Neuropsychological dysfunction in systemic lupus erythematosus is not associated with changes in cerebral blood flow

Cognitive dysfunction is found in a considerable proportion of patients wit h systemic lupus erythematosus (SLE). SPECT provides an estimate of regiona l cerebral blood flow (rCBF) which has been claimed to be sensitive to dete ct brain involvement in SLE. It is, however, uncertain if these perfusion d efects are related to cognitive dysfunction. In the present study we invest igated whether cerebral dysfunction assessed by neuropsychological measures was associated with changes in rCBF. Fifty-two SLE patients were examined with a battery of neuropsychological tests and MRI of the brain. For each p atient (TC)-T-99m-HMPAO-SPECT was performed with the visual cortex as refer ence, and a reduction in rCBF of > 15% was considered abnormal. Regional CB F was performed with an automated computer program quantitatively estimatin g blood perfusion in 16 symmetrical sectors of the brain. Several sectors o f the brain showed varying areas of reduced rCBF with the temporal lobes mo st frequently involved. There were generally no associations between cognit ive level of functioning and reduced rCBF MRI demonstrated cerebral infarct s in 9 (17%) patients. In general rCBF was reduced in all sectors of the br ain in patients with infarcts, although statistical significant difference in rCBF between patients with and without infarcts was only seen in the par ietal lobe. Several neuropsychological functions were influenced by the pre sence of cerebral infarcts. There was no significant association between im munological measures and SPECT findings or neuropsychological measures. Neu ropsychological dysfunction in SLE was associated with the presence of cere bral infarcts detected by MRI, but not by changes in rCBF. SPECT seems to a dd little if any information to that obtained by clinical examination, neur opsychological testing, and MRI. Since anticoagulation may prevent cerebral infarcts, such prophylactic intervention may be of importance in preventin g cognitive deterioration.