Morphing voxels: the hype around structural imaging of headache patients.

Department of Systems Neuroscience, Universitäts-Krankenhaus Eppendorf , Martinistrasse 52, Hamburg, Germany.
Brain (Impact Factor: 10.23). 06/2009; 132(Pt 6):1419-25. DOI: 10.1093/brain/awp116
Source: PubMed

ABSTRACT Neuroimaging analysis using structural data has begun to provide insights into the pathophysiology of headache syndromes. Several independent studies have suggested a decrease in grey matter in pain-transmitting areas in migraine patients. Most of these data are discussed as damage or loss of brain grey matter, reinforcing the idea of migraine as a progressive disease. However, given what we know about the nature of morphometric changes detectable by the methods we have to date, this interpretation is highly speculative and not supported by the data. It is likely that these changes are the consequence and not the cause of the respective headache syndromes, as they are probably not irreversible and only mirror the proportion or duration of pain suffered. Moreover, structural changes are not headache specific and have to be seen in the light of a wealth of pain studies using these methods. The studies in cluster headache patients prompted the use of stereotactic stimulation of the hypothalamic target point identified by functional and structural neuroimaging. Due to the nature of the methods used and due to a high anatomical variance it is more than questionable to use this point as a definite answer to the source of the headache in clusters and even more so when it is uncritically used in individuals. We need a way to study each patient individually using the functional imaging method with the highest spatial and temporal resolution available to enable us to target the seed point for deep brain stimulation on this individual basis. One of the major future challenges is to understand the behavioural consequences and cellular mechanisms underlying neuroanatomic changes in pain and headache.

  • Source
    Headache The Journal of Head and Face Pain 04/2012; 52(1). DOI:10.1111/j.1526-4610.2011.02083.x · 3.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Despite modern antiretroviral therapy, HIV-associated sensory neuropathy affects over 50 % of HIV patients. The clinical expression of HIV neuropathy is highly variable: many individuals report few symptoms, but about half report distal neuropathic pain (DNP), making it one of the most prevalent, disabling, and treatment-resistant complications of HIV disease. The presence and intensity of pain is not fully explained by the degree of peripheral nerve damage, making it unclear why some patients do, and others do not, report pain. To better understand central nervous system contributions to HIV DNP, we performed a cross-sectional analysis of structural magnetic resonance imaging volumes in 241 HIV-infected participants from an observational multi-site cohort study at five US sites (CNS HIV Anti-Retroviral Treatment Effects Research Study, CHARTER). The association between DNP and the structural imaging outcomes was investigated using both linear and nonlinear (Gaussian Kernel support vector) multivariable regression, controlling for key demographic and clinical variables. Severity of DNP symptoms was correlated with smaller total cerebral cortical gray matter volume (r = -0.24; p = 0.004). Understanding the mechanisms for this association between smaller total cortical volumes and DNP may provide insight into HIV DNP chronicity and treatment-resistance.
    Journal of NeuroVirology 01/2014; DOI:10.1007/s13365-014-0236-8 · 3.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cluster headache (CH) is characterized by recurrent episodes of excruciatingly painful, unilateral headache attacks typically accompanied by trigeminal autonomic symptoms. Due to its rhythm with alternating episodes of pain and no-pain, it is an excellent model to investigate whether structural brain changes detected by magnetic resonance based voxel-based-morphometry (VBM) reflect the cause of the disease, may be a consequence of the underlying disease other than pain, or may simply be caused by the sensation of pain itself. We investigated 91 patients with CH in different stages of their disease using VBM and compared them to 78 age- and gender-matched healthy controls. We detected distinct regional gray matter (GM) changes in different brain regions including the temporal lobe, the hippocampus, the insular cortex and the cerebellum. The extent, location and direction of observed GM alterations depended on the state of disease and appeared dynamic in relation to pain state (i.e., pain vs. no-pain). No hypothalamic changes were detected in CH patients compared to healthy controls. The GM changes observed in this study are highly dynamic and thereby reflect the cortical plasticity of the brain in regard to pain. This observed dynamic may provide an explanation of the diverse results of previous VBM studies in pain. Regarding CH the results suggest that the disease is more likely to be caused by a network dysfunction rather than by a single malfunctioning structure.
    01/2014; 6. DOI:10.1016/j.nicl.2014.10.003

Full-text (2 Sources)

Available from
May 30, 2014