Methods: Male Wistar rats (n = 48) were divided into followinggroups: (1) control, saline-treated group (n = 16), (2) dimethylsulfox-ide-treated group (n = 16), (3) group that received lindane, dissolvedin dimethylsulfoxide, in a dose of 8 mg/kg intraperitoneally (n = 16).Eight animals from each group were sacrificed 0.5 and 4 h aftertreatment and brain samples were prepared for further analysis.Acetylcholinesterase activity (mitochondrial and synaptosomal frac-tion) was determined in cerebral cortex, thalamus, hippocampus andnc. caudatus spectrophotometrically.

Results: A significant rise in mitochondrial acetylcholinesteraseactivity was detected in cortex and nucleus caudatus of lindane-trea-ted animals 0.5 h after administration (p < 0.05). This rise was sus-tained in nucleus caudatus within 4 h after treatment (p < 0.05). Incontrast, activity of synaptosomal acetylcholinesterase fraction wassignificantly increased only in thalamus 4 h after lindane administra-tion (p < 0.05).

Conclusion: An increase in acetylcholinesterase activity may beinvolved in mediating acute neurotoxic effects of lindane, at leastin some brain structures in rats.

doi:10.1016/j.clinph.2008.12.016

13. Effect of 2,4-diaminobutyric acid on Retzius cells of theleech—S. Lopicic 1, D. Pathak 1, M. Stanojevic 1, A. Nedeljkov 1,A. Popovic 1, D. Pavlovic 2, D. Cemerikic 1, V. Nedeljkov 1 (1 Insti-tute for Pathological Physiology, Medical Faculty Belgrade, Serbia,2 Ernst Moritz Arndt University, Greifswald, Germany)

Purpose: The aim of this study was to examine the effect of 2,4-diaminobutyric acid (DABA) on Retzius cell of the leech in presenceof 20 mmol/l bicarbonate since this amino acid is present in mam-malian brain as well as in several Lathyrus species, it is shown toproduce convulsions and neuropathologic changes in rats, and thatbicarbonate increases its effect.

Methods: We used classical electrophysiology to measure theresting membrane potential of Retzius nerve cells of the leech Hae-mopis sanguisuga upon application of 10�2 mol/l DABA in presenceof 20 mmol/l bicarbonate.

Results: Bath application of 10�2 mol/l DABA with 20 mmol/lbicarbonate for 3 min. depolarized resting membrane potential by5.33 ± 1.25 mV (n = 5, p = 0.01, t-test). Since the solution of DABAis acidic (pH 6.8), we have also tested the effect of Ringer solutionwith pH adjusted to 6.8 by HCl. This acidic Ringer had no effect onthe cell (depolarization of 1.67 ± 0.48 mV, n = 3, p > 0.05). Thereforethe depolarization observed upon administration of DABA cannotbe attributed to change in pH.

Conclusions: We conclude that DABA in presence of bicarbonatehas depolarizing effect on Retzius cell of the leech, and may contributetothepathogenesisofneurolathyrismandotherneurodegenerativediseases.

doi:10.1016/j.clinph.2008.12.017

14. Effect of ethanol on epileptiform activity induced by nickelon Retzius nerve cells of the leech—D. Pathak 1, S. Lopicic 1,M. Stanojevic 1, A. Nedeljkov 1, A. Popovic 1, D. Pavlovic 2,D. Cemerikic 1, V. Nedeljkov 1 (1 Institute for Pathological physi-ology, Medical faculty Belgrade, Serbia, 2 Ernst Moritz ArndtUniversity, Greifswald, Germany)

Purpose: The purpose of the present study was to investigate theeffect of ethanol in epileptiform activity evoked by blocking calciumchannels with nickel, since ethanol exposure affects many neuronalfunctions, including pacemaker activity of individual nerve cells.

METHODS: We have used classical electrophysiology to measure num-ber of waves of depolarization per minute, wave amplitude, and num-ber of spikes per wave during nickel induced oscillatory epileptiformactivity of Retzius nerve cells of the leech Haemopis sanguisuga priorto and during application of 2% (435 mmol/l) ethanol in Ringer solu-tion. All data represented as average ± SEM. Each trial was performedon five cells and averages calculated from at least 10 waves per cell.

Results: Application of 3 mM nickel induces oscillatory epilepti-form activity in leech Retzius nerve cells, which is shown as waves ofdepolarization, accompanied with repetitive firing of action poten-tials. Addition of 2% ethanol solution suppresses the number ofwaves of depolarization per minute from 8.20 ± 0.78 to 4.30 ± 1.05(p < 0.05, t-test), diminishes wave amplitude from 11.40 ± 0.51 to6.75 ± 0.53 mV (p < 0.001, t-test), and decreases number of spikesper wave from 3.00 ± 0.00 to 0.57 ± 0.30 (p < 0.001, t-test).

Conclusions: Ethanol inhibits epileptiform activity induced bycalcium channel blocker nickel on Retzius nerve cells of the leech.

doi:10.1016/j.clinph.2008.12.018

15. Factors associated with incomplete seizure control in childrenwith cerebral palsy—Predrag Ignjatovic (Clinic of Neurology andPsychiatry for Children and Youth, Belgrade, Serbia)

Purpose: To analyze factors associated with incomplete seizurecontrol in children with cerebral palsy (CP). Methods: The group of30 children with CP and epilepsy, age 3–17 years, was studied retro-spectively. CP types, mental retardation and age of seizure onsetwere also analyzed. To determine prognosis of seizures, childrenwere divided in two subgroups according to the level of seizurecontrol. Results: Fifty-seven percentage of patients were on AEDmonotherapy, while 43% were treated with two or three AEDs.Twenty-three patients (77%) became seizure-free. Complete seizurecontrol was achieved in the majority of children with spastic hemi-plegia (7/9), diplegia (6/8) and spastic quadriplegia (7/10). All chil-dren with mixed type of CP belonged to the subgroup withcomplete seizure control (3/3). Associated mental retardation wasseen in all patients without complete seizure control and in 83% ofseizure-free patients. Seizure onset in the first year of life occurredin 35% of seizure-free children as compared to 86% of children with-out complete control of seizures.

Conclusions: Severity of neurological condition (spastic quadri-plegia), mental retardation and earlier age of seizure onset are fac-tors mainly associated with incomplete seizure control.

doi:10.1016/j.clinph.2008.12.019

16. A diagnostic challenge: Nonconvulsive status epilepticus inelderly—S. Kostic, R. Sujic, Z. Milojevic, V. Cvijanovic, V. Nikolic,D. Vranjes (Department of Neurology, Clinical Hospital CentreZvezdara, Belgrade, Serbia)

Purpose: To point out a differential diagnosis of non-convulsivestatus epilepticus (NCSE) in elderly.

Method: We describe a case of acute confusional state and righthemiparesis due to nonconvulsive status epilepticus, not caused byan ischemic or hemorrhagic stroke as it usually is presumed.

Results: This 67-year-old man presented acute confusional stateand right hemiparesis that suddenly appeared, without headache orvomitus. CT and MRI of the brain revealed neither ischemic nor hem-orrhagic stroke. NCSE lasted up to 5 days, when it was diagnosed byEEG recording discharges originating from the left temporo-parietal

e130 Society Proceedings / Clinical Neurophysiology 120 (2009) e127–e132