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K Partanen

Publications and source records attributed to K Partanen.

At least 19 recordsLinked to original sources
PubMed1997

Decline of frontal lobe functions in subjects with age-associated memory impairment.

OBJECTIVE: To assess frontal lobe functions of subjects with age-associated memory impairment (AAMI) and to examine whether performance on neuropsychological tests is correlated with the volume of the frontal lobes in magnetic resonance imaging. DESIGN: Cross-sectional two-group comparison. SETTING: The Memory Research Clinic of Kuopio University and the Magnetic Resonance Imaging Center of Kuopio University Hospital. PARTICIPANTS: Ninety subjects (mean age, 70.5 years), 43 with AAMI diagnosed according to National Institute of Mental Health criteria and 47 age-matched healthy controls. MEASUREMENTS: Four neuropsychological tests were used to assess frontal lobe function: Verbal Fluency Test (VFT), Modified Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT), and Stroop Test (ST). A 1.5-T magnetic resonance imager was used for volume measurements. RESULTS: The AAMI subjects scored significantly worse on the WCST, ST, and TMT compared with controls (ANCOVA, adjusted for age and education, p < 0.05). The frontal lobe volumes did not differ between AAMI subjects and controls. CONCLUSIONS: AAMI subjects appear to be impaired not only in tests assessing memory but also in tests of executive functions. This finding agrees with previous reports suggesting a central role for frontal dysfunction in memory loss of elderly people.

Aged↗
PubMed1996

Interobserver variability in measuring the dimensions of the abdominal aorta: comparison of ultrasound and computed tomography.

OBJECTIVES: To examine the interobserver variability in measuring the abdominal aorta by ultrasound (US) and computed tomography (CT). DESIGN: A prospective clinical study in a university hospital. MATERIALS: Thirty-three patients whose abdominal aortas were scanned both with CT and US as a part of aneurysm investigation or for a variety of other reasons. METHODS: Three radiologists measured abdominal aortic diameters by US and CT. The interobserver differences (IOD) in US and CT and intraobserver differences for CT-US-pairs were analysed by various statistical methods. A new concept of "clinically acceptable difference" (CAD) was adopted denoting differences of less than 5mm. RESULTS: The IOD in US was 2mm or less in 65% of the anteroposterior and 61% of the transverse measurements and 5mm or more in 11% of the anteroposterior and 14% in the transverse measurements in 102 observer pairs for all aortas. The IODs were significantly larger in measuring the aneurysmal aortas compared with normal aortas (p < 0.001). The CAD-value for the aneurysmal aortas was 84% in the anteroposterior and 82% in the transverse directions. In CT the IODs were 2mm or less in 62% of the anteroposterior and 66% of the transverse measurements and 5mm or more in 12% of both anteroposterior and transverse measurements in 94 observer pairs for all aortas. The CAD-value in the aneurysmal aortas was 91% in the anteroposterior and 85% in the transverse directions. There was no significant difference between the US and CT CAD-levels. The absolute CT-US difference of an individual observer was 2mm or less in 54%, 5mm or more in 17% and 10mm or more in 2% of the anteroposterior measurements in the 95 CT-US pairs. In the transverse direction the corresponding figures were: 2mm or less in 63%, 5mm or more 13% and 10mm or more in 2% of the pairs. The diameters obtained by US were smaller in 84% of the cases compared with those of CT in measuring the maximum aortic diameter in anteroposterior direction, whereas the same figure for the transverse measurements was 59%. CONCLUSIONS: Both US and CT measurements are subject to significant interobserver variability that must be taken into account in the clinical follow-up of small abdominal aortic aneurysms and in screening studies. Neither of these methods can be considered as a 'gold standard'.

Aorta, Abdominal↗
PubMed1996

Slow-wave activity in the spectral analysis of the electroencephalogram and volumes of hippocampus in subgroups of Alzheimer's disease patients.

This study examined patients who fulfilled the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association Work Group criteria for probable Alzheimer's disease (AD; n = 35) and controls for magnetic resonance imaging and psychometric data (n = 16) and for quantitative electroencephalogram data (n = 34). A cluster analysis performed on neuropsychological variables identified 2 AD subgroups: The AD1 group (n = 12) had impaired memory and executive functions but preserved verbal and visuospatial functions. The AD2 group (n = 23) had global impairment. The AD2 group had higher theta amplitude in the temporo-occipital, centroparietal, and frontal derivation and lower peak and mean frequency than the AD1 group or controls. Both AD groups had more severe memory deficits and clearly smaller hippocampal volumes than controls. This may implicate that the degree of damage in ascending activating systems differs in these subgroups, although the damage in the hippocampus is equal.

Aged↗
PubMed1996

SPECT and MRI analysis in Alzheimer's disease: relation to apolipoprotein E epsilon 4 allele.

OBJECTIVES: The epsilon 4 allele of apolipoprotein E (ApoE) is a risk factor for late onset Alzheimer's disease. ApoE is present in senile plaques, neurofibrillary tangles, and cerebrovascular amyloid, and it is implicated in synaptogenesis. The effect of ApoE polymorphism on the volumes of hippocampus, amygdala, and frontal lobe was studied. The hypothesis was that the patients with Alzheimer's disease carrying the epsilon 4 allele have more pronounced atrophy. The relation of ApoE and cerebral blood flow on cortical areas was also assessed. METHODS: Fifty eight patients with Alzheimer's disease at the early stage of the disease and 34 control subjects were studied. Patients with Alzheimer's disease were divided into subgroups according to the number of the epsilon 4 alleles. Volumes were measured by MRI and regional cerebral blood flow ratios referred to the cerebellum were examined by 99mTc-HMPAO SPECT. ApoE genotypes were determined by digestion of ApoE polymerase chain reaction products with the restriction enzyme Hha1. RESULTS: patients with Alzheimer's disease had smaller volumes of hippocampi and amygdala compared with control subjects, and the patients with Alzheimer's disease homozygous for the epsilon 4 allele had the most prominent volume loss in the medial temporal lobe structures. The frontal lobe volumes did not differ significantly. All patients with Alzheimer's disease had bilateral temporoparietal hypoperfusion and the subgroups with one or no epsilon 4 alleles also had frontal hypoperfusion compared with control subjects. The occipital perfusion ratios tended to decrease with increasing number of epsilon 4 alleles. CONCLUSIONS: Patients with Alzheimer's disease homozygous for the epsilon 4 allele seem to have severe damage in the medial temporal lobe structures early in the disease process and differ from the patients with Alzheimer's disease with one or no epsilon 4 alleles.

Age of Onset↗
PubMed1996

Hippocampal volumes in Alzheimer's disease, Parkinson's disease with and without dementia, and in vascular dementia: An MRI study.

Hippocampal atrophy detected by volumetric MRI is a sensitive feature of early Alzheimer's disease (AD), but there are no studies evaluating hippocampal atrophy by MR volumetry in other dementing diseases. We therefore compared hippocampal volumes in a total of 113 subjects: 50 patients with mild to moderate AD, 9 patients with vascular dementia (VaD), 12 patients with idiopathic Parkinson's disease (PD) without dementia, 8 patients with PD and dementia (PDD), and 34 elderly control subjects. Thin, coronal, contiguous images were obtained by a 1.5-T MR imager. All patient groups had significantly smaller volumes of the hippocampus compared with the control group. In the PDD group, the absolute volumes were even smaller than in the AD group. In the PD group, the volumes were diminished to a lesser but significant extent. The volumes in the VaD group varied: of nine patients, two had no atrophy, three had unilateral, and four had bilateral atrophy. We postulate that hippocampal atrophy does not seem to be a specific phenomenon of dementia in AD but also occurs in VaD and PDD, and even in PD when no dementia is present. However, coexistence of AD pathology in our PD and VaD patients cannot be ruled out. Further studies with access to neuropathologic data are needed.

Aged↗
PubMed1996

Severity of hippocampal atrophy correlates with the prolongation of MRI T2 relaxation time in temporal lobe epilepsy but not in Alzheimer's disease.

We analyzed hippocampal volumes and T2 relaxation times by MRI from 78 control subjects, 24 patients with temporal lobe epilepsy, and 55 patients with Alzheimer's disease (AD). In the epilepsy group, the hippocampal volumes were 27% smaller than in control subjects (p < 0.001). The T2 relaxation times were prolonged (8 to 20 ms compared with control subjects) in the head, body, and tail portions of the hippocampus on the focal side (p < 0.01) and also on the contralateral side (p < 0.05) compared with control subjects. In the epilepsy group, the prolongation of T2 relaxation time correlated inversely with the hippocampal volume (p < 0.05). In the AD group, the hippocampal volumes were 35% smaller than in control subjects (p < 0.01). The T2 relaxation times were slightly prolonged (5 to 6 ms) in the head and tail portions of the right hippocampus (p < 0.01), but the T2 relaxation times did not correlate with the hippocampal volumes. These data show that the degree of prolongation of T2 relaxation time is associated with severity of hippocampal atrophy in temporal lobe epilepsy but not in AD.

Adult↗
PubMed1996

MRI in obstetrics: a supplementary method for ultrasonography.

The use of magnetic resonance imaging (MRI) as a complementary diagnostic method was evaluated in a group of 36 complicated pregnancies during the last trimester. Most of the examinations were carried out by two specific MRI sequences, the T1-weighted gradient echo FLASH sequence (TR 120, TE 12) and the T2-weighted fast-spin echo sequence (TR 2000, TE 90). Information additional to that obtained by ultrasonic diagnosis was obtained by MRI in 16 of the 25 cases of foetal malformation and in 5 of the 11 cases with other obstetric problems. Foetal curarization was not necessary in most of the cases. A good MRI technique, for selected obstetric problems and when used in combination with detailed antepartal ultrasonic examinations, can give useful diagnostic information to an obstetrician.

Adult↗
PubMed1996

Familial abdominal aortic aneurysms: screening of 71 families.

OBJECTIVE: To find out the local prevalence of familial abdominal aortic aneurysms. DESIGN: Retrospective open study. SETTING: University hospital, Finland. SUBJECTS: 71 families of patients operated on for abdominal aortic aneurysm. INTERVENTIONS: Ultrasound screening, personal interviews and study of population registers, death certificates and hospital records. MAIN OUTCOME MEASURES: The diagnosis of asymptomatic abdominal aortic aneurysms. RESULTS: 148 of the 291 patients operated on replied to our letter (51%). The ultrasound examination was carried out on 123 siblings and detected abdominal aortic aneurysm in one sister (1/78 about 1%) and four brothers (4/45 about 9%). By the other methods data were obtained on 77 siblings (54 men and 23 women) of whom two sisters and six brothers were found to have abdominal aortic aneurysms. When the figures for the 71 families were combined, 10% of the brothers (10/99) and 3% of the sisters (3/101) had abdominal aortic aneurysms. These siblings were from 11 different families and so the prevalence of families with at least two affected persons was 16% (11/71). The index patient in 65 families was male and the prevalence of risk families (with two or more cases of aneurysm) in this group was 15% (10/65). The index case was a woman in six families giving a prevalence of 33% (2/6) (p = 0.2 between the groups). CONCLUSION: The screening of families of patients with abdominal aortic aneurysms should be restricted to the brothers of these patients.

Adult↗
PubMed1995

MRI of amygdala fails to diagnose early Alzheimer's disease.

We evaluated the ability of MRI of the amygdala to diagnose early Alzheimer's disease (AD). The volume of the amygdala was measured in 54 patients with probable AD, 38 subjects with age-associated memory impairment (AAMI), 34 cognitively normal elderly controls (OC) and 20 young controls (YC). The amygdala was atrophied in all the elderly study groups with atrophy being strongest in the AD group (p < 0.0001). The OC and AAMI groups differed from the YC group (p < 0.05) but not from each other. There was a major overlap between the study groups. The volumes also correlated with age (p < 0.0001) and gender (p < 0.001). A correct classification was achieved in 74% of AD patients and the non-demented elderly subjects. Thus, MRI of amygdala fails to diagnose AD accurately.

Adult↗
PubMed1995

Hippocampal atrophy, acute THA treatment and memory in Alzheimer's disease.

We designed the present study to investigate the hypothesis that progression of hippocampal pathology may decrease the therapeutic effects of anti-cholinesterase drug, tetrahydroaminoacridine, on memory functioning in Alzheimer's disease (AD) patients. Memory, visuoconstructive, executive and vigilance functions were assessed after administration of placebo (p.o.; two placebo sessions) and tetrahydroaminoacridine (one session for 25 and 75 mg, p.o.). Eight patients performed better on list learning test during tetrahydroaminoacridine 75 mg than after placebo or tetrahydroaminoacridine 25 mg. The responders performed during baseline examination better than the non-responders in executive and some declarative memory functions, and had higher MMSE scores than the non-responders. The responders had larger left and right hippocampi than the non-responders. The hippocampal volume correlated with list learning performance. The results suggest that severe hippocampal atrophy may block memory improving effect of an anticholinesterase drug, tetrahydroaminoacridine.

Alzheimer Disease↗
PubMed1995

Volumes of hippocampus, amygdala and frontal lobes in the MRI-based diagnosis of early Alzheimer's disease: correlation with memory functions.

We studied the usefulness of measuring volumes of the hippocampus, amygdala and frontal lobes with coronal magnetic resonance imaging (MRI) scans in the diagnosis of early Alzheimer's disease (AD). We examined 32 patients diagnosed according to the NINCDS-ADRDA criteria of probable AD and 16 age-matched healthy cognitively normal controls. The AD patients had mild dementia with a mean score of 22.8 in the Mini-Mental Status Examination (MMSE). We used a 1.5 T magnetic resonance imager and normalized the volumes for brain area. The AD patients had significantly smaller volumes of the right and the left hippocampus (-38%) (ANOVA, p < 0.0001) and the left frontal lobe (-16%, p < 0.05) compared to controls. The reductions in volumes of the right frontal lobe (-13%), the right amygdala (-14%) or the left amygdala (-18%) were not statistically significant. In the discriminant function analysis which included the volumes of the hippocampus, amygdala, and the frontal lobes and age, the volumes of the left and right hippocampus, the left and right frontal lobe, and the right amygdala entered the model and we could correctly classify 92% of the subjects into AD and control groups (Chi-square 42.6, df 5, p < 0.001). By using the volumes of the hippocampus, the frontal lobes or the amygdala on their alone, the correct classification was achieved in 88%, 65% and 58% of the subjects, respectively. In addition, in AD patients the volumes of the left hippocampus correlated significantly with the MMSE score and with immediate and delayed verbal memory; the smaller the volume the more impaired was their performance. Our data indicate that measurements of volumes of the hippocampus might be useful in diagnosis of early AD.

Aged↗
PubMed1995

Habituation of auditory N100 correlates with amygdaloid volumes and frontal functions in age-associated memory impairment.

We studied the habituation of auditory N100 responses in subjects with age-associated memory impairment (AAMI) and in healthy age-matched volunteers. The findings were correlated with volumes of the amygdala, hippocampus, and frontal lobe measured by magnetic resonance imaging (MRI), as well as with subjects' performance on tests assessing frontal lobe functions and memory. Habituation of N100 did not differ across AAMI subjects and controls. However, in AAMI subjects there was a significant correlation between habituation of N100 and volumes of the amygdala; the more reduced habituation, the smaller volume. In addition, decline in habituation of N100 correlated with impaired performance on a visual memory test (Heaton Visual memory test (Heaton Visual Retention Test; r = 0.77; p < 0.001) and impairment on tests assessing frontal functions (Verbal Fluency, Trail Making Test, and Stroop). Habituation of N100 was not related to age or sex. To our knowledge this is the first study to demonstrate a relationship between habituation of evoked responses, MRI volumetric measures, and performance on psychometric tests. The results suggest that impaired memory and frontal lobe functions in AAMI subjects may be associated with poor habituation of N100. Since habituation reflects focusing of attention to relevant features of stimuli, impairment of this mechanism and subsequent defective memory trace formation may contribute to the observed deficits on memory tests.

Aged↗
PubMed1995

Volumes of hippocampus, amygdala and frontal lobe in Alzheimer patients with different apolipoprotein E genotypes.

An increased frequency of apolipoprotein E E4 allele has been reported in patients with late onset Alzheimer's disease. Apolipoprotein E participates in the transport of cholesterol and other lipids and interferes with the growth and regeneration of both peripheral and central nervous system tissues during development and after injury. Apolipoprotein E is also implicated in synaptogenesis. Apolipoprotein E isoforms differ in binding to amyloid-beta-protein and tau protein in vitro. Here, we wanted to study the effect of apolipoprotein E genotype on the magnitude of damage in the hippocampus, where a marked synapse loss exists in Alzheimer's disease. We measured by magnetic resonance imaging the volumes of the hippocampus, amygdala, and frontal lobes in the three Alzheimer subgroups: patients with 2, 1 or 0 E4 alleles. We also investigated the profile of deficits on tests assessing memory, language, visuospatial, executive, and praxic functions of these Alzheimer subgroups. All Alzheimer patients were at early stage of the disease. We found that Alzheimer patients with E4/4 genotype (N = 5) had smaller volumes of the hippocampus and the amygdala than those with E3/4 (N = 9) and those with E3/3 or E2/3 (N = 12). The difference was significant for the right hippocampus (-54% of control) and the right amygdala (-37% of control). The volumes of the frontal lobes were similar across the Alzheimer subgroups. The patients with E4/4 also showed lowest scores on delayed memory tests and differed from E3/3, 3/2 patients in the list learning test (< 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Abnormal regional benzodiazepine receptor uptake in the prefrontal cortex in patients with panic disorder.

The neuroanatomical networks involved in the initiation of panic attack and the maintenance of panic disorder are poorly understood. This study aimed to elucidate the possible abnormalities in benzodiazepine receptor uptake in the brain of patients with panic disorder. Seventeen unmedicated patients with panic disorder were investigated using 123I-iomazenil single photon emission tomography (SPET). Seventeen healthy age- and sex-matched volunteers served as controls. The SPET scan was taken 90 min after injection of tracer. Eleven of 17 patients (65%) showed an increased (> 2 S.D. higher than the mean of the controls) right-to-left ratio of benzodiazepine receptor uptake in the prefrontal cortex. Also, the mean right-to-left ratio of benzodiazepine receptor uptake in all 17 patients with panic disorder was higher than in the controls (P < 0.001). Our SPET study demonstrated focally altered benzodiazepine receptor uptake in the prefrontal cortices in patients with panic disorder. Magnetic resonance imaging indicated that the affected region was located in the right middle and inferior frontal gyri. The deterioration in information processing in the right prefrontal cortex may be implicated in the generation of panic disorder.

Female↗
PubMed1995

Hemodynamic effects of carotid endarterectomy by magnetic resonance flow quantification.

BACKGROUND AND PURPOSE: Blood flow can be evaluated non-invasively using magnetic resonance phase-contrast flow quantification. The purpose of this prospective study was to assess the feasibility of this method and to evaluate the hemodynamic effects of carotid endarterectomy. METHODS: Volumetric flow rates and peak systolic velocities of the internal and common carotid and the vertebral arteries were measured by magnetic resonance flow quantification. Sixteen patients undergoing 18 endarterectomies had complete flow data recorded preoperatively and 3 days after surgery. RESULTS: The inverse correlation between the angiographic stenosis degree and the preoperative flow rate in the corresponding internal carotid artery was highly significant (r = -.69, P < .001). After endarterectomy, the mean flow in the ipsilateral internal carotid artery improved from 143 to 233 mL/min (P < .001). The mean peak systolic velocity increased from 23 to 37 cm/s (P < .001). No significant changes were seen in the contralateral carotid or the vertebral arteries. The mean total blood flow improved by 81 mL/min (P = .08). In the severely stenosed bifurcations (70% to 99%, n = 11), the flow rate improved by 106 mL/min and in the moderately (30% to 69%, n = 4) or mildly (< 30%, n = 3) stenosed bifurcations by 63 mL/min. If the contralateral carotid artery was occluded or severely stenosed, the improvement was 164 mL/min. CONCLUSIONS: Magnetic resonance flow quantification provides a useful tool for the follow-up of the hemodynamic effects of carotid endarterectomy. Our results indicate that surgery is followed by a significant increase of blood flow in the ipsilateral carotid artery and that there appear to be differences in flow increase between subgroups of patients with different degrees of stenosis.

Aged↗
PubMed1995

The interuncal distance in Alzheimer disease and age-associated memory impairment.

PURPOSE: To examine the value of measurement of the interuncal distance in the diagnosis of mild to moderate Alzheimer disease. METHODS: We measured interuncal distance from coronal MR scans acquired on a 1.5-T imager. We estimated interuncal distance from a total of 141 subjects: 54 patients diagnosed according to the National Institute of Neurological and Communicative Disorders and the Alzheimer's Disease and Related Disorders Association criteria of probable Alzheimer disease, 40 subjects fulfilling the National Institute of Mental Health criteria of age-associated memory impairment, 27 healthy cognitively normal older control subjects, and 20 control subjects younger than 50 years of age. For comparison we normalized interuncal distance for a horizontal line drawn through the inner cranium at the level of the uncus (interuncal distance/intracranial width ratio), for the brain area (interuncal distance/brain area) and for the intracranial area (interuncal distance/intracranial area). RESULTS: The standard interuncal distance and the interuncal distance/intracranial width differed between the young control subjects and the other groups, but did not differ among the control, age-associated memory impairment, and Alzheimer disease groups. The Alzheimer disease group had significantly greater interuncal distance/intracranial area and interuncal distance/brain area compared with age-matched controls. A considerable overlap was found, however, in the values of patients with Alzheimer disease and control subjects. The cutoff point of 30 mm for interuncal distance yielded 37% sensitivity and 72% specificity to distinguish patients with Alzheimer disease from nondemented elderly subjects. Interuncal distance was not significantly related to the clinical severity of Alzheimer disease as assessed by Clinical Dementia Rating Scale and Mini-Mental Status Examination. Instead, there was a strong correlation between standard and normalized interuncal distance and age in the whole study population and in nondemented subjects. CONCLUSIONS: Our results showed that in a series of 54 patients with mild to moderate Alzheimer disease, interuncal distance was not a reliable diagnostic tool. The study also confirmed the strong age dependence for interuncal distance.

Adult↗