Insulin-like growth factor-1 (IGF-1): relation with cognitive functioning and neuroimaging marker of brain damage in a sample of hypertensive elderly subjects.

IGF-1 decline has been related to age-dependent cognitive impairment and dementia. No study examined IGF-1 levels in subjects with a risk factor for brain damage such as hypertension. We investigated the relationship between IGF-1, cognitive functioning and neuroimaging in a sample of 75 hypertensive elderly subjects aged > 65. Cognitive performance were tested by mini mental state examination (MMSE), Cambridge cognitive examination (CAMDEX-R), and the frontal assessment battery (FAB). Among other indices, free IGF-1 in serum was assayed. The radial width of the temporal horn (rWTH) evaluates medial cerebral temporal lobe atrophy. Significant correlations between IGF-1 levels and both total and sub-domain scores of cognition were found. IGF-1 level was significantly lower in cognitively declined group. The lowest IGF-1 -percentile subgroup was significantly cognitively impaired. A statistically non-significant, but lower IGF-1 level was found in the sub-sample with pathologically wider rWTH. Levels of IGF-1 below 79.4 microg/l are associated with cognitive decline, whereas a level above 118 microg/l seems to be a marker of normal cognitive performance. A decreasing of IGF-1 related to a widening of the rWTH suggests an involvement of this hormone in hippocampus atrophy.

A comparison between in vivo and ex vivo HR-MAS 1H MR spectra of a pediatric posterior fossa lesion.

The present case report was aimed at identifying the molecular profile characteristic of a primitive neuro-ectodermal tumor (PNET) in a 3-year-old child affected by a lesion localized in the cerebellar region. The histological diagnosis was medulloblastoma. In vivo single voxel 1H magnetic resonance spectroscopy (MRS) shows high specificity in detecting the main metabolic alterations in the primitive cerebellar lesion; a very high amount of the choline-containing compounds and very low level of creatine derivatives and N-acetylaspartate. Ex vivo high resolution magic angle spinning (HR-MAS) 1H magnetic resonance spectroscopy, performed at 9.4 Tesla on the neoplastic specimen collected during surgery, allows for the unambiguous identification of several metabolites giving a more in-depth evaluation of the metabolic pattern of the lesion. The ex vivo HR-MAS MR spectra show that the spectral detail is much higher than that obtained in vivo and that, for example, myo-inositol, taurine and phosphorylethanolamine contribute to the in vivo signal at 3.2 ppm, usually attributed to choline-containing compounds. In addition, the spectroscopic data appear to correlate with some morphological features of the medulloblastoma. Consequently, the present study shows that ex vivo HR-MAS 1H MRS is able to strongly improve the clinical possibility of in vivo MRS and can be used in conjunction with in vivo spectroscopy for clinical purposes.