Genome-wide association with MRI atrophy measures as a quantitative trait locus for Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with considerable evidence suggesting an initiation of disease in the entorhinal cortex and hippocampus and spreading thereafter to the rest of the brain. In this study, we combine genetics and imaging data obtained from the Alzheimer's Disease Neuroimaging Initiative and the AddNeuroMed study. To identify genetic susceptibility loci for AD, we conducted a genome-wide study of atrophy in regions associated with neurodegeneration in this condition. We identified one single-nucleotide polymorphism (SNP) with a disease-specific effect associated with entorhinal cortical volume in an intron of the ZNF292 gene (rs1925690; P-value=2.6 × 10(-8); corrected P-value for equivalent number of independent quantitative traits=7.7 × 10(-8)) and an intergenic SNP, flanking the ARPP-21 gene, with an overall effect on entorhinal cortical thickness (rs11129640; P-value=5.6 × 10(-8); corrected P-value=1.7 × 10(-7)). Gene-wide scoring also highlighted PICALM as the most significant gene associated with entorhinal cortical thickness (P-value=6.7 × 10(-6)).

Differential corticospinal tract degeneration in homozygous 'D90A' SOD-1 ALS and sporadic ALS

BACKGROUND

The homogeneous genotype and stereotyped phenotype of a unique familial form of amyotrophic lateral sclerosis (ALS) (patients homozygous for aspartate-to-alanine mutations in codon 90 (homD90A) superoxide dismutase 1) provides an ideal model for studying genotype/phenotype interactions and pathological features compared with heterogeneous apparently sporadic ALS. The authors aimed to use diffusion tensor tractography to quantify and compare changes in the intracerebral corticospinal tracts of patients with both forms of ALS, building on previous work using whole-brain voxelwise group analysis.

METHOD

21 sporadic ALS patients, seven homD90A patients and 20 healthy controls underwent 1.5 T diffusion tensor MRI. Patients were assessed using 'upper motor neuron burden,' El Escorial and ALSFR-R scales. The intracranial corticospinal tract was assessed using diffusion tensor tractography measures of fractional anisotropy (FA), mean diffusivity, and radial and axial diffusivity obtained from its entire length.

RESULTS

Corticospinal tract FA was reduced in sporadic ALS patients compared with both homD90A ALS patients and controls. The diffusion measures in sporadic ALS patients were consistent with anterograde (Wallerian) degeneration of the corticospinal tracts. In sporadic ALS, corticospinal tract FA was related to clinical measures. Despite a similar degree of clinical upper motor neuron dysfunction and disability in homD90A ALS patients compared with sporadic ALS, there were no abnormalities in corticospinal tract diffusion measures compared with controls.

CONCLUSIONS

Diffusion tensor tractography has shown axonal degeneration within the intracerebral portion of the corticospinal tract in sporadic ALS patients, but not those with a homogeneous form of familial ALS. This suggests significant genotypic influences on the phenotype of ALS and may provide clues to slower progression of disease in homD90A patients.

No effect of 5HTTLPR or BDNF Val66Met polymorphism on hippocampal morphology in major depression

Neuroimaging research implicates the hippocampus in the aetiology of major depressive disorder (MDD). Imaging genetics studies have investigated the influence of the serotonin transporter-linked polymorphic region (5HTTLPR) and brain-derived neurotrophic factor (BDNF) Val66Met polymorphism on the hippocampus in healthy individuals and patients with depression (MDD). However, conflicting results have led to inconclusive evidence about the effect of 5HTTLPR or BDNF on hippocampal volume (HCV). We hypothesized that analysis methods based on three-dimensional (3D) hippocampal shape mapping could offer improved sensitivity to clarify these effects. Magnetic resonance imaging data were collected in parallel samples of 111 healthy individuals and 84 MDD patients. Manual hippocampal segmentation was conducted and the resulting data used to investigate the influence of 5HTTLPR and BDNF Val66Met genotypes on HCV and 3D shape within each sample. Hippocampal volume normalized by intracranial volume (ICV) showed no significant difference between 5HTTLPR S allele carriers and L/L homozygotes or between BDNF Met allele carriers and Val/Val homozygotes in the group of healthy individuals. Moreover, there was no significant difference in normalized HCV between 5HTTLPR diallelic and triallelic classifications or between the BDNF Val66Met genotypes in MDD patients, although there was a relationship between BDNF Val66Met and ICV. Shape analysis detected dispersed between-group differences, but these effects did not survive multiple testing correction. In this study, there was no evidence of a genetic effect for 5HTTLPR or BDNF Val66Met on hippocampal morphology in either healthy individuals or MDD patients despite the relatively large sample sizes and sensitive methodology.

Apathy and cortical atrophy in Alzheimer's disease

OBJECTIVES

Apathy has been reported as the most prevalent behavioural symptom experienced in Alzheimer's disease (AD), associated with greater functional decline and caregiver distress. The aim of the current study was to investigate structural correlates of apathy in AD using magnetic resonance imaging (MRI) regional volume and regional cortical thickness measures.

METHODS

Semi-structured interviews were conducted with 111 AD patients and their caregivers as part of the European multi-centre study AddNeuroMed. Apathy was measured using the apathy domain of the Neuropsychiatric Inventory (NPI). All AD patients were scanned using a 1.5T MRI scanner and the images analysed using an automated analysis pipeline.

RESULTS

We found apathy to be the most prevalent neuropsychiatric symptom occurring in 57% of patients. Apathetic patients had significantly greater cortical thinning in left caudal anterior cingulate cortex (ACC) and left lateral orbitofrontal cortex (OFC), as well as left superior and ventrolateral frontal regions, than those without apathy symptoms.

CONCLUSIONS

Apathy is mediated by frontocortical structures but this is specific to the left hemisphere at least for patients in the mild to moderate stages of AD.

Altered patterns of cortical activation in ALS patients during attention and cognitive response inhibition tasks

Since amyotrophic lateral sclerosis (ALS) can be accompanied by executive dysfunction, it is hypothesised that ALS patients will have impaired performance on tests of cognitive inhibition. We predicted that ALS patients would show patterns of abnormal activation in extramotor regions when performing tests requiring the inhibition of prepotent responses (the Stroop effect) and the inhibition of prior negatively primed responses (the negative priming effect) when compared to healthy controls. Functional magnetic resonance imaging was used to measure activation during a sparse sequence block design paradigm investigating the Stroop and negative priming effects in 14 ALS patients and 8 healthy age- and IQ-matched controls. Behavioural measures of performance were collected. Both groups' reaction times (RTs) reflected the Stroop effect during scanning. The ALS and control groups did not differ significantly for any of the behavioural measures but did show significant differences in cerebral activation during both tasks. The ALS group showed increased activation predominantly in the left middle temporal gyrus (BA 20/21), left superior temporal gyrus (BA 22) and left anterior cingulate gyrus (BA 32). Neither group's RT data showed clear evidence of a negative priming effect. However the ALS group showed decreased activation, relative to controls, particularly in the left cingulate gyrus (BA 23/24), left precentral gyrus (BA 4/6) and left medial frontal gyrus (BA 6). Greater cerebral activation in the ALS group accompanying the performance of the Stroop effect and areas of decreased activation during the negative priming comparison suggest altered inhibitory processing in ALS, consistent with other evidence of executive dysfunction in ALS. The current findings require further exploration in a larger study.

Antibacterial polyurethane nanocomposites using chlorhexidine diacetate as an organic modifier

Polymer nanocomposites (NCs) are hypothesised to have enhanced barrier properties compared with pristine polymer, allowing more sustained drug release from the materials. In these NC systems active agents are typically incorporated into the polymer matrix and the release kinetics are theoretically perturbed by well dispersed nanoparticle inclusions. An alternative approach is to exploit active agent interactions with the nanoinclusion. In the proposed NC system, the driving hypothesis is that active agents can have dual functionality, acting as both drug and dispersant. Polyurethane-montmorillonite (PEU-MMT) NCs were prepared in which the antimicrobial agent chlorhexidine diacetate (CHX) was evaluated as an organic modifier for silicate dispersion. CHX was incorporated at various concentrations through organic modification of MMT or within the bulk polymer. X-ray diffraction and transmission electron microscopy analysis suggested that intercalated and partially exfoliated NCs were achieved, with better dispersion occurring in the presence of free CHX within the bulk. Tensile testing results showed that variations in the level of organic modification and nanoparticle loading modulated the mechanical properties. Material stiffness increased with nanoparticle loading relative to pristine PEU, and the ultimate properties decreased with nanoparticle and free CHX incorporation. Antibacterial activity against Staphylococcus epidermidis was significant in materials with higher exchanged MMT and NCs containing free CHX, for which 2-log reductions in adherent bacteria were found after 24h. CHX was successfully used to modulate the material properties in its dual role as a dispersant and antimicrobial agent, suggesting that alternative biocides of similar structure may behave comparably within PEU-MMT NC systems.

Brain anatomy and ageing in non-demented adults with Down's syndrome: an in vivo MRI study

BACKGROUND

People with Down's syndrome (DS) are at high risk for developing dementia in middle age. The biological basis for this is unknown. It has been proposed that non-demented adults with DS may undergo accelerated brain ageing.

METHOD

We used volumetric magnetic resonance imaging (MRI) and manual tracing to compare brain anatomy and ageing in 39 non-demented adults with DS and 42 healthy controls.

RESULTS

Individuals with DS had significant differences in brain anatomy. Furthermore, individuals with DS had a significantly greater age-related reduction in volume of frontal, temporal and parietal lobes, and a significantly greater age-related increase in volume of peripheral cerebrospinal fluid (CSF).

CONCLUSIONS

Non-demented adults with DS have differences in brain anatomy and 'accelerated' ageing of some brain regions. This may increase their risk for age-related cognitive decline and Alzheimer's disease (AD).

Multiplex real-time RT-PCR for detection of Wheat streak mosaic virus and Triticum mosaic virus

Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are widespread throughout the southwestern Great Plains states. When using conventional diagnostics such as enzyme-linked immunosorbent assays (ELISA), these two viruses are commonly found together in infected wheat samples. Methods for molecular detection have been developed for wheat viral pathogens, but until recently no multiplex method for detection of both WSMV and TriMV within a single sample was available. Therefore, the objective of this study was to develop a multiplex real-time PCR technique for detection of both pathogens within a single plant sample. Specific primers and probe combinations were developed for detection of WSMV and TriMV, single and multiple reactions were run simultaneously to detect any loss in sensitivity during the multiplex reaction, as well as any cross-reaction with other common wheat viruses. The multiplex reaction was successful in detection of both pathogens, with little difference between single and multiplex reactions, and no cross-reaction was found with other common wheat viruses. This multiplex technique not only will be useful for diagnostic evaluations, but also as a valuable tool for ecological and epidemiology studies, and investigations of host/pathogen interactions, especially when the host is infected with both pathogens.

Creating community action plans for obesity prevention using the ANGELO (Analysis Grid for Elements Linked to Obesity) Framework

Community-based interventions are an important component of obesity prevention efforts. The literature provides little guidance on priority-setting for obesity prevention in communities, especially for socially and culturally diverse populations. This paper reports on the process of developing prioritized, community-participatory action plans for obesity prevention projects in children and adolescents using the ANGELO (Analysis Grid for Elements Linked to Obesity) Framework. We combined stakeholder engagement processes, the ANGELO Framework (scans for environmental barriers, targeted behaviours, gaps in skills and knowledge) and workshops with key stakeholders to create action plans for six diverse obesity prevention projects in Australia (n = 3), New Zealand, Fiji and Tonga from 2002 to 2005. Some sites included sociocultural contextual analyses in the environmental scans. Target groups were under-5-year-olds (Australia), 4-12-year-olds (Australia) and 13-18-year-olds (all four countries). Over 120 potential behavioural, knowledge, skill and environmental elements were identified for prioritization leading into each 2-day workshop. Many elements were common across the diverse cultural communities; however, several unique sociocultural elements emerged in some cultural groups which informed their action plans. Youth were actively engaged in adolescent projects, allowing their needs to be incorporated into the action plans initiating the process of ownership. A common structure for the action plan promoted efficiencies in the process while allowing for community creativity and innovation. The ANGELO is a flexible and efficient way of achieving an agreed plan for obesity prevention with diverse communities. It is responsive to community needs, combines local and international knowledge and creates stakeholder ownership of the action plan.

Alzheimer's disease and Down's syndrome: an in vivo MRI study

BACKGROUND

Individuals with Down's syndrome (DS) are at high risk of developing Alzheimer's disease (AD). However, few studies have investigated brain anatomy in DS individuals with AD.

METHOD

We compared whole brain anatomy, as measured by volumetric magnetic resonance imaging (MRI), in DS individuals with and without AD. We also investigated whether volumetric differences could reliably classify DS individuals according to AD status. We used volumetric MRI and manual tracing to examine regional brain anatomy in 19 DS adults with AD and 39 DS adults without AD.

RESULTS

DS individuals with AD had significantly smaller corrected volumes bilaterally of the hippocampus and caudate, and right amygdala and putamen, and a significantly larger corrected volume of left peripheral cerebrospinal fluid (CSF), compared to DS individuals without AD. The volume of the hippocampus and caudate nucleus correctly categorized 92% and 92% respectively of DS individuals without AD, and 75% and 80% respectively of DS individuals with AD.

CONCLUSIONS

DS individuals with AD have significant medial temporal and striatal volume reductions, and these may provide markers of clinical AD.

Understanding ethics guidelines using an internet-based expert system

National and international guidelines outlining ethical conduct in research involving humans and animals have evolved into large and complex documents making the process of gaining ethics approval a complicated task for researchers in the area. Researchers, in particular those who are relatively new to the ethics approval process, can struggle to understand the parts of an ethics guideline that apply to their research and the nature of their ethical obligations to trial participants. With the scope of medical research likely to continue to expand in the future, it is clear that ethics guidelines will only increase in complexity and number. This paper describes one possible solution to the

PROBLEM

the use of an internet-based expert system to intelligently and interactively distribute the information stored in ethics guidelines to individual researchers. This paper also details how one such system was designed and tested with respect to Australian medical research ethics guidelines.

Dementia in Alzheimer’s Disease: A Comparison of MRI and 1H-MRS Findings Between Alzheimer’s Disease and Mild Cognitive Impairment

Aim:

To compare Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (1H-MRS) between people with Alzheimer's disease (AD) and mild cognitive impairment (MCI).

Background review:

AD is characterised by cognitive impairment. 10-15% of people with MCI progress to dementia each year. The hippocampus is involved in memory functioning and is one of the brain regions first affected by AD. MRI based hippocampal volumetric measurement enables accurate quantification of atrophy. In addition, 1H-MRS can be used to measure concentrations of brain metabolites including myoinositol (mI) and N-acetylaspartate (NAA). NAA is a proxy measure of neuronal density.

Method:

Subjects with AD (n=46), MCI (n=28) and controls (n=39) were scanned using a 1.5 Tesla MR system. Manual tracing of hippocampal volumes was undertaken using Measure software. 1H-MRS voxels of interest were defined in the left and right hippocampi. A point-resolved spectroscopy pulse sequence produced spectra from each voxel and clearly resolved NAA and mI peaks. Statistical analysis was undertaken using SPSS15.

Results:

Hippocampal volumes were significantly reduced between AD and controls (p=0.003) and between AD and MCI (p=0.001). Compared to controls, individuals with AD and MCI had a significant reduction in [NAA]. MCI showed a non-significant increase in [mI]. A positive relationship was found between hippocampal volume and [NAA] and between hippocampal volume and [mI] for MCI.

Conclusions:

AD is associated with decreased viable neuronal density/function (as measured by NAA) and a reduction in hippocampal volume associated with impaired cognitive functioning. The elevated [mI] in MCI may be a “tipping point” into dementia.

A trial of vaccination with the carcinoembryonic antigen (CEA) peptide CAP 1–6D with montanide ISA 51 adjuvant or granulocyte- macrophage colony stimulating factor (GM-CSF) in HLA-A2+ patients with CEA producing adenocarcinomas of gastrointestinal (GI) track

13513

Advances in drug therapy have improved the survival of patients with GI tumors but most patients with metastatic disease are not cured. Immunotherapy is an additional modality of treatment. In this trial, the CEA peptide, CAP 1–6D, was combined with either GM-CSF or montanide ISA 51 as adjuvants and used to vaccinate patients with CEA producing GI tumors. End points were development of peptide responsive immunity, toxicity, and anti-tumor effects. To be eligible, patients were required to have a histologic diagnosis of adenocaricnoma of GI tract origin with a life expectancy of at least 6 months and to have either metastatic disease or to have completed standard adjuvant therapy after resection. Patients were required to have a CEA producing tumor, be HLA-A2 positive, have a performance status of 0–1, test negative for HIV, hepatitis B and C, and have adequate bone marrow, liver and kidney function. Treatment consisted of 1 mg of CAP 1–6D peptide combined with either 250 ug of GM-CSF given intradermally, or 2 ml of Montanide ISA 51 given subcutaneously every 3 weeks for 6 treatments. Blood was drawn for ELISpot assay at each visit. Nine (out of a planned 10) patients, 8 with colorectal cancer and 1 with pancreatic cancer, were entered before the peptide was deemed expired and withdrawn from clinical use by the NCI. Of five colorectal patients with metastatic disease at baseline 4 progressed and 1 had stable disease. The pancreatic cancer patient was treated adjuvantly but progressed during therapy. Three colorectal cancer patients treated adjuvantly were free of disease at baseline and at the completion of therapy. Treatments were well tolerated. ELISpot data on 5 patients showed that 4 patients developed peptide responsive immunity. Responsive patients included those receiving either GM-CSF or Montanide ISA 51 and both adjuvantly treated and progressive metastatic colorectal patients and the progressed pancreatic cancer patient. This vaccine regimen can be safely given to cancer patients and can produce peptide responsive immunity in the ELISpot assay but this does not correlate with clinical anti-tumor effect.

No significant financial relationships to disclose.

Measuring brain stem and cerebellar damage in parkinsonian syndromes using diffusion tensor MRI

OBJECTIVE

To use diffusion tensor MRI to quantify and compare degeneration of the pons and cerebellar peduncles in multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and Parkinson disease (PD) and to relate changes in diffusion measures to clinical features and localized atrophy.

METHODS

We used a region-of-interest approach to measure changes in fractional anisotropy and mean diffusivity in the middle cerebellar peduncles, decussation of the superior cerebellar peduncles, and pons in 17 patients with MSA, 17 with PSP, 12 with PD, and 12 healthy volunteers. We also evaluated atrophy of the cerebellar peduncles and pons on T2-weighted magnetic resonance images in patients with MSA and PSP.

RESULTS

In MSA, fractional anisotropy was markedly reduced in the middle cerebellar peduncles, and mean diffusivity increased both here and in the pons compared with other groups, whereas in PSP, mean diffusivity was strikingly increased in the decussation of superior cerebellar peduncles. Cerebellar ataxia was related to mean diffusivity in the middle cerebellar peduncles (r = 0.71, p = 0.001) and pons (r = 0.60, p = 0.01) in MSA. Diffusion measures were related to localized atrophy in both MSA and PSP.

CONCLUSIONS

Diffusion tensor MRI can be used to quantify neurodegenerative processes in different brain stem and cerebellar structures in multiple system atrophy and progressive supranuclear palsy during life, and may have diagnostic value. Larger studies of early, undifferentiated parkinsonian syndromes are indicated to provide estimates of the relative diagnostic value of diffusion measures, atrophy measures, and visual assessment of scans.

The effect of silica nanoparticulate coatings on serum protein adsorption and cellular response

Serum protein adsorption on colloidal silica surfaces was investigated using a quartz crystal microbalance with dissipation (QCM-D) monitoring. The amount of serum proteins adsorbed on colloidal silica-coated surfaces was not significantly different from the control silica surfaces, with the exception of 21nm colloidal silica which experienced significantly less (P<0.05) fibrinogen adsorption compared with control silica. The adhesion and proliferation of human endothelial cells (C11STH) on nano-scale colloidal silica surfaces were significantly reduced compared with control silica surfaces, suggesting that the conformation of adsorbed proteins on the colloidal silica surfaces plays a role in modulating the amount of cell binding. Fibronectin is one of the main extracellular matrix proteins involved in endothelial cell attachment to biomaterial surfaces. There was reduced binding of a monoclonal anti-fibronectin antibody, that reacted specifically with the cell-binding fragment, to fibronectin-coated colloidal silica surfaces compared with control silica surfaces. This suggests that the fibronectin adsorbed on the colloidal silica-coated surfaces was conformationally changed compared with control silica reducing the availability of the cell-binding domain of fibronectin.

Crystal structures of the methylene chloride disolvates of tetrakis(3,5- dimethoxyphenyl)porphyrin and its isotypic copper(II) and nickel(II) complexes, C52H46N4O8 · 2CH2Cl2, Cu(C52H44N4O8) · 2CH2Cl2, Ni(C52H44N4O8) · 2CH2Cl2

C54H50Cl4N4O8, triclinic, P1̅ (no. 2), a = 11.295(1) Å, b = 11.255(1) Å, c = 11.797(1) Å, α = 108.904(2)°, β = 101.091(2)°, γ = 110.992(2)°, V = 1241.4 Å3, Z = 1, Rgt(F) = 0.056, wRref(F2) = 0.135, T = 100 K.

C54H48Cl4CuN4O8, triclinic, P1̅ (no. 2), a = 11.2204(5) Å, b = 11.3499(6) Å, c = 11.7610(6) Å, α = 109.187(1)°, β = 100.830(1)°, γ = 110.681(1)°, V = 1242.7 Å3, Z = 1, Rgt(F) = 0.033, wRref(F2) = 0.092, T = 100 K.

C54H48Cl4N4NiO8, triclinic, P1̅ (no. 2), a = 11.196(1) Å, b = 11.329(1) Å, c = 11.785(1) Å, α = 109.486(2)°, β = 101.230(2)°, γ = 110.607(2)°, V = 1233.8 Å3, Z = 1, Rgt(F) = 0.040, wRref(F2) = 0.110, T = 100 K.

Development of educational image databases and e-books for medical physics training

Medical physics education and training requires the use of extensive imaging material and specific explanations. These requirements provide an excellent background for application of e-Learning. The EU projects Consortia EMERALD and EMIT developed five volumes of such materials, now used in 65 countries. EMERALD developed e-Learning materials in three areas of medical physics (X-ray diagnostic radiology, nuclear medicine and radiotherapy). EMIT developed e-Learning materials in two further areas: ultrasound and magnetic resonance imaging. This paper describes the development of these e-Learning materials (consisting of e-books and educational image databases). The e-books include tasks helping studying of various equipment and methods. The text of these PDF e-books is hyperlinked with respective images. The e-books are used through the readers' own Internet browser. Each Image Database (IDB) includes a browser, which displays hundreds of images of equipment, block diagrams and graphs, image quality examples, artefacts, etc. Both the e-books and IDB are engraved on five separate CD-ROMs. Demo of these materials can be taken from www.emerald2.net.

Complement regulatory proteins are incorporated into lentiviral vectors and protect particles against complement inactivation

Lentiviral vectors pseudotyped with G glycoprotein from vesicular stomatitis virus (VSV-G) and baculovirus gp64 are inactivated by human complement. The extent of vector inactivation in serum from individual donors was examined and results showed wide donor-dependent variation in complement sensitivity for VSV-G-pseudotyped lentivectors. Amphotropic envelope (Ampho)-pseudotyped vectors were generally resistant to serum from all donors, while gp64-pseudotyped vectors were inactivated but showed less donor-to-donor variation than VSV-G. In animal sera, the vectors were mostly resistant to inactivation by rodent complement, whereas canine complement caused a moderate reduction in titer. In a novel advance for the lentiviral vector system, human complement-resistant-pseudotyped lentivector particles were produced through incorporation of complement regulatory proteins (CRPs). Decay accelerating factor (DAF)/CD55 provided the most effective protection using this method, while membrane cofactor protein (MCP)/CD46 showed donor-dependent protection and CD59 provided little or no protection against complement inactivation. Unlike previous approaches using CRPs to produce complement-resistant viral vectors, CRP-containing lentivectors particles were generated for this study without engineering the CRP molecules. Thus, through overexpression of native DAF/CD55 in the viral producer cell, an easy method was developed for generation of lentiviral vectors that are almost completely resistant to inactivation by human complement. Production of complement-resistant lentiviral particles is a critical step toward use of these vectors for in vivo gene therapy applications.

Word retrieval in amyotrophic lateral sclerosis: a functional magnetic resonance imaging study

The cognitive impairment revealed in some non- demented amyotrophic lateral sclerosis (ALS) patients is characterized by executive dysfunction with widely repeated deficits on tests of verbal (letter) fluency. However, conflicting evidence exists of an impairment on other word retrieval tasks, such as confrontation naming, which do not place heavy demands on executive processes. Previous research has demonstrated intact confrontation naming in the presence of verbal fluency deficits, although naming deficits have been described in other studies. In this investigation, functional MRI (fMRI) techniques were employed to explore whether word retrieval deficits and underlying cerebral abnormalities were specific to letter fluency, which are more likely to indicate executive dysfunction, or were also present in confrontation naming, indicating language dysfunction. Twenty-eight non-demented ALS patients were compared with 18 healthy controls. The two groups were matched for age, intelligence quotient, years of education, and anxiety and depression scores. Two compressed-sequence overt fMRI activation paradigms were employed, letter fluency and confrontation naming, which were developed for use with an older and potentially impaired population. In ALS patients relative to controls, the letter fluency fMRI task revealed significantly impaired activation in the middle and inferior frontal gyri and anterior cingulate gyrus, in addition to regions of the parietal and temporal lobes. The confrontation naming fMRI task also revealed impaired activation in less extensive prefrontal regions, including the inferior frontal gyrus and regions of the temporal, parietal and occipital lobes. These changes were present despite matched performance between patients and controls during each activation paradigm. The pattern of dysfunction corresponded to the presence of cognitive deficits on both letter fluency and confrontation naming in the ALS group. This study provides evidence of cerebral abnormalities in ALS in the network of regions involved in language and executive functions. Moreover, the findings further illustrate the heterogeneity of cognitive and cerebral change in ALS.