R Massetani

Alteration of Cardiac Function in Patients with Temporal Lobe Epilepsy: Different Roles of EEG-ECG Monitoring and Spectral Analysis of RR Variability

Summary: Purpose: Because several reports have described the relation between epilepsy and cardiac arrhythmias and suggest that changes in autonomic neural control of the heart could be involved in the pathogenesis of sudden unexplained death in patients with epilepsy, the aim of this study was to evaluate cardiac function in patients with temporal lobe epilepsy.

Word recall correlates with sleep cycles in elderly subjects

Morning recall of words presented before sleep was studied in relation to intervening night sleep measures in elderly subjects. Night sleep of 30 elderly subjects aged 61–75 years was recorded. Before sleep, subjects were presented with a list of paired non‐related words and cued recall was asked immediately after the morning awakening. Recall positively correlated with average duration of NREM/REM cycles, and with the proportion of time spent in cycles (TCT) over total sleep time (TST). No significant correlations were found with other sleep or wake measures. These results suggest the importance of sleep structure for sleep‐related memory processes in elderly adults.

Evaluation of acute ischemic stroke using quantitative EEG: A comparison with conventional EEG and CT scan

The sensitivity of quantitative electroencephalogram (EEG) was compared with that of conventional EEG in patients with acute ischaemic stroke. In addition, a correlation between quantitative EEG data and computerized tomography (CT) scan findings was carried out for all the areas of lesion in order to reassess the actual role of EEG in the evaluation of stroke. Sixty-five patients were tested with conventional and quantitative EEG within 24 h from the onset of neurological symptoms, whereas CT scan was performed within 4 days from the onset of stroke. EEG was recorded from 19 electrodes placed upon the scalp according to the International 10-20 System. Spectral analysis was carried out on 30 artefact-free 4-sec epochs. For each channel absolute and relative power were calculated for the delta, theta, alpha and beta frequency bands and such data were successively represented in colour-coded maps. Ten patients with extensive lesions documented by CT scan were excluded. The results indicated that conventional EEG revealed abnormalities in 40 of 55 cases, while EEG mapping showed abnormalities in 46 of 55 cases: it showed focal abnormalities in five cases and nonfocal abnormalities in one of six cases which had appeared to be normal according to visual inspection of EEG. In a further 11 cases, where the conventional EEG revealed abnormalities in one hemisphere, the quantitative EEG and maps allowed to further localize abnormal activity in a more localized way. The sensitivity of both methods was higher for frontocentral, temporal and parieto-occipital cortical-subcortical infarctions than for basal ganglia and internal capsule lesions; however, quantitative EEG was more efficient for all areas of lesion in detecting cases that had appeared normal by visual inspection and was clearly superior in revealing focal abnormalities. When we considered the electrode related to which the maximum power of the delta frequency band is recorded, a fairly close correlation was found between the localization of the maximum delta power and the position of lesions documented by CT scan for all areas of lesion excepting those located in the striatocapsular area.

REM latency: Development in the first year of life

The development of REM latency in the first year of life was investigated in two groups of 10 infants each. While 10 infants were normal, the other 10 underwent continuous feeding for various gastrointestinal diseases. Each infant was continuously recorded polygraphically for 24 h. While younger infants (less than or equal to 3 months) manifested predominantly shorter REM latencies (less than or equal to 8 min), older infants (4-13 months) produced a mixed distribution of short and long REM latencies. The total distribution of the REM latencies appears to be bimodal with latencies either shorter than 8 min or longer than 16 min. It is only in the group of older infants that the temporal distribution of REM latencies constitutes a diurnal rhythm, with the longest latencies in the interval between 12:00 and 16:00 and the shortest between 4:00 and 8:00. In the group of older infants, REM latency also depends on the duration of prior wakefulness. Long REM latencies are significantly more often preceded by long episodes of wakefulness than are short REM latencies. The different feeding conditions had only a minor effect on REM latency.

A quantitative study of daytime sleepiness induced by carbamazepine and add-on vigabatrin in epileptic patients.

Introduction – The clinical relevance of daytime sleepiness associated with carbamazepine (CBZ) and vigabatrin (VGB) was objectively assessed by the multiple sleep latency test (MSLT) and nocturnal sleep recordings. Material and methods – Twenty‐six patients with partial epilepsy and mean monthly seizure frequency of 4, aged 18 to 48 years, receiving chronic monotherapy with CBZ and subsequent VGB addition for 2 months (14 patients), were compared with a group of healthy subjects. Subjective daytime sleepiness was complained by 13 patients on CBZ monotherapy and 9 patients during VGB add‐on treatment. Results – No differences in nocturnal sleep parameters, but significantly shorter daytime sleep latencies at the MSLT, were detected in CBZ‐treated patients as compared with healthy controls. Addition of VGB therapy did not further enhance objective daytime sleepiness. Conclusion – Some sleepiness occurs in chronically CBZ‐treated epileptic patients, which can be objectively measured by the MSLT, but it is not aggravated by add‐on VGB.

Dream structure in Parkinson's patients.

Dream reports of patients with Parkinsons disease (PD) were analyzed to ascertain whether cognitive deficits associated with this nonfocal brain pathology influence dream structure or dream recall. Fifteen outpatients with idiopathic PD were sampled (diagnosed from 1 to 10 years and currently in stage II or III of Hoehn and Yarhs scale); all were without psychiatric symptoms or major medical illnesses and were currently being treated with L-dopa. After an adaptation night in the sleep laboratory, each patient spent a night in which he/she was awakened at least twice in rapid eye movement sleep and asked to report dream experience. Thirteen patients were able to report at least one dream. Overall frequency of dream recall (71.4%) was fully compatible with normative data for the elderly. Multiple regression analyses showed that both the length of the dream report as story and the organization of contents into coherent episodes (analyzed using Mandler and Johnsons story grammar) varied significantly in relation to level of cognitive functioning and, in part, of language comprehension, but not in relation to age, illness duration, and dose of L-dopa.

Spontaneous awakening from sleep in infants

Spontaneous awakenings from sleep were studied in a group of 20 infants whose sleep-waking patterns were recorded polygraphically for 24 h. While 10 infants were orally fed the other 10 underwent continuous feeding for various gastrointestinal diseases. Spontaneous awakening from sleep was analysed with regard to the prior sleep state, age and feeding condition. Infants awoke preferentially out of REM sleep and less often out of non-REM sleep. The feeding condition had no significant influence on the distribution of awakenings. The propensity for REM awakenings was significantly greater than would have been expected according to the REM sleep amount. This tendency was more pronounced for younger (less than or equal to 3 months) than for older (greater than or equal to 4 months) infants. REM sleep episodes which were interrupted by awakenings were significantly shorter than uninterrupted ones, since awakenings occurred predominantly shortly after REM sleep onset. It is proposed that the specific pattern of brain activity during REM sleep facilitates the transition from sleep into the waking state, particularly in the youngest infants.

Slow wave sleep (SWS) distribution across night sleep episode in the elderly

Slow wave sleep (SWS) distribution across night sleep was shown to be different between infants and young adults. The present research aimed at studying the SWS distribution across night sleep in elderly subjects. Nine healthy elderly subjects, 61–71 years old, were submitted to nocturnal polygraphic sleep recording. Eleven young subjects, 21–23 years old, were the control group. Recordings were visually analyzed according to Rechtschaffen and Kales rules; the method proposed by Webb and Dreblow was used for scoring SWS. An NREM-REM cycle was defined as a sequence of NREM and REM sleep not interrupted by a waking period longer than 15 minutes. SWS percentage was calculated for each successive NREM episode. No significant association between SWS percentage and cycle rank was shown in elderly subjects, whereas a significant association was observed in the young ones. This kind of SWS distribution could be interpreted as reflecting the restructuring of internal organization of sleep in the elderly.

Visual contrast sensitivity in carbamazepine-resistant epileptic patients receiving vigabatrin as add-on therapy

In 40 adult patients with partial epilepsy resistant to carbamazepine (CBZ) monotherapy at the maximum tolerated individual doses, vigabatrin (VGB) was added to reduce seizure frequency further. In an attempt to evaluate potential drug-related visual side effects, visual contrast sensitivity (VCS), i.e., the ability to perceive minimal differences in luminance between adjacent regions of a grating visual pattern, was assessed before and monthly during a 6-month period of VGB add-on therapy and compared with that of a control group of healthy subjects. Twenty-eight patients completed the prescribed 6-month period of trial and were included in the statistical analysis. VCS measured during CBZ treatment showed a clear loss in all explored spatial frequencies. From the second month of VGB treatment on, VCS exhibited a progressive recovery, especially in the medium-frequency range, although only to a partial extent as compared with that in the controls. This effect saturated at the sixth month. Moreover, a different recovery of VCS to vertical and oblique gratings was observed, which likely suggests a drug effect on visual cortex. VGB add-on therapy was both well tolerated and effective in reducing seizure frequency.

Evaluation of antihistamine-related daytime sleepiness. A double-blind, placebo-controlled study with terfenadine.

The daytime sleepiness potentially associated with antihistamines was evaluated by the multiple sleep latency test (MSLT) in a study comparing terfenadine with placebo. According to a double‐blind, randomized, cross‐over design, 12 healthy men were given either 120 mg terfenadine or placebo once daily in the morning, for 3 consecutive days with a 5‐day interval. EEG‐polygraphic recordings were made each study day at 9.30 and 11.30 a.m., and 1.30, 3.30, and 5.30 p.m., and the tendency to fall asleep was measured. All mean stage‐1 sleep latencies throughout the study failed to show any significant difference between terfenadine and placebo. Accordingly, psychomotor performance assessed by visual and auditory reaction time did not change after treatment. The results of this study confirmed that terfenadine does not induce daytime sleepiness as objectively measured by MSLT.