Search PubMed⌕ Search

Biomedical subjects

M Mascalchi

Publications and source records attributed to M Mascalchi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Hypertension, hyperekplexia, and pyramidal paresis due to vascular compression of the medulla.

MRI showed impingement of the vertebral artery on the left lateral medulla in two patients with arterial hypertension, exaggerated startle reflexes (hyperekplexia), and progressive spastic paresis. One patient underwent microvascular decompression with normalization of arterial hypertension, disappearance of hyperekplexia, and improvement of spastic paresis. The combination of arterial hypertension, hyperekplexia, and progressive spastic paresis should arouse suspicion of neurovascular compression of the lateral medulla.

Electromyography↗
PubMed2000

[Diffusion weighted MR: principles and clinical use in selected brain diseases].

PURPOSE: To define the principles and technical bases of diffusion weighted MR imaging of the brain and report our experience in the evaluation of selected brain disorders including age-related ischemic white matter changes (leukoaraiosis), neoplastic and infective cysts and wallerian degeneration. MATERIAL AND METHODS: Between May 1999 and June 2000 we examined seventeen patients: 10 patients with leukoaraiosis and deterioration of cognitive and motor function, 5 patients with focal cystic lesions (one anaplastic astrocytoma, one glioblastoma, one metastasis from squamous cell lung carcinoma, one pyogenic abscess and one case with cerebral tubercolosis) and 2 patients with wallerian degeneration (one with post-hemorrhagic degeneration of right corticospinal tract and one with post-traumatic degeneration of left optic tract). All patients underwent a standard cranial MR examination including SE T1-, proton density, T2-weighted, FLAIR and diffusion weighted images. Post-contrast T1-weighted sequences were also obtained in the patients with cystic lesions. Diffusion weighted images were acquired with double shot echoplanar sequences. Diffusion sensitizing gradient along the x, y and z axes and b values ranging 800 to 1200 s/mm2 were used. For each slice a set of three orthogonal diffusion "anisotropic" images, an "isotropic" image and a standard T2-weighted image were reconstructed. Postprocessing included generation of the apparent diffusion coefficient maps and of the "trace" image that reflects pixel by pixel the diffusional properties of water particles only. Values of mean diffusivity within regions of interest were computed in the "trace" image and compared with those obtained in contralateral brain areas. In patients with leukoaraiosis the diffusivity in posterior periventricular white matter was compared with that measured in 10 age-matched control subjects without leukoaraiosis. RESULTS: In patients with leukoaraiosis the areas of increased periventricular signal intensity on T2-weighted images showed a significantly higher (p < 0.001) diffusivity (mean values 124.7 +/- 21.3 x 10(-5) mm2/s) as compared to control subjects (mean values 85 +/- 7 x 10(-5) mm2/s). Diffusion weighted images in 2 patients revealed the presence of a small focal area of increased signal and reduced diffusivity in "trace" images consistent with recent ischemic lesion. In neoplastic cystic lesions the central necrotic/cystic content was always hypointense on diffusion weighted images and showed increased diffusivity on "trace" images. On the other hand the central necrotic content of the pyogenic brain abscess was hyperintense and showed low diffusivity. In patients with wallerian degeneration diffusion weighted images and "trace" images demonstrated loss of anisotropy and increased diffusivity in the affected white matter tract relative to the contralateral. DISCUSSION: The increased diffusivity observed in areas of leukoaraiosis and the identification of subclinical acute ischemic lesions by diffusion weighted images might be more useful than standard MR sequences for monitoring the disease progression. Diffusion weighted images allow differentiation of the different parts of focal cystic lesions (edema, solid and cystic/necrotic portion) and are useful to differentiate pyogenic brain abscess from necrotic tumors. In patients with wallerian degeneration the loss of anisotropy and the increase of diffusivity values in the affected tract are probably related to myelin breakdown and allow better recognition of the affected tract relative to standard MR images. CONCLUSIONS: Diffusion weighted MR imaging can be performed during a standard cranial MR examination and add useful clinical information in several brain disorders besides acute ischemic stroke.

Brain Abscess↗
PubMed1999

Transthyretin amyloidosis and superficial siderosis of the CNS.

OBJECTIVE: To describe a previously unreported clinical and radiologic presentation of hereditary transthyretin (TTR)-related amyloidosis. BACKGROUND: Unexplained cerebellar ataxia, pyramidal syndrome, and hearing loss are observed in some patients with TTR-related amyloidoses. METHODS: We performed clinical, radiologic, and pathologic examinations of three family members with TTR-related (Ala36Pro) amyloidosis. RESULTS: The patient was a 69-year-old woman with vitreal amyloid deposits, progressive sensorineural deafness, cerebellar ataxia, pyramidal syndrome, and recurrent transient neurologic symptoms. Cranial MRI showed symmetric thin rims of low signal intensity in T2- and T2*-weighted images in the cortex of the sylvian fissures, of the cerebellar hemispheres and vermis, and in the quadrigeminal plate consistent with superficial siderosis of the CNS. Her older daughter had vitreal amyloid deposits, acute Brown-Sequard syndrome at C4, acute sensorineural deafness, and recurrent transient neurologic symptoms. Cranial MRI at age 48 revealed a rim of low signal intensity in T2- and T2*-weighted images in the superior vermis folia and the right sylvian cortex. In addition, two small hemosiderin deposits were seen in the left parietal cortex. Lumbar puncture yielded colorless CSF with increased ferritin content and was followed by fourth ventricle hemorrhage. Cranial MRI 11 months later showed progression of brain hemosiderin deposits. The younger daughter had vitreal deposits, sensorimotor polyneuropathy, and acute sensorineural hearing but no evidence of siderosis on cranial MRI. She died at age 43 years of posterior fossa subarachnoid hemorrhage, and the neuropathologic examination showed amyloid deposition in the leptomeningeal spaces and vessels. CONCLUSION: Transthyretin-related amyloidosis may cause superficial siderosis of the CNS through subarachnoid bleeding related to meningovascular amyloid deposition.

Adult↗
PubMed1999

Do acute lesions of Wernicke's encephalopathy show contrast enhancement? Report of three cases and review of the literature.

Contrast medium was given intravenously to three nonalcoholic patients who underwent MRI or CT in the acute stage of Wernicke's encephalopathy. Lesions enhancement was not seen in one patient examined within 4 days of clinical onset, was mild in a another 3 days after clinical deterioration and marked in a patient examined 12 days after admission. Contrast enhancement of lesions was present in half of 12 cases of acute disease reported previously. There was a substantial overlap in the time interval between clinical onset and contrast-enhanced CT or MRI in the groups of enhancing and nonenhancing lesions. Since contrast enhancement may be absent in acute WE, proton-density and T2-weighted images are more useful for diagnosis of this reversible but potentially fatal condition.

Acute Disease↗
PubMed1999

Phase-contrast MR angiography of intracranial dural arteriovenous fistulae.

MRI and phase-contrast MR angiography (PC MRA) were obtained in 13 patients with angiographically confirmed intracranial dural arteriovenous fistulae (DAVF). Three- and two-dimensional PC MRA was obtained with low (6-20 cm/s) and high (> 40 cm/s) velocity encoding along the three main body axes. MRI showed focal or diffuse signal abnormalities in the brain parenchyma in six patients, dilated cortical veins in seven, venous pouches in four with type IV DAVF and enlargement of the superior ophthalmic vein in three patients with DAVF of the cavernous sinus. However, it showed none of the fistula sites and did not allow reliable identification of feeding arteries. 3D PC MRA enabled identification of the fistula and enlarged feeding arteries in six cases each. Stenosis or occlusion of the dural sinuses was detected in six of eight cases on 3D PC MRA with low velocity encoding. In six patients with type II DAVF phase reconstruction of 2D PC MRA demonstrated flow reversal in the dural sinuses or superior ophthalmic vein.

Adult↗
PubMed1999

Optic neuropathy in Behçet's disease. Report of two cases.

Orbital magnetic resonance imaging demonstrated increased signal of the optic nerve in short time inversion recovery (STIR) images of two young women with unilateral visual blurring. In both, recurrent oral and genital ulcerations and papulopustular lesions appeared within the next 14-15 months, respectively, allowing a diagnosis of Behçet's disease. Optic neuropathy may be an early manifestation of Behçt's disease and clinical follow-up is crucial for its diagnosis.

Adult↗
PubMed1999

Orbital (desmoid type) fibromatosis.

A case of extra-abdominal fibromatosis (EF) of the orbit is described in a 35-year-old man presenting with progressive exophthalmos, right ptosis and diplopia. MRI showed an orbital mass of intermediate signal in T1-weighted images (WI) and low signal in T2WI, which enhanced non-homogeneously after contrast injection. The histological diagnosis of EF was made and the lesion was surgically removed. No recurrence occurred in 40 months of follow-up.

Journal Article↗
PubMed1999

Expanding lacunae causing triventricular hydrocephalus. Report of two cases.

Two patients are reported in whom the presence of triventricular hydrocephalus and aqueductal obstruction or stenosis due to multiple expanding lacunae in the mesencephalothalamic region possibly corresponds to abnormally dilated perivascular spaces. Placement of a ventriculoperitoneal cerebrospinal fluid (CSF) shunt in one patient and the performance of a third ventricle cisternotomy in the other reversed the hydrocephalic syndrome, but did not modify the complex neuroophthalmological disturbance and rubral tremor presumably related to the compressive effects of the lacunae on adjacent parenchyma. In one patient the number and size of the lacunae were increased 4 years after CSF shunt placement. A review of the literature revealed two cases in which magnetic resonance imaging demonstrated a similar, poorly understood pathological condition.

Brain Diseases↗
PubMed1998

Proton magnetic resonance spectroscopy in an Italian family with spinocerebellar ataxia type 1.

Linkage and DNA analysis, magnetic resonance (MR) imaging, and single-voxel proton MR spectroscopy were obtained in 10 members of an Italian kindred with spinocerebellar ataxia type 1 (SCA1). The size of the basis pontis, cerebellar hemispheres, middle cerebellar peduncles, and medulla oblongata were decreased in 4 members carrying the SCA1 gene, compared with 6 unaffected subjects. Diffuse signal changes in the pons and cerebellum were observed only in the carrier with the longest disease duration and greatest disability. The N-acetylaspartate/creatine ratio and the choline/creatine ratio in the basis pontis were markedly decreased in 2 symptomatic SCA1 carriers and moderately decreased in 2 asymptomatic SCA1 carriers, compared with the unaffected family members and a control group of 10 healthy volunteers. Minor decreases in the N-acetylaspartate/creatine ratio and the normal choline/creatine ratio were observed in the cerebellar hemisphere of the SCA1 carriers. Reduction of the N-acetylaspartate/creatine ratio, demonstrated by MR spectroscopy in the pons, is likely to reflect a loss of neuronal viability and might represent a biochemical marker of SCA1 more sensitive than brainstem and cerebellum atrophy and signal changes shown by MR imaging.

Adult↗
PubMed1998

MRI of spinal cord involvement in Behçet's disease: case report.

MRI demonstrated well-defined areas of signal change and moderate contrast enhancement in the thoracic spinal cord of a patient with Behçet's disease presenting with subacute myelopathy. The patient improved after intravenous steroids, and MRI 5 months later showed a normal spinal cord.

Adult↗
PubMed1998

Syringomyelia in myotonic dystrophy due to spinal hemangioblastoma.

BACKGROUND: Syringomyelia is an uncommon, poorly understood finding in patients with myotonic dystrophy. METHODS: We describe a patient with myotonic dystrophy and neck pain in whom an extensive neuroradiologic diagnostic work-up was carried out. RESULTS: Magnetic resonance imaging revealed a large intramedullary cavity extending from the bulbo-medullary junction to the conus medullaris. After intravenous Gadolinium-DTPA administration, an enhanced nodule was seen at T6. Spinal arteriography showed a single hypervascular nodule and slow flow perimedullary draining veins consistent with hemangioblastoma. After removal of the nodule, a partial collapse of the intramedullary cyst was observed. CONCLUSIONS: Intramedullary tumors can underlie syringomyelia in patients with myotonic dystrophy and have to be actively investigated with modern neuroradiologic investigations.

Adolescent↗
PubMed1998

Transient regression of an intracranial germ cell tumour after intravenous steroid administration: a case report.

Magnetic resonance imaging showed transient regression of the lesion after intravenous steroid administration in a patient with intracranial multifocal germ cell tumour. Prominent lymphocyte infiltration of the tumour was seen at histological examination and presumably accounts for the regression. Germ cell tumour must be included in the differential diagnosis of intracranial mass lesions sensitive to steroids.

Adolescent↗