Magnetic resonance spectroscopy in neurological diagnosis.

Clinical MRS Unit, Huntington Medical Research Institutes, 10 Pico Street, Pasadena, CA 91105, USA.
Neurologic Clinics (Impact Factor: 1.61). 03/2009; 27(1):21-60, xiii. DOI: 10.1016/j.ncl.2008.09.007
Source: PubMed

ABSTRACT In this article, we review the role of MRS in neurologic diagnosis and patient care. Technical discussion focuses on the few remaining issues, localization, spectral display, and interpretation because interesting questions surrounding this widely diverse methodology have been resolved, and a single coherent diagnostic MRS protocol can be applied worldwide on clinical MRI scanners. We provide the most diagnostically useful MRS findings and discuss what is lacking for MRS to become a valuable addition to diagnostic evaluation of neurologic problems. Finally, we muse about the still-underappreciated role of MRS as a molecular neuroimaging technique and predict steady growth of this application as hyperpolarization MR technology approaches the clinic.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introducción: El efecto adverso tóxico crónico más relevante que puede ocasionar la fenitoína es producido sobre el cerebelo pudiendo causar una atrofia cerebelosa irreversible. Objetivo: Llamar la atención sobre la ocurrencia de atrofia cerebelosa en pacientes expuestos a la fenitoína en forma crónica. Resaltar la importancia y posibilidad de efectuar un diagnóstico precoz. Actualizar las hipótesis planteadas en su patogenia. Desarrollo: Breve síntesis histórica de la fenitoína desde su incorporación a la terapéutica de las crisis epilépticas, sus efectos adversos agudos, sub-agudos y crónicos, haciendo énfasis en la atrofia cerebelosa. Se presenta un caso clínico desarrollado durante el tratamiento a largo plazo con fenitoína en una paciente epiléptica. Describimos las hipótesis planteadas hasta ahora sobre los mecanismos fisiopatológicos involucrados en la producción de la atrofia. Se realiza una revisión actualizada y completa de la bibliografía y se citan los autores más pertinentes. Conclusiones: La Atrofia cerebelosa causada por el uso crónico de la fenitoína se produce en un porcentaje bajo de pacientes, aún no determinado; sin embargo, su ocurrencia se debe tener siempre presente en las personas tratadas con fenitoína en forma prolongada. Muy demostrativos de atrofia cerebelosa son algunos exámenes como la TAC y la RNM, cuyos hallazgos pueden preceder a las manifestaciones clínicas, lo que permite realizar un diagnóstico precoz, La aparición de nuevas técnicas neuroradiológicas, como la RNM con tensor de difusión (RNM-DT) prometen contribuir a dilucidar los mecanismos fisiopatológicos involucrados. Se revisan las hipótesis actuales postuladas en la patogenia, como acción toxica directa, anoxia y desaferentación.
    Revista chilena de neuro-psiquiatría. 03/2012; 50(1):42-50.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Essential tremor is regarded to be a disease of the central nervous system. Neuroimaging is a rapidly growing field with potential benefits to both diagnostics and research. The exact role of imaging techniques with respect to essential tremor in research and clinical practice is not clear and a systematic review into the different imaging techniques in essential tremor is lacking the literature. Methods We performed a systematic literature search combining the terms essential tremor and familial tremor with the keywords: imaging, MRI, VBM, DWI, fMRI, PET and SPECT, both in abbreviated as well as in full form. We summarize and discuss the quality and the external validity of each study and place the results in the context of existing knowledge regarding the pathophysiology of essential tremor. Results A total of 48 neuroimaging studies met our search criteria, roughly divided in 19 structural and 29 functional and metabolic studies. The quality of the studies varied, especially concerning inclusion criteria. Functional imaging studies indicated cerebellar hyperactivity during rest and during tremor. The studies also pointed to involvement of the thalamus, the inferior olive and the red nucleus. Structural studies showed less consistent results. Discussion and conclusion Neuroimaging techniques in essential tremor give insight in the pathophysiology of essential tremor indicating involvement of the cerebellum as most consistent finding. GABAergic dysfunction might be a major premise in the pathophysiological hypotheses. Inconsistencies between studies can be partly explained by the inclusion of heterogeneous patient groups. Improvement of scientific research requires more stringent inclusion criteria and application of advanced analysis techniques. Also, the use of multimodal neuroimaging techniques is a promising development in movement disorders research. Currently, the role of imaging techniques in essential tremor in daily clinical practice is limited.
    NeuroImage: Clinical. 01/2014; 5.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Autism Spectrum Disorders (ASD) are neurodevelopmental disorders with multifactorial origin characterized by social communication deficits and the presence of repetitive behaviors/interests. Several studies showed an association between the reelin gene mutation and increased risk of ASD and a reduced reelin expression in some brain regions of ASD subjects, suggesting a role for reelin deficiency in ASD etiology. Reelin is a large extracellular matrix glycoprotein playing important roles during development of the central nervous system. To deeply investigate the role of reelin dysfunction as vulnerability factor in ASD, we assessed the behavioral, neurochemical, and brain morphological features of reeler male mice. We recently reported a genotype-dependent deviation in the ultrasonic vocal repertoire and a general delay in motor development of reeler pups. We now report that adult male heterozygous (Het) reeler mice did not show social behavior and communication deficits during male-female social interactions. Wildtype and Het mice showed a typical light/dark locomotor activity profile, with a peak during the central interval of the dark phase. However, when faced with a mild stressful stimulus (a saline injection) only Het mice showed an over response to stress. In addition to the behavioral studies, we conducted high performance liquid chromatography and magnetic resonance imaging and spectroscopy to investigate whether reelin mutation influences brain monoamine and metabolites levels in regions involved in ASD. Low levels of dopamine in cortex and high levels of glutamate and taurine in hippocampus were detected in Het mice, in line with clinical data collected on ASD children. Altogether, our data detected subtle but relevant neurochemical abnormalities in reeler mice supporting this mutant line, particularly male subjects, as a valid experimental model to estimate the contribution played by reelin deficiency in the global ASD neurobehavioral phenotype.
    Frontiers in Pediatrics 09/2014; 2:95.