Unilateral thalamic stroke does not decrease ipsilateral sleep spindles

STUDY OBJECTIVES

To measure the sleep spindle characteristics in patients with unilateral thalamic stroke.

DESIGN

A prospective study of patients with thalamic stroke and age-matched healthy controls.

SETTING

Department of Neurology of a University Hospital.

PARTICIPANTS

Thirteen patients (mean age: 67 years, SD: 13,44) with an isolated, unilateral acute thalamic stroke and 18 healthy age-matched volunteers.

INTERVENTIONS

A polysomnogram recording from 14 scalp EEG electrodes performed during 2 consecutive nights, the second or third week after the stroke. Only the sleep of the second night was analyzed.

MEASUREMENTS AND RESULTS

Sleep spindles were counted during two separate 10-minute epochs of stage II. Spindles appearing synchronously in both sides with similar amplitude were called "bilateral." Spindles with twice the amplitude in one side than the other were "right" or "left-side predominant". There were 8 patients with posterolateral, 3 with global and 2 with anterior lesions. Eight were right and 5 left-sided. The number of spindles was similar in patients (39.8 +/- 23.4 in 20 minutes) than controls (26.07 +/- 29.07; p=0.173). Spindles with a centroparietal (34%) and centroparieto-occipital localization (22%) were the most frequent. In controls approximately 66% of the spindles had a bilateral and symmetric distribution over the scalp, 23% of the spindles were predominantly left-sided and 5% were predominantly right-sided. In patients, bilateral spindles decreased (p<0.0001) but asymmetric spindles did not change.

CONCLUSION

Unilateral acute thalamic stroke does not decrease sleep spindles ipsilaterally; rather, it seems to produce a bilateral diminution in their number.

Brain impairment in well-nourished chronic alcoholics is related to ethanol intake

To determine the influence of chronic ethanol intake on the central nervous system, we studied 40 asymptomatic, well-nourished, chronic alcoholics (mean age, 42.6 +/- 9.1 years) and 20 age-, sex-, and education-matched control subjects. Studies included neuropsychological testing, visual and short-latency auditory evoked potentials, and morphometric analysis of computed tomography scans. The mean daily ethanol consumption of the alcoholics was 204 gm over an average of 26.4 years. Compared to control subjects, chronic alcoholics exhibited a significant prolongation of the P100 latency of visual evoked potentials, and a prolongation and reduction in the amplitude of the latency of the V wave of short-latency auditory evoked potentials. These abnormalities were related to the lifetime dose of ethanol consumed. Brain morphometric analysis showed that alcoholics had a significantly greater degree of brain shrinkage with age, compared to control subjects. The cortical atrophy index correlated significantly with the lifetime ethanol consumption. Neuropsychological testing in alcoholics compared to controls revealed a significant impairment of frontal skills that was related to age, degree of scholarship, and the presence of frontal atrophy. In conclusion, well-nourished chronic alcoholics exhibited significant brain impairment, as demonstrated by neuropsychological testing, evoked potentials, and brain morphometric analysis, which was correlated with the lifetime dose of ethanol consumed.

Lactitol vs. lactulose in the treatment of chronic recurrent portal-systemic encephalopathy

To compare the efficacy and patient acceptability of lactitol vs. lactulose in chronic recurrent portal-systemic encephalopathy (PSE), 25 cirrhotic patients with a history of repeated episodes of hepatic encephalopathy who required chronic administration of lactulose were included in a controlled cross-over clinical trial in which patients received, at random, lactitol (at an initial dosage of 10 g/6 h) or lactulose (15 ml/6 h, 66% w/v, containing 10 g of lactulose) during a 3 month period and then crossed-over to the alternative treatment for the following 3 months. Doses were adjusted to obtain two bowel movements per day. During the study period the daily protein intake was 40-60 g. Clinical and analytical data (including ammonia levels) were obtained, an EEG and the number connection test were performed and the PSE index was determined before treatment and monthly until the end of the treatment. No significant differences were found between the effects of lactitol and lactulose on the neurological and biological parameters, suggesting that the two treatments could be considered as equally effective. Lactitol was significantly better tolerated than lactulose (P = 0.02), the taste of which was assessed as being too sweet and provoking nausea. In conclusion, lactitol is a good alternative to lactulose for patients with chronic recurrent PSE, especially in those who do not tolerate the excessive sweetness of lactulose.