E. A. Jacobsen

Traumatic brain damage in minor head injury: relation of serum S-100 protein measurements to magnetic resonance imaging and neurobehavioral outcome.

OBJECTIVE The present study was conducted to validate S-100 protein as a marker of brain damage after minor head injury. METHODS We studied 50 patients with minor head injuries and Glasgow Coma Scale scores of 13 to 15 in whom computed tomographic scans of the brain revealed no abnormalities. Serum levels of S-100 protein were measured at admittance and hourly thereafter until 12 hours after injury. Magnetic resonance imaging and baseline neuropsychological examinations were performed within 48 hours, and neuropsychological follow-up was conducted at 3 months postinjury. RESULTS Fourteen patients (28%) had detectable serum levels of S-100 protein (mean peak value, 0.4 microg/L [standard deviation, +/- 0.3]). The S-100 protein levels were highest immediately after the trauma, and they declined each hour thereafter. At 6 hours postinjury, the serum level was below the detection limit (0.2 microg/L) in five (36%) of the patients with initially detectable levels. Magnetic resonance imaging revealed brain contusions in five patients, four of whom demonstrated detectable levels of S-100 protein in serum. The proportion of patients with detectable serum levels was significantly higher when magnetic resonance imaging revealed a brain contusion. In patients with detectable serum levels, we observed a trend toward impaired neuropsychological functioning on measures of attention, memory, and information processing speed. CONCLUSION Determination of S-100 protein levels in serum provides a valid measure of the presence and severity of traumatic brain damage if performed within the first hours after minor head injury.

Reduced neuropsychological test performance in asymptomatic carotid stenosis: The Tromsø Study

Objective: To assess the relationship between asymptomatic carotid stenosis, neuropsychological test performance, and silent MRI lesions. Methods: Performance on several neuropsychological tests was compared in 189 subjects with ultrasound-assessed carotid stenosis and 201 control subjects without carotid stenosis, recruited from a population health study. Subjects with a previous history of stroke were excluded. The test battery included tests of attention, psychomotor speed, memory, language, speed of information processing, motor functioning, intelligence, and depression. Sagittal T1-weighted and axial and coronal T2-weighted spin echo MRI was performed, and presence of MRI lesions (white matter hyperintensities, lacunar and cortical infarcts) was recorded. Results: Subjects with carotid stenosis had significantly lower levels of performance in tests of attention, psychomotor speed, memory, and motor functioning, independent of MRI lesions. There were no significant differences in tests of speed of information processing, word association, or depression. Cortical infarcts and white matter hyperintensities were equally distributed among persons with and without carotid stenosis. Lacunar infarcts were more frequent in the stenosis group (p = 0.03). Conclusions: Carotid stenosis was associated with poorer neuropsychological performance. This could not be explained by a higher proportion of silent MRI lesions in persons with asymptomatic carotid stenosis, making it less likely that the cognitive impairment was caused by silent emboli.

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.

Cerebral computed tomography and electroencephalography compared with neuropsychological findings in systemic lupus erythematosus

Abstract Central nervous system involvement was evaluated in 36 patients with systemic lupus erythematosus (SLE) using cerebral computed tomography (CT), electroencephalography (EEG), and a neuropsychological test battery. The purpose was to investigate whether brain dysfunction as assessed by comprehensive neuropsychological investigation is associated with findings of routine investigation methods such as CT and EEG which are available in most hospitals. Abnormal EEG was found in 19%, and CT revealed cerebral atrophy in 47% of SLE patients. Few neuropsychological functions were affected by the presence of abnormal EEG, cerebral atrophy, or infarcts. Significant associations were found only between cortical atrophy and impairment of tactile spatial problem-solving and motor dexterity, and between cortical infarcts and motor dexterity in the dominant hand. The value of conventional EEG in assessing cerebral SLE is negligible, except for identifying epileptic activity and focal pathology. Cerebral CT has little relevance in predicting brain dysfunction as established by neuropsychological assessment in SLE, except for detecting cortical atrophy and infarcts.

Outcome 1 year after aneurysmal subarachnoid hemorrhage: relation between cognitive performance and neuroimaging

Objective –  To assess the cognitive impairment and the association between neuropsychological measures and neuroimaging 1 year after aneurysmal subarachnoid hemorrhage (SAH).

No association between peridural scar and outcome after lumbar microdiscectomy.

SummaryThe association between postoperative scar formation on MRI and outcome was investigated in 54 out of one hundred patients operated on with microdiscectomy in a prospective cohort study with a one year follow up. The patients were classified as failures or successes at the 12 months follow up according to a clinical overall score. All the 14 failures were investigated with MRI, and 40 patients classified as successes were picked at random for MRI. Patients with signs of recurrent disc herniation on MRI were excluded. The MRI scans were rated according to the presence or absence of scar formation within the spinal canal and the degree of scar enhancement by two independent neuroradiologists ignorant of treatment outcome. No evidence of scar formation was found in 4 patients, a small amount in 11, intermediate in 38 and extensive scar tissue in 1 patient. Slightly enhancing scar tissue was found in 18 patients, intermediate in 27 patients and strong enhancement in 5 patients.No association between the amount or enhancement of peridural scar formation and clinical outcome was found. Both the total clinical score and the difference between pre- and post-operative clinical score were used in the calculations. Testing the different subsets in the clinical overall score, as well as the patient satisfaction VAS score, did not reveal any association.

Detection of cerebral embolic signals in patients with systemic lupus erythematosus

Background: Involvement of the CNS in systemic lupus erythematosus (SLE) is caused by several pathogenic mechanisms including cerebral embolism. Aim: To measure the frequency of microembolic signals (MES) by using transcranial Doppler (TCD) ultrasound and to assess their association with cerebral infarction, neuropsychological dysfunction, and biochemical, sonographic and clinical variables in an unselected group of patients with SLE. Methods: A 1-h TCD recording from the middle cerebral artery was carried out in 55 patients with SLE having a mean age of 46 (SD 13) years. MRI of the brain, carotid artery ultrasonography with intima–media thickness and atherosclerotic plaque assessments were carried out in addition to a broad biochemical and clinical assessment. All patients underwent a neuropsychological assessment. Results: Of the 55 patients, MES were detected in 5 (9%) and cerebral infarcts were found in 9 (18%). A significant association was found between MES and cerebral infarcts and considerably more neuropsychological deficits were found in MES-positive patients compared with the negative group. MES were not associated with other clinical, sonographic and biochemical factors believed to be associated with cerebral embolism. Conclusions: Cerebral embolism may be one of the important mechanisms responsible for the high prevalence of cerebrovascular events and the neuropsychological deficits observed in patients with SLE. Although the number of MES-positive patients was small, the lack of a significant association between MES and other known risk factors for MES suggests a complex pathogenesis for the embolisation in these patients.

Nerve root signs on postoperative lumbar MR imaging. A prospective cohort study with contrast enhanced MRI in symptomatic and asymptomatic patients one year after microdiscectomy.

Summary The association between postoperative nerve root signs and outcome was investigated in 54 out of one hundred patients operated on by lumbar microdiscectomy in a prospective cohort study with one year follow up. The patients were classified as failures or successes at the 12 month follow up according to a clinical overall score. All the 14 failures were investigated with MRI at the one year follow up, and 40 patients classified as successes were picked at random for MRI. Three patients with signs of recurrent disc herniation on MRI were excluded from the study. The MRI scans were independently read by two neuroradiologists who were ignorant of treatment outcome. No association between nerve root thickening, nerve root enhancement or nerve root displacement and the clinical outcome was found when patients with recurrent disc herniation were excluded.

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.

Postoperative Nerve Root Displacement and Scar Tissue A prospective cohort study with contrast-enhanced MR imaging one year after microdiscectomy

Purpose: To investigate the association between postoperative nerve root displacement and epidural scar tissue. Material and Methods: One hundred patients who had undergone lumbar microdiscectomy were included in a prospective cohort study with a 1-year follow-up. the patients were classified as failures or successes at the 12-month follow-up according to a clinical score. Patients with signs of recurrent disc herniation on MR were excluded from the study. All the 13 patients classified as failures were investigated with MR at the 1-year follow-up, and 40 patients classified as successes were picked at random for MR imaging; thus MR was performed in 53 patients. the MR images were independently evaluated by two neuroradiologists. the images were rated according to the presence or absence of nerve root displacement at the surgically treated disc interspace. Scar formation was rated according to two different classification systems. Results: Nerve root displacement was observed in 13 patients. No evidence of scar formation was found in 4 patients, a small amount in 11, intermediate in 37 and extensive scar formation in 1 patient. No association between nerve root displacement and the amount of scar tissue was found. Conclusion: Postoperative nerve root displacement seems to be an independent clinical entity not associated to postoperative scar tissue.