Impaired spatial working memory is a core cognitive deficit observed in people with 22q11 Deletion syndrome (22q11DS) and has been suggested as a candidate endophenotype for schizophrenia. However, to date, the neuroanatomical mechanisms describing its structural and functional underpinnings in 22q11DS remain unclear. We quantitatively investigate the cognitive processes and associated neuroanatomy of spatial working memory in people with 22q11DS compared to matched controls. We examine whether there are significant between‐group differences in spatial working memory using task related fMRI, Voxel based morphometry and white matter fiber tractography.
Materials and Methods:
Multimodal magnetic resonance imaging employing functional, diffusion and volumetric techniques were used to quantitatively assess the cognitive and neuroanatomical features of spatial working memory processes in 22q11DS. Twenty‐six participants with genetically confirmed 22q11DS aged between 9 and 52 years and 26 controls aged between 8 and 46 years, matched for age, gender, and handedness were recruited.
People with 22q11DS have significant differences in spatial working memory functioning accompanied by a gray matter volume reduction in the right precuneus. Gray matter volume was significantly correlated with task performance scores in these areas. Tractography revealed extensive differences along fibers between task‐related cortical activations with pronounced differences localized to interhemispheric commissural fibers within the parietal section of the corpus callosum.
Abnormal spatial working memory in 22q11DS is associated with aberrant functional activity in conjunction with gray and white matter structural abnormalities. These anomalies in discrete brain regions may increase susceptibility to the development of psychiatric disorders such as schizophrenia.
This study examined the psychiatric and neuropsychological profiles of people with psychogenic nonepileptic seizures (PNES).
Twenty-people who had been diagnosed with psychogenic nonepileptic seizures (PNES), but not epilepsy, were recruited into this study. A healthy control group was also recruited and was matched for age and gender. All participants underwent structured psychiatric assessment and psychometric assessment. Neuropsychological assessment was carried out using the Cambridge Neuropsychological Test Battery (CANTAB) after participants passed the Medical Symptom Validity Test (MSVT) of effort.
One patient failed the MSVT and was excluded from the analysis. Therefore, data from 19 people with PNES and their matched healthy controls were analyzed. Compared with controls, people with PNES had significantly higher levels of depressive symptoms, anxiety symptoms, dissociative experiences, and alexithymic traits. In addition, people with PNES had impairments in spatial working memory and attention when compared with healthy controls.
To our knowledge, this is the first study to report that, compared with controls, people with PNES have abnormal cognitive functioning after controlling for effects of effort and FSIQ. People with PNES also have high levels of anxiety, depressive, and dissociative symptoms. In addition, they appear to particularly focus on health problems and show evidence of chronic emotional dysregulation. Further studies are required to replicate our results and to help clarify the pathogenic mechanisms underlying PNES.