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Biomedical subjects

M Locatelli

Publications and source records attributed to M Locatelli.

At least 37 records · Page 2Linked to original sources
PubMed2002

Anatomo-clinical correlation of intraoperative stimulation-induced side-effects during HF-DBS of the subthalamic nucleus.

The efficacy of deep brain stimulation of the subthalamic nucleus (STN) is dependent on the accuracy of targeting. In order to reduce the number of passes and, consequently, the duration of surgery and risk of bleeding, we have set up a new method based on direct magnetic resonance imaging (MRI) localisation of the STN. This procedure allows a short duration of the neurophysiological session (one or two initial tracks). Whenever a supplementary track is needed, the stimulation-induced side effects are analysed to choose from one of the remaining holes in Ben's gun. A good knowledge of anatomical structures surrounding the STN is mandatory to relate side effects to the actual position of the track. In our series of 11 patients (22 sides, 37 tracks), the most common and reproducible side effects were those characterised by motor, sensorial, oculomotor and vegetative signs and symptoms. Moreover, the therapeutic window (distance between the current intensity needed to obtain the best clinical effect and the intensity capable to induce side effects) predicted clinical efficacy in the long-term, and contributed to the choice of which among the examined tracks had to be implanted with the chronic macroelectrode.

Electric Stimulation Therapy↗
PubMed2002

Cerebellar mature teratoma in adulthood.

Mature teratoma of the posterior cranial fossa in adults is extremely rare. We report a particularly rare case of medio-lateral cerebellar mature teratoma that became symptomatic in a middle-aged man. The CT revealed the lesion of heterogeneous density with calcifications in the solid medial portion. Only the MRI could reliably define the borders of the cystic component extending into the left cerebellar lobe. Histologically the presence of fully matured representative tissues of the 3 germ layers ensured the diagnosis of mature teratoma. We suggest that the cyst formation from progressive latent hemorrhage and/or secretion from the gland cells of the tumor, may be responsible for the clinical decompensation even in adulthood.

Cerebellar Neoplasms↗
PubMed2001

Assessment of cure and recurrence after pituitary surgery for Cushing's disease.

BACKGROUND: The treatment of choice in Cushing's disease is transsphenoidal adenomectomy with a recurrence rate ranging 9-23%. We investigated whether abnormal hormonal responses may predict the relapse in "operated" patients followed-up for a long period. METHOD: Sixty-eight surgically treated patients with Cushing's disease were followed-up for 12-252 months. Forty-eight patients underwent selective adenomectomy, 17 enlarged adenomectomy and 3 underwent total hypophysectomy. After surgery ACTH and cortisol levels were measured after stimulatory (desmopressin and CRH) and inhibitory tests (dexamethasone and loperamide). FINDINGS: After operation 46 patients were cured (group A), 15 patients only normalized cortisol levels (group B), 7 patients were surgical failures. During the follow-up, a disease-free condition was maintained in 48 of 61 cases (79%), while a recurrence occurred in 13 patients (21%, 5 of group A and 8 of group B). In 5/13 patients who relapsed an absent inhibition after dexamethasone and an exaggerated response to CRH test preceded the recurrence. In 5 other patients the relapse was suspected by loperamide test. In the 3 remaining cases, positive responses to desmopressin preceded the recurrence. In 7/13 patients who relapsed the pituitary tumour was visualized by MRI/CT imaging. INTERPRETATION: During the follow-up a careful assessment of ACTH dynamics is needed. Although no single test can reliably predict the late outcome, individual patients at risk for relapse may be identified by abnormal responses to desmopressin, CRH and loperamide tests; particularly, the persistent responsiveness to desmopressin may be a criterion of risk for recurrence in patients who only normalized cortisol levels after surgery.

Adenoma↗
PubMed2001

Multiple intracranial lesions in head injury: clinical considerations, prognostic factors, management, and results in 95 patients.

BACKGROUND: The goal of this study was to identify clinical and radiological predictors of prognosis in patients with multiple post-traumatic intracranial lesions. METHODS: We reviewed 95 patients (75 male and 20 female) between the ages of 18 and 70 (average 38) admitted between 1993 and 2000 with multiple post-traumatic intracranial lesions. Intracranial pressure (ICP) monitoring was carried out in 67 patients (70%); 77 received intensive care unit (ICU) treatment. Since in all cases it was possible to identify a clearly predominant lesion, 3 groups of patients emerged from the data: the first with extradural hematoma (EDH), the second with a combination of homolateral subdural (SDH) and intracerebral hematoma (ICH), and the third with pure focal intracerebral hematoma (ICH). RESULTS: Twenty-seven patients were treated conservatively, 2 of whom died (7.4%); both had bilateral ICH and compression of the basal cisterns. Sixty-eight patients underwent one or more surgeries; 8 died (11.7%). In the group with EDH-predominant lesions (27 cases) all patients were operated (16 for multiple lesions); no one died. In the group with SDH+ICH-predominant lesions, 26 of 32 patients were operated (10 had multiple procedures); 6 died (18.7%), 3 were vegetative. In the group with ICH-predominant lesion, 15 of 36 patients were operated (7 bilaterally); 4 died (11%). Decompressive craniectomy proved to be a useful means to control ICP. Bilateral lobectomy is not recommended because of poor results. Immediate postoperative computed tomography (CT) scan proved to be mandatory to detect additional surgically treatable lesions (16 cases). Statistical analysis was performed by means of chi(2) analysis and multiple linear regression model. The multiple linear regression model was used to ascertain risk factors independently associated with the outcome. The type of lesion (presence of SDH+ICH predominant lesion), the worst recorded Glasgow Coma Scale (GCS) score, the presence of prolonged increased ICP, and the absence of pupillary reflexes were all statistically significant predictors of a bad outcome (dead or vegetative state). CONCLUSIONS: Multiple lesions have the same prognosis as the corresponding single lesions; therefore, their management should be guided by the predominant pathology.

Adult↗
PubMed2001

Clinical predictors of drug response in obsessive-compulsive disorder.

The aim of this study was to evaluate which clinical variables might influence the antiobsessional response to proserotonergic drugs in a sample of patients with obsessive-compulsive disorder (OCD). One hundred fifty-nine patients with DSM-IV OCD underwent a 12-week standardized treatment with fluvoxamine, clomipramine, citalopram, or paroxetine. According to treatment response, defined as a reduction of the Yale-Brown Obsessive Compulsive Scale total score >35%, patients were divided into two groups. Ninety patients (56.6%) responded to treatment and 69 (43.4%) did not. Responders had a significantly higher frequency of positive family history for OCD (FH-OCD) in their first-degree relatives, whereas nonresponders had an earlier onset and a higher frequency of "poor insight" subtype and somatic obsessions. The predictive value of all these variables was tested by a stepwise logistic regression analysis that confirmed poor insight and FH-OCD to be the best predictors of poor and good drug treatment response, respectively. These preliminary findings need additional investigations toward a better definition of the genetic and biological heterogeneity of patients with OCD, and they underlie the importance of collecting the insight score and family history for psychiatric disorders in the pretreatment assessment.

Adolescent↗
PubMed2001

Abnormal pattern of cortical activation associated with voluntary movement in obsessive-compulsive disorder: an EEG study.

OBJECTIVE: Converging evidence in patients with obsessive-compulsive disorder (OCD) shows abnormalities of prefrontal areas and basal ganglia, which are also involved in motor control. Event-related desynchronization of mu and beta EEG rhythms is considered a correlate of motor activation during motor preparation and execution, followed by cortical idling or inhibition indicated by event-related synchronization. The authors investigated the circuits involved in motor behavior in OCD by using event-related desynchronization/synchronization. METHOD: Data on alpha and beta event-related desynchronization/synchronization with self-paced movement of the right thumb were obtained by using 29-channel EEG in 10 untreated OCD patients and 10 normal subjects. RESULTS: OCD patients showed delayed onset of mu event-related desynchronization with movement preparation and less postmovement beta synchronization, compared to normal subjects. CONCLUSIONS: Delayed event-related desynchronization in OCD is consistent with involvement of structures related to motor programming, such as basal ganglia. Lower levels of postmovement beta synchronization suggest impairment of the inhibitory system in OCD.

Adult↗
PubMed2001

[Spiral-CT with multiplanar reconstructions (MPRS) in the evaluation of ureteral neoplasms: preliminary results].

PURPOSE: Urothelial tumors of the upper urinary tract (renal pelvis and ureters) are rare: the most common of these are Transitional Cell Carcinomas (TCC), usually localized in the bladder (75% of cases), whereas only 7-10% arise in the renal pelvis and 2,5-5% in the ureter. Multicentricity is not infrequent and synchronous or metachronous tumors have been reported to develop in 11-13% of patients with upper urinary tract cancer and 2-4% of those with bladder cancer. The presence of additional lesions can change patient management. Clinically these tumors may present with hematuria or flank pain, but sometimes there are no specific clinical findings. Radiological studies play an important role in tumor detection and staging and in follow up. The diagnosis is usually performed by IVU and US, while CT is generally employed in the staging. Our purpose was to verify the role of Spiral CT with Multiplanar Reconstructions (MPRs) in the evaluation of ureteral tumors. MATERIAL AND METHODS: Nine patients with ureteral neoplasms were examined with a single detector spiral-CT, using the following parameters: 120 kV, 200 mA; 5 mm collimation, pitch 1.4, slice reconstruction every 5 mm; image acquisition 2-5 minutes after injection of 120 cc of contrast medium (300 mgI/ml). All the exams were transferred to a separate workstation to obtain curvilinear MPRs. RESULTS: Spiral CT on the axial plane visualized 4 urothelial tumors as concentric ureteral wall thickening; 3 as intraluminal soft tissue masses, with involvement of almost the entire urinary tract, as far as the bladder in 1 case. In other 2 patients there were synchronous lesions which presented both patterns (wall thickening and intraluminal mass). In all cases the lesions exhibited moderate enhancement after c.m. injection. Medium- to high-grade hydronephrosis above the tumors was always present. On MPRs both ureteral involvement and dilated, urine-filled upper urinary tract were clearly represented on coronal and sagittal oblique planes; these images allowed to visualize the craniocaudal extension of short or long lesions, and to detect multicentricity. DISCUSSION: The radiological diagnosis of ureteral tumors is usually performed by IVU, US and CT. IVU allows to visualize the tumors as filling defects or irregular narrowing of the ureteral lumen. IVU however is unable to show the real extent of the tumor in obstructive disease or in nonfunctioning kidney. US visualizes the lesion as an echoic mass in the lumen, although it is sometimes difficult to differentiate neoplastic lesions from other filling defects and to visualize the entire ureteral tract. CT is generally employed in the staging of ureteral tumors. CT findings are usually very useful for distinguishing ureteral neoplasms from other filling defects based on their attenuation and enhancement characteristics. Spiral CT with MPRs allows to obtain panoramic views of the urinary tract; these images are more effective than those of IVU, because of their capability to show the longitudinal extension of the lesion and the presence of multicentric tumors. Furthermore with MPRs it is possible to visualize the ureteral tract distal to the lesion, overcoming the limitations of IVU in nonfunctioning kidney or obstructive disease. CONCLUSIONS: Spiral CT with MPRs is useful in the evaluation of ureteral tumors as it is capable of visualizing the whole extension of the lesion and the presence or absence of multicentric lesions, which can change patient management.

Aged↗
PubMed2000

Characterization of unifocal liver lesions with pulse inversion harmonic imaging after Levovist injection: preliminary results.

The aim of this study was to evaluate capabilities of pulse inversion harmonic imaging (PIHI) in characterization of unifocal liver lesions. We evaluated with PIHI (HDI5000, ATL, Bothell, Wash.) and spiral CT 46 consecutive patients with a single liver lesion identified by fundamental US [7 hepatocellular carcinomas (HCC), 2 cholangiocarcinomas, 7 focal nodular hyperplasias (FNH), 17 hemangiomas and 13 metastases]. The PIHI was performed before and 30 s, 2 and 4 min after bolus administration of Levovist (2.5 g, 300 mg/ml). Scans were digitally stored and reviewed using a dedicated software. Hepatocellular carcinoma was hyperechoic on 30-s scan, and hypoechoic (n = 5) or isoechoic (n = 2) on 2-min scan. Cholangiocarcinoma had inhomogeneous persistent enhancement. Focal nodular hyperplasia was hyperechoic (n = 5) or isoechoic (n = 2) on 30-s scan, hyperechoic (n = 4), isoechoic (n = 2) or slightly hypoechoic (n = 1) on 2-min scan. Large hemangioma revealed peripheral enhancement on 30-s scan which extended centripetally on 2-min scan. Small hemangioma appeared isoechoic on 2-min scan in all but two cases in which they were hypoechoic on 2-min scans and hyperechoic on 4-min scan. Metastasis was hypoechoic on all scans, 70% with rim enhancement. Similar changes in enhancement pattern have been observed at spiral CT. The 30-s and the 2-min scans revealed a conclusive importance in characterization of HCC, cholangiocarcinoma, and large hemangioma. The 2-min scan often furnished enough information for characterization of small hemangioma and metastasis. The 4-min scan allowed characterization of two hemangiomas which appeared hypoechoic on 2-min scans. In the other cases it did not provide further information. Diagnosis of FNH is usually reached with Colour Doppler US; PIHI should be used when colour Doppler is biased by artefacts or when colour Doppler findings are not characteristic. Our results seem to show that PIHI could be a valuable alternative diagnostic approach to spiral CT for unifocal liver lesion characterization. This hypothesis needs to be confirmed with an increased number of lesions.

Adult↗
PubMed2000

Serum liver enzymes in Turner syndrome.

UNLABELLED: Increased serum concentrations of liver enzymes are sometimes observed, in the absence of clinical symptoms of liver disease, in patients with Turner syndrome. The purpose of this study was to evaluate, in our Turner patients, serum liver enzyme levels and to find a cause for their increase. In 70 Turner patients, serum AST, ALT, GGT levels were evaluated every 6 months during a period of 0. 8-21.9 years. In patients in whom increased values of liver enzymes were found, serological markers for infectious hepatitis, serum hepatitis C virus RNA and virus genotype, IgG and IgA antibodies to gliadin and endomysium, coeruloplasmin, copper, alpha(1)-antitrypsin, total proteins and electrophoresis, IgG, IgA, IgM, fibrinogen, prothrombin, alkaline phosphatase, creatine kinase and total and direct bilirubin were also determined. Antinuclear, anti-smooth muscle and anti-liver-kidney microsome antibodies together with antithyroglobulin and anti-thyroid peroxidase antibodies were determined in all patients and in 166 age-matched female controls. In 22 patients, increased liver enzymes were observed, not related to karyotype. Follow-up showed that the hepatic disorder did not worsen with the time. Serological markers of hepatitis C virus were positive in three patients. When the serum liver enzyme increase was first observed in the other 19 patients with high enzyme levels (group A), 14 patients had never been submitted to hormonal treatment, 4 were on oestrogen/gestagen treatment and 1 was being treated with both growth hormone and oestrogen. Coeliac disease, alpha(1)-antitrypsin deficiency and Wilson disease were ruled out by appropriate investigations. In 8/19 group A patients, antinuclear and/or anti-smooth muscle antibodies were present versus 6/48 of patients with normal liver enzymes (group B). Thyroid antibodies were found in 8/19 patients in group A and in 13/48 in group B. Weight excess SDS was significantly higher in Turner girls with liver enzyme increase. Ultrasonography, performed in 17 patients of group A, showed mild hepatomegaly in 4 and increased echogenicity with fatty infiltration in 6. CONCLUSION: Hepatic abnormalities in Turner syndrome are not progressive. Oestrogen should not be considered the main cause of increased liver enzymes in Turner syndrome since most of our patients with this finding had not been previously treated with oestrogens. An auto-immune pathogenesis might be considered in some cases, whereas the association with weight excess seems the most frequent cause of liver disorder in Turner syndrome.

Adolescent↗
PubMed2000

The importance of substance P and calcitonin gene related peptide as vasodilator neuropeptide during acute phase of experimental posthemorrhagic vasospasm.

BACKGROUND: Several immunohistochemical studies conducted in the acute phase following SAH have demonstrated a marked depletion of certain peptides like Substance P (SP), Calcitonin Gene Related Peptide (CGRP) from the adventitia of perivascular nerves. The present experimental study was carried out with the aim of determining whether the depletion of these peptides could be a protection mechanism against the factors which sustain the vasospasm. METHODS: To accomplish this goal, we administered specific antiserum to block the potential effect of neuropeptides (SP and CGRP) prior to SAH. Our study tried also to realize whether difference can be demonstrated between endothelium-dependent (SP) and endothelium-independent vasodilatory mechanisms (CGRP) during the acute phase ofvasospasm. Twenty-three rabbits were divided in 5 experimental groups: Group A included normal control animals, Group B included rabbits who received saline injection prior to SAH, Group C included animals who received preimmune serum, groups D and E included animals who received respectively antiserum against CGRP and against SP prior to SAH. The antisera were administered into the cisterna magna by means of percutaneous suboccipital puncture. After 15 minutes 1 ml of autologous non-heparinized blood was injected in the same way. After 20 minutes the animals were sacrificed by cardiac perfusion. The basilar artery was removed by means of transclival approach and it was included in Epon 812. Mean diameters and luminal areas of the arteries were measured with morphometric method on sections of 2-3 microm of thickness. RESULTS: The results showed a reduced mean diameter and luminal areas in the group B comparing to normal controls of the group A. A marked vasospasm is mainly evident in group D and E. In group C the vasospasm is not significantly different from that of group B. No significant difference was demonstrated between group D and group E. CONCLUSIONS: We can conclude that: 1) the marked depletion of neuropeptides in the early phases of vasospasm represents a functional phenomenon in order to reduce the effectiveness of spasmogenic stimula. In fact the inhibition of the activity of these neuropeptides worses the entity of the vasospasm. 2) During the acute phase of vasospasm the endothelium-dependent vasodilatory mechanism is still functioning. No significant difference in the entity of vasospasm has been demonstrated between inhibition of SP (endothelium-dependent) and CGRP (endothelium-independent). Inactivation of such a mechanism occurs during late phases.

Animals↗
PubMed1999

Detection of liver metastases with pulse inversion harmonic imaging: preliminary results.

The aim of this study is to evaluate capability of contrast enhanced ultrasonography (US) using pulse inversion harmonic imaging (PIHI) to detect liver metastases in comparison to fundamental B-mode ultrasound and spiral CT. Thirty-six consecutive patients with known malignancies and sonographically proved or suspicious liver metastases have been examined with fundamental B-mode US, with PIHI 2', 4' and 6' after Levovist injection and with four phase spiral-CT. Presence, conspicuity and number of lesions have been evaluated comparing PIHI with fundamental B-mode US and spiral-CT. A strong grey-scale enhancement of the liver parenchyma has been observed 2' and 4' after Levovist injection. The optimum parenchymal enhancement and contrast difference between liver and metastases was observed during the 2' measurements. PIHI revealed more lesions than fundamental B-mode US in 56 % of patients, while in 39 % and in 5 % revealed respectively the same number and fewer lesions. PIHI and spiral-CT were in agreement in 67 % of patients, while in 22 % and 11 % PIHI revealed respectively more and fewer lesions. PIHI accurancy presents restrictions in anterior superficial and in deep liver areas, whereas it may be superior to spiral-CT in studying sub-diaphragmatic liver regions.

Aged↗
PubMed1999

[IDDM-Sardinia Project: a study model on the etiopathogenesis of insulin-dependent diabetes mellitus and other autoimmune pathologies. Gruppi di studio IDDM-Sardegna].

The "IDDM-Sardinia project" started in the beginning '90s and this main objective was, and still is, to clarify the epidemiological aspects of insulin-dependent diabetes mellitus in Sardinia, an island with a high incidence of the disease. Initially, the project included three main aims: 1) to continue monitoring the incidence of the disease and to design maps of geographical distribution of it in the island; 2) to study the pre-diabetes period, by assaying islet-related autoantibodies (ICA, GADA and IA-2icA), and to design models of prediction in a general population from a large cohort of 10,000 schoolchildren, and 3) to investigate the natural history of the disease by monitoring the appearance of islet-related autoantibodies in a cohort of 19,000 newborn. Most recently, new research lines branched from these main topics, and now the project is also investigating other autoimmune diseases, in particular coeliac disease and autoimmune thyroiditis. In this paper we still summarise and discuss the state-of-the-art of the whole project.

Adolescent↗
PubMed1998

Commutability of control materials in glycohemoglobin determinations.

The intermethod variabilities of control materials and patient blood samples for the measurement of glycohemoglobin were compared. Sets of 50 blood samples and 15 control materials were analyzed by HPLC and affinity and immunochemical methods. For each pair of methods, the distances of the materials from the regression line of patient blood results (expressed as normalized residuals) were calculated. Only two of 15 controls had normalized residuals exceeding 3 standard deviations from the regression line. Total hemoglobin (Hb) content, Hb derivatives, and cellulose acetate electrophoresis demonstrated that only a minority of controls could be considered similar to patients' blood samples. We selected Menarini's and our home-prepared controls to simulate calibration of the different techniques by these materials. Intermethod calibration succeeded mostly in harmonizing results obtained by HPLC methods. On the contrary, calibration of the immunochemical techniques (Boehringer and Roche) did not improve intermethod agreement to a clinically useful level.

Chromatography, Affinity↗