The hyperthermia and the hypothermia elicited by 5 mg/kg, i.p. or 30 mg/kg i.p. of morphine in rats are abolished by a previous lesion of the midbrain raphe resulting in a lowering of forebrain 5‐HT and 5‐hydroxyindolacetic acid. Lesions lateral to the midbrain raphe which do not modify brain 5‐HT are without effect on body temperature changes induced by morphine. Animals lesioned in the midbrain raphe are still able to respond with a hyperthermia or with a hypothermia when they are treated respectively with 2,4‐dinitrophenol or phentolamine.
Background
Cerebral ventriculomegaly is an abnormal feature characteristic of myotonic dystrophy type 1 (DM1). This retrospective study investigated the morphologic changes accompanied by ventriculomegaly in DM1 on brain MRI.
Methods
One hundred and twelve adult patients with DM1 and 50 sex- and age-matched controls were assessed. The imaging characteristics for evaluations included the z-Evans Index (ventriculomegaly), callosal angle (CA), enlarged perivascular spaces in the centrum semiovale (CS-EPVS), temporo-polar white matter lesion (WML) on 3D fluid-attenuated inversion recovery (FLAIR), disproportionately enlarged subarachnoid-space hydrocephalus (DESH), and pathological brain atrophy. The “z-Evans Index” was defined as the maximum z-axial length of the frontal horns to the maximum cranial z-axial length. To determine the imaging characteristics and genetic information (CTG repeat numbers) that were associated with the z-Evans Index, we used binominal logistic regression analyses.
Results
The z-Evans Index was significantly larger in the patients than in the controls (0.30 ± 0.05 vs. 0.24 ± 0.02; p < 0.01). The z-Evans Index was independently associated with the callosal angle (p < 0.01) and pathological brain atrophy (p < 0.01) but not with age, gender, CTG repeat numbers, or CS-EPVS. Of the 34 patients older than 49 years, 7 (20.6%) were considered to have DESH.
Conclusions
Our MRI study revealed a normal pressure hydrocephalus (NPH)-like appearance as a morphologic finding accompanied by ventriculomegaly in DM1 that tends to occur in elderly patients.
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