Headache is recognized as one of the most prevalent neurological disorders, and is the most frequently reported symptom following injury to the head, brain, or neck. Although studies of central nervous system abnormalities in headache sufferers have emerged in recent years, less is known about the associated functional impairments. The research literature addressing neuropsychological consequences of headache has been far from conclusive. Migraine has been most extensively studied, with some consistent evidence of subtle but potentially significant changes in cognition occurring during and between migraine episodes. It also appears likely that migraine patients with aura experience more neuropsychological deficits than those without aura. While the literature devoted to understanding the neurocognitive profile of migraine sufferers is growing, much less research has addressed the neuropsychology of tension-type headache and posttraumatic headache (PTHA). There is some suggestion of poorer neuropsychological function in tension-type headache than controls, but the evidence is inconclusive. The PTHA population is highly varied in degree and location of trauma, preexisting headache condition, and other injury-related variables, allowing little generalization across studies. This paper summarizes research regarding the cognitive symptoms associated with migraine, tension-type headache, and PTHA, provides an overview of the cognitive side effects of headache medications, and addresses clinical implications and priorities for future research.
"These nuclei connect to limbic cortical areas and play a role in the modulation of alertness (a), learning and memory (an and md) and attention, planning , organization, abstract thinking, and multitasking (md). Previous clinical studies have reported deficits of attention, memory, and information speed that were worse in MWA patients than in MWoA and HC (for review, see [O'Bryant et al., 2006]). Future studies should aim at correlating structural alterations in these thalamic nuclei with neuropsychological tests assessing their functional performance. "
[Show abstract][Hide abstract] ABSTRACT: Background and objectives:
The thalamus exerts a pivotal role in pain processing and cortical excitability control, and migraine is characterized by repeated pain attacks and abnormal cortical habituation to excitatory stimuli. This work aimed at studying the microstructure of the thalamus in migraine patients using an innovative multiparametric approach at high-field magnetic resonance imaging (MRI).
We examined 37 migraineurs (22 without aura, MWoA, and 15 with aura, MWA) as well as 20 healthy controls (HC) in a 3-T MRI equipped with a 32-channel coil. We acquired whole-brain T1 relaxation maps and computed magnetization transfer ratio (MTR), generalized fractional anisotropy, and T2* maps to probe microstructural and connectivity integrity and to assess iron deposition. We also correlated the obtained parametric values with the average monthly frequency of migraine attacks and disease duration.
T1 relaxation time was significantly shorter in the thalamus of MWA patients compared with MWoA (P < 0.001) and HC (P ≤ 0.01); in addition, MTR was higher and T2* relaxation time was shorter in MWA than in MWoA patients (P < 0.05, respectively). These data reveal broad microstructural alterations in the thalamus of MWA patients compared with MWoA and HC, suggesting increased iron deposition and myelin content/cellularity. However, MWA and MWoA patients did not show any differences in the thalamic nucleus involved in pain processing in migraine.
There are broad microstructural alterations in the thalamus of MWA patients that may underlie abnormal cortical excitability control leading to cortical spreading depression and visual aura.
Human Brain Mapping 04/2014; 35(4). DOI:10.1002/hbm.22266 · 5.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Trellis coded quantization (TCQ) is an efficient technique for
encoding memoryless sources. Furthermore TCQ can be incorporated into a
transform coding structure (such as the discrete cosine transform) for
encoding monochrome and color images with fixed rate or
entropy-constrained schemes. In all these cases an expanded codebook is
partitioned into subsets used to label the branches of an appropriate
graph (trellis). For a given data sequence, the Viterbi algorithm is
then used to find the minimum mean square error path through the
trellis. We present a generic architecture scheme that can be easily
adapted to the different TCQ image compression methods. We also present
a formal model that permits a regular and modular design solution that
is optimal for a particular set of area and/or speed constraints
Image Processing, 1996. Proceedings., International Conference on; 10/1996
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