Behavioural symptoms are common in moderate to severe Alzheimer's disease (AD) and are improved by memantine with the most pronounced effect on agitation/aggression. Dextromethorphan in combination with quinidine is the only drug approved by US Food and Drug Administration for the treatment of pseudobulbar affect (PBA) on the basis of efficacy in patients with multiple sclerosis or amyotrophic lateral sclerosis. The aim of our study was to evaluate the efficacy of memantine on PBA in patients with AD.

In a prospective, double-blind, case-control study to assess PBA with pathological laughter and crying scale patients were administered memantine (final dose of 20 mg daily) or citalopram (20 mg once daily), each for 10 weeks. The number of episodes of involuntary emotional expression, Neuropsychiatric Inventory (NPI) and Overt Aggression Scale-Modified (OAS-M) total scores were also recorded. Furthermore, the platelet serotonin (5-HT) concentration was measured.

Although memantine had beneficial effects on PBA, it also had a crucial impact on behavioural symptoms, especially aggression and agitation (to an average of 3.5 times higher end-point scores on OAS-M and increase of NPI total scores for an average of 114% of initial value). Therefore, the study was prematurely stopped. In addition, we had evidenced a drop of platelet 5-HT concentration (to an average of 73% of initial value).

Surprisingly, our research showed the opposite action of memantine on neuropsychiatric symptoms as expected. In a limited number of AD patients with PBA, memantine had a beneficial effect on involuntary emotional expression, but it potentiated agitation/aggression, irritability and caused a crucial drop of the platelet 5-HT concentration.

Enlarged tonsils and adenoids (part of Waldeyer's ring) are responsible for obstructive sleep disordered breathing. Obstructive sleep disordered breathing episodes lead to hypoxaemia, hypercapnia and a state of arousal, all of which affect normal development of the nervous system. In this study, two hypotheses were tested: (1) obstructive sleep disordered breathing is caused by adenotonsillar hypertrophy and is associated with hypoxia and brain dysfunction; and (2) children with obstructive sleep disordered breathing more commonly display emotional lability, depressive behaviour and anxiety.

A total of 225 children were examined. The study group consisted of 121 children with adenotonsillar hypertrophy (87 aged six to nine years and 34 aged 10 to 13 years) and with obstructive sleep apnoeas and hypopnoeas confirmed by polysomnography. Patients were compared with 104 children with no obstructive sleep disordered breathing and no adenotonsillar hypertrophy (74 aged six to nine years and 30 aged 10 to 13 years). The following tests were used to measure the children's emotional disorders: the children's depression inventory; the state-trait anxiety inventory for children; and the emotional instability scale. The average values and standard deviations were calculated for all results. Student's t-test was used to compare differences in all groups of children. The minimum level of p < 0.05 was set as statistically significant.

Children with adenotonsillar hypertrophy are more likely to experience poor brain development and sleep problems. They also have emotional disturbances. In the sick and healthy children aged six to nine years, mean results for the emotional instability scale were statistically significantly different in the two groups, being higher in children with adenotonsillar hypertrophy than in healthy children. Mean values for the children's depression inventory test were higher in children with adenotonsillar hypertrophy, but the differences were not statistically significant. In the state-trait anxiety inventory for children test, the mean T score was T = 1.760 and the level of significance was p = 0.08 for both groups. Since the standard level of significance was p < 0.05, the differences in mean values for the state-trait anxiety inventory for children test bordered on statistical significance. There were no differences between tests results in the older children (10 to 13 years).

Recent studies have confirmed the negative emotional effect of adenotonsillar hypertrophy induced obstructive sleep disordered breathing in children aged six to nine years. The main problems are emotional lability, and anxiety and depressive disturbances. Such emotional problems subside in older children (aged 10 to 13 years).