Biomedical subjects

Simonetta Gerevini

Publications and source records attributed to Simonetta Gerevini.

5 recordsLinked to original sources

PubMed2005

Prognostic significance of JC virus DNA levels in cerebrospinal fluid of patients with HIV-associated progressive multifocal leukoencephalopathy.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) remains a frequent and life-threatening complication of human immunodeficiency virus (HIV) infection in the era of highly active antiretroviral therapy (HAART). Although one-half of patients with this disease will survive, the outcome is unpredictable at diagnosis, and prognostic markers are needed. METHODS: JC virus (JCV) DNA levels were measured in cerebrospinal fluid (CSF) samples obtained from 61 HIV-infected patients with PML, including 38 patients who were treated with HAART and 23 patients who did not receive HAART, with use of real-time polymerase chain reaction. The diagnostic reliability of the assay was evaluated by comparing CSF findings with histopathological findings in patients with PML or other HIV-related diseases of the central nervous system. The prognostic value was assessed by comparing JCV DNA levels with survival and other patient variables. RESULTS: The assay had a diagnostic sensitivity of 76% and specificity of 100%. In the first CSF sample obtained after onset of PML symptoms, JCV DNA values ranged from undetectable to 7.71 log copies/mL (median, 3.64 log copies/mL). JCV DNA levels >3.64 log copies/mL correlated significantly with shorter survival and lower CD4+ cell counts in patients not receiving HAART. However, neither relationship was found in patients who were treated with HAART. The analysis of sequential CSF samples obtained from 24 patients demonstrated a marked decrease in JCV DNA levels over time in HAART-treated patients showing PML stabilization, but not in untreated or HAART-treated patients with progressively fatal disease. CONCLUSIONS: Measurement of JCV DNA levels in CSF samples may be a useful virological marker for management of PML in patients receiving HAART.

Adult↗

PubMed2005

Spinal cord sonography in newborns: anatomy and diseases.

Sonography of the spinal cord is a relatively recent acquisition that makes it possible to evaluate the content of the vertebral canal and study its pathologies. The aim of this study was to verify the reliability of ultrasound images by comparing them with magnetic resonance ones in healthy controls as well as in patients referred to us between 1991 and 2004. In this period, we studied 436 newborns: 88 without any suspicion of disease as normal controls, and 348 with suspected congenital diseases or in order to screen the children of diabetic mothers, a group that has shown an increased incidence of dysraphism. After explaining normal sonograms, we describe the pathological pictures observed in the 12 pathological cases in our series: conus hypomobility in five cases; lack of visualization of the conus medullaris in one case; and an enlarged ependymal canal in six cases. Four cases presented all three pathological conditions, and seven the association of two pathologies. All of these patients also underwent magnetic resonance imaging (MRI), which confirmed the ultrasound findings in four cases: three cases of enlarged ependymal canal and one of tethered cord hypomobility of the roots with an associated lipoma; the MRI findings were normal in the other seven cases. Sonography was highly specific but not very sensitive, because it is partially conditioned by patient collaboration. Nevertheless, subsequent MRI confirmed 37% of the suspected pathological cases. The ultrasound resolution of both normal and pathological spinal cord structures was particularly clear. The images were similar, easily comparable and often identical to the MRI results, although MRI was certainly more sensitive. The advantages of sonography are its non-invasiveness, low cost, the virtually ubiquitous availability of ultrasound equipment, the simplicity and rapidity of the examination, and its specificity. We believe that the indications for its use are lumbo-sacral skin alterations, neurological disorders caused by congenital malformations, traumas due to childbirth or a lumbar puncture, occult dysraphism, all of the compressive spinal cord neo-formations involving nerves, the dura mater and vertebral bone and joint structures, and the screening of the newborns of diabetic mothers.

Case-Control Studies↗

PubMed2003

Age-related changes in conventional, magnetization transfer, and diffusion-tensor MR imaging findings: study with whole-brain tissue histogram analysis.

PURPOSE: To investigate the influence of aging on conventional magnetic resonance (MR) imaging-, magnetization transfer MR imaging-, and diffusion-tensor MR imaging-derived measurements. MATERIALS AND METHODS: Dual-echo T1-weighted magnetization transfer and diffusion-tensor MR images of the brain were obtained in 89 healthy subjects. Normalized brain parenchymal volume (NBV) was measured by using a fully automated technique. Magnetization transfer ratio (MTR), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) histograms were created for the whole brain (MTR values) or for a large representative portion of it (ADC and FA values). Bivariate correlations were assessed by using the Spearman rank correlation coefficient. A stepwise selection procedure was used to identify the combination of variables that were most influenced by subject age in a multivariate regression model. RESULTS: Significant correlations were found between subject age and the following variables: number of hyperintense areas in the brain at T2-weighted MR imaging (r = 0.63, P <.001), NBV (r = -0.79, P <.001), mean ADC (r = 0.34, P =.001), ADC peak height (r = -0.34, P =.001), and FA peak height (r = -0.57, P <.001). NBV correlated significantly with number of hyperintense areas (P <.001), MTR peak height (P <.001), mean ADC (P =.001), ADC peak height (P =.001), and FA peak height (P <.001). The final multivariable regression model included NBV and number of hyperintense areas at T2-weighted MR imaging as independent predictors of subject age. CONCLUSION: In addition to the extent of T2-weighted MR imaging hyperintense areas and the measurement of NBV, diffusion-tensor MR imaging provides additional in vivo information about microstructural age-related brain tissue changes.

Adult↗

PubMed2003

Traumatic subarachnoid hemorrhage on the computerized tomography scan obtained at admission: a multicenter assessment of the accuracy of diagnosis and the potential impact on patient outcome.

OBJECT: The goal of this study was fourfold: 1) to determine the incidence of traumatic subarachnoid hemorrhage (tSAH) in patients with traumatic brain injury (TBI); 2) to verify agreement in the diagnosis of tSAH in a multicenter study; 3) to assess the incidence of tSAH on the outcome of the patient; and 4) to establish whether tSAH itself leads to an unfavorable outcome or whether it is a sign of major brain trauma associated with severe posttraumatic lesions. METHODS: Computerized tomography (CT) scans obtained in 169 head-injured patients on admission to 12 Italian intensive care units during a 3-month period were examined. The scans were collected for neuroradiological review and were used for the analysis together with data from a multicenter database (Neurolink). A review committee found a high incidence of tSAH (61%) in patients with TBI and a moderate agreement among centers (K = 0.57). Significant associations were observed between the presence and grading of tSAH and patient outcomes, and between the presence of tSAH and the severity of the CT findings. Logistic regression analysis showed that the presence of tSAH and its grading alone do not assume statistical significance in the prediction of unfavorable outcome. CONCLUSIONS: Traumatic SAH frequently occurs in patients with TBI, but it is difficult to detect and grade. Traumatic SAH is associated with more severe CT findings and a worse patient outcome.

Adolescent↗

PubMed2002

Irreversible disability and tissue loss in multiple sclerosis: a conventional and magnetization transfer magnetic resonance imaging study of the optic nerves.

OBJECTIVES: To assess, by magnetic resonance imaging, the volumes and magnetization transfer ratio (MTR) values of optic nerves (ONs) from patients with multiple sclerosis (MS) who had incomplete or no visual recovery after optic neuritis; and to compare these quantities with those derived from ONs from patients with MS who showed a marked clinical recovery after optic neuritis, ONs from healthy volunteers, and ONs from patients with Leber hereditary optic neuropathy (LHON). METHODS: Conventional and magnetization transfer magnetic resonance images of the ONs were obtained from 30 patients with MS, 18 healthy volunteers, and 10 patients with LHON. The ON from patients with MS were classified as clinically unaffected (n = 18); clinically affected with recovery (n = 20; visual acuity > or =20/25 at least 6 months after optic neuritis); and clinically affected with incomplete or no recovery (n = 22; visual acuity <20/25 at least 6 months after optic neuritis). The ON volumes and MTR values were measured. RESULTS: Volumes (P =.002) and MTR values (P<.001) of the ONs from patients with MS and incomplete or no recovery were both lower than those of the ONs from patients with MS and recovery, but not different from those of the ONs from patients with LHON. Volumes and MTR values of the affected ONs from patients with MS and recovery did not differ from those of clinically unaffected ONs, which were similar to those of healthy volunteers. CONCLUSION: These findings suggest that, in patients with MS, neurodegeneration is associated with persistent functional deficits secondary to incomplete recovery from relapses.

Adolescent↗