Neurology September 2009 Volume 73 Issue 12

Objective: We tested the hypothesis that impaired kidney function in the elderly is associated with a more rapid rate of cognitive decline.Methods: Baseline serum was used to calculate estimated glomerular filtration rate (eGFR), using the Modification of Diet in Renal Disease formula, for 886 elderly without dementia participating in the Rush Memory and Aging Project, a prospective, observational cohort study. Kidney function was also dichotomized into impairment or no impairment based on eGFR < or >=60 mL/min/1.73 m2. Structured cognitive testing was performed at baseline and at annual evaluations, using a battery of 19 cognitive tests summarized into global cognition and 5 cognitive domains.Results: In mixed-effects models adjusted for age, sex, and education, a lower eGFR at baseline was associated with a more rapid rate of cognitive decline (estimate 0.0008, SE <0.001, p = 0.017). The increased rate of cognitive decline associated with a 15-mL/min/1.73 m2 lower eGFR at baseline (approximately 1 SD) was similar to the effect of being 3 years older at baseline. Impaired kidney function at baseline was associated with a more rapid rate of cognitive decline (estimate -0.028, SE <0.009, p = 0.003). The increased rate of cognitive decline associated with impaired kidney function at baseline was approximately 75% the effect of ApoE4 allele on the rate of cognitive decline. Baseline kidney function was associated with declines in semantic memory, episodic memory, and working memory but not visuospatial abilities or perceptual speed.Conclusion: Impaired kidney function is associated with a more rapid rate of cognitive decline in old age.(C)2009AAN Enterprises, Inc.

Objective: To investigate whether baseline CSF biomarkers are associated with hippocampal atrophy rate as a measure of disease progression in patients with Alzheimer disease (AD), patients with mild cognitive impairment (MCI), and controls, controlling for baseline neuropsychological and MRI findings.Methods: We assessed data from 31 patients with AD, 25 patients with MCI, and 19 controls (mean age 68 +/- 8 years; 39 [52%] female) who visited our memory clinic and had received serial MRI scanning (scan interval 1.7 +/- 0.7 years). At baseline, CSF biomarkers (amyloid [beta] 1-42, tau, and tau phosphorylated at threonine 181 [p-tau]) were obtained, as well as neuropsychological data. Baseline MRI scans were assessed using visual rating scales for medial temporal lobe atrophy (MTA), global cortical atrophy, and white matter hyperintensities. Hippocampal atrophy rates were estimated using regional nonlinear "fluid" registration of follow-up scan to baseline scan.Results: Stepwise multiple linear regression, adjusted for age and sex, showed that increased CSF p-tau levels ([beta] [standard error]: -0.79 [0.35]) at baseline was independently associated with higher subsequent hippocampal atrophy rates (p < 0.05), together with poorer memory performance (0.09 [0.04]) and more severe MTA (-0.60 [0.21]). The association of memory function with hippocampal atrophy rate was explained by the link with diagnosis, because it disappeared from the model after we additionally corrected for diagnosis.Conclusions: Baseline CSF levels of tau phosphorylated at threonine 181 are independently associated with subsequent disease progression, as reflected by hippocampal atrophy rate. This effect is independent of baseline neuropsychological and MRI predictors. Our results imply that predicting disease progression can best be achieved by combining information from different modalities.(C)2009AAN Enterprises, Inc.

Background: Plasma exchange (PE) is used to treat severe episodes of CNS demyelination unresponsive to corticosteroids. Predictors of long-term response are not well known.Methods: We retrospectively reviewed the medical records of 41 patients consecutively treated by PE between January 1995 and July 2007. The primary outcome was improvement at 6 months after PE defined as decrease of >=1 point in the Expanded Disability Status Scale (EDSS) score for patients with EDSS <=7.5 or 1.5 points with EDSS >=8.0 or improvement of more than 2 lines in the visual acuity chart for patients with optic neuritis (ON).Results: Twenty-five patients (61%) were women, and the median age was 33 years (range 14-57 years). Twenty-three (56%) had multiple sclerosis, 2 (5%) had clinically isolated syndrome, 2 (5%) had Marburg disease, 7 (17%) had acute disseminated encephalomyelitis, 4 (10%) had neuromyelitis optica, 2 (5%) had idiopathic ON, and 1 (2%) had idiopathic transverse myelitis. The median EDSS score before the attack was 1.0 (range 0-6.5). At PE onset, the median EDSS score was 7.0 (range 3.0-9.5). Sixteen patients (39%) improved at discharge, and 26 (63%) improved at 6 months. In the multivariate analysis, early initiation of PE (odds ratio [OR] 6.29, 95% confidence interval [CI] 1.18-52.96) and improvement at discharge (OR 7.32, 95% CI 1.21-44.38) were significantly associated with response at 6 months.Conclusions: Plasma exchange (PE) was associated with clinical improvement in 63% of patients at 6 months. Early initiation of PE and improvement at discharge were predictors of this response. Twelve patients (48%) who did not improve early did so during follow-up.(C)2009AAN Enterprises, Inc.

Objective: To determine the spectrum of clinical, neuropsychological, and neuroradiologic features in patients with autosomal recessive primary microcephaly (MCPH) due to ASPM gene mutations.Methods: ASPM was sequenced in 52 unrelated MCPH probands. In patients with ASPM mutations, we evaluated the clinical phenotype, cognition, behavior, brain MRI, and family.Results: We found homozygous or compound heterozygous ASPM loss-of-function mutations in 11 (22%) probands and 5 siblings. The probands harbored 18 different mutations, of which 16 were new. Microcephaly was severe after 1 year of age in all 16 patients, although in 4 patients the occipital-frontal circumference (OFC) at birth was decreased by only 2 SD. The OFC Z score consistently decreased after birth. Late-onset seizures occurred in 3 patients and significant pyramidal tract involvement in 1 patient. Intellectual quotients ranged from borderline-normal to severe mental retardation. Mild motor delay was noted in 7/16 patients. Language development was delayed in all patients older than 3 years. Brain MRI (n = 12) showed a simplified gyral pattern in 9 patients and several malformations including ventricle enlargement (n = 7), partial corpus callosum agenesis (n = 3), mild cerebellar hypoplasia (n = 1), focal cortical dysplasia (n = 1), and unilateral polymicrogyria (n = 1). Non-neurologic abnormalities consisted of short stature (n = 1), idiopathic premature puberty (n = 1), and renal dysplasia (n = 1).Conclusions: We provide a detailed description of features associated with ASPM mutations. Borderline microcephaly at birth, borderline-normal intellectual efficiency, and brain malformations can occur in ASPM-related primary hereditary microcephaly.(C)2009AAN Enterprises, Inc.

Background: Although up to 15% of patients with whiplash injury develop chronic headache, the basis and mechanisms of this posttraumatic headache are not well understood.Methods: Thirty-two patients with posttraumatic headache following whiplash injury were investigated within 14 days after the accident and again after 3 months using magnetic resonance-based voxel-based morphometry. Twelve patients developed chronic headache lasting longer than 3 months and were studied a third time after 1 year.Results: Patients who developed chronic headache revealed decreases in gray matter in the anterior cingulate and dorsolateral prefrontal cortex after 3 months. These changes resolved after 1 year, in parallel to the cessation of headache. The same patients who developed chronic headache showed an increase of gray matter in antinociceptive brainstem centers, thalamus, and cerebellum 1 year after the accident.Conclusion: We demonstrate adaptive gray matter changes of pain processing structures in patients with chronic posttraumatic headache in regard to neuronal plasticity, thus providing a biologically plausible basis for this common, disabling problem.(C)2009AAN Enterprises, Inc.