G. Dal Pozzo

MRI of spinal epidural lymphoma

We reviewed the MRI features in eight patients with spinal epidural lymphoma (clinically primary in 4 patients); one patient had multiple lesions. The cervical spine was involved in one patient, the thoracolumbar spine in 5 and the sacrum in two. Mean longitudinal extension of the epidural lesion was 2.6 vertebral segments. The tumours were homogeneously isointense with the spinal cord on T1-weighted images and isointense or hyperintense on proton-density and T2-weighted images. The spinal cord was compressed in four patients but showed signal changes in only one. In five patients the lesions communicated through the intervertebral formaina with paravertebral soft tissue masses. In all but one of the patients diffuse signal changes in the vertebral body marrow consistent with osteolytic or osteobalstic changes were identified adjacent to or at distance from the epidural lesion. Vertebral collapse was observed in two patients.

Intrathecal synthesis of free immunoglobulin light chains and IgM in initial multiple sclerosis.

We studied the intrathecal synthesis of free kappa, free lambda immunoglobulin light chains and of IgM in 33 consecutive patients with possible or probable MS at the time of their first diagnosis. Nineteen patients presented free kappa or lambda light chain bands in CSF after agarose isoelectric focusing, protein transfer to nitrocellulose and immunostaining with specific antisera. Nineteen patients had increased CSF levels of free kappa light chains as measured with a competitive ELISA. Fourteen had an increased IgM index, as evaluated with a sandwich ELISA. Twenty‐six patients displayed CSF oligoclonal IgG bands in CSF and 25 had cerebral magnetic resonance imaging lesions suggestive of MS. The local production of free immunoglobulin light chains and IgM is often detected in the CSF of patients with early MS.

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.

Magnetic Resonance Imaging of Cerebral Associative White Matter Bundles Employing Fast-Scan Techniques

Rapid scan techniques have introduced new sequence parameters as well as novel contrast concepts into everyday magnetic resonance imaging (MRI). In particular contrast characteristics of fast-spin echo (FSE) sequences showed some significant differences when compared to conventional spin echo images. The purpose of this work was to demonstrate the capabilities of FSE MRI in identifying and characterizing the in vivo anatomy of the main cerebral associative systems. Between March and November 1995, 20 healthy adult volunteers (12 males, 8 females, mean age 35 years) were submitted to a cranial MRI examination (1.5 Philips Gyroscan NT). In all cases axial and coronal 2-dimensional FSE T2-weighted and 2-dimensional inversion recovery FSE T1-weighted images were obtained. All MRI images were examined by a neuroradiologist (G. Dal Pozzo) for the depiction of the following compact white matter fiber bundles: anterior commissure, corpus callosum, superior fronto-occipital fasciculus, cingulum, fornix, mammillothalamic tract, uncinate fasciculus, superior and inferior longitudinal fasciculus. All these associative pathways could be well identified on T2-weighted images due to a lower signal intensity with respect to the surrounding white matter. On T1-weighted images only the corpus callosum, the anterior commissure and the fornix could always be identified. Correlation with myelin-specific colorations (Luxol fast blue stains) in anatomic atlases and a review of the literature on the myelinization process during infancy indicate that the short T2 relaxation times of the aforementioned cerebral associative systems may be due to heavy myelination and high fiber density. The correct visualization of interintrahemispheric associative white matter fiber bundles may play an important role in white matter disorders like dys- and demyelinating diseases and in the spreading of vasogenic edema and/or tumor being useful for their staging.

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 Binswangers 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.

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.

Risonanza magnetica e H-MRS dell'encefalo in soggetti con LES ad esordio pediatrico

Systemic lupus erythematosus can produce disturbances in the CNS, characterized by seizures, headache, encephalopathy, chorea, cerebral infarction and psychosis. We used magnetic resonance and spectroscopy, in order to provide anatomical and metabolic information on the direct involvement of the CNS in LES. This study shows how these non-invasive techniques are well tolerated by children and young adults and how the levels of N-acetylaspartate correlate with the severity of the disease.

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.

Divergence pseudoparalysis: a case report.

Divergence paralysis is a clinical syndrome that is characterized by esotropia and diplopia at distance fixation and fusion at near fixation. This syndrome is thought to result from a lesion in the brain stem, probably in the midbrain or in the pontine region. This paper reports a case in which ocular motility disturbances, simulating divergence paralysis, were caused by a bilateral and symmetrical restrictive syndrome involving the medial rectus muscles.

SACROCOCCYGEAL CHORDOMA : CLINICORADIOLOGICAL STUDY

A case of sacrococcygeal chordoma is presented. We review the literature and we discuss the problems related to the etiology, the symptoms, the diagnosis and the treatment of this rare neoplasm. We present and discuss here the importance and the different possibilities of new diagnostic techniques, such as the CT and the MRI in the diagnosis and management of sacrococcygeal chordoma.