decades.Methods: We compared dementia incidence in 2 independent subcohorts of persons aged 60-90 years from the Rotterdam Study, a population-based cohort study. The first subcohort started in 1990 (n = 5,727), the second in 2000 (n = 1,769). Participants were dementia-free at baseline and followed for at maximum 5 years. We calculated age-adjusted dementia incidence rates for the 2 subcohorts in total, in 10-year age strata, and for men and women separately. We also compared mortality rates, differences in prevalence of vascular risk factors, and medication use. Finally, we compared brain volumes and the extent of cerebral small vessel disease in participants who underwent brain imaging 5 years after the baseline examinations.Results: In the 1990 subcohort (25,696 person-years), 286 persons developed dementia, and in the 2000 subcohort (8,384 person-years), 49 persons. Age-adjusted dementia incidence rates were consistently, yet nonsignificantly, lower in the 2000 subcohort in all strata, reaching borderline significance in the overall analysis (incidence rate ratio 0.75, 95% confidence interval [CI] 0.56-1.02). Mortality rates were also lower in the 2000 subcohort (rate ratio 0.63, 95% CI 0.52-0.77). The prevalence of hypertension and obesity significantly increased between 1990 and 2000. This was paralleled by a strong increase in use of antithrombotics and lipid-lowering drugs. Participants in 2005-2006 had larger total brain volumes (p < 0.001) and less cerebral small vessel disease (although nonsignificant in men) than participants in 1995-1996.Conclusions: Although the differences in dementia incidence were nonsignificant, our study suggests that dementia incidence has decreased between 1990 and 2005.GLOSSARY: CI: confidence intervalDSM-III-R: Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revisedGMS: Geriatric Mental StateIRR: incidence rate ratioMMSE: Mini-Mental State ExaminationWML: white matter lesion(C)2012 American Academy of Neurology

Objective: To investigate medical decision-making capacity (MDC) in patients with acute traumatic brain injury (TBI) across a range of injury severity.Methods: We evaluated MDC cross-sectionally 1 month after injury in 40 healthy controls and 86 patients with TBI stratified by injury severity (28 mild [mTBI], 15 complicated mild [cmTBI], 43 moderate/severe [msevTBI]). We compared group performance on the Capacity to Consent to Treatment Instrument and its 5 consent standards (expressing choice, reasonable choice, appreciation, reasoning, understanding). Capacity impairment ratings (no impairment, mild/moderate impairment, severe impairment) on the consent standards were also assigned to each participant with TBI using cut scores referenced to control performance.Results: One month after injury, the mTBI group performed equivalently to controls on all consent standards. In contrast, the cmTBI group was impaired relative to controls on the understanding standard. No differences emerged between the mTBI and cmTBI groups. The msevTBI group was impaired on almost all standards relative to both control and mTBI groups, and on the understanding standard relative to the cmTBI group. Capacity compromise (mild/moderate or severe impairment ratings) on the 3 clinically complex standards (understanding, reasoning, appreciation) occurred in 10%-30% of patients with mTBI, 50% of patients with cmTBI, and 50%-80% of patients with msevTBI.Conclusions: One month following injury, MDC is largely intact in patients with mTBI, but is impaired in patients with cmTBI and msevTBI. Impaired MDC is prevalent in acute TBI and is strongly related to injury severity.GLOSSARY: CCTI: Capacity to Consent to Treatment InstrumentcmTBI: complicated mild traumatic brain injuryGCS: Glasgow Coma ScaleGOAT: Galveston Orientation and Amnesia TestLOC: loss of consciousnessMDC: medical decision-making capacitymsevTBI: moderate/severe traumatic brain injurymTBI: mild traumatic brain injuryPTA: post-traumatic amnesiaTBI: traumatic brain injuryUAB: University of Alabama at Birmingham(C)2012 American Academy of Neurology

Objective: To evaluate whether the distribution of seizures throughout the day is the same in ambulatory outpatient conditions as observed in inpatient conditions.Methods: We analyzed records from consecutive patients who had ambulatory EEG monitoring for 24 to 72 hours using Digitrace(TM) EEG recording system. The participants maintained a log of symptoms and signaled the time when symptoms occurred by pushing an event button. Additionally, automatic seizure and spike detection was performed on each record using Persyst detection software.Results: Of 831 reports analyzed, 44 unique patients had definite ictal events. There were a total of 129 electrographic seizures (34 subclinical) with timing as follows: frontal (31), temporal (71), and generalized, posterior, or central (27). Frontal lobe seizures occurred more frequently between 12 AM and 12 PM as compared to temporal lobe seizures, which occurred more frequently between 12 PM and 12 AM (p = 0.017). Analysis of frontal lobe seizures revealed a cluster of 10 seizures centered at 6:33 AM (range 5:15-7:30 AM) with p = 0.0064. Temporal lobe seizures had a cluster of 24 seizures centered at 8:49 PM (range 6:45-11:56 PM) with p = 0.0437.Conclusion: In ambulatory outpatient conditions, electrographic seizures follow day/night patterns similar to those observed in hospital conditions. Frontal seizures occur preferentially in the early morning hours and temporal lobe seizures occur in the early evening hours.GLOSSARY: RMS: root mean square(C)2012 American Academy of Neurology

Objective: To assess the association of multiple sclerosis (MS) with concurrent restless legs syndrome (RLS) and daytime sleepiness. We also prospectively examined whether women with MS had an increased risk of developing RLS during 4 years of follow-up.Methods: The main analysis was based on a cross-sectional study of 65,544 women (aged 41-58 years) free of diabetes, arthritis, and pregnancy, who were participating in the Nurses' Health Study II cohort. Participants were considered to have RLS if they met 4 RLS diagnostic criteria recommended by the International Restless Leg Syndrome Study Group and had restless legs >=5 times/month. MS was self-reported and confirmed by medical record review.Results: Among women with MS, the prevalence of RLS and severe RLS (15+ times/month) were 15.5% and 9.9% in 2005, respectively, relative to 6.4% and 2.6% among women without MS. After adjustment for potential confounders and the presence of other sleep disorders, women with MS had a higher likelihood of having RLS (odds ratio [OR] = 2.72, 95% confidence interval [CI] 1.89-3.93), severe RLS (OR = 4.12, 95% CI 2.65-6.42), and daily daytime sleepiness (OR = 2.11, 95% CI 1.31-3.42) compared with women without MS. Among the 172 women who had MS and were free of RLS in 2005, 9 developed RLS (5.2%) during a 4-year period and all had severe RLS. The adjusted relative risk of severe RLS was 3.58 (95% CI 1.53-8.35), comparing women with MS at baseline with those without MS.Conclusion: Women with MS had a significantly higher prevalence of RLS and daytime sleepiness and an increased risk of developing RLS in the future.GLOSSARY: BMI: body mass indexCI: confidence intervalMS: multiple sclerosisNHS: Nurses' Health StudyOR: odds ratioRLS: restless legs syndrome(C)2012 American Academy of Neurology

Objective: Classic infantile Pompe disease affects many tissues, including the brain. Untreated infants die within their first year. Although enzyme-replacement therapy (ERT) significantly increases survival, its potential limitation is that the drug cannot cross the blood-brain barrier. We therefore investigated long-term cognitive development in patients treated with ERT.Methods: We prospectively assessed cognitive functioning in 10 children with classic infantile Pompe disease who had been treated with ERT since 1999. Brain imaging was performed in 6 children.Results: During the first 4 years of life, developmental scores in 10 children ranged from above-average development to severe developmental delay; they were influenced by the type of intelligence test used, severity of motor problems, speech/language difficulties, and age at start of therapy. Five of the children were also tested from 5 years onward. Among them were 2 tetraplegic children whose earlier scores had indicated severe developmental delay. These scores now ranged between normal and mild developmental delay and indicated that at young age poor motor functioning may interfere with proper assessment of cognition. We found delayed processing speed in 2 children. Brain imaging revealed periventricular white matter abnormalities in 4 children.Conclusions: Cognitive development at school age ranged between normal and mildly delayed in our long-term survivors with classic infantile Pompe disease treated with ERT. The oldest was 12 years. We found that cognition is easily underestimated in children younger than 5 years with poor motor functioning.GLOSSARY: BSID II: Bayley Scales of Infant Development, Second EditionERT: enzyme-replacement therapyGriffiths: Griffiths Mental Development ScalesMDI: mental development indexPDI: psychomotor development indexWISC-III: Wechsler Intelligence Scales for Children, Third Edition.(C)2012 American Academy of Neurology