Brain magnetic resonance imaging and multimodal evoked potentials in benign and secondary progressive multiple sclerosis

Brain MRI and multimodal evoked potentials (EPs) were obtained for 13 patients with benign multiple sclerosis and 13 patients with secondary progressive multiple sclerosis, matched for age and duration of the disease, to investigate the nature of the disability in multiple sclerosis. Patients with secondary progressive multiple sclerosis had significantly greater lesion loads for five of seven periventricular regions and for three of nine regions separate from the ventricles. Patients with secondary progressive multiple sclerosis also had more severe infratentorial atrophy scores (p = 0.04), whereas there were no differences between the two groups in number and extent of enhancing lesions. The frequencies were significantly higher and severities greater for multimodal EP abnormalities of all the modalities in patients with secondary progressive multiple sclerosis. At least one EP component was absent in 12 (92%) patients with secondary progressive multiple sclerosis but in only one patient (8%) with benign multiple sclerosis (p < 0.001). There was neurophysiological evidence for cervical cord involvement in eight (61%) patients with secondary progressive multiple sclerosis and in one with benign multiple sclerosis (p < 0.01). These data indicate that the total amount of lesions, the distribution, and the nature of the pathological process might all account for the development of disability in multiple sclerosis.

Early diagnosis of optic glioma in children with neurofibromatosis type 1

Twenty-five asymptomatic patients with neurofibromatosis type 1 (NF 1), aged 6-21 years, underwent the following examinations: intracranial magnetic resonance testing (MRI), visual acuity testing, ophthalmoscopy, and visual field and pattern reversal visual evoked potentials (VEPs). MRI showed enlargement of one or both optic nerves in six children, with bilateral involvement in three. VEPs were normal in all these patients; two of them had abnormalities on other visual examinations, although there were no subjective visual disturbances. These results show that VEPs cannot be considered as a screening test for optic pathway lesions in children with NF 1, as previously stated, and that other types of visual function examination may be more sensitive. These data may contribute to the establishment of more precise guidelines for the evaluation and treatment of children with NF 1.

Evidence of a congenital midline brain anomaly in pituitary dwarfs: a magnetic resonance imaging study in 101 patients

BACKGROUND

Magnetic resonance imaging (MRI) of the brain in pituitary dwarfs has revealed a previously unknown entity: ectopia of the posterior pituitary (PPE), absence or hypoplasia of the pituitary stalk and hypoplasia of the anterior pituitary. The pathogenesis of these findings was explained originally by a traumatic transection of the pituitary stalk during delivery. A high incidence of breech delivery has been reported in these groups, but the traumatic hypothesis cannot explain the findings in the relatively high percentage of patients with normal delivery, nor account for a different feature also found in other pituitary dwarfs consisting of pituitary hypoplasia with normal posterior pituitary. A second hypothesis could then been proposed, based on dysgenesis or abnormal embryonic development of both adenohypophysis and neurohypophysis.

OBJECTIVE

To review the value and significance of these two different etiopathogenetic hypotheses by analyzing clinical, endocrinological, and MRI findings in a large population of pituitary dwarfs.

METHODS

One hundred and one consecutive patients with congenital idiopathic growth hormone deficiency (CIGHD) were studied by MRI; they were compared with a control group of 46 healthy short children. A complete clinico-endocrinological evaluation was obtained in both patients and controls to assess the perinatal history, the pituitary-hypothalamic function, and the neurological status. MRI studies were evaluated both qualitatively and quantitatively and the pituitary volume (PV) was calculated in both patients and controls. Quantitative data were statistically analyzed to compare the mean PV of the patients with the mean PV of controls, the hormonal therapy, the single or multiple pituitary hormone deficiency, and the presence of breech delivery.

RESULTS

MRI revealed PPE in 59 patients and a normal posterior pituitary (NPP) in 42. PV was extremely small in patients with PPE and in patients with NPP associated with a severely narrowed pituitary stalk; mean PV was significantly lower in CIGHD patients when compared with that of healthy short children. PV was not influenced by hormonal therapy and did not differ between patients with single and multiple pituitary hormone deficiency and between patients with normal and breech delivery. PPE patients differed from NPP patients for a higher male/female ratio (3:1 vs 1:1) and for a greater frequency of multiple pituitary hormone deficiency (49% vs 12%), breech delivery (32% vs 7%), and associated congenital brain anomalies (12% vs 7%). In PPE patients breech delivery was strongly associated with multiple pituitary hormone deficiency.

CONCLUSION

On the basis of this study the traumatic hypothesis could theoretically explain the pathogenesis of PPE only in 32% of the patients with this condition. On the basis of modern understanding of embryogenesis of anterior and posterior pituitary, it is then justified to propose that a defective induction of mediobasal structure of the brain in the early embryo could account for both the complex morphological MRI abnormality and the clinico-endocrinological features encountered in all PPE patients. The close contiguity between the future pituitary and hypothalamus, the peculiar association with congenital midline brain anomalies, and the recent data about a possible role of Pit-1 gene, all support the hypothesis of a congenital defect. Finally, breech delivery can be considered not as a cause of PPE, but as an effect of the embryonic pituitary-hypothalamic abnormalities.

Modern imaging techniques in GH secretory disorders

Magnetic resonance images of the pituitary-hypothalamic area in patients with GH secretory disorders, divided into two groups (hypersecretory and hyposecretory), were studied. In the first group there were 42 patients with pituitary adenoma; size, signal characteristics, direction of growth, and type of enhancement were analyzed and compared with similar studies in 40 age and sex matched control patients with non-GH secreting pituitary adenomas. No significant differences were found except for a higher frequency of chiasm involvement and a more pronounced contrast enhancement in the control group. The hyposecretory group was composed of 101 patients with congenital idiopathic growth hormone deficiency (CIGHD). MR revealed morphological abnormalities consisting of hypoplastic anterior pituitary and ectopic posterior pituitary (PPE) in 59 patients, without evidence of a complete pituitary stalk; in 42 patients the posterior pituitary was in normal position and the pituitary stalk visible. The group with PPE showed a greater frequency of multiple pituitary hormone deficiency (51% vs 12%), breech delivery (30% vs 7%) and associated congenital brain anomalies (12% vs 7%). These data suggest that CIGHD could be the result of a congenital midline brain anomaly in a significant proportion of patients.

Caudate nucleus abnormalities in obsessive-compulsive disorder: measurements of MRI signal intensity

A previous magnetic resonance imaging (MRI) study from our group reported increased size of the right caudate nucleus in obsessive-compulsive patients compared with control subjects. To test the hypothesis of a structural abnormality underlying such volume alteration, MRI signal intensity (SI), as an index of T1 relaxation values, was measured in the caudate nucleus of the same sampling data. Results showed higher SI values in the left caudate nucleus compared with the right in the patient group, whereas no asymmetry was found in the control group.

[Development of a teleradiology system]

PURPOSE

the development of a cost-effective diagnostic system for transmitting high-resolution images on normal phone lines.

MATERIALS AND METHODS

A 486 PC with super VGA screen, 16,800-band external modem and graphic software.

RESULTS

the graphic software allows the PC to be connected to the video output of MRI, CT or US units, or to a video camera as in the case of X-ray units. Image spatial resolution is as high as 1,024 x 768 lines. Transmission times are lower than 45 seconds, corresponding to files of 50-80 kbytes. In 6 months, more than 130 Megabytes (500 images) were transmitted between our diagnostic center and our consultants in northern Italy, France and California.

CONCLUSIONS

this cost-effective teleradiology system allows real-time image transmissions between diagnostic centers all over the world for scientific updating and quick reference purposes. Portable units can be developed.

Memory functions and temporal-limbic morphology in schizophrenia

Several psychopathological and morphological studies support the hypothesis of temporal-limbic involvement in the pathophysiology of schizophrenia. In the present study, magnetic resonance imaging was used to evaluate the areas of the temporal lobes and related structures in 18 schizophrenic patients and 18 normal control subjects who were homogeneous for sex and age. The Wechsler Memory Scale was used to assess the memory functions of all subjects. Although the MRI data did not reveal any significant differences between the two groups, the Wechsler Memory Scale indices of memory functions showed significant differences between the schizophrenic patients and the control subjects.

Three dimensional time-of-flight magnetic resonance angiography in carotid artery surgery: a comparison with digital subtraction angiography

Three dimensional time-of-flight magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA), considered the gold-standard technique, were compared for pre- and postoperative evaluation of the carotid bifurcation. Images of suitable quality of 194 bifurcations were available with both techniques. Percentage stenosis was graded into 5 groups: A = 0-29%, B = 30-59%, C = 60-89%, D = 90-99%, E = 100% (occlusion). Preoperative MRA (126 bifurcations) overgraded the stenosis in 14 cases and undergraded it in 11. The two techniques agreed in 101 cases and the extent of misgrading was never more than one category. Regression analysis showed a good correlation between the two methods. Severe ulceration was better identified by DSA. As far as the surgical indication was concerned, MRA had a sensitivity of 92.6% and a specificity of 98.3%. In 68 operated cases, postoperative MRA and intraoperative completion angiography showed a satisfactory endarterectomy with no residual stenosis in any of the cases. In conclusion, MRA seems an accurate modality for imaging of carotid bifurcations. Significant limitations still exist for an adequate demonstration of intracranial circulation.

Database for serial magnetic resonance imaging in multiple sclerosis

The unique sensitivity of magnetic resonance imaging (MRI) in detecting disease activity in multiple sclerosis (MS) and the objective nature of the information obtained suggest that MRI will be a useful and reliable way of monitoring treatment trials. There is a need to develop an appropriate database which would provide a standardised means of assessment, not only of MRI, but also of essential clinical information. As part of the program of Concerted Action in Multiple Sclerosis, funded by the Commission of the European Community (CEC), we have developed a database for recording serial brain MRI results. The database consists of core, entry and follow-up sections. Both entry and follow-up parts are subdivided into clinical, MR system and MRI data. We expect that the use of this database will maximise efficiency of MRI monitoring in MS treatment trials, particularly in multicentre studies.

Superficial siderosis of the CNS: MR diagnosis and clinical findings

PURPOSE

To report the clinical and neuroradiologic findings of superficial siderosis of the CNS, due to chronic subarachnoid bleeding of unknown origin.

MATERIALS AND METHODS

We observed seven cases. The main clinical manifestations were progressive deafness and ataxia. Four patients had had previous cranial or cervical trauma, with root avulsion in two, many years before onset of deafness and ataxia. Neuroradiologic studies included MR (0.5 T in four and 1.5 T in three) and angiography of the brain in all cases, CT in six cases, MR of the spine in six, and myelography in four.

RESULTS

MR demonstrated a rim of marked hypointensity in T2-weighted images, consistent with hemosiderin deposits, on the surface of cerebellum, brain stem, inferior part of cerebral hemispheres, and spinal cord. CT showed cerebellar atrophy in five cases, and a rim of mild hyperdensity around the brain stem in two. Angiographic studies were negative. Myelography showed cervical nerve root avulsion in two cases and a cervicodorsal extradural cyst in one. Cerebrospinal fluid contained RBCs in all the six examined cases.

CONCLUSION

Although CT may occasionally suggest the diagnosis of superficial siderosis, MR demonstrates this abnormality to better advantage.

Brain stem magnetic resonance imaging and evoked potential studies of symptomatic multiple sclerosis patients

In this study we evaluated the sensitivity of neuroradiological and neurophysiological tests for detecting brain stem (BS) lesions in multiple sclerosis patients, since the recent introduction of the gradient motion rephasing technique has markedly increased the image quality of magnetic resonance imaging (MRI). From 50 MS patients (33 women and 17 men; mean age 35.9 +/- 8.3 years; mean duration of the disease 7.2 +/- 4.1 years) with clinical signs of BS involvement, brain MRI, BS auditory evoked potentials (BAEPs), and left and right median somatosensory evoked potentials (mSEPs) were obtained. BS MRI lesions were detected in 41 patients (82%); in 14 cases they were located in the medulla oblongata, in 55 in the pons, and in 24 in the midbrain. Single lesions were present in 20 patients, while two or more BS lesions were demonstrated in 21 patients; 30 patients had at least one lesion located close to the inner or the outer cerebrospinal fluid border. BAEPs were abnormal in 19 of the 50 patients (38%), and BS components of mSEPs were abnormal in 15 of 46 (33%). With combined use of these neurophysiological techniques, BS abnormalities were revealed in 24 patients (48%). Only 1 patient had neurophysiological BS abnormalities and normal MRI. Moreover, there was a good correlation (74%) between the clinical and MRI BS findings in the 23 patients with signs referable to focal neurological BS lesions. The concordances considering clinical and evoked potential reports were positive, but less marked.(ABSTRACT TRUNCATED AT 250 WORDS)

The radiologist and common cervicobrachial neuralgia

The neuroradiological methods used for the diagnosis of common cervicobrachial neuralgia are not the same in all medical centres and hospitals, one of the main reasons for this lack of unanimity being differences in organization and availability of equipment. However, the modern diagnostic approach should include magnetic resonance as first examination. MRI is the most informative and the least hazardous of all exploratory methods, and it detects or excludes a much greater number of causes than any other radiological technique. False-negative results, as well as late, incomplete or wrong diagnosis are therefore reduced to the minimum. False-positive results can be avoided by a good knowledge of the physiological incidence of uncodiscarthrosis with age.

Increased right caudate nucleus size in obsessive-compulsive disorder: detection with magnetic resonance imaging

Magnetic resonance images were used to measure the volume of the head of the caudate nucleus in 20 patients with obsessive-compulsive disorder and 16 normal control subjects. The obsessive-compulsive patients showed a significant increase in the volume of the right side of the head of the caudate nucleus compared with that of control subjects. This finding was not correlated with demographic, psychopathological, or clinical characteristics.

Solitary plasmacytoma of the sphenoid sinus involving the pituitary fossa: a case report and review of the literature

A rare case of solitary plasmacytoma of the sphenoid sinus involving the pituitary fossa is reported. A 50-year-old woman with a history of diplopia and a mass in the sphenoid sinus and the sellar region, documented by computed tomography, was referred to our department with a presumed diagnosis of nonfunctioning pituitary adenoma. The clinical and biochemical characteristics were unrevealing, but magnetic resonance imaging examination demonstrated the extrapituitary origin of the lesion. The patient was operated on by the transsphenoidal approach, and the lesion was histologically diagnosed as a plasmacytoma. Review of the literature disclosed 11 previously described cases of myelomatous disease presenting clinically as a pituitary adenoma. Our case demonstrates that magnetic resonance imaging investigation may help in distinguishing the extrapituitary origin of a mass involving the pituitary fossa.

Imaging of tumors of the central nervous system

Research in diagnosing and understanding brain tumors in neuroradiology is influenced by the investigative tools available to neuroradiologists. CT has represented the gold standard for the past two decades. The role of angiography has become complementary; relevant in the therapeutic phase of embolization of meningiomas or base of the skull tumors or in intra-arterial chemotherapy for gliomas. In 1991, the MR imaging revolution continues to provide new insights in the diagnosis, classification, and understanding of the biology of brain tumors. Interest has been focused mainly on information provided by MR imaging and MR spectroscopy. Spectroscopy is being used in a more systematic way and in large series with different histologic tumor types. Spectra from tumors are definitely different from those of normal brain, although no specific patterns for histologic types were found, with the possible exception of meningiomas. Comparison with positron emission tomography is considered to be useful. Analysis of rare tumors using MR imaging allows better understanding, classification, diagnosis, and surgical therapy of lesions such as central neurocytomas, hamartomatous tumors, and lymphomas. An attempt at a better classification for brain tumors was proposed and may prove to be very useful for systematization and communication.

MRI, antibody-guided scintigraphy, and glucose metabolism in uveal melanoma

To evaluate the usefulness of structural and biochemical imaging techniques for the diagnosis of uveal melanoma, 12 patients with choroidal melanoma were examined. Magnetic resonance imaging was used in 11 of 12 patients, as one had a metal prosthesis. All the subjects underwent single photon planar scintigraphy (SPPS) and single photon emission computed tomography (SPECT) using the 99mTc-labeled F(ab')2 of the anti-melanoma monoclonal antibody 225.28S ([99mTc]MoAb) and positron emission tomography (PET) using [18F]fluorodeoxyglucose ([18F]FDG). Magnetic resonance identified 6 of 11 melanotic lesions (definite melanomas) and 4 of 11 hypomelanotic lesions (probable melanomas), whereas in one case it was inconclusive. [99mTc]MoAb uptake was observed in 5 of 12 lesions using SPPS and 8 of 12 lesions using SPECT. [18F]FDG uptake was observed in 3 of 12 lesions by PET. These results demonstrate that both MR and radioimmunoscintigraphy are sensitive techniques for the diagnosis of choroidal melanomas and suggest that the detection of melanomas by MR, SPPS, and SPECT is largely dependent upon their size. The validity of these conclusions was verified in four subjects in whom the diagnosis was based on MR and/or SPECT findings only and confirmed by histology. The finding that only some of the uveal melanomas of larger size are visualized based on [18F]FDG uptake suggests that melanomas can have either high or low glucose consumption.

Paraclinical tests in acute-onset optic neuritis: basal data and results of a short follow-up

Up to now it is still doubtful whether there is a real risk of developing multiple sclerosis (MS) after initial monosymptomatic optic neuritis (ON). In this study we evaluated 43 patients with isolated acute-onset ON, in order to demonstrate the presence of oligoclonal bands (OBs) in the cerebrospinal fluid (CSF) and any additional clinically silent central nervous system (CNS) lesions. All examinations were performed from 5 days to 4 months (mean 43 days), from the onset of visual disturbances. Brain magnetic resonance imaging (MRI) detected white matter areas with increased signal in 21 patients (49%), while somatosensory and brainstem auditory evoked potentials revealed CNS abnormalities in only 5 patients (12%). OBs were present in the CSF of 20 patients (46%). Visual evoked potentials were abnormal in 39 patients (91%). Seven out of the 37 patients (19%) with at least one year follow-up, (mean duration of the follow-up = 32 months, range = 12-74), developed clinically definite MS (CDMS). All 7 patients had positive brain MRI and 6 had positive CSF examination at the basal evaluation. Our data suggest that MRI and CSF-OBs are the most reliable means of identifying patients with isolated ON who subsequently develop CDMS. They may therefore have a predictive value in defining MS risk.

Magnetic resonance imaging in monitoring the treatment of multiple sclerosis: concerted action guidelines

Serial gadolinium enhanced MRI of the brain detects much clinically silent disease activity in early relapsing-remitting and secondary progressive multiple sclerosis (MS), and thus has an important role in monitoring the effects of therapy. Based on the proceedings of a recent Commission of the European Communities (CEC) workshop and a review of the literature, guidelines are presented for using MRI to monitor treatment trials in MS. The guidelines consider: A) MRI system and techniques; B) patient selection; C) trial design; D) analysis of results. Priorities for future research are also indicated.

Hypothalamic-pituitary dysfunction in growth hormone-deficient patients with pituitary abnormalities

Hypothalamic-pituitary function was studied in 45 patients with idiopathic GH deficiency (GHD), 33 of whom had pituitary abnormalities on magnetic resonance imaging: pituitary hypoplasia, undescended stalk and ectopia of the posterior lobe in 8 patients with isolated GHD (IGHD) (group I) and in 12 patients with multiple pituitary hormone deficiency (MPHD) (group II); isolated pituitary hypoplasia in 13 patients with IGHD (group III); no evidence of pituitary abnormalities in the remaining 12 patients with IGHD (group IV). Sellar and pituitary volumes were significantly lower in groups I, II, and III than in group IV (P less than 0.001). No significant differences were observed between group I and group II in the GH response to GHRH1-44 expressed both as peak serum GH and area under the curve. Mean GH peak in group III and IV was significantly higher than that in group I (P less than 0.005) and II (P less than 0.001), as were the mean AUC (P less than 0.005), suggesting hypothalamic defect. Delayed peak serum TSH after TRH was found in all patients of group II, and overt hypothyroidism in 11 of them. Furthermore, basal hyperprolactinemia was present in 6 patients and adrenal insufficiency in 7 cases of group II. Finally, a reduced response of FSH to GnRH was observed in all these patients (P less than 0.005 vs. each of the other groups), and clinical hypogonadism was present in all of them. We suggest that: 1) A high incidence of pituitary abnormalities seems to be present in idiopathic GHD patients; 2) Pituitary hormone deficiencies are more dependent on the type of the hypothalamic-pituitary abnormality than on the size of the pituitary per se: the association of pituitary hypoplasia, undescended stalk and ectopia of the posterior lobe should possibly be considered a distinct entity reflecting an early abnormality in hypothalamic development; 3) The majority of patients with IGHD or MPHD probably have a primary hypothalamic releasing hormone deficiency even if pituitary hypoplasia is associated; 4) Magnetic resonance imaging may have a role in the diagnosis and prognosis of patients with GHD through differentiation between patients who are at risk for developing MPHD vs. those who are candidates for having a persistently isolated GHD.