Social cognition in cervical dystonia: phenotype and relationship to anxiety and depression

BACKGROUND AND PURPOSE

Anxiety and depression are common disabling comorbidities in cervical dystonia (CD) and may predispose to social withdrawal and social cognitive impairments. The relationship between social cognition and depressive/anxiety symptoms in CD is under-investigated.

METHODS

Forty-six CD patients (40 women; mean age ± SD, 55.57 ± 10.84 years) were administered the following social cognition battery: Affect Naming, Prosody Face and Pair Matching subtests from the Wechsler Adult Intelligence Scale IV and Wechsler Memory Scale IV (social perception), reality-known and reality-unknown false belief reasoning tasks (theory of mind), Empathy Quotient and Social Norms Questionnaire 22 (social behaviour), alongside the Benton Facial Recognition Task (non-emotional facial discrimination). Alongside CD severity, the Hospital Anxiety and Depression Scale measured depressive/anxiety comorbid diagnostic status and severity, and the Liebowitz Social Anxiety Scale assessed social phobia. Social cognition tasks were standardized using published normative data and a cut-off of z < -1.5 for impairment.

RESULTS

More than 90% of our CD patients performed normally on social perception and social behaviour tests. Performance on impaired belief reasoning (theory of mind) was impaired in 10 of 46 (21.74%); five of 46 (10.87%) were impaired on the Empathy Quotient. Better performance on the Affect Naming task was associated with comorbid anxiety (η²  = 0.09, medium-to-large effect size) and greater anxiety, depression and social phobia severity. Worse performance on the Empathy Quotient was associated with comorbid depression (η²  = 0.11, medium-to-large effect size) and greater depression severity. CD patients had significantly more difficulties with fearful face identification (P < 0.001).

CONCLUSIONS

Greater social perception abilities in CD patients with more severe anxiety and depression suggest efficient modulation and self-adaptation of social cognitive skills.

Young Women do it Better: Sexual Dimorphism in Temporal Discrimination

The temporal discrimination threshold (TDT) is the shortest time interval at which two sensory stimuli presented sequentially are detected as asynchronous by the observer. TDTs are known to increase with age. Having previously observed shorter thresholds in young women than in men, in this work we sought to systematically examine the effect of sex and age on temporal discrimination. The aims of this study were to examine, in a large group of men and women aged 20–65 years, the distribution of TDTs with an analysis of the individual participant’s responses, assessing the “point of subjective equality” and the “just noticeable difference” (JND). These respectively assess sensitivity and accuracy of an individual’s response. In 175 participants (88 women) aged 20–65 years, temporal discrimination was faster in women than in men under the age of 40 years by a mean of approximately 13 ms. However, age-related decline in temporal discrimination was three times faster in women so that, in the age group of 40–65 years, the female superiority was reversed. The point of subjective equality showed a similar advantage in younger women and more marked age-related decline in women than men, as the TDT. JND values declined equally in both sexes, showing no sexual dimorphism. This observed sexual dimorphism in temporal discrimination is important for both (a) future clinical research assessing disordered mid-brain covert attention in basal-ganglia disorders, and (b) understanding the biology of this sexual dimorphism which may be genetic or hormonal.

A family study on primary blepharospasm

BACKGROUND

Previous family studies provided evidence that blepharospasm (BSP) can aggregate in families but did not give accurate and reliable information on the characteristics and degree of familial clustering.

AIM

To evaluate the proportion of familial and non-familial BSP cases, the clinical expression of dystonia within families, the inheritance pattern, and the extent of penetrance.

METHODS

The study was based on the examination of the first degree relatives of 56 probands with primary BSP.

RESULTS

The 56 families produced a potential population of 436 first degree relatives of whom 296 were alive and 233 were examined. The proportion of index patients with at least one first degree relative affected by BSP, or adult onset dystonia other than BSP, was 27%. There was a remarkable degree of phenotypic variability of dystonia within families. Similar segregation ratios were calculated for probands' siblings and children. Under the assumption of autosomal dominant transmission of adult onset dystonia, penetrance was about 20%.

CONCLUSIONS

The findings of this family study are relevant for accurately counselling the families of patients with BSP and may help identify the most appropriate study design to explore genetic susceptibility in BSP.