Roger A. Barker

Visualising disease progression on multiple variables with vector plots and path plots (2009)

Lazic, Stanley E, Mason, Sarah L, Michell, Andrew W, Barker, Roger A

Abstract Background It is often desirable to observe how a disease progresses over time in individual patients, rather than graphing group averages; and since multiple outcomes are typically recorded...

The distinct cognitive syndromes of Parkinson's disease: 5 year follow-up of the CamPaIGN cohort (2009)

Williams-Gray, Caroline H., Evans, Jonathan R., Goris, An, Foltynie, Thomas, Ban, Maria, Robbins, Trevor W., ...

Cognitive abnormalities are common in Parkinson's disease, with important social and economic implications. Factors influencing their evolution remain unclear but are crucial to the development of...

Neurobiology of Disease Catechol O-Methyltransferase val 158 met Genotype Influences Frontoparietal Activity during Planning in Patients with Parkinson’s Disease (2008)

Adam Hampshire, Trevor W. Robbins, Adrian M. Owen, Roger A. Barker

Cognitive dysfunction commonly occurs even in the early stages of Parkinson’s disease (PD). Impairment on frontostriatally based executive tasks is particularly well described but affects only a...

Attentional control in Parkinson's disease is dependent on COMT val158met genotype (2008)

Williams-Gray, Caroline H., Hampshire, Adam, Barker, Roger A., Owen, Adrian M.

Cognitive deficits occur even in the earliest stages of Parkinson's disease. Some such deficits are known to relate to dysfunction in dopaminergic frontostriatal networks, and may be influenced by a...

Hypothalamic involvement in Huntington's disease: an in vivo PET study (2008)

Politis, Marios, Pavese, Nicola, Tai, Yen F., Tabrizi, Sarah J., Barker, Roger A., Piccini, Paola

Recent studies have shown alterations in metabolism, sleep and circadian rhythms as well as in several neuropeptides derived from the hypothalamic–pituitary axis in Huntington's disease patients;...

Tau and alpha-synuclein in susceptibility to, and dementia in, Parkinson's disease (2007)

Clark, Graeme R, Foltynie, Thomas, Lewis, Simon J. G, Brown, Joanne, ...

Objective: Parkinson's disease (PD) is a neurodegenerative condition that typically presents as a movement disorder but is known to be associated with variable degrees of cognitive impairment...

Microglial activation in presymptomatic Huntington's disease gene carriers (2007)

Tai, Yen F., Pavese, Nicola, Gerhard, Alexander, Tabrizi, Sarah J., Barker, Roger A., Brooks, David J., ...

Microglial activation may play a role in the pathogenesis of Huntington's disease (HD). Using 11C-(R)-PK11195 (PK) positron emission tomography (PET), we investigated microglial activation in HD...

Huntington disease patients and transgenic mice have similar pro-catabolic serum metabolite profiles (2006)

Underwood, Benjamin R., Broadhurst, David, Dunn, Warwick B., Ellis, David I., Michell, Andrew W., Vacher, Coralie, ...

There has been considerable progress recently towards developing therapeutic strategies for Huntington's disease (HD), with several compounds showing beneficial effects in transgenic mouse models....

Huntington disease patients and transgenic mice have similar pro-catabolic serum metabolite profiles (2006)

Underwood, Benjamin R., Broadhurst, David, Dunn, Warwick B., Ellis, David I., Michell, Andrew W., Vacher, Coralie, ...

There has been considerable progress recently towards developing therapeutic strategies for Huntington's disease (HD), with several compounds showing beneficial effects in transgenic mouse models....

The cognitive ability of an incident cohort of Parkinson's patients in the UK. The CamPaIGN study (2004)

Foltynie, Thomas, Brayne, Carol E. G., Robbins, Trevor W., Barker, Roger A.

We have used multiple sources to identify a population‐representative cohort of newly diagnosed patients with parkinsonism and Parkinson’s disease in the UK over a 2‐year period. All...

The cognitive ability of an incident cohort of Parkinson's patients in the UK. The CamPaIGN study (2003)

Foltynie, Thomas, Brayne, Carol E. G., Robbins, Trevor W., Barker, Roger A.

We have used multiple sources to identify a population-representative cohort of newly diagnosed patients with parkinsonism and Parkinson’s disease in the UK over a 2-year period. All patients have...

Progressive striatal and cortical dopamine receptor dysfunction in Huntington's disease: a PET study (2003)

Pavese, Nicola, Andrews, Thomasin C., Brooks, David J., Ho, Aileen K., Rosser, Anne E., Barker, Roger A., ...

We have studied the progression of striatal and extrastriatal post‐synaptic dopaminergic changes in a group of 12 patients with Huntington’s disease using serial 11C‐raclopride PET, a...

The cognitive ability of an incident cohort of Parkinson's patients in the UK. The CamPaIGN study (2003)

Foltynie, Thomas, Brayne, Carol E. G., Robbins, Trevor W., Barker, Roger A.

We have used multiple sources to identify a population-representative cohort of newly diagnosed patients with parkinsonism and Parkinson’s disease in the UK over a 2-year period. All patients have...

Unilateral transplantation of human primary fetal tissue in four patients with Huntington's disease: NEST-UK safety report ISRCTN no 36485475 (2002)

Rosser, Anne Elizabeth, Barker, Roger A., Harrower, T., Watts, C., Farrington, M., Ho, A. K., ...

Objectives: Huntington’s disease (HD) is an inherited autosomal dominant condition in which there is a CAG repeat expansion in the huntingtin gene of 36 or more. Patients display progressive motor,...

Unilateral transplantation of human primary fetal tissue in four patients with Huntington's disease: NEST-UK safety report (ISRCTN no 36485475). (2002)

Rosser, Anne Elizabeth, Barker, Roger A., Harrower, T., Watts, C., Farrington, M., Ho , A. K., ...

Objectives: Huntington’s disease (HD) is an inherited autosomal dominant condition in which there is a CAG repeat expansion in the huntingtin gene of 36 or more. Patients display progressive motor,...

Unilateral transplantation of human primary fetal tissue in four patients with Huntington's disease: NEST-UK safety report ISRCTN no 36485475 (2002)

Rosser, Anne Elizabeth, Barker, Roger A., Harrower, T., Watts, C., Farrington, M., Ho, A. K., ...

Objectives: Huntington’s disease (HD) is an inherited autosomal dominant condition in which there is a CAG repeat expansion in the huntingtin gene of 36 or more. Patients display progressive motor,...

Unilateral transplantation of human primary fetal tissue in four patients with Huntington's disease: NEST-UK safety report (ISRCTN no 36485475). (2002)

Rosser, Anne Elizabeth, Barker, Roger A., Harrower, T., Watts, C., Farrington, M., Ho , A. K., ...

Objectives: Huntington’s disease (HD) is an inherited autosomal dominant condition in which there is a CAG repeat expansion in the huntingtin gene of 36 or more. Patients display progressive motor,...

The potential for circuit reconstruction by expanded neural precursor cells explored through porcine xenografts in a rat model of Parkinson's disease (2002)

Armstrong, Richard J. E., Hurelbrink, Carrie B., Tyers, Pam, Ratcliffe, Emma L., Richards, Andrew, Dunnett, Stephen Bruce, ...

Neural precursors with the properties of neural stem cells can be isolated from the developing brain, can be expanded in culture, and have been suggested as a potential source of cells for neuronal...

The potential for circuit reconstruction by expanded neural precursor cells explored through porcine xenografts in a rat model of Parkinson's disease (2002)

Armstrong, Richard J. E., Hurelbrink, Carrie B., Tyers, Pam, Ratcliffe, Emma L., Richards, Andrew, Dunnett, Stephen Bruce, ...

Neural precursors with the properties of neural stem cells can be isolated from the developing brain, can be expanded in culture, and have been suggested as a potential source of cells for neuronal...

Dopaminergic modulation of high-level cognition in Parkinson's disease: the role of the prefrontal cortex revealed by PET (2002)

Cools, Roshan, Stefanova, Elka, Barker, Roger A., Robbins, Trevor W., Owen, Adrian M.

This study examined the effects of l‐dopa medication in patients with Parkinson’s disease on cortical and subcortical blood flow changes during two tasks known to involve frontostriatal...

Enhanced or Impaired Cognitive Function in Parkinson's Disease as a Function of Dopaminergic Medication and Task Demands (2001)

Cools, Roshan, Barker, Roger A., Sahakian, Barbara J., Robbins, Trevor W.

We investigated how dopamine (DA) systems contribute to cognitive performance in the domain of learning and attentional flexibility by examining effects of withdrawing DA-ergic medication in patients...

Mechanisms of cognitive set flexibility in Parkinson's disease (2001)

Cools, Roshan, Barker, Roger A., Sahakian, Barbara J., Robbins, Trevor W.

Previous research on cognitive set shifting in patients with Parkinson's disease has often been confounded by concept formation, rule learning, working memory and/or general slowing of cognitive...

Immune Problems in Central Nervous System Cell Therapy

Barker, Roger A., Widner, Håkan

Summary: Transplantation of cells and tissues to the mammalian brain and CNS has revived the interest in the immunological status of brain and its response to grafted tissue. The previously held view...

Immune Problems in Central Nervous System Cell Therapy

Barker, Roger A., Widner, Håkan

Summary: Transplantation of cells and tissues to the mammalian brain and CNS has revived the interest in the immunological status of brain and its response to grafted tissue. The previously held view...