The range and clinical impact of cognitive impairment in French patients with ALS: A cross-sectional study of neuropsychological test performance
AP-HP, Centre référent maladies rares SLA, Département de Neurologie. Amyotrophic Lateral Sclerosis
(Impact Factor: 2.37).
05/2011; 12(5):372-8. DOI: 10.3109/17482968.2011.580847
Our objective was to assess the spectrum and clinical associations of cognitive impairment in French patients with ALS, and determine the effect of cognitive impairment on survival in this population. One hundred and thirty-one patients were enrolled in a cross-sectional cohort study of neuropsychological test performance. ANOVA and χ(2) tests assessed differences in clinical characteristics between impaired and unimpaired patients; multiple regression determined which features contributed most strongly to cognitive status, and Cox models compared survival. Fifty-three patients (40%) were categorized as cognitively impaired based on test performance. Thirteen (10%) patients had frontotemporal dementia (FTD) clinically; all scored in the moderate to severely impaired range on testing. Impaired patients had less education (p = 0.001), and severely impaired patients were more likely to have bulbar onset than unimpaired patients (p < 0.001). Severe cognitive impairment predicted shorter survival (p = 0.007), even when controlled for motor severity (p = 0.001). In summary, 10% of a consecutive series of French ALS patients had overt dementia and 40% were cognitively impaired by neuropsychological testing. We conclude that lower education level and possibly bulbar-onset ALS were associated with impairment. As in other causes of dementia, higher education attainment may protect against clinical cognitive deterioration in ALS. French patients with severe cognitive impairment have shorter survival time.
Available from: Pierre-François Pradat
- "Autopsy studies have shown that degeneration of central nervous system structures is not restricted to the primary motor cortex and the pyramidal tract [5–8]. In addition to motor signs, cognitive signs are detected by neuropsychological tests in about 50% of patients with sporadic ALS and typical frontotemporal dementia (FTD) occurs in approximately 10% of the patients [9, 10]. Association of ALS and FTD occurs in the majority of C9ORF72-linked familial ALS (FALS) [11, 12]. "
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ABSTRACT: Neuroimaging allows investigating the extent of neurological systems degeneration in amyotrophic lateral sclerosis (ALS). Advanced MRI methods can detect changes related to the degeneration of upper motor neurons but have also demonstrated the participation of other systems such as the sensory system or basal ganglia, demonstrating in vivo that ALS is a multisystem disorder. Structural and functional imaging also allows studying dysfunction of brain areas associated with cognitive signs. From a biomarker perspective, numerous studies using diffusion tensor imaging showed a decrease of fractional anisotropy in the intracranial portion of the corticospinal tract but its diagnostic value at the individual level remains limited. A multiparametric approach will be required to use MRI in the diagnostic workup of ALS. A promising avenue is the new methodological developments of spinal cord imaging that has the advantage to investigate the two motor system components that are involved in ALS, that is, the lower and upper motor neuron. For all neuroimaging modalities, due to the intrinsic heterogeneity of ALS, larger pooled banks of images with standardized image acquisition and analysis procedures are needed. In this paper, we will review the main findings obtained with MRI, PET, SPECT, and nuclear magnetic resonance spectroscopy in ALS.
Available from: Francisco Javier Rodriguez de Rivera
- "Although cognitive impairment was initially considered anecdotal, signs of fronto-temporal dysfunction can be observed in up to 50% of ALS patients. Ten to 15% of ALS patients meet diagnostic criteria for fronto-temporal dementia   . "
- "Cognitive impairment in ALS was described by Pierre Marie in the 19 th century , but was considered uncommon until recently. Overt frontotemporal dementia (FTD) occurs in approximately 15% of people with ALS, but up to 50% are classified as impaired if measured by neuropsychological tests  . Primary progressive aphasia, semantic dementia and the behavioral variant are subtypes of FTD that affect executive function, language, judgment, personality, and behavior. "
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ABSTRACT: Amyotrophic lateral sclerosis (ALS), first described by Jean-Martin Charcot in the 1870s, is an age-related disorder that leads to degeneration of motor neurons. The disease begins focally in the central nervous system and then spreads relentlessly. The clinical diagnosis, defined by progressive signs and symptoms of upper and lower motor neuron dysfunction, is confirmed by electromyography. Additional testing excludes other conditions. The disease is heterogeneous, but most patients die of respiratory muscle weakness less than 3 years from symptom-onset. Like other age-related neurodegenerative diseases, ALS has genetic and environmental triggers. Of the five to 10% of cases that are inherited, mutations have been discovered for a high proportion. In addition to genetic factors, age, tobacco use, and athleticism may contribute to sporadic ALS, but important etiologies are unidentified for most patients. Complex pathophysiological processes, including mitochondrial dysfunction, aggregation of misfolded protein, oxidative stress, excitotoxicity, inflammation and apoptosis, involve both motor neurons and surrounding glial cells. There is clinical and pathological overlap with other neurodegenerative diseases, particularly frontotemporal dementia. The mechanisms leading to disease propagation in the brain are a current focus of research. To date, one medication, riluzole, licensed in 1996, has been proved to prolong survival in ALS. Numerous clinical trials have so far been unable to identify another neuroprotective agent. Researchers now aim to slow disease progression by targeting known pathophysiological pathways or genetic defects. Current approaches are directed at muscle proteins such as Nogo, energetic balance, cell replacement, and abnormal gene products resulting from mutations. Until better understanding of the causes and mechanisms underlying progression lead to more robust neuroprotective agents, symptomatic therapies can extend life and improve quality of life. Palliative care programs such as hospice give emotional and physical support to patients and families throughout much of the disease course.
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