Biomedical subjects

Gianpaolo Basso

Publications and source records attributed to Gianpaolo Basso.

5 recordsLinked to original sources

PubMed2006

Hyperemesis gravidarum complicated by Wernicke encephalopathy: background, case report, and review of the literature.

Wernicke encephalopathy (WE) is a rare but known complication of severe hyperemesis gravidarum caused by thiamine deficiency. This article presents an unusual case that occurred at our institution and reviews the 48 previously published cases of WE in pregnancy. Considering all the 49 cases, the mean (+/-standard deviation) patients' age was 26.7 +/- 4.9 years, the mean gestational age when WE manifested was 14.3 +/- 3.4 weeks, and the mean duration of vomiting and feeding difficulties was 7.7 +/- 2.8 weeks. Wernicke's classic triad (confusion, ocular abnormalities, and ataxia) manifested in only 46.9% (23 of 49) of the patients. Confusion affected 63.3% (31 of 49) of the patients, ocular signs 95.9% (47 of 49) and symptoms 57.1% (28 of 49), and ataxia 81.6% (40 of 49). Deterioration of consciousness affected 53.1% (26 of 49) of the subjects and memory impairment 61.2% (30 of 49). Complete remission of the disease occurred in only 14 of 49 cases. Symptom resolution required months and permanent impairments were common. The overall pregnancy loss rate, directly (spontaneous fetal loss) and indirectly (planned abortion) attributable to WE, was 47.9% (23 of 49). The diagnosis of WE is clinical and can be rapidly confirmed by magnetic resonance imaging. We emphasize the importance of thiamine supplementation to women with prolonged vomiting in pregnancy, especially before intravenous or parenteral nutrition. We also underline the necessity to promptly replace vitamin B1 when neurologic symptoms and/or signs develop in a patient with hyperemesis gravidarum.

Adult↗

PubMed2005

Retinotopic mapping in the human visual cortex using vascular space occupancy-dependent functional magnetic resonance imaging.

Recently, we introduced a new methodology, vascular space occupancy functional magnetic resonance imaging, which detects brain activation on the basis of blood volume changes in parenchymal microvasculature and may provide higher spatial specificity than the blood oxygenation level-dependent method. To study whether this technique can be used for advanced brain mapping applications, we performed retinotopic mapping using alternating horizontal and vertical wedges that stimulate different portions of the visual field. The results using vascular space occupancy functional magnetic resonance imaging showed clear boundaries for V1/V2/VP/V4v in the ventral areas and V1/V2/V3/V3A in the dorsal areas, similar to the maps obtained using blood oxygenation level-dependent functional magnetic resonance imaging. Vascular space occupancy functional magnetic resonance imaging is a useful addition to the other neuroimaging techniques. Disadvantages of vascular space occupancy functional magnetic resonance imaging include lower contrast-to-noise ratio (about 1/3 of that of blood oxygenation level-dependent method) and limited volume coverage (nine slices for TR=3 s).

Adult↗

PubMed2005

Temporal production and visuospatial processing.

Current models of prospective timing hypothesize that estimated duration is influenced either by the attentional load or by the short-term memory requirements of a concurrent nontemporal task. In the present study, we addressed this issue with four dual-task experiments. In Exp. 1, the effect of memory load on both reaction time and temporal production was proportional to the number of items of a visuospatial pattern to hold in memory. In Exps. 2, 3, and 4, a temporal production task was combined with two visual search tasks involving either pre-attentive or attentional processing. Visual tasks interfered with temporal production: produced intervals were lengthened proportionally to the display size. In contrast, reaction times increased with display size only when a serial, effortful search was required. It appears that memory and perceptual set size, rather than nonspecific attentional or short-term memory load, can influence prospective timing.

Adult↗

PubMed2003

Distributed neural systems for temporal production: a functional MRI study.

Using functional magnetic resonance imaging (fMRI), we investigated the neural substrates for computing time intervals. Five right-handed males were asked to judge if a digit probe belonged to a string of digits presented immediately before but to provide their response only after 1.5s had elapsed. This time estimation condition, compared with control working memory and motor tasks, was associated with increased activity in the middle occipital gyri, in the right inferior parietal lobe, and bilaterally in the prefrontal cortex. We argue that activity elicited in the occipital lobe provides duration information about visual stimuli that can be quantified at the level of the inferior parietal lobe. Comparison with time reference information depends on the bilateral prefrontal cortex.

Adult↗

PubMedDate not supplied

Human brain language processing areas identified by functional magnetic resonance imaging using a lexical decision task.

The purpose of this study was to validate a functional magnetic resonance imaging (fMRI) paradigm to activate both anterior and posterior language areas while collecting accuracy and reaction time data on subjects' performance. The paradigm was based on alternating graphemic and lexical decision tasks. In line with the classical model of language organisation, based on lesion data, and with the results of previous neuroimaging studies, cortical activation associated with lexical decision-making was strongly lateralised to the left hemisphere and involved a network of regions in the frontal, temporal and parietal lobes. Single subject analysis demonstrated that the activation paradigm we propose is suitable for detecting language processing areas in humans for clinical studies.

Adult↗