Correlation between multimodal evoked potentials and magnetic resonance imaging in multiple sclerosis

Sixty multiple sclerosis (MS) patients (33 definite, 13 probale and 14 suspected were investigated by computed tomography (CT), magnetic resonance imaging (MRI), multimodality evoked potentials (EPs) and cerebrospinal fluid (CSF) electrophoresis. MRI abnormalities were found in 50 cases, while at least one abnormal evoked potential was detected in each of 52 cases. Brain-stem auditory evoked potentials were more sensitive than MRI for the detection of brain-stem involvement. All the patients with oligoclonal bands had abnormal MRI and none of the patients with normal MRI had oligoclonal bands in the CSF. The number and the extent of MRI lesions were significantly correlated with the duration of disease and with the degree of disability. Our observations stress the importance of the combined use of MRI and EPs in detecting silent CNS lesions in MS patients.

Nonrefractory temporal lobe epilepsy: 1.5-T MR imaging

Thirty-one patients with temporal lobe epilepsy (TLE) of mild to moderate severity, well controlled by pharmacotherapy (nonrefractory TLE), and with negative findings at computed tomography, were studied with magnetic resonance (MR) imaging at 1.5 T. Examination disclosed significant findings in 16 patients: mesial temporal abnormalities (n = 9), basitemporal abnormalities (n = 2), and alterations in frontoparietal white matter (n = 5). Coronal views and sequences with a 120-msec echo time (TE) depicted lesions in 16 patients; axial views depicted lesions in only nine of 16 patients; sequences with a 35-msec TE depicted lesions in only ten. These results underline the importance of screening with MR imaging in nonrefractory TLE patients and suggest that the MR imaging sequence of choice is a thin-section, coronal, T2-weighted sequence.

Long-term noninvasive single photon emission computed tomography monitoring of perfusional changes after EC-IC bypass surgery

The rCBF was evaluated using I-123 HIPDM and single photon emission computed tomography (SPECT) on 14 patients undergoing extracranial-intracranial (EC-IC) bypass surgery because of internal carotid artery (ICA) occlusion. Before surgery, all patients showed cortical areas of hypoperfusion over the affected cerebral hemisphere. Shortly after EC-IC bypass a rCBF increase was observed in six patients. However, at the 6 and 12 month follow-ups, with angiographic control of bypass patency, rCBF studies did not show any significant rCBF change. Long-term noninvasive tomographic monitoring of perfusion changes occurring after EC-IC bypass surgery failed to show a long-lasting improvement in perfusion.

Cerebral arterial spasm after subarachnoid hemorrhage. A case report with SPECT and iodine-123 HIPDM

Cerebral arterial spasm following subarachnoid hemorrhage can be responsible for secondary neurological deficits and can influence history, prognosis, and results of surgical treatment. The demonstration of vasospasm can be important for therapy. The use of I-123 HIPDM and SPECT in evaluating regional cerebral blood flow showed the effects on cerebral perfusion of diffuse arterial spasm in a case of subarachnoid hemorrhage and its recovery. There was a parallel with clinical neurological status.

Comparison between magnetic resonance imaging and other techniques in 39 multiple sclerosis patients

Till now there are no specific laboratory tests to confirm the diagnosis of Multiple Sclerosis (MS). For this reason the diagnosis of MS is based on the clinical evidence of central nervous system white matter disease with temporal and spatial dissemination of the lesions. Recent advances in neurophysiology and imaging techniques can provide more objective criteria towards more accurate and earlier diagnosis, detecting clinically unsuspected lesions. We evaluated 39 MS patients (23 definite, 7 probable, 9 possible) by Magnetic Resonance Imaging (MRI), CT scan, Evoked Potentials (EPs) testing and Cerebrospinal Fluid analysis. MRI was abnormal in 34 cases (87%) and CT scan in 14 (36%); EPs were also abnormal in 34 cases. 30 patients had both EPs and MRI alterated and 4 patients had alterated only one of the two investigations. The frequency of EPs alterations was: VEP 74%, Median SEP 44%, Tibial SEP 59% and BAEP 54%. The BAEP was more sensitive than MRI in detecting brainstem involvement. On the other hand MRI was more sensitive than SEPs in detecting somatosensory pathways involvement. The combined use of the two techniques allowed a reclassification of 10 out of 16 possible or probable MS cases.