The trajectory of autism symptoms over time differed in different domains, suggesting that they may be, at least in part, separable. Variability in language, NVIQ and symptom severity increased over time. Caution is required when interpreting the findings from assessments of children with autism at age 2 years. At this age measures of rate of non-verbal communication might be more informative than scores on standard psychometric tests. Predictive validity of assessments at age 3 years was greater.

Our data support the hypothesis that tau and alpha-synuclein are involved in shared or converging pathways in the pathogenesis of PD, and suggest that the tau inversion influences the development of cognitive impairment and dementia in patients with idiopathic PD. These findings have potentially important implications for understanding the interface between tau and alpha-synuclein pathways in neurodegenerative disorders and for unraveling the biological basis for cognitive impairment and dementia in PD.

We investigated the utility of the Cambridge Behavioural Inventory (CBI), a carer-completed questionnaire, in a large cohort with Parkinson's disease (PD) (n = 215). In a sub-cohort of 112 patients with PD, the CBI was found to be a valid instrument compared with the Neuropsychiatric Inventory, PDQ-39 and UPDRS, with high internal consistency. Furthermore, in the whole cohort, the CBI was sensitive to changes in behaviour with disease progression. Comparison between CBI scores in PD and other neurodegenerative diseases, including Huntington's disease (HD) (n = 75), Alzheimer's disease (AD) (n = 96) and frontal variant frontotemporal dementia (fvFTD) (n = 64), revealed distinct profiles for each disease. Predominant deficits were "sleep"' and "self care" in PD; "memory" in HD and AD; and "motivation" and "stereotypic behaviours" in fvFTD. The CBI is a robust, easy-to-use and valid instrument, which has the capacity to discriminate between neurodegenerative diseases, and may be of value in monitoring therapeutic interventions.

Four separate categories of description relating to limbs and locomotion are recognized. Gross variation in limb structure characterizes descriptions at the ordinal level. Detailed morphology of the external features, and of limb bones, extends diagnosis to the familial and generic levels. The gaits of mammals describe locomotory behaviour.In all of these categories, definitions tend to be imprecise and the terminology to be misapplied. This descriptive terminology is critically reviewed in the light of advancing research and a synthetic framework for ordering future studies is proposed.

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