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K Partanen

Publications and source records attributed to K Partanen.

At least 19 recordsLinked to original sources
PubMed2006

Assessing the outcome of stroke: a comparison between MRI and clinical stroke scales.

OBJECTIVES: To assess the correlation of diffusion-weighted (DWI) and perfusion-weighted imaging (PWI) findings with the severity of acute neurologic deficit and their ability to predict short and long-term clinical outcomes of stroke. The ability of DWI and PWI to predict the outcome was compared with the ability of clinical stroke scales to predict the outcome. METHODS: Forty-eight patients with acute stroke underwent diffusion DWI and PWI on the first and eighth day after the ictus. Clinical and functional scales were carried out before each scan and 3 months after the stroke. RESULTS: The volumes of both the DWI and the PWI lesions correlated well with the acute neurologic deficit and the final outcome. The first day PWI (r = 0.64) and the National Institutes of Health Stroke Scale (NIHSS) scores (r = 0.70) correlated well with the final outcome. However, in logistic regression analysis, only the NIHSS score at the acute stage was the only independent predictor of the long-term clinical outcome. CONCLUSION: While the PWI and DWI lesion volumes correlated well with the outcome of the stroke, the imaging measurements did not improve the prognostic power over plain clinical stroke scale scores.

Aged↗
PubMed2004

Preoperative clinical evaluation, outline of surgical technique and outcome in temporal lobe epilepsy.

Temporal lobe epilepsy (TLE) is the most common type of refractory epilepsy. The mechanisms of epileptogenesis and seizure semiology of the mesial and neocortical temporal lobe epilepsy are discussed. The evaluation and selection of patients for TLE surgery requires team work: the different clinical aspects of neuropsychological evaluation, magnetic resonance and functional imaging (positron emission tomography, single photon emission computed tomography and magnetoenephalography) are reviewed. In our programme of epilepsy surgery at Kuopio University Hospital, Finland, we have performed 230 temporal resections from 1988 until 2002. Preoperative diagnostic EEG-videotelemetry often required intracranial monitoring and it has proved to be safe and efficient. The indications and technique for tailored temporal lobe resection with amygdalohippocampectomy used in our institution, as well as the complications, are described. Our analysis of outcome after temporal lobe surgery included 140 consecutive adult patients between 1988 and 1999; one year after the operation in unilateral TLE the Engel I-II outcome was observed in 68% of the patients. Outcome of surgery improved significantly after introduction of the standardised MR imaging protocol from 1993; 74% of patients with unilateral TLE achieved Engel I-II outcome.

Electroencephalography↗
PubMed2002

Percutaneous bone grafting in the treatment of the delayed union and non-union of tibial fractures.

The classic method of open bone grafting in the treatment of un-united tibial fractures has been associated with some complications. A novel, minimally invasive, percutaneous technique of bone grafting is described. Forty-one consecutive patients with delayed union or non-union of a tibial fracture was treated with percutaneous bone grafting from 1993 to 1999. The mean age of the patients was 41 (15-86) years. Twenty-seven patients had grade I-III open fractures. The fractures had initially been treated in a cast (n=26), external fixator (n=14) or intramedullary nail (n=1). Two patients had an earlier unsuccessful Phemister-Charnley-type bone-grafting procedure for delayed union. The mean interval from injury to percutaneous bone grafting was 21 (13-66) weeks. Thirty-seven of the 41 un-united fractures healed in 13 (10-48) weeks after the percutaneous bone grafting. The mean hospital stay was 1 day. No infections, bleeding or neural complications existed. Percutaneous bone grafting appeared to be as effective as open techniques, and possessed considerable advantages. It is safe, time saving and economical, it involves minimal trauma at the fracture site and it avoids major donor site problems.

Adolescent↗
PubMed2002

Reproducibility of scoring emphysema by HRCT.

PURPOSE: We evaluated the reproducibility of three visual scoring methods of emphysema and compared these methods with pulmonary function tests (VC, DLCO, FEV1 and FEV%) among farmer's lung patients and farmers. MATERIAL AND METHODS: Three radiologists examined high-resolution CT images of farmer's lung patients and their matched controls (n=70) for chronic interstitial lung diseases. Intraobserver reproducibility and interobserver variability were assessed for three methods: severity, Sanders' (extent) and Sakai. Pulmonary function tests as spirometry and diffusing capacity were measured. RESULTS: Intraobserver kappa-values for all three methods were good (0.51-0.74). Interobserver kappa varied from 0.35 to 0.72. The Sanders' and the severity methods correlated strongly with pulmonary function tests, especially DLCO and FEV1. CONCLUSION: The Sanders' method proved to be reliable in evaluating emphysema, in terms of good consistency of interpretation and good correlation with pulmonary function tests.

Aged↗
PubMed2002

Long term outcome of temporal lobe epilepsy surgery: analyses of 140 consecutive patients.

OBJECTIVE: To analyse the long term results of temporal lobe epilepsy surgery in a national epilepsy surgery centre for adults, and to evaluate preoperative factors predicting a good postoperative outcome on long term follow up. METHODS: Longitudinal follow up of 140 consecutive adult patients operated on for drug resistant temporal lobe epilepsy. RESULTS: 46% of patients with unilateral temporal lobe epilepsy became seizure-free, 10% had only postoperative auras, and 15% had rare seizures on follow up for (mean (SD)) 5.4 (2.6) years, range 0.25 to 10.5 years. The best outcome was after introduction of a standardised magnetic resonance (MR) imaging protocol (1993-99): in unilateral temporal lobe epilepsy, 52% of patients became seizure-free, 7% had only postoperative auras, and 17% had rare seizures (median follow up 3.8 years, range 0.25 to 6.5 years); in palliative cases (incomplete removal of focus), a reduction in seizures of at least 80% was achieved in 71% of cases (median follow up 3.1 years, range 1.1 to 6.8 years). Most seizure relapses (86%) occurred within one year of the operation, and outcome at one year did not differ from the long term outcome. Unilateral hippocampal atrophy with or without temporal cortical atrophy on qualitative MR imaging (p < 0.001, odds ratio (OR) 5.2, 95% confidence interval (CI) 2.0 to 13.7), other unitemporal structural lesions on qualitative MR imaging (p < or = 0.001, OR 6.9, 95% CI 2.2 to 21.5), onset of epilepsy before the age of five years (p < 0.05, OR 2.9, 95% CI 1.2 to 7.2), and focal seizures with ictal impairment of consciousness and focal ictal EEG as a predominant seizure type (p < 0.05, OR 3.4, 95% CI 1.2 to 9.1) predicted Engel I-II outcome. Hippocampal volume reduction of at least 1 SD from the mean of controls on the side of the seizure onset (p < 0.05, OR 3.1, 95% CI 1.1 to 9.2) also predicted Engel I-II outcome. CONCLUSIONS: Outcome at one year postoperatively is highly predictive of long term outcome after temporal lobe epilepsy surgery. Unitemporal MR imaging abnormalities, early onset of epilepsy, and seizure type predominance are factors associated with good postoperative outcome.

Adult↗
PubMed2001

[18F]FDG-PET reveals temporal hypometabolism in patients with temporal lobe epilepsy even when quantitative MRI and histopathological analysis show only mild hippocampal damage.

BACKGROUND: The relationship between reduced glucose metabolism in positron emission tomography with fludeoxyglucose F 18 ([(18)F]FDG-PET) and hippocampal damage (HD) in patients with temporal lobe epilepsy is still unclear. OBJECTIVE: To determine whether the presence and severity of HD verified by quantitative magnetic resonance imaging (QMRI) and histopathological analysis affect the degree of hypometabolism. PATIENTS AND METHODS: Sixteen patients with drug-resistant temporal lobe epilepsy underwent [(18)F]FDG-PET and QMRI (hippocampal volumetry and T2 relaxometry) before surgery. Histopathological analysis of the hippocampus included measurements of neuronal loss, proliferation of glial cells, and mossy fiber sprouting. The asymmetry in glucose metabolism described the degree of hypometabolism. RESULTS: Temporal hypometabolism was not related to severity of HD as measured by QMRI or histopathological analysis. The degree of hypometabolism did not differ in patients with mild, moderate, or severe HD. In addition, [(18)F]FDG-PET revealed significant temporal hypometabolism even though hippocampal QMRI findings were normal or showed only mild HD. Thus, glucose consumption was reduced over and above the histopathological changes. CONCLUSIONS: [(18)F]FDG-PET is sensitive for localizing the epileptogenic region in patients with temporal lobe epilepsy. However, it is insensitive to reflect the severity of HD.

Adolescent↗
PubMed2001

Diffusion and perfusion MR imaging in acute ischemic stroke: a comparison to SPECT.

Diffusion (DWI) and perfusion (PWI) magnetic resonance imaging are relatively new methods of clinical imaging that probably can detect infarcted (DWI) and hypoperfused but still salvageable tissue (PWI) in acute human stroke. Forty-six acute stroke patients were imaged within 24 h of ictus, on the second day and after a week. SPECT was also performed on 23 patients in the acute phase (first or second day). On the first day, mean volume of hypoperfused tissue was significantly greater (P<0.001) than the infarcted tissue. The initial hypoperfusion volume correlated significantly with the final infarct size (P<0.001). The initial perfusion-diffusion mismatch correlated significantly with the infarct growth (P< or =0.001). The hypoperfusion volumes measured from PWI and SPECT correlated significantly (P<0.001). In conclusion, combined DWI and PWI is a powerful tool in evaluating the hemodynamics of acute ischemic stroke and can predict the infarct growth during 1 week.

Aged↗
PubMed2001

Hippocampal and amygdaloid damage in partial epilepsy: a cross-sectional MRI study of 241 patients.

Patients with drug-refractory temporal lobe epilepsy (TLE) often have hippocampal and amygdaloid damage. The present study investigated the factors associated with the occurrence and severity of damage in patients with partial epilepsy. Magnetic resonance imaging was used to measure the volumes of the hippocampus and the amygdala in 241 patients with different durations of epilepsy. We also investigated the association of damage with the location of seizure focus and clinical factors (age at onset of seizures, lifetime seizure number and medical history of complex febrile convulsions, intracranial infection or status epilepticus) with regression analysis. We found that high lifetime seizure number (P<0.05), history of complex febrile convulsions (P<0.01), and age < or = 5 years at the time of the first seizure (P<0.01) were significant risk factors for reduced hippocampal volume in TLE patients. The severity of amygdaloid damage did not differ between TLE patients with different durations of epilepsy or seizure frequency, but complex febrile convulsions (P<0.05) and intracranial infection (P<0.05) were associated with amygdaloid damage. In patients with extratemporal or unclassified partial epilepsy, the hippocampal and amygdaloid volumes did not differ when patients with different durations of epilepsy were compared with controls. The present findings indicate that a high seizure number, the occurrence of complex febrile convulsions, and an early onset of seizures contribute to hippocampal volume reduction in patients with TLE. The data provided have important implications with regard to early and effective management and seizure control in vulnerable patients.

Adolescent↗
PubMed2001

Effects of preservation method and beta-glucanase supplementation on ileal amino acid digestibility and feeding value of barley for poultry.

1. Effects of preservation method (drying or air-tight storage of whole grain and ensiling of rolled high-moisture grain) and beta-glucanase supplementation (Econase) on apparent ileal amino acid digestibilities and metabolisable energy content of barley were evaluated with Ross broiler chickens. In addition, the effect of barley preservation method was assessed using Leghorn cockerels. 2. Birds were given either a semi-purified soyabean meal basal diet or a mixture of the basal diet and barley (50:50 on dry matter basis). Apparent ileal digestibilities (AID) of nutrients were assessed using the slaughter technique. AID of nutrients and nutrient digestibility measured using excreta (AED) were determined using chromium mordanted straw as an indigestible marker. 3. In broilers, AID of amino acids, dry matter and organic matter were lower for dried than air-tight stored barley, particularly for diets based on ensiled barley. In cockerels, barley preservation method had no effect on amino acid AID. The AED of nutrients and nitrogen corrected apparent metabolisable energy content (AMEn) was highest for ensiled barley across both experiments. 4. beta-glucanase supplementation increased nutrient digestibility, phosphorus retention and AMEn content of air-tight stored and dried barley diets in particular but had only negligible effects on ensiled barley. Beta-glucanase improved the AID of amino acids in dried barley but not in air-tight stored or ensiled barley. 5. Amino acid digestibilities were lower in broilers than cockerels and the effect of barley preservation on feeding value of barley was different for broilers and cockerels.

Amino Acids↗
PubMed2001

MR urography in evaluation of acute flank pain: T2-weighted sequences and gadolinium-enhanced three-dimensional FLASH compared with urography. Fast low-angle shot.

OBJECTIVE: The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain. SUBJECTS AND METHODS: Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference. RESULTS: Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the detection of stones 3D FLASH was superior, with a sensitivity of 96.2% and 100% and specificity of 100% and 100% for observers A and B, respectively, compared with a sensitivity of 57.7% and 53.8% and a specificity of 100% and 100%, respectively, for T2-weighted sequences. The best degree of obstruction was seen with 3D FLASH, and the interobserver agreement was excellent for stone detection (kappa = 0.97). CONCLUSION: T2-weighted sequences alone are not sufficient for examining patients with acute flank pain. However, the combined use of both T2-weighted and 3D FLASH sequences will ensure better confidence in the evaluation of acute suspected renal colic. MR urography can replace conventional excretory urography when the latter is contraindicated or undesirable.

Acute Disease↗
PubMed2001

MR volumetry of the entorhinal, perirhinal, and temporopolar cortices in drug-refractory temporal lobe epilepsy.

BACKGROUND AND PURPOSE: The occurrence of damage in the entorhinal, perirhinal, and temporopolar cortices in unilateral drug-refractory temporal lobe epilepsy (TLE) was investigated with quantitative MR imaging. METHODS: Volumes of the entorhinal, perirhinal, and temporopolar cortices were measured in 27 patients with unilateral drug-refractory TLE, 10 patients with extratemporal partial epilepsy, and 20 healthy control subjects. All patients with TLE were evaluated for epilepsy surgery and underwent operations. RESULTS: In left TLE, the mean volume of the ipsilateral entorhinal cortex was reduced by 17% (P <.001 compared with control subjects) and that of the ipsilateral temporopolar cortex by 17% (P <.05). In right TLE, the mean ipsilateral entorhinal volume was reduced by 13% (P < or =.01), but only in patients with hippocampal atrophy. Asymmetry ratios also indicated ipsilateral cortical atrophy. When each patient was analyzed individually, the volume of the ipsilateral hippocampus was reduced (> or = 2 SD from the mean of controls) in 63% and that of the entorhinal cortex in 52% of patients with TLE. Furthermore, ipsilateral entorhinal (left: r = 0.625, P <.001; right: r = 0.524, P < or =.01), perirhinal (left: r = 0.471, P <.05), and temporopolar (right: r = 0.556, P <.01) volumes correlated with ipsilateral hippocampal volumes. There was no association, however, with clinically or pathologically identified causes of epilepsy, duration of epilepsy, or age at onset of epilepsy. Mean cortical volumes were unaffected in extratemporal partial epilepsy. CONCLUSION: Subpopulations of patients with unilateral TLE have ipsilateral damage in the entorhinal and temporopolar cortices. The damage is associated with hippocampal damage.

Adolescent↗
PubMed2000

[11 C]Flumazenil binding in the medial temporal lobe in patients with temporal lobe epilepsy: correlation with hippocampal MR volumetry, T2 relaxometry, and neuropathology.

OBJECTIVE: To detect reduced [11C]flumazenil in patients with temporal lobe epilepsy (TLE) and to relate binding to histopathology. METHODS: The authors studied 16 patients who underwent epilepsy surgery because of drug-resistant TLE using [11C]flumazenil PET and quantitative MRI. In 12 patients, resected hippocampus was available for histologic analysis. [11C]Flumazenil binding potential (fitted BP) was assessed with the simplified reference tissue model. RESULTS: [11C]Flumazenil fitted BP in the medial temporal lobe was reduced in all patients with abnormal hippocampal volumetry or T2 relaxometry on MRI. Fitted BP was also reduced in 46% of the patients with hippocampal volume within the normal range and in 38% of patients with less than 2 SD T2 prolongation. In all MRI-negative/PET-positive patients, the histologic analysis verified hippocampal damage. Also, [11C]flumazenil fitted BP correlated with the severity of reduced hippocampal volume, T2 prolongation, and histologically assessed neuronal loss and astrogliosis. CONCLUSION: [11C]Flumazenil PET provides a useful tool for investigating the hippocampal damage in vivo even in patients with no remarkable hippocampal abnormalities on quantitative MRI.

Adolescent↗
PubMed2000

Hippocampus in Alzheimer's disease: a 3-year follow-up MRI study.

BACKGROUND: Due to the progressive nature of Alzheimer's disease (AD), it has been proposed that serial imaging studies tracking the course of progression might improve the diagnostic accuracy of AD. METHODS: Longitudinal changes in hippocampal volumes were evaluated using magnetic resonance imaging (MRI) over a period of 3 years in 27 AD patients and 8 control subjects. RESULTS: A statistically nonsignificant trend towards accelerated volume loss in the AD group compared to control subjects was observed. During the study period, the average shrinkage of the hippocampal volume ranged from -2.2% to -5.8% in control subjects, and from -2.3% to -15.6% in AD patients. CONCLUSIONS: The observed changes at an individual level were small, and within the accuracy range of the measurements. Therefore, serial MRI of the hippocampus did not offer any advantage over a single MRI to support the diagnosis of AD in this study sample.

Aged↗
PubMed2000

Diagnosis of Alzheimer's disease: MRI of the hippocampus vs delayed recall.

Hippocampal volume measurements using magnetic resonance imaging (MRI) and assessment of performance in tests of delayed recall are among the most useful aids for diagnosing early Alzheimer's disease (AD) on an individual level. However, their comparative diagnostic accuracy has not been previously addressed. In this study we compared the diagnostic accuracy of these two methods in 57 patients with probable AD according to the NINCDS-ADRDA criteria, and 34 age- and gender-matched control subjects. The discriminatory power of the hippocampal volumes and delayed recall performance, Russel's Adaptation of the Visual Reproduction Test (VRT), were compared in discrimination function and receiver operator characteristic analyses. Right and left hippocampal volumes resulted in correct classification of 85.7-86.8% of the study subjects, respectively, while performance in the VRT resulted in correct classification of 93.4% of subjects. The area under curve value was 0.93 for the left hippocampus and 0.96 for the VRT. These data suggest that assessment of delayed recall with the VRT is of high diagnostic accuracy, and may surpass the diagnostic accuracy of hippocampal volumetry.

Adaptation, Psychological↗
PubMed2000

MRI volumetry of the hippocampus, amygdala, entorhinal cortex, and perirhinal cortex after status epilepticus.

Neuronal damage has been observed in the medial temporal lobe of both humans and animals following status epilepticus. The aim of the present study was to investigate the occurrence of medial temporal lobe damage in status epilepticus patients treated in hospital with a predetermined protocol and to assess whether the changes progress in a long-term follow-up. The volumes of the hippocampus, amygdala, entorhinal and perirhinal cortices were measured using magnetic resonance imaging (MRI) in nine adult patients with status epilepticus 3 weeks, 6 and 12 months after the insult. The control group included 20 healthy subjects. The etiology of status epilepticus was an acute process in one patient and a chronic process in eight cases. The mean duration of secondarily generalized tonic-clonic status epilepticus episodes was 1 h and 44 min. Volumetric MRI indicated that none of the patients developed marked volume reduction in the hippocampus, amygdala, or the entorhinal and perirhinal cortices during the 1-year follow-up period. Status epilepticus does not invariably lead to a progressive volume reduction in the medial temporal lobe structures of adult patients treated promptly in hospital with a predetermined protocol for rapid cessation of seizure activity.

Adolescent↗
PubMed2000

Quantitative MRI of the hippocampus and amygdala in severe depression.

BACKGROUND: There is little evidence to support possible structural changes in the amygdala and hippocampus of patients with severe depression. METHODS: Quantitative MRI of the amygdala and hippocampus, as well as proton spectroscopy (MRS) of mesial temporal structures were studied in 34 drug-resistant in-patients with major depression and compared with 17 age-matched controls. Volumetric MRI data were normalized for brain size. RESULTS: The volume of the left hippocampus was significantly smaller in the patients compared with the controls. Both groups exhibited similar significant hippocampal asymmetry (left smaller than right). The patients, but not the controls, had significant asymmetry of the amygdalar volumes (right smaller than left). No differences were observed between the patients and controls in the T2 relaxation times for the hippocampus and amygdala. Mesial temporal lobe MRS revealed a significantly elevated choline/creatine ratio in the patients compared with the controls. CONCLUSIONS: This quantitative MRI study provides support for a possible association between structural and biochemical substrates and severe drug-resistant major depression.

Adult↗
PubMed2000

Quantitative MRI volumetry of the entorhinal cortex in temporal lobe epilepsy.

The entorhinal cortex (Brodmann's area 28) is located at the anterior aspect of the parahippocampal gyrus ventral to the amygdala and the hippocampus. It is reciprocally interconnected with the hippocampus via glutamatergic pathways. We investigated whether the entorhinal cortex is damaged in human temporal lobe epilepsy (TLE). The volume of the entorhinal cortex was measured using magnetic resonance imaging (MRI) in 36 patients with cryptogenic TLE and in 21 controls. The mean volumes of the entorhinal cortex on the focal side did not differ from controls. In 11 of 36 patients, however, the entorhinal cortex volume was reduced by 25%. Entorhinal volume correlated with hippocampal volume in TLE (ipsilaterally, r= 0.454, P<0.01; contralaterally, r = 0.340, P<0.05). Further, 64% of patients with 25% entorhinal cortex damage had ipsilateral hippocampal atrophy. On the other hand, right focal TLE patients with hippocampal atrophy had a 19% volume reduction of the ipsilateral entorhinal cortex (P<0.05). The volume of the entorhinal cortex correlated with the duration of TLE (r= -0.335, P< 0.05). The present study indicates that the entorhinal cortex might be damaged in a subpopulation of patients with cryptogenic TLE. In most cases, volume reduction was associated with hippocampal damage. These data suggest that entorhinal damage contributes to the symptomatology in TLE.

Adolescent↗