Hans Sjøholm

Prophylactic hyperdynamic postoperative fluid therapy after aneurysmal subarachnoid hemorrhage: a clinical, prospective, randomized, controlled study.

OBJECTIVETo investigate the role of prophylactic hyperdynamic postoperative fluid therapy in preventing delayed ischemic neurological deficits attributable to cerebral vasospasm. METHODSWe designed a prospected, randomized, controlled study and included 32 patients with subarachnoid hemorrhage. Sixteen patients received hypervolemic hypertensive hemodilution fluid therapy; the other 16 patients received normovolemic fluid therapy. All patients were monitored for at least 12 days, with clinical assessments, transcranial Doppler recordings, single-photon emission computed tomographic (SPECT) scanning, and routine computed tomographic scanning. For fluid balance monitoring, a number of blood samples were obtained on a daily basis and continuous central venous pressure and mean arterial blood pressure measurements were performed for both groups. All patients received intravenous nimodipine infusions between Day 1 and Day 12. End points of this study were clinical outcomes, clinically evident and transcranial Doppler sonography-evident vasospasm, SPECT findings, complications, and costs. Clinical examinations (using the Glasgow Outcome Scale) performed 1 year after discharge, together with neuropsychological assessments and SPECT scanning, were the basis for the evaluation of clinical outcomes. RESULTSNo differences were observed between the two groups with respect to cerebral vasospasm (as observed clinically or on transcranial Doppler recordings). When regional cerebral blood flow was evaluated by means of SPECT analysis performed on Day 12 after subarachnoid hemorrhage, no differences were revealed. One-year clinical follow-up assessments (with the Glasgow Outcome Scale), including SPECT findings and neuropsychological function results, did not demonstrate any significant group differences. Costs were higher and complications were more frequent for the hyperdynamic therapy group. CONCLUSIONNeither early nor late outcome measures revealed any significant differences between the two subarachnoid hemorrhage treatment models.

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

Abstract Cognitive dysfunction is found in a considerable proportion of patients with systemic lupus erythematosus (SLE). SPECT provides an estimate of regional cerebral blood flow (rCBF) which has been claimed to be sensitive to detect brain involvement in SLE. It is, however, uncertain if these perfusion defects are related to cognitive dysfunction. In the present study we investigated 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 patient 99mTC-HMPAO-SPECT was performed with the visual cortex as reference, and a reduction in rCBF of > 15 % was considered abnormal. Regional CBF was performed with an automated computer program quantitatively estimating blood perfusion in 16 symmetrical sectors of the brain. Several sectors of the brain showed varying areas of reduced rCBF with the temporal lobes most frequently involved. There were generally no associations between cognitive level of functioning and reduced rCBF. MRI demonstrated cerebral infarcts in 9 (17 %) patients. In general rCBF was reduced in all sectors of the brain in patients with infarcts, although statistical significant difference in rCBF between patients with and without infarcts was only seen in the parietal lobe. Several neuropsychological functions were influenced by the presence of cerebral infarcts. There was no significant association between immunological measures and SPECT findings or neuropsychological measures. Neuropsychological dysfunction in SLE was associated with the presence of cerebral infarcts detected by MRI, but not by changes in rCBF. SPECT seems to add little if any information to that obtained by clinical examination, neuropsychological testing, and MRI. Since anticoagulation may prevent cerebral infarcts, such prophylactic intervention may be of importance in preventing cognitive deterioration.

123I-β-CIT SPECT demonstrates increased presynaptic dopamine transporter binding sites in basal ganglia in vivo in schizophrenia

RationaleThe dopamine hypothesis for schizophrenia postulates overactivity of dopamine transmission in the basal ganglia. Most effective antipsychotic drugs block postsynaptic dopamine receptors, but in-vivo imaging studies have not been able to show changes in these receptors in drug-naive schizophrenics.ObjectivesThe presynaptic dopamine transporter (DAT) is thought to be an important regulator of synaptic dopamine concentration. We have used SPECT with 123I-β-CIT, which has a high affinity for DAT, in order to further examine the dopamine hypothesis for schizophrenia.MethodsSix patients with chronic schizophrenia treated with classic dopamine D2-receptor blocking neuroleptics were investigated. The number of DAT binding sites in the basal ganglia was calculated and compared with five healthy volunteers and ten parkinsonian patients.ResultsThe schizophrenic patients showed a 36–63% increase in DAT binding sites compared with the volunteers, whereas the parkinsonian patients showed a 57–96% decrease. The differences between the groups were highly significant (even after correction for different age composition within the groups).ConclusionsThere was an increased number of DAT binding sites in the schizophrenic patients treated with dopamine D2-receptor blocking neuroleptics. This fits well with several recent reports that have shown increased volumes of basal ganglia in this patient category. It thus appears that there is an increased number of presynaptic dopamine releasing nerve terminals in the basal ganglia, possibly as a biological adaptation to counteract the postsynaptic dopamine D2-receptor blockade.

Fatigue in patients with lupus is not associated with disturbances in cerebral blood flow as detected by SPECT

ObjectivesFatigue is a common complaint in patients with systemic lupus erythematosus (SLE). We investigated whether focal or general disturbances of cerebral blood flow (CBF), as assessed by SPECT, were associated with the presence of fatigue in an unselected group of SLE patients.MethodsFifty-six patients were included. Mean age was 47.5 years (±12.7), mean disease duration 14.7 years (±8.9), and disease activity measured by SLE disease activity index (SLEDAI) was 5.7 (±5.4). Fatigue was assessed by the Fatigue Severity Scale (FSS) and CBF by Tc-99m-hexamethyl propylamine oxime (HMPAO)-SPECT. The images were read and processed quantitatively by a computer program using the primary visual cortex as reference region and > 15% CBF deviation as definition of abnormality.ResultsThe mean FSS score was 4.6 (±1.8). SPECT revealed focal CBF disturbances in 17 patients (30.4 %). Generalized symmetrical CBF reductions were present in 32 patients (57.1 %). There were no significant associations between CBF disturbances in any region of the brain and the degree of fatigue.ConclusionsFatigue in SLE patients is not related to focal or general CBF disturbances. Therefore, factors that do not influence blood flow seem responsible for the fatigue phenomenon.

Nigro-striatal degeneration demonstrated in parkinsonian patients with iodine-123-beta-CIT SPECT: Methods of quantitation

Single photon emission computed tomography (SPECT) images were obtained in 3 healthy volunteers and 7 parkinsonian patients 22 h after injection of 120 MBq iodine‐123‐beta‐CIT. There was a high radioactivity in the striatal region against a uniform background in the volunteers but pronouncedly reduced striatal activity in the patients. Total striatal activity in each hemisphere of each individual was calculated as the sum of all activity in excess of the background in all reconstructed images. There was a high correlation between reduction of striatal activity and motor scores in the unified rating scale for parkinsonism (URSP) for the patients. A method developed for calculation of the activity distribution along the length axis of the striatum indicated a more pronounced degeneration in the putamen compared with the caudate nucleus in the patients. Iodine‐123‐beta‐CIT SPECT appears to be a good quantitative method for nigro‐striatal degeneration in parkinsonian patients.

Beta-CIT-SPECT combined with UPDRS appears to distinguish different parkinsonian conditions

Objectives– An earlier study in l‐dopa responding patients with idiopathic Parkinsons disease documented that progressive nigro‐striatal degeneration shown with single photon emission computed tomography (SPECT) and the cocain analog iodine‐123‐beta‐CIT (beta‐CIT) correlated linearly with increasing motor scores in the Unified Parkinsons Disease Rating Scale (UPDRS). Here we have extended the study to include 2 tremor patients with mild parkinsonism, 2 poor l‐dopa responders with parkisonism and 2 non l‐dopa responders with severe parkinsonism. Methods– SPECT scanning was performed 20 h after injection of beta‐CIT and UPDRS was done at the time of beta‐CIT injection. Results– All patients in the present study showed less nigro‐striatal degeneration in relation to UPDRS motor scores than the patients with idiopathic Parkinsons disease. Conclusion– The results suggest that the the combination of beta‐CIT‐SPECT and UPDRS motor scores has the potential to differentiate idiopathic Parkinsons disease from other parkinsonian conditions.