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M Mascalchi

Publications and source records attributed to M Mascalchi.

At least 73 records · Page 4Linked to original sources
PubMed1993

Cine-MR imaging of aqueductal CSF flow in normal pressure hydrocephalus syndrome before and after CSF shunt.

Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction.

Adolescent↗
PubMed1992

Slowly progressive familial dementia with recurrent strokes and white matter hypodensities on CT scan.

We describe 2 normotensive sisters presenting slowly progressive dementia associated with acute or subacute focal neurological symptoms, unilateral or bilateral motor signs, and dysarthria. Their father, who died in the seventh decade, had a similar clinical picture. Computerized axial tomography (CT) scan of the head showed symmetrical hypodensities in the periventricular white matter and mild to moderate hydrocephalus. In these patients a diagnosis of Binswanger's disease was based on the clinical features supported by white matter changes on CT scan. Our study suggests that genetic factors may play a role in the etiology of Binswanger's disease.

Adult↗
PubMed1992

Multiple lesions in cerebral white matter in two young adults with thoracic extramedullary tumours.

Cranial MRI showed multiple lesions in white matter that were thought to be consistent with multiple sclerosis in two young adults presenting with symptoms of progressive myelopathy. MRI of the cervicothoracic spine around one and two years after onset showed the myelopathy to be due to mid-thoracic tumours. The tumours (an extradural meningioma and intradural neuroma) were resected with complete resolution of myelopathy in one patient but no recovery in the other. Spinal MRI (or myelography) should be performed in young patients presenting with signs of progressive myelopathy even when cranial MRI shows a picture typical of multiple sclerosis.

Adult↗
PubMed1992

Spinal intramedullary subependymomas: case report and review of the literature.

A cervical spinal intramedullary subependymoma in a 53-year-old man is reported, and the relevant literature is reviewed. Spinal cord subependymomas seem to follow a benign course. Radiotherapy should not be administered to these patients. Magnetic resonance imaging, even with enhancement, is not able to distinguish between a subependymoma and the more common ependymoma.

Ependymoma↗
PubMed1992

Magnetic resonance imaging of degenerative diseases of the central nervous system.

MRI enables a better assessment than CT of the bulk loss, i.e. atrophy, which is a characteristic feature of all the degenerative diseases of CNS, at least in their advanced phases. Moreover, in several of these disorders, proton density, balanced and T2 weighted MR images can show symmetric areas of abnormally low or high signal intensity in the deep gray nuclei or white matter. Since these signal abnormalities are not specific of degenerative diseases of the CNS, their shape and distribution have to match those of the histopathological changes characteristic of each disease, before they could represent useful ancillary signs. Combination of the above MRI findings with appropriate clinical and laboratory features will however be crucial to the diagnosis in any single case.

Adult↗
PubMed1992

Rhabdomyosarcoma of the petrous ridge. CT and MR imaging in an atypical case with multiple cranial nerve palsy.

The CT and MR findings are reported in a case of biopsy proven rhabdomyosarcoma of the skull base. The tumor presumably originated in a pneumatized petrous ridge and had an atypical presentation of multiple cranial nerve palsy. The lesion exhibited a soft tissue density and a nonexpansile bone destruction on unenhanced CT. On MR imaging the lesion showed homogeneous intermediate signal intensity on T1 weighted images and a high signal intensity on proton density and T2 weighted images. The scanty literature on CT and MR features of rhabdomyosarcoma of the head and neck is reviewed.

Child, Preschool↗
PubMed1991

Delayed intracerebral hemorrhage after CSF shunt for communicating "normal-pressure" hydrocephalus. Case report.

A patient with arterial hypertension and a history of cerebrovascular accidents presented with communicating normal-pressure hydrocephalus. Two weeks after ventriculo-peritoneal CSF shunt he had a fatal intracerebral hemorrhage. Delayed intracerebral hemorrhage is an extremely rare complication of ventricular CSF shunting, the possible mechanisms of which are briefly discussed.

Aged↗
PubMed1991

Leukoaraiosis: a reappraisal. II. MRI studies.

Magnetic resonance imaging is more sensitive than computed tomography to brain white matter changes of undefined significance observed in elderly subjects termed leuko-araiosis. Cross-sectional clinical studies have shown that these changes are more frequent or are more extensive in patients with cerebrovascular disease or vascular risk factors. Pathological studies have revealed that a number of alterations may underlie focal white matter changes including complete and incomplete lacunar infarcts, état criblé, dilated perivascular (Virchow-Robin) spaces, demyelination, and gliosis. Diffuse white matter changes are more difficult to explain. These might result from confluence of focal changes, or from diffuse white matter ischemia (incomplete infarct). Alternatively, they may be related to alterations of the transependymal CSF flow. Longitudinal studies in asymptomatic subjects correlating the MRI picture with clinical, pathophysiological, and histopathological data are needed in order to establish the significance and prognostic value of the different processes underlying LA, and to plan therapeutic strategies to prevent or treat them.

Aged↗
PubMed1991

An analysis of the arterial input curve for technetium-99m-HMPAO: quantification of rCBF using single-photon emission computed tomography.

Arterial radioactivity content after the intravenous administration of HMPAO in seven human subjects was analyzed. Arterial sampling of 99mTc-HMPAO was performed on each subject over a 25-min period postinjection. The lipophilic fraction of the tracer present in the blood was rapidly extracted with octanol. An analysis of the time course of the extracted and nonextracted octanol fractions was performed in order to calculate the arterial input of the tracer available for brain extraction. HMPAO net regional brain clearances were then calculated and compared with rCBF values obtained in the same patients using 99mTc-microspheres injected into the left ventricle of the heart. HMPAO brain clearances were 0.41 +/- 0.01 and 0.27 +/- 0.01 ml/min/g for grey and white matter, respectively. Linear regression analysis was performed and the following result was obtained: clearance (HMPAO) = 0.07 + 0.43 . rCBF with a high significance (p less than 0.001). This equation can be used for the transformation of HMPAO clearances into rCBF values. Our study demonstrates that by using HMPAO and SPECT it is possible to obtain a quantitative estimate of rCBF in humans.

Adult↗
PubMed1990

Leuko-araiosis: a reappraisal. I. CT studies.

Leuko-araiosis is a purely descriptive term indicating images of bilateral, patchy or diffuse areas of decreased density frequently observable in the deep white matter on brain CT scans of adults and elderly subjects. While in earlier studies these images were considered as the "in vivo" expression of leukoencephalopathy associated with Binswanger disease, subsequently they have been reported in a rather broad spectrum of clinical conditions, including healthy aging and dementia of different types. Evidence of arterial hypertension and lacunar stroke is found in only two-thirds of subjects with leuko-araiosis. The results of pathological studies are conflicting about the nature of leukoencephalopathy, and the type and severity of medullary artery involvements. Probably several mechanisms underlie leuko-araiosis. They might act separately or be combined in different cases. Classification by physiopathological mechanism may be a suitable aim of future research in this field.

Aging↗
PubMed1990

Leukoaraiosis, intracerebral hemorrhage, and arterial hypertension.

To investigate whether the observed association of leukoaraiosis with intracerebral hemorrhage is direct or mediated by risk factors, we compared 116 patients with intracerebral hemorrhage confirmed by computed tomography and 155 controls without intracerebral hemorrhage, evaluating the prevalence of leukoaraiosis and vascular risk factors. Leukoaraiosis was observed in 21 (18%) of the 116 patients and in 12 (8%) of the 155 controls (p less than 0.01). Only two (6%) of the 31 patients with lobar hemorrhage had leukoaraiosis on computed tomograms, compared with 17 (24%) of the 71 patients with basal ganglionic hemorrhage (p less than 0.05). Leukoaraiosis was significantly correlated with intracerebral hemorrhage after controlling for age and sex by using multiple logistic regression analysis, while the correlation disappeared after controlling for hypertension. Our results indicate that leukoaraiosis is not an independent risk factor for intracerebral hemorrhage.

Brain↗
PubMed1990

Fast multiphase MR imaging of aqueductal CSF flow: 1. Study of healthy subjects.

Gradient-echo MR sequences are more sensitive to flow phenomena than spin-echo sequences are. We investigated aqueductal CSF flow by fast multiphase imaging. Fast multiphase imaging offers the opportunity to perform a dynamic study of fluid motion that is synchronous with the cardiac cycle. A section perpendicular to the cerebral aqueduct was imaged in 18 healthy volunteers. Serial, gated (every 50 msec from the ECG R wave), flow-compensated modulus images with 70 degrees-flip-angle excitation pulses were obtained with a single acquisition. The behavior vs time of CSF signal in the aqueduct was compared with that in the lateral ventricles. The former showed a peak at 0.47 +/- 0.1 fractions of a heart cycle after the R wave. No periodicity with the heart rate was observed for the ventricular CSF signal intensity. The mean CSF signal intensity in the aqueduct was found to range from about twice to three times that in the lateral ventricles over a cardiac cycle. Fast multiphase imaging is a sensitive and practical sequence for the MR investigation of aqueductal CSF flow. Its potential in patients with hydrocephalus is studied in a companion article.

Adult↗
PubMed1990

Fast multiphase MR imaging of aqueductal CSF flow: 2. Study in patients with hydrocephalus.

The signal intensity in the region corresponding to the cerebral aqueduct was evaluated in three patients with noncommunicating tension hydrocephalus (caused by aqueductal obstruction in two and type I Arnold-Chiari malformation in the other), seven patients with suspected normal-pressure hydrocephalus (three of whom subsequently underwent successful shunting), and 10 patients with ex vacuo (atrophic) hydrocephalus. A gradient-echo MR sequence, called fast multiphase imaging, was used. Serial images corresponding to different phases of the cardiac cycle were acquired. No flow-related enhancement was observed over the entire cardiac cycle in the patients with noncommunicating hydrocephalus. Patients with normal-pressure hydrocephalus showed a higher aqueductal CSF signal intensity, consistent with increased systolic flow rates, than patients with ex vacuo hydrocephalus. When comparing the above two groups of patients with a control group of healthy volunteers, significantly higher and lower values of the (mean) maximum aqueductal signal intensity were found in the normal-pressure hydrocephalus patients and the ex vacuo hydrocephalus patients, respectively. Fast multiphase MR evaluation of aqueductal CSF flow may help to differentiate patients with different types of hydrocephalus.

Adult↗
PubMed1990

Subcortical arteriosclerotic encephalopathy: single photon emission computed tomography-magnetic resonance imaging correlation.

Regional cerebral blood flow was studied using 99mTc-HM-PAO and single photon emission computed tomography (SPECT) in five healthy subjects and in eight patients with clinical and computed tomography (CT) features of subcortical arteriosclerotic encephalopathy. All the patients and controls underwent magnetic resonance imaging (MRI). Circumscribed cortical hypoperfusion was observed in three patients, and in one case there was no evidence of cortical or sulcal alterations on MRI. In all the patients, a reduction of the white matter perfusion was found in periventricular and/or supraventricular regions. This pattern was substantially correlated with the typical white matter hyperintensities shown by MRI scans. These findings support the hypothesis that white matter hypoperfusion is the most prominent functional abnormality in subcortical arteriosclerotic encephalopathy.

Aged↗
PubMed1989

Computed tomography, magnetic resonance imaging and pathological correlations in a case of Binswanger's disease.

The results of 3 computed tomography (CT) examinations carried out over a 7 year period and of a post-mortem magnetic resonance (MR) study showed aspects of a white matter disease in a hypertensive patient suffering from vascular dementia. Histopathology revealed the primary cause of dementia to be a white matter degeneration sparing the U fibers. Rarefaction of both the myelin sheaths and the axons was present together with severe thickening of the medullary arteries. These findings support the existence of Binswanger's disease (BD) as a distinct variety of arteriosclerotic dementia. CT and MR imaging are valuable aids for diagnosis. However, since there are many other causes of CT and MR demonstrated diffuse white matter degeneration in the elderly, a conclusive diagnosis of BD requires pathological confirmation.

Dementia, Vascular↗
PubMed1989

Histopathological correlates of leuko-araiosis in patients with ischemic stroke.

A neuropathological study was carried out in 4 cases of ischemic stroke with leuko-araiosis (LA), 3 cases of clinically suspected Binswanger's subcortical arteriosclerotic encephalopathy (SAE) also showing LA, and 3 cases without LA. Unlike the SAE cases, in 3 of the cases in the first group the white matter changes corresponding to LA could not be explained by ischemic mechanisms related to small vessel changes.

Aged↗