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1.
Public Health ; 186: 211-216, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32861086

ABSTRACT

BACKGROUND: Both increased and decreased health service usage and unmet care needs are more prevalent among unemployed people than in the general population. STUDY DESIGN: This study investigates the associations of substance-related and mood disorders among long-term unemployed people with styles of healthcare attendance in Finland. METHODS: The study material consisted of the health register information on 498 long-term unemployed people in a project screening for work disabilities. The data were analysed by mixed methods: qualitative typological analysis was applied to identify differential healthcare attendance styles, and the associations of the obtained styles with mental health disorders were analysed quantitatively by multinomial logistic regression. RESULTS: Three styles, characterized as smooth, faltering and marginalized, were identified. Compared with participants with the smooth attendance style without mental disorders, those with the faltering style had tenfold relative risk for substance-related disorder and fourfold relative risk for mood disorder. Those with the marginalized style had fivefold relative risk for substance-related disorder and twofold relative risk for mood disorder. Adjusting for background characteristics did not alter the statistical significance of substance-related disorder. In the case of mood disorders, the statistical significance persisted throughout the adjustments in the faltering style. CONCLUSION: Dysfunctional use of health services is more common among people with substance-related or mood disorders, who are at risk of drifting towards long-term unemployment and work disabilities. The early detection of those with faltering or marginalized healthcare attendance style may prevent prolonged unemployment, enable rehabilitation measures and reduce the risk of disability pensions.


Subject(s)
Mood Disorders/therapy , Patient Acceptance of Health Care/psychology , Substance-Related Disorders/therapy , Unemployment/statistics & numerical data , Adult , Female , Finland , Humans , Male , Middle Aged , Qualitative Research , Young Adult
2.
Bioresour Technol ; 164: 149-54, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24852647

ABSTRACT

Mining and mineral processing of gold-bearing ores often release arsenic to the environment. Ammonium is released when N-based explosives or cyanide are used. Nitrification of simulated As-rich mining waters was investigated in batch bioassays using nitrifying cultures enriched in a fluidized-bed reactor (FBR). Nitrification was maintained at 100mg AsTOT/L. In batch assays, ammonium was totally oxidized by the FBR enrichment in 48 h. As(III) oxidation to As(V) occurred during the first 3h attenuating arsenic toxicity to nitrification. At 150 and 200mg AsTOT/L, nitrification was inhibited by 25%. Candidatus Nitrospira defluvii and other nitrifying species mainly colonized the FBR. In conclusion, the FBR enriched cultures of municipal activated sludge origins tolerated high As concentrations making nitrification a potent process for mining water treatment.


Subject(s)
Arsenic/pharmacology , Mining , Nitrification/drug effects , Wastewater/chemistry , Alkalies/analysis , Ammonium Compounds/analysis , Bacteria/drug effects , Bacteria/metabolism , Batch Cell Culture Techniques , Biological Assay , Bioreactors/microbiology , Denaturing Gradient Gel Electrophoresis , Hydrogen-Ion Concentration , Nitrates/analysis , Nitrites/analysis
3.
Spinal Cord ; 52(3): 202-8, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24418961

ABSTRACT

STUDY DESIGN: Prospective clinical case-control study. OBJECTIVES: The aim of this study was to use diffusion tensor imaging (DTI) to assess the state of cerebral white matter tracts after spinal cord injury (SCI). The DTI metrics were evaluated in relation to neurological deficits and to the size and level of the spinal cord lesions. SETTING: Tampere University Hospital, Tampere, Finland. METHODS: Thirty-four patients (n=34) with clinically complete and incomplete SCI were evaluated using the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). DTI metrics (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) were calculated for multiple levels along the course of the corticospinal tract. The state of the spinal cord after injury was assessed using conventional magnetic resonance imaging (MRI). DTI parameters were compared with 40 orthopedically injured control subjects. RESULTS: Statistically significant differences in the DTI values between patients and controls were detected in the posterior area of the centrum semiovale. In this area, the FA values were lower in the patients compared with controls (P=0.008). For patients with clinically complete injury, the difference was even more significant (P=0.0005). Motor and sensory scores of the ISNCSCI correlated positively with FA and negatively with ADC values of the centrum semiovale. A moderate association was observed between the macroscopic changes in the spinal cord and the DTI abnormalities in the centrum semiovale. CONCLUSION: In patients with chronic SCI, DTI changes can be observed in the cerebral white matter. These alterations are associated with the clinical state of the patients.


Subject(s)
Diffusion Tensor Imaging , Image Processing, Computer-Assisted , Spinal Cord Injuries/pathology , Spinal Cord/pathology , Adolescent , Adult , Anisotropy , Brain Injuries/pathology , Brain Injuries/physiopathology , Case-Control Studies , Chronic Disease , Diffusion Tensor Imaging/methods , Female , Humans , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Prospective Studies , Spinal Cord Injuries/physiopathology , Young Adult
4.
Biodegradation ; 25(3): 417-23, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24166158

ABSTRACT

The dispersion of nitrogenous compounds and heavy metals into the environment is frequent during mining activities. The effects of nickel (Ni) and cobalt (Co) on denitrification of simulated mine waters were investigated in batch bioassays and fluidized-bed reactors (FBRs). At pH 7, batch tests revealed that Co did not exhibit inhibition on denitrification even at 86.6 mg/L. Ni showed to be inhibitory at 50 and 100 mg/L by decreasing nitrate removal efficiencies of 18 and 65 %, respectively. In two FBRs, operated at 7-8 and 22 °C, 5.5 mg/L Ni did not affect nitrate and nitrite removals because of FBR potential of diluting soluble Ni feed concentration. On the contrary, the effluent pH clearly decreased in both FBR1 and FBR2 because of nickel sulfide precipitation and Ni inhibition of the last two steps of denitrification. When Ni injection was stopped, the process recovered more slowly at 22 than 7-8 °C. This is the first study reporting the effect of Ni on denitrification in biological FBRs.


Subject(s)
Microbial Consortia/drug effects , Mining , Nitrates/metabolism , Water Pollutants, Chemical/metabolism , Batch Cell Culture Techniques , Biodegradation, Environmental , Bioreactors , Cobalt/pharmacology , Denitrification , Humans , Hydrogen-Ion Concentration , Kinetics , Microbial Consortia/physiology , Nickel/pharmacology , Oxidation-Reduction , Temperature
5.
Biodegradation ; 25(3): 425-35, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24166159

ABSTRACT

Mining often leads to nitrate and metal contamination of groundwater and water bodies. Denitrification of acidic water was investigated in two up-flow fluidized-bed reactors (FBR) and using batch assays. Bacterial communities were enriched on ethanol plus nitrate in the FBRs. Initially, the effects of temperature, low-pH and ethanol/nitrate on denitrification were revealed. Batch assays showed that pH 4.8 was inhibitory to denitrification, whereas FBR characteristics permitted denitrification even at feed pH of 2.5 and at 7-8 °C. Nitrate and ethanol were removed and the feed pH was neutralized, provided that ethanol was supplied in excess to nitrate. Subsequently, Fe(II) and Cu impact on denitrification was investigated within batch tests at pH 7. Iron supplementation up to 100 mg/L resulted in iron oxidation and soluble concentrations ranging from 0.4 to 1.6 mg/L that stimulated denitrification. On the contrary, 0.7 mg/L of soluble Cu significantly slowed denitrification down resulting in about 45 % of inhibition in the first 8 h. Polymerase chain reaction-denaturant gradient gel electrophoresis demonstrated the co-existence of different denitrifying microbial consortia in FBRs. Dechloromonas denitrificans and Hydrogenophaga caeni were present in both FBRs and mainly responsible for nitrate reduction.


Subject(s)
Actinomycetales/metabolism , Comamonadaceae/metabolism , Mining , Nitrates/metabolism , Water Pollutants, Chemical/metabolism , Actinomycetales/drug effects , Batch Cell Culture Techniques , Biodegradation, Environmental , Bioreactors , Comamonadaceae/drug effects , Copper/pharmacology , Denitrification , Ferrous Compounds/pharmacology , Humans , Hydrogen-Ion Concentration , Kinetics , Oxidation-Reduction , Temperature
6.
Acta Neurol Scand ; 122(5): 343-9, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20055768

ABSTRACT

OBJECTIVE: To study the occurrence of dysphagia and dysphonia in persons with post-polio syndrome admitted into the centre for neurological rehabilitation in Finland. MATERIALS AND METHODS: Fifty-one persons with post-polio syndrome who were rehabilitated at Käpylä Rehabilitation Centre, Helsinki, Finland, in 2003-2004 were interviewed on problems with swallowing and voice production. Pulmonary function testing and grip strength measurement were performed. A clinical assessment of oral motor and laryngeal functions was carried out for those who reported daily problems with voice production or swallowing. RESULTS: Fifteen persons (29.4%) reported daily problems with swallowing or voice production. In the clinical assessment, the most commonly observed deficits in swallowing included decreased pharyngeal transit (n = 13) and the food catching in the throat (n = 4). The disturbance of co-ordination of breathing and voice production was seen in 12 persons. There were no significant differences in any of the potential predictors between the groups. CONCLUSIONS: Professionals need to be aware of the routine evaluation of dysphagia and dysphonia in patients with post-polio syndrome.


Subject(s)
Deglutition Disorders/etiology , Dysphonia/etiology , Postpoliomyelitis Syndrome/complications , Postpoliomyelitis Syndrome/rehabilitation , Adult , Aged , Deglutition Disorders/rehabilitation , Dysphonia/rehabilitation , Female , Finland/epidemiology , Hand Strength/physiology , Humans , Male , Middle Aged , Postpoliomyelitis Syndrome/epidemiology , Rehabilitation Centers , Respiratory Function Tests , Retrospective Studies
7.
J Neurol Neurosurg Psychiatry ; 79(7): 808-12, 2008 Jul.
Article in English | MEDLINE | ID: mdl-17991701

ABSTRACT

BACKGROUND: Earlier studies have shown that aetiology makes a difference in the outcome of epilepsy, but there is a paucity of follow-up studies to evaluate the possibilities of achieving seizure freedom in initially refractory epilepsy. METHODS: We evaluated the cause of epilepsy based on high-resolution brain MRI and patient history in 119 consecutive thoroughly examined adult patients with refractory focal epilepsy followed up in our centre. We also evaluated the influence of aetiology and duration of epilepsy in this patient cohort on the chances of achieving 12-month remission in a 2-year follow-up. RESULTS: The major finding was that a substantial group of patients achieved remission; 30 (25%) initially refractory patients achieved at least 12 months remission during follow-up. A total of 40.0% of the patients with cryptogenic aetiology had achieved 12-month remission compared with the 16.2% patients with symptomatic aetiologies (age-adjusted OR 3.74, 95% CI 1.54 to 9.07, p = 0.004). Aetiologies often considered for surgical treatment (hippocampal sclerosis, cortical dysplasia, vascular malformation, tumour and dual pathology) carried an almost six-fold risk of persistent seizures compared with cryptogenic epilepsy (age-adjusted OR 5.85, 95% CI 2.00 to 17.11, p = 0.001). CONCLUSIONS: Patients with vascular malformation and dual pathology as aetiology were most refractory, none being in remission for 12 months. There were also patients achieving 12-month remission after a long period of active epilepsy. These results encourage physicians to continue with new drug trials, especially on patients with no possibilities of epilepsy surgery, as well as on those still having seizures after epilepsy surgery.


Subject(s)
Anticonvulsants/therapeutic use , Epilepsies, Partial/drug therapy , Epilepsies, Partial/etiology , Adolescent , Adult , Aged , Cross-Sectional Studies , Disease-Free Survival , Epilepsies, Partial/pathology , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Time Factors , Treatment Outcome
8.
Exp Neurol ; 196(1): 47-53, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16084513

ABSTRACT

The effects of cortical spreading depression (SD) on evoked dopamine release in mesolimbic (nucleus accumbens) and nigrostriatal (nucleus caudatus) terminal fields were studied by in vivo voltammetry in anesthetized rats. Dopamine release was evoked by electrical stimulation of medial forebrain bundle (20 Hz, 100 pulses). Local application of 3 M KCl on the dura initiated SD in the cortex. It was found that SD modulated evoked dopamine release in subcortical structures at the same time when the wave of depression of cortical activity reached reciprocally connected subcortical areas. This cortical depression increased stimulated dopamine release in the nucleus accumbens and decreased dopamine release in the nucleus caudatus. In agreement with these results, electrical stimulation of the prefrontal cortex at 20 Hz, synchronized with medial forebrain bundle stimulation, decreased evoked dopamine release in the nucleus accumbens. Areas of the cortex which modulated dopamine release in these two terminal fields were spatially separated by at least 5 mm from each other. It is proposed that depression and activation of evoked dopamine release in the nucleus caudatus and nucleus accumbens following SD are indicative of tonic activation of the nigrostriatal and tonic inhibition of the mesolimbic dopaminergic terminals by cortex in normal conditions. SD in the cortex, modulating neurotransmitter release in subcortical structures, may have a general impact on redistribution of oxygen supply in these subcortical areas and on behavior associated with brain trauma, migraine, insult or seizures, i.e. the kind of neuropathology which may cause SD type phenomena also in human brain.


Subject(s)
Cortical Spreading Depression/physiology , Dopamine/metabolism , Nucleus Accumbens/physiology , Substantia Nigra/physiology , Animals , Electric Stimulation , Male , Rats , Rats, Wistar
9.
Neurobiol Dis ; 15(2): 188-95, 2004 Mar.
Article in English | MEDLINE | ID: mdl-15006688

ABSTRACT

Mice carrying mutated human APPswe and PS1 (A246E) transgenes (A/P mice) show age-dependent memory impairment in hippocampus-dependent tasks. Moreover, the mice show normal learning in the water maze within a day but impairment across days. We recorded LTP in a slice preparation (CA1) and in chronically implanted animals (dentate gyrus, or DG) at 17-18 months of age. The genotypes did not differ in the basal synaptic transmission. Also, LTP induction and its maintenance over 60 min did not differ between A/P and control mice. However, the fEPSP enhancement in vivo decayed to 77% of its maximum in 24 h in A/P mice while remaining at 96% in control mice. The time course of the LTP decay in the A/P mice corresponds to their behavioral impairment and indicates that Abeta accumulation in the dentate gyrus may interfere with the signal transduction pathways responsible for memory consolidation.


Subject(s)
Alzheimer Disease/genetics , Amyloid beta-Peptides/toxicity , Amyloid beta-Protein Precursor/genetics , Hippocampus/metabolism , Long-Term Potentiation/genetics , Membrane Proteins/genetics , Memory Disorders/genetics , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Animals , Dentate Gyrus/growth & development , Dentate Gyrus/metabolism , Dentate Gyrus/pathology , Disease Models, Animal , Excitatory Postsynaptic Potentials/genetics , Hippocampus/growth & development , Hippocampus/pathology , Humans , In Vitro Techniques , Male , Memory Disorders/metabolism , Memory Disorders/pathology , Mice , Mice, Transgenic , Phenotype , Plaque, Amyloid/genetics , Plaque, Amyloid/metabolism , Plaque, Amyloid/pathology , Presenilin-1 , Synaptic Transmission/genetics
10.
Adv Tech Stand Neurosurg ; 29: 87-132, 2004.
Article in English | MEDLINE | ID: mdl-15035337

ABSTRACT

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.


Subject(s)
Epilepsy, Temporal Lobe/diagnosis , Epilepsy, Temporal Lobe/surgery , Electroencephalography , Epilepsy, Temporal Lobe/physiopathology , Epilepsy, Temporal Lobe/psychology , Humans , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Magnetoencephalography , Neuropsychological Tests , Neurosurgical Procedures/adverse effects , Tomography, Emission-Computed, Single-Photon , Treatment Outcome
11.
J Neurol Neurosurg Psychiatry ; 73(5): 486-94, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12397139

ABSTRACT

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.


Subject(s)
Epilepsy, Temporal Lobe/surgery , Adult , Brain/pathology , Cognition Disorders/diagnosis , Cognition Disorders/etiology , Electroencephalography , Epilepsy, Temporal Lobe/complications , Epilepsy, Temporal Lobe/diagnosis , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Palliative Care , Postoperative Period , Preoperative Care
13.
AJNR Am J Neuroradiol ; 22(8): 1490-501, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11559496

ABSTRACT

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.


Subject(s)
Cerebral Cortex/pathology , Entorhinal Cortex/pathology , Epilepsy, Temporal Lobe/diagnosis , Epilepsy, Temporal Lobe/drug therapy , Magnetic Resonance Imaging , Adolescent , Adult , Atrophy , Dominance, Cerebral , Drug Resistance , Epilepsies, Partial/diagnosis , Epilepsy, Temporal Lobe/physiopathology , Female , Hippocampus/pathology , Humans , Male , Middle Aged
14.
Arch Neurol ; 58(6): 933-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11405808

ABSTRACT

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.


Subject(s)
Epilepsy, Temporal Lobe/diagnosis , Fluorodeoxyglucose F18 , Glucose/metabolism , Hippocampus/pathology , Magnetic Resonance Imaging , Tomography, Emission-Computed , Adolescent , Adult , Epilepsy, Temporal Lobe/metabolism , Epilepsy, Temporal Lobe/surgery , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Statistics, Nonparametric , Tomography, Emission-Computed/methods
15.
Epilepsia ; 41 Suppl 6: S24-9, 2000.
Article in English | MEDLINE | ID: mdl-10999515

ABSTRACT

PURPOSE: If the sprouting of granule cell axons or mossy fibers in the dentate gyrus is critical for the generation of spontaneous seizures in temporal lobe epilepsy (TLE), one could hypothesize that epileptic animals or humans with increased sprouting would have more frequent seizures. This hypothesis was tested by analyzing the data gathered from experimental and human epilepsy. METHODS: In experiment I (rats with "newly diagnosed" TLE), self-sustained status epilepticus was induced in rats by electrically stimulating the amygdala. Thereafter, the appearance of spontaneous seizures was monitored by continuous video-electroencephalography (EEG) until the animal developed two spontaneous seizures and for 11 d thereafter. Rats were perfused for histology, and mossy fibers were stained using the Timm method. In experiment II (rats with "recently diagnosed" TLE), status epilepticus was induced in rats and the development of seizures was monitored by video-EEG for 24 h/d every other day for 60 days. All animals were then perfused for histology. In experiment III (rats with "chronic" TLE), animals were monitored by video-EEG for 24 h/d every other day for 6 months before histologic analysis. To assess mossy fiber sprouting in human TLE, hippocampal sections from 31 patients who had undergone surgery for drug-refractory TLE were stained with an antibody raised against dynorphin. RESULTS AND CONCLUSIONS: Our data indicate that the density of mossy fiber sprouting is not associated with the total number of lifetime seizures or the seizure frequency in experimental or human TLE.


Subject(s)
Epilepsy, Temporal Lobe/diagnosis , Mossy Fibers, Hippocampal/ultrastructure , Neuronal Plasticity , Amygdala/physiology , Animals , Dentate Gyrus/ultrastructure , Electric Stimulation , Epilepsy, Temporal Lobe/epidemiology , Female , Humans , Male , Middle Aged , Mossy Fibers, Hippocampal/physiology , Rats , Rats, Sprague-Dawley , Severity of Illness Index , Status Epilepticus/chemically induced , Status Epilepticus/diagnosis
16.
Neurology ; 54(12): 2252-60, 2000 Jun 27.
Article in English | MEDLINE | ID: mdl-10881249

ABSTRACT

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.


Subject(s)
Epilepsy, Temporal Lobe/diagnostic imaging , Flumazenil/pharmacokinetics , Hippocampus/metabolism , Temporal Lobe/metabolism , Adolescent , Adult , Anticonvulsants/therapeutic use , Benzodiazepines/therapeutic use , Epilepsy, Temporal Lobe/diagnosis , Epilepsy, Temporal Lobe/therapy , Female , GABA Modulators/pharmacokinetics , Hippocampus/diagnostic imaging , Hippocampus/pathology , Hippocampus/surgery , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Temporal Lobe/diagnostic imaging , Temporal Lobe/pathology , Tomography, Emission-Computed , Treatment Outcome , Valproic Acid/therapeutic use , Vigabatrin/therapeutic use
17.
Ann N Y Acad Sci ; 911: 369-91, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10911886

ABSTRACT

Recent anterograde and retrograde studies in the rat have provided detailed information on the origin and termination of the interconnections between the amygdaloid complex and the hippocampal formation and parahippocampal areas (including areas 35 and 36 of the perirhinal cortex and the postrhinal cortex). The most substantial inputs to the amygdala originate in the rostral half of the entorhinal cortex, the temporal end of the CA1 subfield and subiculum, and areas 35 and 36 of the perirhinal cortex. The amygdaloid nuclei receiving the heaviest inputs are the lateral, basal, accessory basal, and central nuclei as well as the amygdalohippocampal area. The heaviest projections from the amygdala to the hippocampal formation and the parahippocampal areas originate in the lateral, basal, accessory basal, and posterior cortical nuclei. These pathways terminate in the rostral half of the entorhinal cortex, the temporal end of the CA3 and CA1 subfields or the subiculum, the parasubiculum, areas 35 and 36 of the perirhinal cortex, and the postrhinal cortex. The connectional data are summarized and the underlying principles of organization of these projections are discussed.


Subject(s)
Amygdala/physiology , Hippocampus/physiology , Neural Pathways/physiology , Parahippocampal Gyrus/physiology , Animals , Brain Mapping , Humans
19.
Epilepsia ; 40(7): 921-30, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10403216

ABSTRACT

PURPOSE: To evaluate combined [18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and 122-channel whole-scalp magnetoencephalography (MEG) in lateralizing the epileptogenic cortex in patients whose routine presurgical evaluations gave discordant results about the location of the epileptic focus. METHODS: Nine patients (five women, four men) aged 13-40 years were studied. Subdural EEG (SEEG) was recorded from eight patients. Six patients were operated on. RESULTS: In seven of nine patients, PET and MEG agreed in localizing the epileptogenic cortex. When PET and MEG were in congruence, SEEG agreed with the findings. In five of six operated-on patients, PET and MEG results were congruent, and the outcome of the operation was successful. Two patients had discordant PET and MEG results. In one patient, PET showed bitemporal hypometabolism, whereas MEG showed epileptiform activity in the right parietal lobe. The surgical outcome of the palliative temporal lobectomy was poor. Another patient had unilateral temporal hypometabolism in PET and bitemporal activity in MEG. She was not operated on. CONCLUSIONS: In most patients, PET and MEG were congruent in locating the epileptogenic cortex. Thus the combination of these techniques may provide useful support for the localization of the seizure onset and reduce the need for invasive procedures.


Subject(s)
Cerebral Cortex/physiopathology , Epilepsy/diagnosis , Fluorodeoxyglucose F18 , Magnetoencephalography , Tomography, Emission-Computed , Adolescent , Adult , Cerebral Cortex/pathology , Cerebral Cortex/surgery , Electrodes, Implanted , Electroencephalography/statistics & numerical data , Epilepsy/physiopathology , Epilepsy/surgery , Female , Humans , Male , Subdural Space , Treatment Outcome
20.
Seizure ; 8(3): 181-3, 1999 May.
Article in English | MEDLINE | ID: mdl-10356378

ABSTRACT

This report describes the long-term follow-up of 56 patients with refractory partial epilepsy who, within 3 months of vigabatrin add-on therapy (3 g/day), showed a reduction in monthly seizure frequency of more than 50%. The short-term (6 months) and long-term (5 years) effects of vigabatrin on seizure frequency in this patient cohort have been published separately. The reduction in seizure frequency appeared to be long-lasting in the patients followed-up (n = 36) and, importantly, a significant number of the patients (n = 7) became seizure-free, especially during long-term treatment. Thus, the efficacy of vigabatrin appears to be progressive, at least in patients who show an early response to treatment. These results are consistent with experimental findings that suggest that vigabatrin may have anti-epileptogenic and neuroprotective effects.


Subject(s)
Anticonvulsants/therapeutic use , Epilepsy/drug therapy , gamma-Aminobutyric Acid/analogs & derivatives , Chronic Disease , Cohort Studies , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Prognosis , Retrospective Studies , Treatment Outcome , Vigabatrin , gamma-Aminobutyric Acid/therapeutic use
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