Journal of the neurological sciences
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Multiple sclerosis (MS) is characterised by focal areas that undergo cycles of demyelination and remyelination. Although conventional magnetic resonance imaging is very effective in localising areas of damage, these techniques are not pathology specific. A newer technique, T(2) relaxation, can separate water from brain into three compartments: (1) a long T(2) component (>2 s) arising from CSF, (2) an intermediate T(2) component (~80 ms) attributed to intra- and extra-cellular water and (3) a short T(2) component (~20 ms) assigned to water trapped in between the myelin bilayers (termed myelin water). ⋯ Two lesions showed low MWF in the core suggesting demyelination upon first appearance. At later time points, one lesion showed a decrease in volume of low MWF, reflecting remyelination whereas the volume of low MWF in the other lesion core remained constant. This work provides evidence that MWF and WC can monitor demyelination and remyelination in MS.
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The CACNA1A gene codes for the alpha(1A) pore-forming subunit of Ca(2+) voltage-gated Cav2.1 channels. CACNA1A mutations are responsible for Familial Hemiplegic Migraine (FHM) type 1, Episodic Ataxia (EA) type 2 and Spinocerebellar Ataxia type 6. The structure of the human gene includes, at present, 49 exons; however almost nothing is known about the 5' regulatory region, and there is now evidence suggesting the presence of additional exons at the 3' of the gene. ⋯ At the 3' end of the gene a new exon 48, followed by a strong poly-A signal, was identified as well as a new splice variant. The 5 bp insertion (g.38429_38430insCTTTT) in this exon was found in an EA patient. The two new regions can open the way for the study of human CACNA1A gene expression regulation and can be sites of mutations associated with FHM or EA phenotypes.
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Case Reports
Isolated facio-lingual hypoalgesia and weakness after a hemorrhagic infarct localized at the contralateral operculum.
Isolated facio-lingual hypoesthesia and weakness is rare. We describe a case of isolated facio-lingual hypoesthesia and weakness after a hemorrhagic infarct localized at the contralateral operculum. ⋯ Brain magnetic resonance imaging showed a subacute hemorrhagic infarct in the right frontal operculum, which spread slightly to the right temporo-parietal operculum. (123)IMP-SPECT showed hypoperfusion in the right fronto-temporo-parietal operculum, as detected by MRI, without apparent diaschisis within the brain. Neuroimaging findings for our patient suggested the involvement of the primary somatosensory-motor cortices (S1 and M1) and the secondary somatosensory cortex (S2), which receive trigemino-thalamo-cortical pathways.
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A number of patients with Parkinson's Disease (PD) complain of painful sensations that might be related not only to peripheral factors (muscle spasms, postural abnormalities) but also to an abnormal processing of nociceptive inputs in the Central Nervous System (CNS). To test this hypothesis, we recorded scalp CO(2) laser evoked potentials (LEPs) to foot skin stimulation in 11 pain-free treated PD patients affected by hemiparkinson (during the off state), in 6 pain-free drug-naïve hemiparkinsonian patients and in 11 healthy subjects. ⋯ ANOVA showed that the N2/P2 amplitude was significantly lower and pain rating significantly increased in treated PD patients than in controls in both the affected and unaffected sides, while in drug-naïve PD patients the reduction of the N2/P2 amplitude and the increase in pain rating were observed only in the affected side. These results suggest that in pain-free PD patients there is an abnormal nociceptive input processing that may be independent of the clinical expression of parkinsonian motor signs.
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Severe, abrupt onset headache raises concern for aneurysmal subarachnoid hemorrhage (SAH). The current standard work-up is brain CT scan followed by LP if the CT is non-diagnostic in patients with a normal neurological exam. Some have suggested that angiography is also indicated in this common clinical situation. Is evaluation with brain CT and LP for thunderclap headache to rule out SAH sufficient and is angiography needed? ⋯ Although our methods have important limitations, we believe that this analysis will give clinicians better tools to decide whether or not to pursue further work-up with angiography in patients with thunderclap headache and normal neurological exam, CT, and LP.