Multimodal predictors for Alzheimer disease in nonfluent primary progressive aphasia

OBJECTIVE

Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD) are hypothesized to cause clinically distinct forms of primary progressive aphasia (PPA) that predominantly affect expressive speech. AD is thought to cause logopenic progressive aphasia (LPA), and FTLD may cause progressive nonfluent aphasia (PNFA). We sought to determine the value of clinical characterization, neuropsychological analysis, and MRI atrophy in predicting pathology of LPA and PNFA.

METHODS

Patients with LPA (n = 19) and patients with PNFA (n = 19) were evaluated with neuropsychological assessments, structural MRI, CSF analysis, and neuropathologic examination.

RESULTS

Twelve of 19 patients with LPA (63%) and 6 of 19 patients with PNFA (32%) had neuropathologic findings or CSF biomarkers consistent with AD. Neuropsychological testing showed that naming was more impaired in patients with AD, and letter-guided fluency was more affected in patients with a non-AD disorder. Voxel-based morphometry analysis revealed that in patients with AD, patients with LPA and PNFA had significant posterior-superior temporal atrophy; in patients with non-AD, patients with LPA had peri-Sylvian atrophy and patients with PNFA had dorsolateral prefrontal and insular atrophy. Receiver operator characteristic curve analysis showed that combining neuropsychological testing with MRI atrophy pattern had 90% specificity for pathology or CSF biomarkers consistent with AD, and combining clinical features with neuropsychological analysis had 100% sensitivity for pathology or CSF biomarkers consistent with AD.

CONCLUSIONS

Neither PPA phenotyping nor imaging alone is a reliable predictor of pathology. Multimodal predictors, such as combining neuropsychological testing with MRI analysis, can improve noninvasive prediction of underlying pathology in nonfluent forms of PPA.

Survival profiles of patients with frontotemporal dementia and motor neuron disease

BACKGROUND

Frontotemporal dementia and amyotrophic lateral sclerosis are neurodegenerative diseases associated with TAR DNA-binding protein 43- and ubiquitin-immunoreactive pathologic lesions.

OBJECTIVE

To determine whether survival is influenced by symptom of onset in patients with frontotemporal dementia and amyotrophic lateral sclerosis.

DESIGN, SETTING, AND PATIENTS

Retrospective review of patients with both cognitive impairment and motor neuron disease consecutively evaluated at 4 academic medical centers in 2 countries.

MAIN OUTCOME MEASURES

Clinical phenotypes and survival patterns of patients.

RESULTS

A total of 87 patients were identified, including 60 who developed cognitive symptoms first, 19 who developed motor symptoms first, and 8 who had simultaneous onset of cognitive and motor symptoms. Among the 59 deceased patients, we identified 2 distinct subgroups of patients according to survival. Long-term survivors had cognitive onset and delayed emergence of motor symptoms after a long monosymptomatic phase and had significantly longer survival than the typical survivors (mean, 67.5 months vs 28.2 months, respectively; P < .001). Typical survivors can have simultaneous or discrete onset of cognitive and motor symptoms, and the simultaneous-onset patients had shorter survival (mean, 19.2 months) than those with distinct cognitive or motor onset (mean, 28.6 months) (P = .005).

CONCLUSIONS

Distinct patterns of survival profiles exist in patients with frontotemporal dementia and motor neuron disease, and overall survival may depend on the relative timing of the emergence of secondary symptoms.

Abnormal TDP-43 immunoreactivity in AD modifies clinicopathologic and radiologic phenotype

BACKGROUND

TAR DNA-binding protein 43 (TDP-43) is one of the major disease proteins in frontotemporal lobar degeneration with ubiquitin immunoreactivity. Approximately one-fourth of subjects with pathologically confirmed Alzheimer disease (AD) have abnormal TDP-43 (abTDP-43) immunoreactivity. The aim of this study was to determine whether subjects with pathologically confirmed AD and abTDP-43 immunoreactivity have distinct clinical, neuropsychological, imaging, or pathologic features compared with subjects with AD without abTDP-43 immunoreactivity.

METHODS

Eighty-four subjects were identified who had a pathologic diagnosis of AD, neuropsychometric testing, and volumetric MRI. Immunohistochemistry for TDP-43 was performed on sections of hippocampus and medial temporal lobe, and positive cases were classified into one of three types. Neuropsychometric data were collated and compared in subjects with and without abTDP-43 immunoreactivity. Voxel-based morphometry was used to assess patterns of gray matter atrophy in subjects with and without abTDP-43 immunoreactivity compared with age- and sex-matched controls.

RESULTS

Twenty-nine (34%) of the 84 AD subjects had abTDP-43 immunoreactivity. Those with abTDP-43 immunoreactivity were older at onset and death and performed worse on the Clinical Dementia Rating scale, Mini-Mental State Examination, and Boston Naming Test than subjects without abTDP-43 immunoreactivity. Subjects with and without abTDP-43 immunoreactivity had medial temporal and temporoparietal gray matter loss compared with controls; however, those with abTDP-43 immunoreactivity showed greater hippocampal atrophy. Multivariate logistic regression adjusting for age at death demonstrated that hippocampal sclerosis was the only pathologic predictor of abTDP-43 immunoreactivity.

CONCLUSIONS

The presence of abnormal TDP-43 immunoreactivity is associated with a modified Alzheimer disease clinicopathologic and radiologic phenotype.

Clinical features of pathologic subtypes of behavioral--variant frontotemporal dementia

OBJECTIVE

To identify clinical features in behavioral-variant frontotemporal dementia that may help predict tau-positive pathology.

METHODS

Clinical and historical features of patients with pathologically confirmed tau-positive and tau-negative frontotemporal lobar degeneration from 1970 to 2006 were retrospectively reviewed in a blinded fashion. The initial clinical features of those patients who eventually met consensus criteria for frontotemporal dementia were examined using univariate and cluster analyses to explore characteristics that may be associated with tau pathology.

RESULTS

Fifty-six patients (24 tau-positive cases) were included in the analysis. There was no difference in demographics between the tau-positive and tau-negative cases. Univariate analysis showed that poor planning and/or judgment was more commonly associated with tau-positive pathology (P = .03). Cluster analysis using behavioral characteristics identified 2 groups of patients: cluster 1 contained mainly tau-positive cases (57%) and cluster 2 was mostly tau-negative cases (71%). Poor planning and/or judgment was a common presenting sign in the first group (P < .001), while the second group was more likely to present with impaired regulation of personal conduct (P < .001) and a decline in personal hygiene (P = .005).

CONCLUSIONS

Poor planning and/or judgment was associated with behavioral-variant frontotemporal dementia patients who had tau-positive pathology. The constellation of impaired personal conduct and a paucity of dysexecutive symptoms identified tau-negative patients.

Progressive aphasia secondary to Alzheimer disease vs FTLD pathology

BACKGROUND

The pathology causing progressive aphasia is typically a variant of frontotemporal lobar degeneration, especially with ubiquitin-positive inclusions (FTLD-U). Less commonly the underlying pathology is Alzheimer disease (AD).

OBJECTIVE

To compare clinicopathologic and MRI features of subjects with progressive aphasia and AD pathology to subjects with aphasia and FTLD-U pathology and subjects with typical AD.

METHODS

We identified 5 subjects with aphasia and AD pathology and 5 with aphasia and FTLD-U pathology with an MRI from a total of 216 aphasia subjects. Ten subjects with typical AD clinical features and AD pathology were also identified. All subjects with AD pathology underwent pathologic reanalysis with TDP-43 immunohistochemistry. Voxel-based morphometry (VBM) was used to assess patterns of gray matter atrophy in the aphasia cases with AD pathology, aphasia cases with FTLD-U, and typical AD cases with AD pathology, compared with a normal control group.

RESULTS

All aphasic subjects had fluent speech output. However, those with AD pathology had better processing speed than those with FTLD-U pathology. Immunohistochemistry with TDP-43 antibodies was negative. VBM revealed gray matter atrophy predominantly in the temporoparietal cortices, with notable sparing of the hippocampus in the aphasia with AD subjects. In comparison, the aphasic subjects with FTLD-U showed sparing of the parietal lobe. Typical AD subjects showed temporoparietal and hippocampal atrophy.

CONCLUSIONS

A temporoparietal pattern of atrophy on MRI in patients with progressive fluent aphasia and relatively preserved processing speed is suggestive of underlying Alzheimer disease pathology rather than frontotemporal lobar degeneration with ubiquitin-only immunoreactive changes.

Ornithine transcarbamylase deficiency presenting as encephalopathy during adulthood following bariatric surgery

BACKGROUND

Neurological complications following bariatric surgery are rare. Whereas nutritional deficiencies are the most common cause of neurological symptoms, the unmasking of previously subclinical metabolic disorders can also lead to significant morbidity.

OBJECTIVE

To characterize the clinical presentation, serum biochemical fluctuations, and functional enzymatic analysis of a case of functional ornithine transcarbamylase deficiency unmasked by a dietary change following bariatric surgery.

DESIGN

Case report.

SETTING

Tertiary referral center, hospital (inpatient) setting.

PATIENT

A 29-year-old woman who presented with intermittent encephalopathy associated with recurrent hyperammonemia.

INTERVENTIONS

Clinical, biochemical, and mutational studies.

RESULTS

The pattern of intermittent hyperammonemia and encephalopathy following oral and parenteral nutrition suggested a urea cycle abnormality. Functional enzymatic assay results showed markedly reduced ornithine transcarbamylase activity in the absence of known coding mutations.

CONCLUSION

Previously asymptomatic ornithine transcarbamylase deficiency should be suspected in adult patients who develop recurrent hyperammonemia and encephalopathy following bariatric surgery.

Childhood obesity among Head Start enrollees in southeastern Minnesota: prevalence and risk factors

BACKGROUND

Up to 32% of US Head Start enrollees in inner-city settings have been reported to be obese. However, little is known about the prevalence of overweight and associated risk factors in Head Start enrollees in non-inner-city settings.

OBJECTIVES

To determine the prevalence of childhood obesity from 1998 to 2001 and associated risk factors for overweight among Head Start enrollees in southeast Minnesota.

METHODS

The study was designed as a cross-sectional study. Subjects were 788 children ages three to five years who were enrolled in Head Start of Olmsted and Freeborn Counties, Minnesota, between 1998 and 2001. Anthropometric data and other sociodemographic variables were collected. The Centers for Disease Control and Prevention (CDC) classification for body mass index (BMI) was used (ie, overweight is > 95th percentile BMI for age). Data were fit to a logistic regression model to identify risk factors associated with overweight.

RESULTS

From 1998 to 2001, the overall prevalence of overweight and at risk for overweight was 12.9% and 12.2%, respectively. The prevalence of overweight from 1998 to 2001 remained steady, but the prevalence of at risk doubled from 8.2% in 1998 to 16.1% in 2001. On the basis of BMI at the time of enrollment in Head Start, Mexican origin (OR = 2.76; P = .002) and speaking English as a second language (ESL) at home (OR = 1.75; P = .026) were independent predictors for overweight.

CONCLUSIONS

The Head Start setting in a nonurban area does not confer any more or less risk for overweight for enrollees, compared to those in urban settings. Children within a certain ethnic group (eg, Mexican) and those who speak English as a second language at home have a higher risk of being overweight. Specific early interventions for these children in a Head Start setting are warranted.

Cognitive impairment and celiac disease

OBJECTIVE

To characterize the clinical, radiological, and electrophysiological laboratory profiles and histological features of patients who developed cognitive impairment temporally associated with celiac disease.

DESIGN

Case series.

SETTING

Referral center.

PATIENTS

Patients with the onset of progressive cognitive decline within 2 years of symptomatic onset or with a severe exacerbation of biopsy-proved adult celiac disease were identified from the Mayo Clinic medical records from January 1, 1970, to December 31, 2005. Patients were excluded if an alternate cause of their cognitive impairment was identified.

RESULTS

Thirteen patients (5 women) were identified. The median age at cognitive impairment onset was 64 years (range, 45-79 years), which coincided with symptom onset or exacerbation of diarrhea, steatorrhea, and abdominal cramping in 5 patients. Amnesia, acalculia, confusion, and personality changes were the most common presenting features. The average initial Short Test of Mental Status score was 28 of a total of 38 (range, 18-34), which was in the moderately impaired range. The results of neuropsychological testing suggested a trend of a frontosubcortical pattern of impairment. Ten patients had ataxia, and 4 of them also had peripheral neuropathy. Magnetic resonance imaging of the head showed nonspecific T2 hyperintensities, and electroencephalography showed nonspecific diffuse slowing. Deficiencies in folate, vitamin B(12), vitamin E, or a combination were identified in 4 patients, yet supplementation did not improve their neurological symptoms. Three patients improved or stabilized cognitively with gluten withdrawal. A detailed histological analysis revealed nonspecific gliosis.

CONCLUSIONS

A possible association exists between progressive cognitive impairment and celiac disease, given the temporal relationship and the relatively high frequency of ataxia and peripheral neuropathy, more commonly associated with celiac disease. Given the impact for potential treatment of similar cases, recognition of this possible association and additional studies are warranted.

MRI correlates of alien leg-like phenomenon in corticobasal degeneration

We describe the clinical and neuroradiologic correlates in two patients with the clinical picture of CBD and alien leg phenomena. The MRI brain scan in both had unique focal abnormalities in the corresponding leg area of the homunculus that may be the substrate for the alien limb features.

Effect of food on the pharmacokinetics of osmotic controlled-release methylphenidate HCl in healthy subjects

The effect of a high-fat meal on the pharmacokinetics of OROS(R) (methylphenidate HCl), an osmotic controlled-release formulation of methylphenidate HCl, was investigated in healthy subjects. Mean peak methylphenidate plasma concentrations occurred slightly later and peak methylphenidate plasma concentrations and AUC values were slightly higher (approximately 10-30%) in the presence of food than in the absence of food. There was no difference in the plasma elimination half-life of methylphenidate between the fed and fasted state. Similarly, peak concentrations and AUC values for alpha-phenyl-2-piperidine acetic acid (PPA; ritalinic acid), the major metabolite of methylphenidate, were slightly higher in the presence of food than in its absence. The 90% confidence interval (CI) for the treatment ratio (fed/fasted) for C(max) was 120.6%-140. 0% for the 18-mg dose and 105.4-119.3% for a 36-mg dose. The 90% CI for the treatment ratio for AUC(infinity) was 114.6-125.7% for the 18-mg dose and 115.1-124.6% for the 36-mg dose. PPA levels were measured following the 18-mg dose and the 90% CI of the treatment ratio was 106.8-115.4% for C(max) and 97.9-103.6% for AUC(infinity). These results indicate the absence of dose dumping from OROS (methylphenidate HCl) in the presence of food. Food does not impede drug absorption and OROS (methylphenidate HCl) may be administered in the fed or fasted state. There were no differences in the adverse event profile between the fed and fasted state.

[Research on hydrokinetics of self-intermittent vaccum root canal drainage]

A hydrokinetically simulated sucking was made to study the self-intermittent vacuum drainage of the root canal.Results showed that due to the shape difference between diameters at the upper and lower parts of the canal,the high-speed air-flow at the lower-end opening can drain the fluid below the opening out while the lower-speed air-flow at the upper opening is not likely to make the saliva and see page in the oral cavity reenter the root cavity.The above mentioned are in conformity with the Bernoulli's equation.

Compact, magneto-optic Q-switched, neodymium-doped bismuth germinate crystal (Nd:BGO) laser pumped by a laser diode

The magneto-optic Q-switched operation of a neodymium-doped bismuth germinate crystal (Nd:BGO) laser that is end pumped by a cw 500-mW laser diode is reported. The crystal is a new host for Nd lasers. Here it acts as a magneto-optic modulator as well as a laser medium. A pulse energy of 2 µJ with a FWHM of 100 ns has been obtained. The device operates at a repetition rate of 1 kHz, and the fluctuation of the shot-to-shot intensity is less than ±1%.