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Myelin basic protein (MBP), a major myelin antigen, is considered a potential target of the immunopathologic process in Multiple Sclerosis (MS). MBP-specific T lymphocytes indeed mediate experimental allergic encephalomyelitis, the animal model of MS. Furthermore in vivo- activated T cell clones reactive to MBP were detected in the peripheral blood of patients, but not of healthy individuals (1). For these reasons the T cell response against this self-antigen is being extensively investigated in patients with MS.

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of the central nervous system (CNS),1,2 characterized by infiltrating cells, predominantly T cells,3,4 in the sites of active demyelinization. In the cerebrospinal fluid (CSF), the majority of cells are CD4 T lymphocytes,5,6 while CD8 T cells are depressed during the acute phases, as well as in peripheral blood. Functional studies of CSF lymphocytes were hampered by the small number of cells available after lumbar puncture. In this study we established cloned T cell lines from the CSF of one MS patient to investigate their phenotype and functional capacities.

The classical radioisotopic technique for assessing cerebral perfusion is based on the single carotid injection of a diffusible gas such as 133Xe and external recording of the wash-out slopes over the brain; assuming the instantaneous distribution, following injection, of the tracer to the whole brain matter, flow can be calculated from wash-out rates (13). This is a dynamic approach, based on the external recording of time activity curves. However, blood flow (and eventually other functions) of an organ can also be investigated using steady state rather than dynamic approaches. All steady state methods for assessing flow are essentially based on the extraction principle of Sapirstein (19). This states that if a tracer is completely extracted from the circulation in its first pass through an organ the concentration in different parts of the organ is proportional to blood flow. The advantage of steady state over dynamic measurements would be the possibility of obtaining much higher counting statistics, which are required for the tomographic (and therefore tridimensional) assessment of the intracerebral distribution of radioactive isotopes.

Medical therapy of acute focal cerebral ischemia in man has made no substantial progress thus far (1,6,13).

The role of regional cerebral blood flow (rCBF) in the assessment of cerebrovascular disorders has been challenged by its unrewarding clinical revenue. This difference between the technical difficulties and the clinical benefits must be acknowledged fully and depends on the fact that measurement of the rCBF may be of value in the diagnosis of cerebrovascular accidents, but if not correlated with functional conditions of the tissue affected is not of value in judging the clinical course and prognosis.

The effects on the EEG tracings of a short lasting digital occlusion of the carotid artery in the neck has long since been used as a functional test in the clinical assessment on cerebrovascular patients. The occurance of EEG slowing during this manoeuvre is the expression of a cerebral ischemic anoxia and probably of a defective collateral circulation.