Tapani Keränen

University of Eastern Finland, Kuopio, Eastern Finland Province, Finland

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Publications (114)255.54 Total impact

  • Kai A Lehtimäki · Tapani Keränen · Johanna Palmio · Jukka Peltola ·
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    ABSTRACT: Experimentally induced seizures are associated with increased production of inflammatory cytokines in the nervous system. Elevated cerebrospinal fluid levels of cytokine interleukin-6 (IL-6) have been found after a single generalized seizure in human patients. After prolonged seizures, levels of IL-6 have been shown to be even higher compared with single seizures. In the present study, we determined the levels of proconvulsive IL-1beta and anticonvulsive IL-1ra in cerebrospinal fluid after single tonic-clonic seizures as well as after prolonged seizures. The levels of cytokines were measured using enzyme-linked immunosorbent assay. We found that after single seizures, a slight increase in anticonvulsive IL-1ra levels was found; however, after prolonged partial or recurrent tonic-clonic seizures, the levels of IL-1ra were significantly elevated, together with decreased IL-1beta levels. Our results indicate that after severe seizures, the balance between IL-1-type cytokines is changed towards a neuroprotective and anticonvulsive direction with an overproduction of IL-1ra with respect to potentially neurotoxic IL-1beta. This reaction may serve as a defense mechanism of the nervous system against excitotoxic neuronal damage.
    NeuroImmunoModulation 10/2009; 17(1):19-22. DOI:10.1159/000243081 · 1.88 Impact Factor
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    Kai Eriksson · Tapani Keränen · Reetta Kälviäinen ·
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    ABSTRACT: Fosphenytoin, phosphate ester pro-drug of phenytoin, was developed to overcome complications associated with parenteral phenytoin administration in treatment of acute symptomatic seizures, short-term prophylaxis and treatment of repetitive or prolonged seizures and status epilepticus. To evaluate the current position of fosphenytoin in treatment algorithms compared to phenytoin. This review focuses on pharmacokinetics and dynamics, clinical efficacy and tolerability of fosphenytoin in children and adults. Published literature shows that intravenous fosphenytoin has a similar adverse effect profile than phenytoin when it is administered as recommended. There is no evidence of clear benefit that would justify the higher price of the fosphenytoin compared to phenytoin.
    Expert Opinion on Drug Metabolism & Toxicology 07/2009; 5(6):695-701. DOI:10.1517/17425250902997975 · 2.83 Impact Factor
  • Kai Eriksson · Tapani Keränen ·
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    ABSTRACT: IntroductionChemistryPharmacologyPharmacokineticsDrug interactionsSerum level monitoringEfficacyAdverse effectsCurrent place in therapyReferences
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    ABSTRACT: In a case-control study with prevalence sampling, the authors explored the correlates for nocturia and their population-level impact. In 2003-2004, questionnaires were mailed to 6,000 subjects (aged 18-79 years) randomly identified from the Finnish Population Register (62.4% participated; 53.7% were female). Questionnaires contained items on medical conditions, medications, lifestyle, sociodemographic and reproductive factors, urinary symptoms, and snoring. Nocturia was defined as > or =2 voids/night. In age-adjusted analyses, factors associated with nocturia were entered into a multivariate model. Backward elimination was used to select variables for the final model, with adjustment for confounding. Although numerous correlates were identified, none affected > or =50% of nocturia cases of both sexes. The factors with the greatest impact at the population level were (urinary) urgency (attributable number/1,000 subjects (AN) = 24), benign prostatic hyperplasia (AN = 19), and snoring (AN = 16) for men and overweight and obesity (AN = 40), urgency (AN = 24), and snoring (AN = 17) for women. Moreover, correlates included prostate cancer and antidepressant use for men, coronary artery disease and diabetes for women, and restless legs syndrome and obesity for both sexes. Although several correlates were identified, none accounted for a substantial proportion of the population burden, highlighting the multifactorial etiology of nocturia.
    American journal of epidemiology 06/2009; 170(3):361-8. DOI:10.1093/aje/kwp133 · 5.23 Impact Factor
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    ABSTRACT: Whether repeated brief seizures can cause neuronal damage is controversial. Cerebrospinal fluid (CSF) total tau (T-tau) and phosphorylated tau (P-tau) measurements have been suggested for the diagnosis of Alzheimer's disease, and T-tau may also be a marker of axonal damage and neuronal degeneration. We studied T-tau and P-tau levels and P-tau/T-tau ratio in CSF after epileptic seizures in order to determine whether they are increased after seizures. A total of 54 patients with tonic-clonic or partial secondarily generalized seizures due to various etiologies were studied and CSF obtained within 48h after the seizure. There were no statistical differences in the levels of T-tau (p=0.09, ANOVA) or P-tau (p=0.60) between different etiologic groups or controls. No patients with epilepsy of unknown origin had abnormal CSF T-tau whereas 11 patients with acute or remote symptomatic seizures had abnormal T-tau levels and the P-tau/T-tau ratio showed significant differences between the groups and controls (p=0.003). Epileptic seizures with unknown etiology did not increase CSF tau levels. Abnormal tau levels were associated with either acute or remote symptomatic seizures with known etiology. The presence of elevated CSF tau increases the probability of symptomatic cause in a patient with a seizure.
    Seizure 06/2009; 18(7):474-7. DOI:10.1016/j.seizure.2009.04.006 · 1.82 Impact Factor
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    Tapani Keränen · Mervi Tuhkasaari · Hanna Kuusisto ·

    European Journal of Clinical Pharmacology 06/2009; 65(9):955-6; author reply 957. DOI:10.1007/s00228-009-0661-4 · 2.97 Impact Factor
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    T Alapirtti · S Rinta · J Hulkkonen · R Mäkinen · T Keränen · J Peltola ·
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    ABSTRACT: Experimental and clinical studies have shown that prolonged seizures result in increased cytokine production in the central nervous system. The purpose of this study was to examine plasma concentrations of interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1Ra), and interleukin-1 beta (IL-1beta) in 20 patients with epilepsy undergoing a video-EEG study. Plasma samples were obtained at the onset of the recordings and 3, 6, 12 and 24 h after the index seizure. Localization of the seizure focus and classification of epilepsy was based on concordant electroclinical findings in the video-EEG study, and on MRI examination. Patients were divided into two groups: temporal lobe epilepsy (TLE) (n=11), and extratemporal lobe epilepsy (XLE) (n=9). RESULTS: Only the TLE group showed significant increase in plasma levels of IL-6 peaking at 6 h postictally. Postictal plasma levels of IL-1RA and IL-1beta did not significantly differ from baseline levels in either of the patient groups. IL-1RA showed a decreasing trend (p>0.059) in TLE patients during 12 to 24 postictal hours. CONCLUSIONS: This study further supports the role of focal seizures in regulation of cytokine responses.
    Journal of the neurological sciences 05/2009; 280(1-2):94-7. DOI:10.1016/j.jns.2009.02.355 · 2.47 Impact Factor
  • T. Keränen · K. Reinikainen · P. J. Riekkinen ·

    Acta Neurologica Scandinavica 04/2009; 69(S98):87-88. DOI:10.1111/j.1600-0404.1984.tb02399.x · 2.40 Impact Factor

  • Acta Neurologica Scandinavica 04/2009; 69(S98):93-94. DOI:10.1111/j.1600-0404.1984.tb02402.x · 2.40 Impact Factor

  • Acta Neurologica Scandinavica 04/2009; 69(S98):99-100. DOI:10.1111/j.1600-0404.1984.tb02405.x · 2.40 Impact Factor

  • Acta Neurologica Scandinavica 04/2009; 69(S98):89-90. DOI:10.1111/j.1600-0404.1984.tb02400.x · 2.40 Impact Factor

  • European Journal of Neurology 03/2009; 16(4):e75. DOI:10.1111/j.1468-1331.2009.02557.x · 4.06 Impact Factor

  • Acta Neurologica Scandinavica 03/2009; 65(S90):190-190. DOI:10.1111/j.1600-0404.1982.tb03446.x · 2.40 Impact Factor
  • T. Keränen · K. Reinikainen · J. Lehtinen · T. Saari · P. J. Riekkinen ·

    Acta Neurologica Scandinavica 03/2009; 65(S90):208-209. DOI:10.1111/j.1600-0404.1982.tb03456.x · 2.40 Impact Factor
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    ABSTRACT: Previous studies have associated coeliac disease (CD) and gluten sensitivity (defined as the presence of anti-gliadin antibodies and positive immunogenetics) with cerebellar degeneration and epilepsy with occipital calcifications. Hippocampal sclerosis (HS) in temporal lobe epilepsy (TLE) is a potentially progressive disorder with unknown aetiology; however, autoimmunity has been implicated as one of the possible mechanisms leading to HS. The purpose of this study is to analyze CD-associated antibodies and gluten sensitivity in a well-characterised group of patients with refractory focal epilepsy. We measured anti-gliadin, anti-tissue-transglutaminase and anti-endomysium antibodies, and coeliac-type human leukocyte antigen (DQ2 and DQ8), in 48 consecutive patients with therapy-resistant, localisation-related epilepsy. The patients were categorised into the following three groups on the basis of ictal electro-clinical characteristics and the findings of high resolution MRI: TLE with HS (n = 16), TLE without HS (n = 16) and extratemporal epilepsy (n = 16). Patients with suspected CD or gluten sensitivity underwent duodenal biopsies. Seven patients in total were gluten sensitive; all of these patients fell in the TLE with HS group. On the other hand, none of the TLE without HS patients or those with extratemporal epilepsy were gluten sensitive (p<0.0002). The results of duodenal biopsies showed that three of the seven gluten-sensitive patients had histological evidence of CD and four had inflammatory changes consistent with early CD without villous atrophy. Four of the patients with gluten sensitivity had evidence of dual pathology (HS+another brain lesion), whereas none of the remaining patients did (p<0.0002). The present study demonstrates a previously unrecognised link between gluten sensitivity and TLE with HS. This association was very robust in this well-characterised group of patients; thus gluten sensitivity should be added to the list of potential mechanisms leading to intractable epilepsy and HS.
    Journal of neurology, neurosurgery, and psychiatry 02/2009; 80(6):626-30. DOI:10.1136/jnnp.2008.148221 · 6.81 Impact Factor
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    ABSTRACT: Status epilepticus is a medical emergency. Most epileptic seizures last for 1-4 minutes and seizures lasting over five minutes, should be treated as status epilepticus. EEG is essential for diagnostics and the monitoring of treatment effect. The treatment for status epilepticus, irrespective of aetiology, can be divided into first-aid medications, such as buccal midazolam or rectal diazepam, first-line medications such as intravenous diazepam or lorazepam, and second-line medications such as fosphenytoin and valproate for adults and phenobarbital for children. Third-line treatment is suppressive general anaesthesia, monitored by continuous EEG. Antiepileptic medication of patients with epilepsy should be carefully re-evaluated after episode of status epilepticus.
    Duodecim; lääketieteellinen aikakauskirja 01/2009; 125(22):2469-71.
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    ABSTRACT: Established markers of brain damage, neuron-specific enolase (NSE) and S-100b protein (S-100), may increase after status epilepticus, but whether a single tonic-clonic or complex partial seizure induces elevation of these markers is not known. Furthermore, it is unclear whether the risk of seizure-related neuronal damage in temporal lobe epilepsy (TLE) differs from that in extratemporal lobe epilepsies (XTLE). The aim of this study was to analyze NSE and S-100 in patients with TLE and XTLE after acute seizures. The levels of NSE and S-100 were measured in serum before (0h) and at 3, 6, 12, and 24h after acute seizures in 31 patients during inpatient video-EEG monitoring. The patients were categorized into the TLE and the XTLE group based on video-EEG recordings and MRI findings. Fifteen patients had TLE and 16 XTLE. Index seizures were mainly complex partial seizures (n=21). In TLE mean+/-S.D. values for NSE levels (mug/L) were 8.36+/-2.64 (0h), 11.35+/-3.84 (3h), 13.48+/-4.49 (6h), 12.95+/-5.46 (12h) and 10.33+/-3.13 (24h) (p=0.006, ANOVA). In XTLE the changes were not significant (p=0.3). There was less increase in the levels of S-100 in TLE (p=0.05) and no significant change in XTLE (p=0.4). The levels of markers of neuronal damage were increased in patients with TLE, not only after tonic-clonic but also after complex partial seizures. These data suggest that TLE may be associated with brain damage.
    Epilepsy Research 07/2008; 81(2-3):155-60. DOI:10.1016/j.eplepsyres.2008.05.006 · 2.02 Impact Factor
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    J Peltola · M Peltola · A Auvinen · T Keränen · S Liimatainen · E Kharazmi · M Fallah ·
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    ABSTRACT: This aim of the study was to ascertain the importance of clinical parameters on the response to treatment in refractory epilepsy patients on levetiracetam (LEV). We retrospectively evaluated medical records of 132 patients aged 17-78 years with refractory epilepsy (defined as a failure of at least two antiepileptic drugs due to the lack of efficacy) exposed to LEV. We analyzed the response (seizure freedom or continuing LEV) using logistic regression. Of 132 patients exposed to LEV, 103 cases continued the drug. Of the discontinuations (29/132), 75% were for lack of efficacy and 25% for tolerability problems. Twenty-three percent of the previously refractory patients achieved seizure freedom for at least 1 year with LEV in combination therapy. The dose of LEV in 80% of seizure-free patients was 1000 mg/day or less. The duration of epilepsy, age and sex were not associated with response to LEV. Seizure freedom was associated with epileptic syndrome or etiology. If no specific syndrome was recognized, there was a significantly greater chance for response compared with temporal lobe epilepsy (OR 20.76; 95% CI 2.12-203.61). Our study was based on the careful clinical evaluation of the patients with extensive use of video EEG (50%) and MRI scans (95%). These clinical predictors were evasive in previous studies. This study showed that they are worth pursuing but significantly larger groups of patients need to be investigated to reach significant findings.
    Acta Neurologica Scandinavica 06/2008; 117(5):332-6. DOI:10.1111/j.1600-0404.2007.00956.x · 2.40 Impact Factor
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    J Peltola · M Peltola · A Auvinen · J Raitanen · M Fallah · T Keränen ·
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    ABSTRACT: We evaluated long-term retention rates of newer antiepileptic drugs (AED) in adults with localization-related epilepsy retrospectively. We estimated retention rates by Kaplan-Meier method in all 222 patients (age > or = 16) with localization-related epilepsy exposed to new AED at the Tampere University Hospital. There were 141 patients exposed to lamotrigine, 78 to levetiracetam, 97 to topiramate, 68 to gabapentin, and 69 to tiagabine. Three-year retention rate for lamotrigine was 73.5%, levetiracetam 65.4%, topiramate 64.2%, gabapentin 41.7%, and tiagabine 38.2%. The most common cause for withdrawal of these AED was lack of efficacy. Our study suggests that there are clinically significant differences among gabapentin, lamotrigine, levetiracetam, tiagabine, and topiramate as treatment for focal epilepsy in everyday practice. Gabapentin and tiagabine seem to be less useful than the other three AED. Furthermore, our study supports the value of retention rate studies in assessing outcome of the drugs in clinical practice.
    Acta Neurologica Scandinavica 06/2008; 119(1):55-60. DOI:10.1111/j.1600-0404.2008.01062.x · 2.40 Impact Factor
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    T Keränen · M Tuhkasaari · H Kuusisto ·

    European Journal of Neurology 05/2008; 15(4):e30. DOI:10.1111/j.1468-1331.2008.02068.x · 4.06 Impact Factor

Publication Stats

2k Citations
255.54 Total Impact Points


  • 2011-2014
    • University of Eastern Finland
      • School of Pharmacy
      Kuopio, Eastern Finland Province, Finland
  • 1993-2011
    • Tampere University Hospital (TAUH)
      Tammerfors, Province of Western Finland, Finland
    • Kemira Espoo Research Center
      Esbo, Uusimaa, Finland
  • 1994-2010
    • University of Tampere
      • • Department of Neurology and Rehabilitation
      • • Department of Pharmacological Sciences
      • • Medical School
      • • Department of Neurology
      Tammerfors, Pirkanmaa, Finland
  • 1988-2009
    • University of Kuopio
      • Department of Neurology
      Kuopio, Northern Savo, Finland
  • 1983-2009
    • Kuopio University Hospital
      • Department of Neurology
      Kuopio, Eastern Finland Province, Finland
  • 2003-2004
    • University of Turku
      • Department of Neurology
      Turku, Province of Western Finland, Finland
    • Pirkanmaa Hospital District
      Tammerfors, Province of Western Finland, Finland