- Email: [email protected]
Abnormalities of PR-VEPs in dyslexia depend on stimulus spatial and temporal frequencies
74P
105. Saccadic and smooth pursuit eye dystrophy. - M. Versino, R. Poli, A. S. Lanfranchi, G. Sand&i, V. Cosi rologico ‘C. Mondino’ IRCCS, Univ.
Society
movements in myotonic Romani, R. Bergamaschi, (Pondazione Istituto NeuPavia)
We studied eye movements in 23 subjects suffering from myotonic dystrophy (MyD) and in 36 age-matched controls. Eye movements were recorded with the bitemporal electooculographic technique and analyzed with a personal computer. Saccades were elicited in accordance with a reflexive paradigm and for each subject we evaluated the following parameters: amplitude/duration and amplitude/peak velocity relationships, accuracy and latency. Smooth pursuit eye movements were elicited in accordance with a triangular ramp paradigm and for each subject we evaluated the target velocity/performance index (PI) relationship. In mean value comparisons, the MyD group showed an increase in saccade duration and a reduction in peak velocity, accuracy and latency and smooth pursuit PI. On an individual basis, among the MyD group we detected a higher occurrence of subjects with an ahnormal saccade duration, peak velocity and accuracy. In conclusion, we suggest that eye movement evaluation should be part of the neurophysiological protocol to evaluate MyD patients.
106. Median nerve SSEPS and C reflexes to double MERRP patient. - A. Romani, C.A. Galbnberti, G. Piccolo, R. Bergamaschi, M. Versino, A. Zilioli, V. Cosi (Pondazione Istituto Neurologico ‘C. IRCCS, Universita di Pavia)
stimuli in a R. Callieco, D. Gaspari, Mondino ‘
A patient with a molecular genetic diagnosis of myoclonus epilepsy with ragged-red fibers (MERRF syndrome) was submitted to a median nerve stimulation paradigm, during which single stimuli were cyclically alternated with four types of double stimuli (ISI: 25, 50, 75 and 100 ms). The responses to single stimuli showed increased amplitudes of parietal components. With double stimuli the response to the test stimulus was suppressed at 25 ms ISI, greatly facilitated at 50 and 75 ms ISIS and, to a lower degree, at 100 ms ISI. C reflexes (opponent pollicis) occurred in 29% of single stimuli, never followed the test stimulus with 25 ms ISI, and occurred in 84%, 89% and 56% of the test stimuli with 50, 75 and 100 ms ISI, respectively. The method provides direct evidence for the association between cortical excitability, its time-course and the occurrence of C reflexes in cortical reflex myoclonus.
107. Abnormalities of PR-VEPs in dyslexia depend on stimulus spatial and temporal frequencies. - (A. Romani, S. Conte, R. Cailieco, E. Partesana, C.A. Zambrino, G. Lanzi, V. Cosi (Fondazione Istituto Neuroiogico ‘C. Mondino’ IRCCS, Universit& di Pavia) Nine subjects (8 boys and 1 girl) affected from dyslexia and 9 age and sex matched controls were submitted to checkerboard pattern reversal visual evoked potentials (PRVEPs), mean luminance 60 cd/m*; contrast 50%, in four paradigms, systematically varying spatial (0.5 and 2 cpd) and temporal (2.1 and 8 reversals/s) stimulus frequencies. For transient PR-VEPs (time-base 250 ms) latencies and amplitudes of N70, PlOO and N140 were considered, and for steady-state PR-VEPs (time-base 2000 ms) amplitudes and phases of the second, fourth and sixth harmonics of the Fourier transform were considered. Dyslexics showed abnormalities of the transient PR-VEP only at the low spatial frequency (N70 amplitude and latency reduction, N140 latency increase) and abnormalities of the steady-state PR-VEP at both spatial frequencies (reduction of the fourth and sixth harmonic amplitude). A stepwise discriminating analysis was able to correctly classify all 18 subjects using 4 PR-VEP parameters. These data support the hypothesis of a selective magnocellular/transient subsystem involvement in dyslexia.
Proceedings
108. Spectral analysis of RR variability and correlation with EEG focus in patients with partial epilepsy. - R. Massetani, G. Strataa, R. Gaili, S. Gori, U. Limbrunoa, D. Di Santoa, M. Mariania (Institute of Neurology. aInstitute of Cardiology, University of Pisa) Some experimental evidence shows that right structures of CNS have an influence on autonomic control of the heart rate greater than the left structures and a study on patients affected by stroke provides partial support for this hypothesis; in fact an increase of supraventricular arrhytmias was found only in patients with right hemisphere strokes. To evaluate a correlation between the side of EEG focus and autonomic control of the heart, 30 patients (12 males and 18 females) with partial epilepsy, in which some alterations of cardiac activity were described in the literature, were studied and compared with a group of normal subjects. Patients showed in 10 cases EEG abnormalities in the right hemisphere, in I I cases in the left hemisphere and in the remaining 9 cases abnormalities were detected all over the scalp. All patients were evaluated by simultaneous ambulatory 24 h EEG-ECG monitoring, while in normal subjects only ECG recording was used. The occurrence of ventricular and supraventricular arrhitmias detected interictally during monitoring was not different from that observed in normal subjects, Besides power spectral analysis, RR variability was carried out in the supine position and during head up tilt. The computer program automatically calculated the autoregressive coefficients necessary to define the power spectrum of RR variability and the two major spectral components detectable at low frequency (LF) and at high frequency (HF), respectively, were a measurement of sympathetic and parasympathetic functions. The LF/HF ratio represents the sympathovagal balance. In epileptic patients a significant reduction of RR variability was found in base conditions and during head up tilt; both spectral indices, LF and HF, were involved in the same way, so that percentage values of LF and HF components and HF/LF ratio did not differ significantly from the control group. When these data were related to the side of EEG focus a greater alteration of autonomic control of the heart was found in patients with right localization of EEG abnormalities.
109. Evaluation of sleep pattern and daytime sleepiness in patients treated for partial epilepsy. - E. Bonanni, C. Gneri, R. Massetani (Institute of Neurology, University of Pisa) The multiple sleep latency test (MSLT) sleep propensity in healthy subjects seems to be influenced by night sleep duration and drug assumption The aim of the present study was to determine the part of sleep alteration and kind of therapy in the daytime sleepiness of epileptic patients with complex partial seizures. The sample was made up of 34 patients, 16 females and 18 males, aged between 20 and 40 years regularly attending the Epilepsy Clinic for a firm diagnosis of partial epilepsy (complex partial seizures with monthly frequency >4). Sixteen patients were receiving monotherapy with carbamazepine (6001600 mglday) and 18 were on polytherapy with carbamazepine (6001600 mg/day) and phenobarbital (100 mg/day) with plasma concentration stable within the therapeutic range. In all cases the neurological examination was negative, CT-scan and NMR normal and history of psychiatric disorders absent. A control group of healthy subjects, aged between 24 and 42 years, was taken as reference. The evaluation of nocturnal sleep was carried out by polysonmographic recording, after a night of adaptation, using the usual criteria. The vigilance was estimated by means of MSLT and of visual simple reaction times (TRV). The patients on polytherapy had shorter mean sleep latency with the MSLT and worse performance with the TRV than patients on monotherapy and control subjects, Compared to the control subjects, only mirror sleep abnormalities including increased stage 2, and decreased stage REM were observed in all patients, regardless of treatment (monotherapy or polytherapy). Results suggest that daytime sleepiness seems to be related to polytherapy rather the sleep disturbances.
105. Saccadic and smooth pursuit eye dystrophy. - M. Versino, R. Poli, A. S. Lanfranchi, G. Sand&i, V. Cosi rologico ‘C. Mondino’ IRCCS, Univ.
Society
movements in myotonic Romani, R. Bergamaschi, (Pondazione Istituto NeuPavia)
We studied eye movements in 23 subjects suffering from myotonic dystrophy (MyD) and in 36 age-matched controls. Eye movements were recorded with the bitemporal electooculographic technique and analyzed with a personal computer. Saccades were elicited in accordance with a reflexive paradigm and for each subject we evaluated the following parameters: amplitude/duration and amplitude/peak velocity relationships, accuracy and latency. Smooth pursuit eye movements were elicited in accordance with a triangular ramp paradigm and for each subject we evaluated the target velocity/performance index (PI) relationship. In mean value comparisons, the MyD group showed an increase in saccade duration and a reduction in peak velocity, accuracy and latency and smooth pursuit PI. On an individual basis, among the MyD group we detected a higher occurrence of subjects with an ahnormal saccade duration, peak velocity and accuracy. In conclusion, we suggest that eye movement evaluation should be part of the neurophysiological protocol to evaluate MyD patients.
106. Median nerve SSEPS and C reflexes to double MERRP patient. - A. Romani, C.A. Galbnberti, G. Piccolo, R. Bergamaschi, M. Versino, A. Zilioli, V. Cosi (Pondazione Istituto Neurologico ‘C. IRCCS, Universita di Pavia)
stimuli in a R. Callieco, D. Gaspari, Mondino ‘
A patient with a molecular genetic diagnosis of myoclonus epilepsy with ragged-red fibers (MERRF syndrome) was submitted to a median nerve stimulation paradigm, during which single stimuli were cyclically alternated with four types of double stimuli (ISI: 25, 50, 75 and 100 ms). The responses to single stimuli showed increased amplitudes of parietal components. With double stimuli the response to the test stimulus was suppressed at 25 ms ISI, greatly facilitated at 50 and 75 ms ISIS and, to a lower degree, at 100 ms ISI. C reflexes (opponent pollicis) occurred in 29% of single stimuli, never followed the test stimulus with 25 ms ISI, and occurred in 84%, 89% and 56% of the test stimuli with 50, 75 and 100 ms ISI, respectively. The method provides direct evidence for the association between cortical excitability, its time-course and the occurrence of C reflexes in cortical reflex myoclonus.
107. Abnormalities of PR-VEPs in dyslexia depend on stimulus spatial and temporal frequencies. - (A. Romani, S. Conte, R. Cailieco, E. Partesana, C.A. Zambrino, G. Lanzi, V. Cosi (Fondazione Istituto Neuroiogico ‘C. Mondino’ IRCCS, Universit& di Pavia) Nine subjects (8 boys and 1 girl) affected from dyslexia and 9 age and sex matched controls were submitted to checkerboard pattern reversal visual evoked potentials (PRVEPs), mean luminance 60 cd/m*; contrast 50%, in four paradigms, systematically varying spatial (0.5 and 2 cpd) and temporal (2.1 and 8 reversals/s) stimulus frequencies. For transient PR-VEPs (time-base 250 ms) latencies and amplitudes of N70, PlOO and N140 were considered, and for steady-state PR-VEPs (time-base 2000 ms) amplitudes and phases of the second, fourth and sixth harmonics of the Fourier transform were considered. Dyslexics showed abnormalities of the transient PR-VEP only at the low spatial frequency (N70 amplitude and latency reduction, N140 latency increase) and abnormalities of the steady-state PR-VEP at both spatial frequencies (reduction of the fourth and sixth harmonic amplitude). A stepwise discriminating analysis was able to correctly classify all 18 subjects using 4 PR-VEP parameters. These data support the hypothesis of a selective magnocellular/transient subsystem involvement in dyslexia.
Proceedings
108. Spectral analysis of RR variability and correlation with EEG focus in patients with partial epilepsy. - R. Massetani, G. Strataa, R. Gaili, S. Gori, U. Limbrunoa, D. Di Santoa, M. Mariania (Institute of Neurology. aInstitute of Cardiology, University of Pisa) Some experimental evidence shows that right structures of CNS have an influence on autonomic control of the heart rate greater than the left structures and a study on patients affected by stroke provides partial support for this hypothesis; in fact an increase of supraventricular arrhytmias was found only in patients with right hemisphere strokes. To evaluate a correlation between the side of EEG focus and autonomic control of the heart, 30 patients (12 males and 18 females) with partial epilepsy, in which some alterations of cardiac activity were described in the literature, were studied and compared with a group of normal subjects. Patients showed in 10 cases EEG abnormalities in the right hemisphere, in I I cases in the left hemisphere and in the remaining 9 cases abnormalities were detected all over the scalp. All patients were evaluated by simultaneous ambulatory 24 h EEG-ECG monitoring, while in normal subjects only ECG recording was used. The occurrence of ventricular and supraventricular arrhitmias detected interictally during monitoring was not different from that observed in normal subjects, Besides power spectral analysis, RR variability was carried out in the supine position and during head up tilt. The computer program automatically calculated the autoregressive coefficients necessary to define the power spectrum of RR variability and the two major spectral components detectable at low frequency (LF) and at high frequency (HF), respectively, were a measurement of sympathetic and parasympathetic functions. The LF/HF ratio represents the sympathovagal balance. In epileptic patients a significant reduction of RR variability was found in base conditions and during head up tilt; both spectral indices, LF and HF, were involved in the same way, so that percentage values of LF and HF components and HF/LF ratio did not differ significantly from the control group. When these data were related to the side of EEG focus a greater alteration of autonomic control of the heart was found in patients with right localization of EEG abnormalities.
109. Evaluation of sleep pattern and daytime sleepiness in patients treated for partial epilepsy. - E. Bonanni, C. Gneri, R. Massetani (Institute of Neurology, University of Pisa) The multiple sleep latency test (MSLT) sleep propensity in healthy subjects seems to be influenced by night sleep duration and drug assumption The aim of the present study was to determine the part of sleep alteration and kind of therapy in the daytime sleepiness of epileptic patients with complex partial seizures. The sample was made up of 34 patients, 16 females and 18 males, aged between 20 and 40 years regularly attending the Epilepsy Clinic for a firm diagnosis of partial epilepsy (complex partial seizures with monthly frequency >4). Sixteen patients were receiving monotherapy with carbamazepine (6001600 mglday) and 18 were on polytherapy with carbamazepine (6001600 mg/day) and phenobarbital (100 mg/day) with plasma concentration stable within the therapeutic range. In all cases the neurological examination was negative, CT-scan and NMR normal and history of psychiatric disorders absent. A control group of healthy subjects, aged between 24 and 42 years, was taken as reference. The evaluation of nocturnal sleep was carried out by polysonmographic recording, after a night of adaptation, using the usual criteria. The vigilance was estimated by means of MSLT and of visual simple reaction times (TRV). The patients on polytherapy had shorter mean sleep latency with the MSLT and worse performance with the TRV than patients on monotherapy and control subjects, Compared to the control subjects, only mirror sleep abnormalities including increased stage 2, and decreased stage REM were observed in all patients, regardless of treatment (monotherapy or polytherapy). Results suggest that daytime sleepiness seems to be related to polytherapy rather the sleep disturbances.