Language impairment in Huntington's disease

Language alterations in Huntington's disease (HD) are reported, but their nature and correlation with other cognitive impairments are still under investigation. This study aimed to characterize the language disturbances in HD and to correlate them to motor and cognitive aspects of the disease. We studied 23 HD patients and 23 controls, matched for age and schooling, using the Boston Diagnostic Aphasia Examination, Boston Naming Test, the Token Test, Animal fluency, Action fluency, FAS-COWA, the Symbol Digit Modalities Test, the Stroop Test and the Hooper Visual Organization Test (HVOT). HD patients performed poorer in verbal fluency (p<0.0001), oral comprehension (p<0.0001), repetition (p<0.0001), oral agility (p<0.0001), reading comprehension (p=0.034) and narrative writing (p<0.0001). There was a moderate correlation between the Expressive Component and Language Competency Indexes and the HVOT (r=0.519, p=0.011 and r=0.450, p=0.031, respectively). Language alterations in HD seem to reflect a derangement in both frontostriatal and frontotemporal regions.

Diagnosis and biomarkers of predementia in Alzheimer's disease

In view of the growing prevalence of Alzheimer's disease (AD) worldwide, there is an urgent need for the development of better diagnostic tools and more effective therapeutic interventions. At the earliest stages of AD, no significant cognitive or functional impairment is detected by conventional clinical methods. However, new technologies based on structural and functional neuroimaging, and on the biochemical analysis of cerebrospinal fluid (CSF) may reveal correlates of intracerebral pathology in individuals with mild, predementia symptoms. These putative correlates are commonly referred to as AD-related biomarkers. The relevance of the early diagnosis of AD relies on the hypothesis that pharmacological interventions with disease-modifying compounds are likely to produce clinically relevant benefits if started early enough in the continuum towards dementia. Here we review the clinical characteristics of the prodromal and transitional states from normal cognitive ageing to dementia in AD. We further address recent developments in biomarker research to support the early diagnosis and prediction of dementia, and point out the challenges and perspectives for the translation of research data into clinical practice.