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.

The role of systematic reviews and meta-analyses of incidence and prevalence studies in neuroepidemiology.

BACKGROUND: Systematic reviews and meta-analyses on the incidence and prevalence of neurological conditions are important methods of quantifying the burden and risk of disease. METHODS: The rigorous methodology required in order to minimize publication bias, account for study heterogeneity, and variation in study quality are described. When appropriate, a meta-analysis is a powerful statistical tool that can help synthesize a vast literature quantitatively, taking into account study heterogeneity. As the epidemiology of neurological conditions continue to be widely studied internationally, systematic reviews and meta-analyses have become essential. RESULTS: If not conducted carefully, systematic reviews and meta-analyses in neuroepidemiology may lead to erroneous conclusions. It is important to consider various methodological, clinical and statistical factors at all stages of the review and analysis process. Detailed documentation should be kept to assist in the reporting process. CONCLUSIONS: Published reporting standards should be consulted when conducting systematic reviews and meta-analyses of the incidence and prevalence of neurological conditions, though reporting standards specific to neuroepidemiology are urgently needed.

MS incidence and prevalence in Africa, Asia, Australia and New Zealand: A systematic review.

OBJECTIVES: Studies of multiple sclerosis (MS) incidence and prevalence from Africa, Asia, Australia and New Zealand are relatively scarce. We systematically reviewed MS incidence and prevalence in these regions including a standardized evaluation of study quality. METHODS: We searched MEDLINE and EMBASE databases for studies of MS prevalence or incidence in Africa, Asia, Australia and New Zealand published in English or French between January 1, 1985 and January 31, 2011. Study quality was assessed using a standardized tool. All steps of the review were performed in duplicate. RESULTS: Of 3925 citations identified, 28 studies met inclusion criteria and 21 of these were from Asia. Quality scores ranged from 1/8 to 8/8; the lowest scores were observed in studies from Asia (median 4/8, IQR 3,6). Prevalence was lowest in South African Blacks (0.22/100,000) and highest amongst Australian-born individuals in Australia (125/100,000). Prevalence increased over time in many countries. MS prevalence increased with increasing latitude only in some regions, and prevalence varied significantly with ethnicity. Eight studies reported incidence, which ranged from 0.67/100,000/year in Taiwan to 3.67/100,00/year in Australia. CONCLUSIONS: This comprehensive study provides an update of MS epidemiology in Africa, Asia, Australia, and New Zealand. Incidence and prevalence were lowest in Africa and Asia and highest in Australia, but many Asian studies were of poor quality. Use of consistent case ascertainment methods, standardized data collection tools, and similar outcomes would all improve study quality and comparability. The underlying basis of observed ethnic differences is an important area for future study.

Psychogenic dystonia.

Psychogenic dystonia has been a controversial diagnosis over the past century. While this entity does exist, it makes up the minority of cases of dystonia seen at specialized centres. The diagnosis of psychogenic dystonia must only be undertaken by a neurologist with considerable experience in the assessment and treatment of organic dystonia. Features in the history and physical examination will reveal both clinical inconsistencies and incongruities with organic dystonia that support a psychogenic cause for the patient's symptoms. Patients with psychogenic dystonia suffer from motor conversion disorder, and co-morbid depression, anxiety and disorders of personality are frequent. While there have been no neuroimaging studies to date in patients with psychogenic dystonia, imaging studies in patients with organic dystonia offer insights on how one might assess this problem using functional neuroimaging. Neurophysiologic studies in patients with organic forms of dystonia may also be employed to further distinguish psychogenic from organic dystonia when doubt exists. The prognosis of psychogenic dystonia is disappointing, with the majority of patients suffering significant long-term disability. Recommendations are given regarding disclosure of the diagnosis of psychogenic dystonia to the patient as well as appropriate treatment.

Selective decrease in serotonin synthesis rate in rat brainstem raphe nuclei following chronic administration of low doses of amitriptyline: an effect compatible with an anti-migraine effect.

The effects of chronic, low-dose amitriptyline on serotonin (5-HT) synthesis rate were measured in rat brain using autoradiography and the trapping of alpha-[14C]-methyl-L-tryptophan (alpha-[14C]-MTrp). Rats received amitriptyline (2 mg/kg per day) or saline via intraperitoneal osmotic minipumps for 21 days. Amitriptyline had no effect on any physiological parameters measured, or on free or total plasma tryptophan levels. However, amitriptyline exerted selective decreases of 15% and 17% (P < 0.001) in serotonin synthesis rates in the dorsal and median raphe nuclei, respectively. There was no reduction in any of the projection areas studied, including the cerebral cortex, hippocampus, thalamus, hypothalamus or striatum. The data suggest that chronic low doses of amitriptyline can lead to sustained 5-HT re-uptake inhibition selectively in the raphe nuclei, an effect compatible with tonic activation of 5-HT(1A) autoreceptors and inhibition of 5-HT synthesis. The failure of chronic amitriptyline treatment to affect 5-HT synthesis rate in the projection areas may ensure an adequate regulation of pain pathways implicated in migraine headache, an effect possibly related to amitriptyline anti-migraine efficacy.

In-patient treatment of chronic daily headache using dihydroergotamine: a long-term follow-up study.

BACKGROUND: The treatment of chronic daily headache (CDH) due to medication overuse remains a common and difficult problem. For selected patients refractory to outpatient management we have used a treatment protocol using dihydroergotamine (DHE) as introduced by Raskin, during a brief (typically 48 hours) in-patient stay. While many studies have documented the short-term efficacy of the DHE protocol, there are limited data on its long-term effects. The purpose of this study was to evaluate quality of life, at three months post treatment and the present time. METHODS: A retrospective chart review of all patients admitted for the DHE protocol from 1991 to 1996 revealed 174 cases. Of these, 132 patients were interviewed by phone. RESULTS: The DHE protocol was shown to decrease headache frequency, severity, headache medication use, and absences from work both at three months and the time of interview. CONCLUSION: This study has the largest patient base and the longest follow-up period for the use of DHE for CDH. The results confirm that the DHE protocol is helpful in breaking the cycle of CDH, although the long-term outcomes of this study are more conservative than other studies have reported.