Absence of N‐acetylaspartate in the human brain: Impact on neurospectroscopy?

Martin, Ernst; Capone, Andrea; Schneider, Jacques; Hennig, Jürgen; Thiel, Thorsten

doi:10.1002/ana.102.abs

Cited by 40 publications

(48 citation statements)

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“…Conditioning pulse protocols have reliably demonstrated reduced intracortical inhibition as a characteristic feature of ALS [Menon et al, 2015; Yokota et al, 1996; Ziemann et al, 1997], which may be partly ameliorated by reducing glutamatergic influence through administration of Riluzole—the only licensed disease‐modifying therapy in ALS [Stefan et al, 2001; Vucic et al, 2013a]. Postmovement beta rebound corresponds well to a period of reduced cortico‐spinal tract excitability, and the present data suggest that ALS patients differ in the speed of transition to this state after movement.…”

Section: Discussionmentioning

confidence: 99%

Altered cortical beta‐band oscillations reflect motor system degeneration in amyotrophic lateral sclerosis

Proudfoot

Rohenkohl

Quinn

et al. 2016

Human Brain Mapping

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Continuous rhythmic neuronal oscillations underpin local and regional cortical communication. The impact of the motor system neurodegenerative syndrome amyotrophic lateral sclerosis (ALS) on the neuronal oscillations subserving movement might therefore serve as a sensitive marker of disease activity. Movement preparation and execution are consistently associated with modulations to neuronal oscillation beta (15–30 Hz) power. Cortical beta‐band oscillations were measured using magnetoencephalography (MEG) during preparation for, execution, and completion of a visually cued, lateralized motor task that included movement inhibition trials. Eleven “classical” ALS patients, 9 with the primary lateral sclerosis (PLS) phenotype, and 12 asymptomatic carriers of ALS‐associated gene mutations were compared with age‐similar healthy control groups. Augmented beta desynchronization was observed in both contra‐ and ipsilateral motor cortices of ALS patients during motor preparation. Movement execution coincided with excess beta desynchronization in asymptomatic mutation carriers. Movement completion was followed by a slowed rebound of beta power in all symptomatic patients, further reflected in delayed hemispheric lateralization for beta rebound in the PLS group. This may correspond to the particular involvement of interhemispheric fibers of the corpus callosum previously demonstrated in diffusion tensor imaging studies. We conclude that the ALS spectrum is characterized by intensified cortical beta desynchronization followed by delayed rebound, concordant with a broader concept of cortical hyperexcitability, possibly through loss of inhibitory interneuronal influences. MEG may potentially detect cortical dysfunction prior to the development of overt symptoms, and thus be able to contribute to the assessment of future neuroprotective strategies. Hum Brain Mapp 38:237–254, 2017. © 2016 Wiley Periodicals, Inc.

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Section: Discussionmentioning

confidence: 99%

Altered cortical beta‐band oscillations reflect motor system degeneration in amyotrophic lateral sclerosis

Proudfoot

Rohenkohl

Quinn

et al. 2016

Human Brain Mapping

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“…This and many other observations have led many to conclude that NAA is a neuronal marker. This conclusion was questioned by Martin et al 52 who reported MR spectra with little or no NAA in a three year-old patient with developmental deficits. This report was followed by several letters to the editor discussing the role of NAA as a neuronal marker.…”

Section: N-acetylaspartatementioning

confidence: 95%

Recent Advances in Magnetic Resonance Neurospectroscopy

Rosen

Lenkinski

2007

Neurotherapeutics

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Summary:Over the past two decades, proton magnetic resonance spectroscopy (proton MRS) of the brain has made the transition from research tool to a clinically useful modality. In this review, we first describe the localization methods currently used in MRS studies of the brain and discuss the technical and practical factors that determine the applicability of the methods to particular clinical studies. We also describe each of the resonances detected by localized solvent-suppressed proton MRS of the brain and discuss the metabolic and biochemical information that can be derived from an analysis of their concentrations. We discuss spectral quantitation and summarize the reproducibility of both single-voxel and multivoxel methods at 1.5 and 3-4 T. We have selected three clinical neurologic applications in which there has been a consensus as to the diagnostic value of MRS and summarize the information relevant to clinical applications. Finally, we speculate about some of the potential technical developments, either in progress or in the future, that may lead to improvements in the performance of proton MRS.

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“…Proton ( 1 H) magnetic resonance spectroscopy (MRS) of the human brain in vivo makes it possible to measure the pool size of certain chemical constituents presumed to be metabolically important, including amino acids (eg Nacetylaspartate or NAA), amines, sugars, and bioenergetic metabolites (Martin et al, 2001). The promise inherent to measuring metabolites in the living brain has made MRS methodology very attractive to investigators interested in psychiatric illness.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Brain Metabolites by 1H Magnetic Resonance Spectroscopy in Patients with Schizophrenia: A Systematic Review and Meta-Analysis

Steen

Hamer

Lieberman

2005

Neuropsychopharmacol

245

183

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A systematic review of the literature identified 64 published English-language papers that used proton ( 1 H) magnetic resonance spectroscopy to measure N-acetylaspartate (NAA) concurrently in healthy controls and in patients with a diagnosis of schizophrenia (SZ). A total of 1209 controls and 1256 patients have been evaluated, with 88% of studies carried out at 1.5 T field strength, and 77% of studies focused on patients with chronic SZ. There is consistent evidence that NAA is reduced in a broad range of tissues in the SZ brain. Broad consensus (X10 studies) is emerging that NAA levels are reduced X5% in hippocampus and in both cortical gray matter (GM) and white matter (WM) of the frontal lobe. There is no evidence to support a hypothesis that relative NAA levels are reduced to a different degree in frontal lobe GM and WM, nor is there robust evidence of a difference in NAA levels between patients with firstepisode and chronic SZ. Study reliability may be a problem, as most studies appear to be underpowered. With simple assumptions about the inherent difference in NAA levels between patients and controls, it can be calculated that a minimum sample size of approximately 39 patients and 39 controls is required for acceptable statistical power. Only three of 64 studies included enough subjects to have 80% power to detect a 10% NAA reduction in patients, and no studies were adequately powered to detect a 5% NAA reduction with 80% power.

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Absence of N‐acetylaspartate in the human brain: Impact on neurospectroscopy?

Cited by 40 publications

References 0 publications

Altered cortical beta‐band oscillations reflect motor system degeneration in amyotrophic lateral sclerosis

Altered cortical beta‐band oscillations reflect motor system degeneration in amyotrophic lateral sclerosis

Recent Advances in Magnetic Resonance Neurospectroscopy

Measurement of Brain Metabolites by 1H Magnetic Resonance Spectroscopy in Patients with Schizophrenia: A Systematic Review and Meta-Analysis

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