Adolescent Disc Degeneration - No Headache Association

The objective of the study was to determine whether adolescents with headache have more disc degeneration in the cervical spine than headache-free controls. This study is part of a population-based follow-up study of adolescents with and without headache. At the age of 17 years, adolescents with headache at least three times a month ( N = 47) and adolescents with no headache ( N = 22) participated in a magnetic resonance imaging (MRI) study of the cervical spine. Of the 47 headache sufferers, 17 also had weekly neck pain and 30 had neck pain less than once a month. MRI scans were interpreted independently by three neuroradiologists. Disc degeneration was found in 67% of participants, with no difference between adolescents with and without headache. Most of the degenerative changes were located in the lower cervical spine. In adolescence, mild degenerative changes of the cervical spine are surprisingly common but do not contribute to headache.

Detection and appearance of intraparenchymal haematomas of the brain at 1.5 T with spin-echo, FLAIR and GE sequences: poor relationship to the age of the haematoma

The specific appearance of blood related to time at T1- and T2-weighted spin-echo (SE) sequences is generally accepted; thus, these sequences are classically used for estimating the age of haematomas. Magnetic resonance imaging at 1.5 T, including T1- and T2-weighted SE fluid-attenuated inversion recovery (FLAIR) and T2*-weighted gradient-echo (GE) sequences, was performed on 82 intraparenchymal haematomas (IPHs) and 15 haemorrhagic infarcts (HIs) in order to analyse the appearance at different stages and with different sequences, and to investigate how reliably the age of hematomas can be estimated. The IPHs had been previously detected by CT, were spontaneous ( n=72) or traumatic ( n=10) in origin and were of different sizes (2 mm to 7 cm) and ages (from 7.5 h to 4 years after acute haemorrhagic event). The age of the lesion was calculated from the moment when clinical symptoms started or the traumatic event occurred. The 15 patients with HIs were patients with ischaemic stroke in whom there was either a suspicion of haemorrhagic transformation on CT, or haemorrhage was detected as an additional finding on MR performed for other indications. Patients with conditions that could affect the SI of blood, such as anticoagulant therapy or severe anaemia, were excluded. The signal intensity pattern of the lesions was analysed and related to their ages without prior knowledge of the clinical data. All lesions were detected with T2*-weighted GE. T1-weighted SE missed 13 haematomas and T2-weighted SE and FLAIR sequences missed five. Haemorrhagic transformation was missed in three infarcts by T1-, T2-weighted SE and FLAIR. The signal pattern on FLAIR was identical to that on T2-weighted SE. For all sequences, a wide variety of signal patterns, without a clear relationship to the age of the haematomas, was observed. There was a poor relationship between the real MR appearance of IPHs and the theoretical appearance on SE sequences. T2*-weighted GE was effective for detecting small bleedings but was not useful for estimating the age of a lesion. The FLAIR does not provide any more information than T2-weighted SE.

Extrastriatal dopamine D(2) receptors in Parkinson's disease: a longitudinal study

Most antiparkinsonian drugs are known to act through central dopamine D(2) receptor agonism. A previous longitudinal positron emission tomography (PET) study has indicated that, in the striatum of Parkinson's disease (PD) patients, dopamine D(2) receptor binding declines at a relatively fast annual rate of 2-4% (compared to the rate of <1%/year in healthy individuals). In the present study, the examination of longitudinal changes in D(2) receptors was extended to extrastriatal brain regions in PD. Eight early PD patients were examined twice with PET, approximately 3 years apart, using a high-affinity extrastriatal D(2)/D(3) receptor tracer, [(11)C]FLB 457. Both the MRI-referenced region-of-interest method and the voxel-based statistical analysis method were used independently in the analysis. Regional D(2)-like availabilities (binding potentials) in the left dorsolateral prefrontal cortex, the left temporal cortex and the left and right medial thalami were significantly decreased at the second examination by 20-37% (corresponding to an annual decline of 6-11%). Thus, the annual loss of extrastriatal D(2) availability in PD is up to three times faster than the rate previously reported in the putamen. Our longitudinal study shows first evidence concerning cortical D(2) receptor loss in the progression of PD, although it is not possible to distinguish between the effects of the therapy and the disease.

Evaluation of brain tumor metabolism with [11C]choline PET and 1H-MRS

BACKGROUND

The signal of choline containing compounds (Cho) in proton magnetic resonance spectroscopy (1H-MRS) is elevated in brain tumors. [11C]choline uptake as assessed using positron emission tomography (PET) has also been suggested to be higher in brain tumors than in the normal brain. We examined whether quantitative analysis of choline accumulation and content using these two novel techniques would be helpful in non-invasive, preoperative evaluation of suspected brain tumors and tumor malignancy grade.

METHODS

12 patients with suspected brain tumor were studied using [11C]choline PET, gadolinium enhanced 3-D magnetic resonance imaging and 1H-MRS prior to diagnostic biopsy or resection. Eleven normal subjects served as control subjects for 1H-MRS.

RESULTS

The concentrations of Cho and myoinositol (mI) were higher and the concentration of N-acetyl signal/group (NA) lower in brain tumors than in the corresponding regions of the normal brain. There were no significant differences in metabolite concentrations between low- and high-grade gliomas. In non-tumorous lesions Cho concentrations were lower and NA concentrations higher than in any of the gliomas. Enormously increased lipid peak differentiated lymphomas from all other lesions. The uptake of [11C]choline at PET did not differ between low- and high-grade gliomas. The association between Cho concentration determined in 1H-MRS and [11C]choline uptake measured with PET was not significant.

CONCLUSION

Both 1H-MRS and [11C]choline PET can be used to estimate proliferative activity of human brain tumors. These methods seem to be helpful in differential diagnosis between lymphomas, non-tumorous lesions and gliomas but are not superior to histopathological methods in estimation of tumor malignancy grade.

Role of laparoscopy and laparoscopic ultrasound in staging of pancreatic tumours

BACKGROUND AND AIMS

Radiological imaging alone is not reliable enough in staging of pancreatic cancer. Not only because of poor sensitivity but also because there is a tendency to overstage tumours. The aim of the study was to compare the efficiency of spiral computed tomography (CT), transabdominal ultrasound (US), laparoscopy (LAP) and laparoscopic ultrasound (LUS) in staging of pancreatic tumours.

MATERIAL AND METHODS

In this prospective study 27 patients underwent pancreatic tumour staging with CT, US, LAP and LUS. The reference standard was operative evaluation or in case of disseminated disease laparoscopic assessment.

RESULTS AND CONCLUSIONS

Although LAP was hindered by adhesions in 11% of the patients the benefit of LAP staging was evident in detecting peritoneal carcinomatosis. The assessment of the local tumour expansion of a pancreatic carcinoma was difficult for all staging modalities. LUS did not change the decision whether to proceed with laparotomy once. In our experience routine use of laparoscopic staging does not benefit patients with pancreatic tumour but in selected cases it may prevent unnecessary laparotomy.

Personality traits and brain dopaminergic function in Parkinson's disease

A distinctive personality type, characterized by introversion, inflexibility, and low novelty seeking, has been suggested to be associated with Parkinson's disease. To test the hypothesis that Parkinson's disease is associated with a specific dopamine-related personality type, the personality structures of 61 unmedicated Parkinson's disease patients and 45 healthy controls were examined. Additionally, in 47 Parkinson's disease patients, the dopaminergic function in the brain was directly measured with 6-[(18)F]fluoro-l-dopa ((18)F-dopa) positron emission tomography (PET) with MRI coregistration. The novelty-seeking personality score, supposedly associated with the parkinsonian personality, was slightly lower in the Parkinson's disease group compared with controls, but it did not have a significant relationship with (18)F-dopa uptake in any of the brain regions studied (r = -0.12 to 0.11, P > 0.15). The harm-avoidance personality score, associated with anxiety and depression, was clearly increased in patients with Parkinson's disease and it had a paradoxical, highly significant positive correlation with the (18)F-dopa uptake in the right caudate nucleus (r = 0.53, P = 0.04, Bonferroni corrected for 220 comparisons). Although the results of this study are not in disagreement with the concept of low-novelty-seeking personality type in Parkinson's disease, the personality type does not seem to be dopamine dependent. The correlation between the personality trait of harm avoidance and (18)F-dopa may reflect a specific feedback circuitry of neurotransmitters that is associated with negative emotionality in Parkinson's disease.

Rate of progression in Parkinson's disease: a 6-[18F]fluoro-L-dopa PET study

The aim of this study was to investigate the rate of progression in Parkinson's disease (PD) with 6-[(18)F]fluoro-L-dopa (FDOPA) positron emission tomography (PET). We investigated 21 patients with PD and eight healthy controls. Ten of the patients were de novo at the time of the first PET scan and antiparkinsonian medication was started thereafter, with a favourable response. A FDOPA PET scan was carried out twice at an approximately 5-year interval. The regions of interest were drawn on individual magnetic resonance imaging (MRI) images, matched with the PET images. At the first PET scan, in PD patients the mean k(i)(occ) (x 10(-3) min(-1)) in the anterior putamen was 5.6 +/- 2.7 (mean +/- S.D.; 55% of the control mean) and in the posterior putamen 4.5 +/- 2.4 (45% of the control mean). The k(i)(occ) value for the caudate nucleus was 7.5 +/- 2.1 (x 10(-3) min(-1); 76% of the control mean). The FDOPA uptake declined by the time of the second PET scan and the annual rate of decline was 8.3 +/- 6.3% (P < 0.001) of the baseline mean in the anterior putamen and 10.3 +/- 4.8% (P < 0.001) in the posterior putamen. In the caudate nucleus, FDOPA uptake decreased by 5.9 +/- 5.1% (P < 0.001) of the baseline mean per year. The estimated preclinical period was longest for the posterior putamen being 6.5 years. For the anterior putamen the preclinical period was 4.6 years. In the caudate nucleus, the estimated FDOPA uptake was at normal level at disease onset. In healthy controls, there was no significant decline in FDOPA uptake in any striatal subregion. Our results suggest that the disease process in PD first affects posterior putamen, followed by the anterior putamen and the caudate nucleus, but once started, the absolute rate of decline is the same. In healthy controls, no significant decline in FDOPA was detected.

Detection of response to COMT inhibition in FDOPA PET in advanced Parkinson's disease requires prolonged imaging

The aim was to investigate whether the improved 6-[(18)F]fluoro-L-dopa (FDOPA) availability induced by catechol-O-methyltransferase (COMT) inhibition can be more clearly seen during late than during standard (early) imaging in FDOPA uptake in Parkinson's disease (PD) patients with severe dopaminergic hypofunction. Six PD patients and six healthy controls were investigated up to 3.5 h after FDOPA injection with and without a single 400-mg dose of a peripheral COMT inhibitor, entacapone. Prolonged (late) imaging showed a significantly higher increase in FDOPA uptake than standard 1.5 h (early) imaging after entacapone both in controls and in PD patients. The increase in the (putamen-occipital):occipital ratios was 37.4% during early and 70.4% during late imaging in controls. In PD patients, there was no significant change in the ratios during early imaging, but the late imaging showed a significant increase in the putamen-to-occipital ratio of 54.2% after COMT inhibition. Late imaging reveals more clearly the prolonged FDOPA availability induced by COMT inhibition leading to higher cumulated striatal activity compared with early imaging. This might be worth considering in FDOPA studies, especially if investigations are planned to do without blood sampling. Late imaging shows the storing potential of FDA better than is seen during early FDOPA PET imaging after entacapone administration. In patients with severe presynaptic dopaminergic hypofunction, its detection requires prolonged imaging.

Reproducibility and effect of levodopa on dopamine transporter function measurements: a [18F]CFT PET study

The objective of this article was to study the reproducibility and effect of levodopa on dopamine transporter function measurements using 2beta-carbomethoxy-3beta-(4-[18F]fluorophenyl)tropane ([18F]CFT) positron emission tomography (PET). Seven de novo patients with Parkinson's disease (PD) were studied twice, before and after three months of levodopa medication. Eight healthy volunteer subjects participated in the reproducibility study. The [18F]CFT PET scan was done twice with an interval of approximately 2.5 months. The regions of interest (anterior and posterior putamen, caudate nucleus, and cerebellum) were drawn on individual magnetic resonance imaging (MRI) images, matched with the PET images, and copied onto the PET images. The [18F]CFT uptake was calculated as the region-cerebellum:cerebellum ratio at 180 to 210 minutes. Three-month levodopa treatment in PD patients had no significant effect on [18F]CFT uptake in any striatal subregion between the two PET scans. In PD patients, the percent change from baseline was 4.1% in the anterior putamen, 1.9% in the posterior putamen, and 4.0% in the caudate nucleus. No significant differences in [18F]CFT uptake between the first and second PET scan in any striatal subregion occurred in healthy controls. The intraclass correlation, indicating the reproducibility of the PET scan within subjects, was 0.94 for the anterior putamen, 0.86 for the posterior putamen, and 0.91 for the caudate nucleus. The percent change from baseline was 4.0% in the anterior putamen, 1.1% in the posterior putamen, and 2.8% in the caudate nucleus. Long-term levodopa treatment in PD patients had no effect on the [18F]CFT uptake in the striatum and the test-retest reproducibility was very high. These findings confirm [18F]CFT as a suitable ligand to monitor progression of PD.

Radiotherapy treatment planning and long-term follow-up with [(11)C]methionine PET in patients with low-grade astrocytoma

PURPOSE

To evaluate the feasibility of [(11)C]-methionine positron emission tomography (MET PET) in radiotherapy (RT) treatment planning and long-term follow-up in patients with low-grade glioma.

PATIENTS

Thirteen patients with low-grade astrocytoma and 1 with anaplastic astrocytoma underwent sequential MET PET and magnetic resonance imaging (MRI) before and 3, 6, 12, and 21-39 months after RT, respectively. Ten patients were studied after initial debulking surgery or biopsy and 4 in the recurrence phase.

METHODS

A total of 58 PET scans were performed. After transmission scanning, a median dose of 425 MBq of MET was injected intravenously and emission data was acquired 20 min after injection for 20 min. The uptake of MET in tumor area was measured as standardized uptake value (SUV) and tumor-to-contralateral brain SUV ratios were generated to assess irradiation effects on tumor metabolism. Functional imaging with PET was compared with concurrent MRI in designing the RT planning volumes and in assessment of response to RT during a median follow-up time of 33 months.

RESULTS

In 12 patients (86%), tumor area was clearly discernible in the baseline PET study. In the remaining 2 patients with a suspected residual tumor in MRI, PET showed only a diffuse uptake of MET interpreted as negative in the original tumor area. In the dose planning of RT, MET PET was helpful in outlining the gross tumor volume in 3 of 11 cases (27%), whereas PET findings either coincided with MRI (46%) or were less distinctive (27%) in other cases. In quantitative evaluation, patients with a low tumor SUV initially had significantly better prognosis than those with a high SUV. Tumor-to-contralateral brain uptake ratios of MET discriminated well patients remaining clinically stable from those who have since relapsed or died of disease.

CONCLUSION

Quantitative MET PET has prognostic value at the time of initial treatment planning of low-grade glioma. Some patients may benefit of RT volume definition with MET PET, which seems to disclose residual tumor better than MRI in selected cases. Stable or decreasing uptake of MET in tumor area after RT during follow-up seems to be a favorable sign.

Central and peripheral nervous system dysfunction in the clinical variation of Salla disease

OBJECTIVE

To evaluate the degree of possible peripheral nervous system (PNS) involvement in addition to CNS manifestations in Salla disease, a free sialic acid storage disorder leading to severe mental retardation with a wide clinical variation.

BACKGROUND

Salla disease is a lysosomal storage disorder that affects the white matter of the CNS. MRI findings and recent 1H MRS study results provide evidence for delayed central myelination, but there is no previous evidence for PNS involvement in this disease. The gene coding for a presumptive sialic acid transport protein has recently been identified, and the first disease-causing mutations have been characterized.

METHODS

Nerve conduction studies; evoked potentials to visual (VEP), brainstem auditory (BAEP), and somatosensory stimuli (SEP); and EEG were carried out on 22 patients (age range 2 months to 57 years) with biochemically and genetically confirmed Salla disease. Brain MRI were available on 14 patients.

RESULTS

Nerve conduction studies revealed abnormalities in nearly half of the patients (10/21). The four severely disabled patients and the oldest patient had greatly reduced nerve conduction velocities and prolonged distal latencies compatible with demyelinating polyneuropathy. In addition, SEP was abnormal in the majority of the patients, but VEP and BAEP in only a few cases. PNS involvement was clearly associated with both the phenotypic severity and MRI findings.

CONCLUSIONS

The results indicate that dysmyelination in Salla disease occurs not only in the CNS but also in the peripheral nervous system, contributing to the phenotypic variation, which can now be correlated with the molecular basis of the disease.

Bone mineral density of the lumbar spine in patients with advanced rheumatoid arthritis. Influence of functional capacity and corticosteroid use

We investigated factors that are related to generalized osteoporosis in advanced rheumatoid arthritis (RA). In this cross-sectional study we measured trabecular bone mineral density (BMD), by quantitative computerized tomography (QCT), in the lumbar spine of 57 patients with RA, most of whom were premenopausal women. In our material, 27 out of 57 patients (47%) had BMD <-1 SD expressed as Z-score and five patients had suffered from fractures. Our study shows that a cumulative corticosteroid dose (r = -0.41, p<0.010) and functional impairment (r = -0.37, p<0.050) were negatively related to spinal BMD, while daily intake of calcium correlated positively on BMD (r = 0.37, p<0.010). Our results indicate that low BMD is common in patients with advanced RA and it is associated with long-term corticosteroid use. Thus, in clinical practice we have to consider the benefits and harms of corticosteroid treatment and preventive therapy to osteoporosis.

Interferon-alpha treatment decreases serum cross-linked C-terminal telopeptide of type I collagen in haematological diseases

Interferon-alpha (IFN-alpha) is used in the treatment of many haematological diseases and it is known that IFN-alpha may affect bone turnover. The effect of IFN-alpha on bone metabolism was studied in 10 haematological patients. The mean duration of the treatment was 4 (range: 2.8-7.2) months. Besides the usual markers of bone metabolism, levels of the cross-linked C-terminal telopeptide of type I collagen (ICTP), the N-terminal propeptide of type I procollagen (PINP) and the bone-specific alkaline phosphatase were measured. The bone mineral density was measured by computed tomography. During IFN-alpha treatment, serum ICTP decreased from a mean of 5.4 (range: 1.8-12.4) to 3.6 (range: 1.4-8.8) microg/l (P = 0.017). All other variables reflecting bone metabolism remained unaltered during IFN-alpha treatment. The bone mineral density remained unchanged. It was concluded that the observed decrease in ICTP may be an indicator of a beneficial therapeutic effect of IFN-alpha on bone turnover, resulting in decreased bone resorption. However, it is possible that elevated pretreatment ICTP values reflected disease of the bone marrow.

Usefulness of a dopamine transporter PET ligand [(18)F]beta-CFT in assessing disability in Parkinson's disease

OBJECTIVES

The usefulness of a novel dopamine transporter PET ligand, [(18)F]beta-CFT in assessing disability in Parkinson's disease was studied.

METHODS

Twenty seven patients with Parkinson's disease in different disability stages (of which nine were patients with early disease) and nine healthy controls were studied. The regions of interest were drawn on a magnetic resonance image resliced according to the PET image.

RESULTS

There was a significant reduction in [(18)F]beta-CFT uptake in the posterior putamen (to 18% of the control mean, p<0.00001), anterior putamen (28%, p<0.00001), and caudate nucleus (51%, p<0.00001) in the total population of patients with Parkinson's disease. The reduction in [(18)F]beta-CFT uptake was more pronounced with more severe disability of the patients, the correlations between the total motor score of the unified Parkinson's disease rating scale (UPDRS) and [(18)F]beta-CFT uptake being significant in the posterior putamen (r=-0.62 p=0.0005), anterior putamen (r=-0.64, p=0.0003), and the caudate nucleus (r=-0.62, p=0.0006). There was a significant negative correlation with putaminal [(18)F]beta-CFT uptake and the hypokinesia and rigidity scores, but not with the tremor score of the UPDRS motor part. In nine patients with early disease and without any antiparkinsonian medication the reduction in the [(18)F]beta-CFT uptake (average of ipsilateral and contralateral side) was reduced in the total putamen to 34% of the mean control value (p<0.00001). The corresponding figures in the other brain areas were: posterior putamen 21% (p<0.00001), anterior putamen 43% (p<0.00001), and caudate nucleus 76% (p<0.01). The reductions in [(18)F]beta-CFT uptake were more severe in the contralateral than in the ipsilateral side. Individually, [(18)F]beta-CFT uptake in the putamen in all patients was below 3 SD from the control mean.

CONCLUSIONS

[(18)F]beta-CFT is a sensitive marker of nigrostriatal dopaminergic dysfunction in Parkinson's disease and can be used in the diagnosis, assessment of disease severity, and follow up of patients.

Bone mineral density after allogeneic bone marrow transplantation

Bone turnover markers and bone mineral density (BMD) were studied in 25 adult patients (14 females, 11 males) who had undergone allogeneic bone marrow transplantation (BMT). The interval from BMT to the first examination was at least 1 year (mean 3, range 1-10). Mean age of the patients at the time of first evaluation was 42 (range 19-54) years. Blood samples and urine collections for evaluation of biochemical factors reflecting skeletal turnover were performed together with the first BMD measurement. BMD was measured from the lumbar vertebrae (L2 to L4) with computed tomography and results were expressed as Z-scores. At the time of the first measurement five patients (20%) had Z-scores <-2.5 s.d. and 12 patients (48%) between -1 and -2.5 s.d. In 12 patients BMD assessments were repeated and it seemed that reduction in BMD had mostly occurred during and shortly after BMT and remained the same during follow-up. The cross-linked carboxyterminal telopeptide of type I collagen (ICTP) correlated negatively with BMD (r = -0.45, P = 0.045) as did bone-specific alkaline phosphatase (BAP; r = -0.64, P = 0.002). No correlation between BMD and time interval from diagnosis to BMT, conditioning regimen, corticosteroid use or hospital stay during transplantation was found. In conclusion, bone disease is common after BMT. Our findings demonstrate an increased collagen and bone turnover and a high risk of osteoporosis. BMD measurements must be repeated regularly and collagen markers such as ICTP and BAP can be beneficial in estimating the activity of bone disease.

A new metabolite contributing to N-acetyl signal in 1H MRS of the brain in Salla disease

OBJECTIVE

To determine whether N-acetylaspartate (NAA) is reduced in patients with Salla disease, a neurodegenerative disorder.

BACKGROUND

1H MRS allows the brain metabolism to be studied noninvasively in vivo. N-acetyl (NA) is composed primarily of NAA, which is regarded as a neuronal marker. The NA signal in 1H MRS is reduced in several neurodegenerative disorders. Increased NA signal has thus far only been found in Canavan's disease as a result of NAA accumulation in the brain tissue. In Salla disease, an autosomal recessive free sialic acid storage disorder, N-acetylneuraminic acid (NANA), accumulates in lysosomes of brain tissue.

METHODS

The authors studied eight patients with Salla disease (age range, 6 to 44 years) and eight age-matched healthy volunteers using quantitative 1H MRS. The spectra were obtained from two selected 8-cm3 volumes of interest localized in the basal ganglia and in the parietal white matter using conventional 1.5-T MRI equipment. The spectral resonance lines of NA groups, creatine and phosphocreatine (Cr), and choline-containing compounds (Cho) were analyzed quantitatively. All MR images were evaluated to verify the state of myelination.

RESULTS

1H MRS from parietal white matter revealed 34% higher NA and 47% higher Cr concentrations, and a 35% lower Cho concentration in the patients with Salla disease compared with the age-matched control subjects. The patients had a 22% higher water content in their parietal white matter, whereas in the basal ganglia the water concentrations did not differ significantly. In the patients' basal ganglia the Cr concentration was 53% higher.

CONCLUSIONS

NAA is considered to be a neuronal marker that, except for Canavan's disease, has been found or assumed to be either stable or reduced. However, in Salla disease the high NA signal may have a contribution from accumulated lysosomal NANA, which offsets the possible loss of NAA. The high Cr is in line with the increased glucose uptake found in our earlier 2-fluoro-2-deoxy-D-glucose-PET study, reflecting increased energy demand. It is worth noting that in a conventional 1H MRS ratio-based analysis these underlying abnormalities would have remained undetected. Our study thus emphasizes the importance of a quantitative assessment of metabolite concentrations in 1H MRS for detecting altered brain metabolism.

Brain involvement in Salla disease

BACKGROUND AND PURPOSE

Our purpose was to document the nature and progression of brain abnormalities in Salla disease, a lysosomal storage disorder, with MR imaging.

METHODS

Fifteen patients aged 1 month to 43 years underwent 26 brain MR examinations. In 10 examinations, signal intensity was measured and compared with that of healthy volunteers of comparable ages.

RESULTS

MR images of a 1-month-old asymptomatic child showed no pathology. In all other patients, abnormal signal intensity was found: on T2-weighted images, the cerebral white matter had a higher signal intensity than the gray matter, except in the internal capsules. In six patients, the white matter was homogeneous on all images. In four patients, the periventricular white matter showed a somewhat lower signal intensity; in five patients, a higher signal intensity. In the peripheral cerebral white matter, the measured signal intensity remained at a high level throughout life. No abnormalities were seen in the cerebellar white matter. Atrophic changes, if present, were relatively mild but were found even in the cerebellum and brain stem. The corpus callosum was always thin.

CONCLUSION

In Salla disease, the cerebral myelination process is defective. In some patients, a centrifugally progressive destructive process is also seen in the cerebral white matter. Better myelination in seen in patients with milder clinical symptoms.

Striatal uptake of a novel PET ligand, [18F]beta-CFT, is reduced in early Parkinson's disease

[18F] beta-CFT is a novel PET ligand for dopamine reuptake sites. In this study, [18F]beta-CFT uptake was studied in nine patients with early Parkinson's disease (PD) without antiparkinsonian medication and in six age-matched controls. The uptake of [18F]beta-CFT was calculated as a (region-cerebellum)/cerebellum ratio at 150-210 min after injection. The mean uptake in the putamen contralateral to the predominant symptoms (1.04+/-0.40, mean +/- SD; P<0.001) was reduced to 31% of the mean control value. In the "ipsilateral" putamen, the ratio in PD patients (1.50+/-0.50, P<0.001) was reduced to 45% of the control mean (3.33+/-0.61). Individually, all PD patients had [18F]beta-CFT uptake values below 2 SD from the control mean in the contralateral putamen. The decline in [18F]beta-CFT uptake in the caudate nucleus was milder than that seen in the putamen. The uptake was reduced contralaterally (2.19+/-0.47, P<0.01) to 67% and ipsilaterally (2.49+/-0.54, P<0.05) to 77% of the control mean (3.17+/-0.61). In the medial frontal cortex or dorsolateral prefrontal cortex, no significant difference in [18F]beta-CFT uptake between patients and controls was seen. In conclusion, [18F]beta-CFT is a powerful ligand to demonstrate presynaptic dopaminergic defect in PD and shows a clear separation of patient and control values.

Suppression of GH secretion in pituitary gigantism by continuous subcutaneous octreotide infusion in a pubertal boy

We describe a 12-y-old boy with excessive growth hormone and prolactin secretion presumably due to diffuse somatotroph hyperplasia. Until mid-puberty, his growth rate was under reasonable control, with high-dose octreotide injections every 8 h combined with a dopamine agonist. As his growth velocity started to increase, the efficacy of continuous s.c. octreotide infusion on GH secretion was tested. Similar total daily doses (600 microg) of octreotide were administered either by incremental s.c. injections at 8 h intervals, or by continuous s.c. infusion, two-thirds of the amount during night-time to control the presumed high nocturnal growth hormone (GH) peaks of the pubertal growth spurt. An overnight GH profile showed inadequate suppression of GH levels by incremental injections, while continuous s.c. infusion efficiently brought down the GH secretion. Another somatostatin analogue, lanreotide as a single depot injection was not effective. A 6-mo trial on the s.c. infusion regimen significantly reduced growth hormone secretion (as judged by IGF-I and IGFBP3 concentrations), and normalized growth velocity overcoming the pubertal growth spurt. It also caused a decrease in the pituitary size in magnetic resonance images. We conclude that the efficacy of octreotide infusion in suppressing GH secretion is superior to incremental injections with the same dose.

Intracranial aneurysms in three patients with disseminated Lyme borreliosis: cause or chance association?

METHODS

Three patients with Borrelia burgdorferi infection and intracranial aneurysms are described.

RESULTS

All three patients had neurological symptoms. Perivascular and vasculitic lymphocytic inflammation were detected in the brain biopsy specimen of one patient. The aneurysm was located in the internal carotid arteries in two patients and in the basilar artery in one patient. The aneurysm ruptured in two patients.

CONCLUSIONS

Cerebral lymphocytic vasculitis and intracranial aneurysms may be associated with B burgdorferi infection. It is suggested that inflammatory changes caused by B burgdorferi in vessel walls may be a pathogenetic mechanism for the formation of aneurysms.

Inflammatory brain changes in Lyme borreliosis. A report on three patients and review of literature

Despite a rapid increase in the number of patients with Lyme neuroborreliosis (LNB), its neuropathological aspects are poorly understood. The objective of this study was evaluation of neuropathological, microbiological, and magnetic resonance imaging (MRI) findings in three patients with the Borrelia burgdorferi infection and neurological disease from whom brain tissue specimens were available. Perivascular or vasculitic lymphocytic inflammation was detected in all specimens. Large areas of demyelination in periventricular white matter were detected histologically and by MRI in one patient. The disease had a fatal outcome in this patient. Brain MRI suggested malignancies in two patients before histopathological studies were carried out. One of these two patients was a child with sudden hemiparesis. Another was a 40-year-old man presenting with epileptic seizures and MRI-detected multifocal lesions, which disappeared after repeated courses of antibiotics. We conclude that cerebral lymphocytic vasculitis and multifocal encephalitis may be associated with B. burgdorferi infection. The presence of B. burgdorferi DNA in tissue samples from areas with inflammatory changes indicates that direct invasion of B. burgdorferi may be the pathogenetic mechanism for focal encephalitis in LNB.

CT, MRI, and PET in a case of intractable epilepsy

We report the case of a child with drug-refractory partial epilepsy in whom computed tomography showed no abnormality and magnetic resonance imaging showed a noninvasive cystic lesion in the left hippocampus. The finding in the positron emission tomography study with L-[methyl-11C]-methionine as a tracer suggested a tumor. This finding was confirmed histologically.

Spinal epidural abscess: an unusual cause of sciatica

A previously healthy patient was admitted to our hospital because of low back pain and sciatica. For 4 weeks preceding the admission, he had been treated with nonsteroidal antiinflammatory analgetics and bed rest with a clinical diagnosis of lumbar disc herniation. On admission, the patient was subfebrile but developed general symptoms of septic infection by the next day. Computed tomography and magnetic resonance imaging of the lumbar spine revealed a spinal epidural abscess and spondylodiscitis at the L5-S1 level. During an emergency laminotomy, gross pus in abundance was evacuated from the epidural space; microbiological cultures from the pus and blood yielded Staphylococcus aureus. The unique clinical presentation of our patient combined with merely indolent symptoms of infection delayed the correct diagnosis. We are not aware of any similar reports of patients with lower spinal epidural abscess whose primary presentation was sciatic pain.

Leber's "plus": neurological abnormalities in patients with Leber's hereditary optic neuropathy

Previous studies suggest that Leber's hereditary optic neuropathy (LHON) may be a systemic disorder with manifestations in organs other than the optic nerves. To evaluate nervous system involvement 38 men and eight women with LHON were re-examined. The patients were divided into three groups according to mtDNA analysis--namely, patients with the 11778 or with the 3460 mutation and patients without these primary mutations. Fifty nine per cent of patients had neurological abnormalities but there was no significant difference between the three groups. Movement disorders were the most common finding; nine patients had constant postural tremor, one chronic motor tic disorder, and one parkinsonism with dystonia. Four patients had peripheral neuropathy with no other evident cause. Two patients had a multiple sclerosis-like syndrome; in both patients MRI showed changes in the periventricular white matter. Thoracic kyphosis occurred in seven patients, five of whom had the 3460 mutation. In one patient the 3460 mutation was associated with involvement of the brain stem. It is suggested that various movement disorders, multiple sclerosis-like illness, and deformities of the vertebral column may associate pathogenetically with LHON.

Localized proton NMR spectroscopy in the striatum of patients with idiopathic Parkinson's disease: a multicenter pilot study

Single voxel proton MRS was used to study brain metabolism in the striatum of patients diagnosed with idiopathic Parkinson's disease (PD). Peak metabolite ratios in long echo time spectra were evaluated in 151 patient spectra and 97 age-matched control spectra collected at four participating institutions using identical hardware and clinical protocols. Combining data from all ages (27-83 years old) showed no significant difference between patient and control ratios. However, in an elderly subset of patients (51-70 years old), a significant decrease in striatal N-acetylaspartate (NAA)/choline (Cho) was observed. Also, a significant decrease in the mean NAA/Cho ratio was observed in patients versus controls for patients not being treated with Sinemet (Du Pont Pharm, Wilmington, DE) (hereafter referred to as levodopa/carbidopa). This result is consistent with the hypothesis that NAA may provide a reversible spectroscopic marker for neuronal dysfunction, although a prospective follow-up study will be needed to confirm this. Quantitation of MRS would be useful to exclude the possibility that a change in Cho levels affected the NAA/Cho ratios.

Striatal D2 dopamine receptor binding characteristics in vivo in patients with alcohol dependence

Striatal D2 dopamine receptor characteristics of nine male patients with alcohol dependence abstinent for 1-68 weeks and eight healthy male volunteers were studied in vivo with positron emission tomography. The selective D2 receptor ligand [11C]raclopride and equilibrium model was used for D2 receptor density (Bmax) and affinity (Kd) measurements. A trend for a decreased striatal D2 receptor density and for reduced D2 receptor affinity was observed in patients with alcohol dependence. These parameters were not statistically significantly different between alcoholics and controls, but the ratio between D2 receptor density and affinity (Bmax/Kd or the striatum/cerebellum ratio from the high specific activity scan) was highly significantly lower in alcoholics than that of controls. In conclusion, the low D2 dopamine receptor Bmax/Kd ratio (striatum/cerebellum ratio) indicates that specific aspects of striatal [11C]raclopride binding in vivo are deviant in alcoholics compared to controls. The result is compatible with a reduced avidity of striatal dopamine D2 receptors in alcoholics, which is in line with the idea that D2 dopaminergic mechanisms are involved in the biology of alcohol dependence in man.

Phenotypic variation and magnetic resonance imaging (MRI) in Salla disease, a free sialic acid storage disorder

Salla disease (SD) is a recessively inherited lysosomal storage disorder particularly common in the Finnish population. Patients with SD are normal at birth, but develop psychomotor delay and ataxia during the first year of life. Phenotypic variation of SD is wide, ranging from severely disabled children to mentally retarded adults capable of living under sheltered conditions. In the present study four unusually severely affected patients were investigated by detailed clinical examination, magnetic resonance imaging (MRI) and analysis of the excretion of free sialic acid in urine. MRI study, reported here for the first time, revealed a similarly defective myelination pattern in seven patients. The myelination process seemed to cessate at the level of an infant of a few months of age. Genetic linkage study of the families of the severely affected patients suggested linkage to the recently discovered SD locus on the long arm of chromosome 6. Locus heterogeneity therefore is an unlikely explanation of the phenotypic variation in SD.

MRI and plain radiographics in acute frontal sinus infections

Twenty-seven patients with acute frontal sinusitis, collected during a 4-month period, were examined with plain radiographics and MRI both at the time of diagnosis and one month later. Findings in the frontal and ethmoidal sinuses were recorded. Frontal sinus trephination was performed in 13 of the 27 cases. The study shows that MRI is as reliable as X-ray in diagnosing an acute paranasal sinus infection with clinical symptoms. Frontal sinusitis is not an isolated disease affecting only the frontal sinuses: Mucosal pathology can also be found widely in the ethmoidal cells, and this pathology seems to persist in many cases for weeks. MRI showed its capability in confirming these findings. MRI was not found to be an over-diagnosing method in registering the secretions and mucosal swelling during an acute paranasal sinus infection.

Dorsal CSF space at CI-II level. Technique of cervical myelography

The width of the dorsal CSF space at the CI-II lateral puncture site was measured, both in extension and in the neutral position of the head, in 60 patients undergoing cervical myelography. The sagittal diameter of the dorsal CSF space did not change in 22 patients, was larger in extension in 27 patients, and larger in the neutral position in 11 patients. In three patients with a large dorsal CSF space the change in diameter was more than 2 mm whereas in other patients the change was minimal. Lateral CI-II puncture may be performed safely both in extension and in the neutral position. Distribution of the contrast medium was more satisfactory if the head was extended.

CT examination of spinal tumours

Forty-five patients with a spinal, intraspinal or paraspinal tumour were evaluated by computed tomography. All examinations revealed pathological findings. In 30 cases the extent of the tumour was determined at surgery and in only two cases was there a discrepancy from the CT findings. Twenty-nine patients also underwent conventional myelography, three of which were negative. In the estimation of the extent of extradural tumours or bone involvement, CT was superior to other methods, but the size and localization of intradural tumours were estimated equally well by CT and conventional myelography. In patients with an intramedullary lesion CT was necessary to distinguish a solid neoplasm from a cystic lesion. In CT examinations of intraspinal tumours, intrathecal contrast medium increased the amount of information obtained especially in the thoracic and cervical regions, but was not necessary if myelograms were available. Intravenous contrast medium helped in the evaluation of some intraspinal neoplasms but did not improve the delineation of the paraspinal components.