Correlation between Apolipoprotein E genotype and brain metabolism in amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

The aim of the study was to evaluate the metabolic correlates of Apolipoprotein E (APOE) genotype in amyotrophic lateral sclerosis (ALS) and to investigate the role of ε2 as a risk factor for cognitive impairment.

METHODS

A total of 159 ALS cases underwent APOE and ALS-related genes analysis, neuropsychological assessment and cerebral ¹⁸ F-2-fluoro-2-deoxy-D-glucose positron emission tomography. The APOE genotype was regressed against whole brain metabolism as assessed by ¹⁸ F-2-fluoro-2-deoxy-D-glucose positron emission tomography, with age, sex, education, type of onset and C9orf72 status as covariates.

RESULTS

Brain metabolism was significantly positively correlated with APOE genotype from ε2/ε2 to ε3/ε4 in the left prefrontal [Brodmann area (BA) 10], orbitofrontal (BAs 11, 45, 47) and anterior cingulate (BA 32) cortices. There was a tendency to a relative hypometabolism going towards the ε2/ε2 extreme.

CONCLUSIONS

We found a highly significant, relatively lower metabolism in association with the ε2 allele in extra-motor areas typically affected in frontotemporal dementia (left prefrontal, orbitofrontal and anterior cingulate cortices), strengthening the finding of a role of ε2 as a risk factor for cognitive impairment in ALS. Our data suggested a link between cholesterol homeostasis and neurodegeneration.

Spatial epidemiology of amyotrophic lateral sclerosis in Piedmont and Aosta Valley, Italy: a population-based cluster analysis

BACKGROUND AND PURPOSE

The analysis of the spatial distribution of cases could give important cues on putative environmental causes of a disease. Our aim was to perform a spatial analysis of an amyotrophic lateral sclerosis (ALS) cohort from the Piedmont and Aosta Valley ALS register (PARALS) over a 20-year period.

METHODS

The address at the moment of diagnosis was considered for each ALS case. Municipalities' and census divisions' resident populations during the 1995-2014 period were obtained. A cluster analysis was performed adopting both Moran's index and the Kulldorff spatial scan statistic.

RESULTS

A total of 2702 ALS patients were identified. An address was retrieved for 2671 (99%) patients. Moran's index was -0.01 (P value 0.83), thus revealing no clusters. SaTScan identified no statistically significant clusters. When census divisions were considered, Moran's index was 0.13 (P value 0.45); SaTScan revealed one statistically significant small cluster in the province of Alessandria. Here, 0.0099 cases were expected and three cases were observed (relative risk 304.60; 95% confidence interval 109.83-845.88, P value 0.03).

DISCUSSION

Our study showed a substantial homogeneous distribution of ALS cases in Piedmont and Aosta Valley. The population-based setting and the adoption of proper statistical analyses strengthen the validity of our results. Such a finding further suggests the involvement of multiple environmental and genetic factors in ALS pathogenesis.

Genetic counselling in ALS: facts, uncertainties and clinical suggestions

The clinical approach to patients with amyotrophic lateral sclerosis (ALS) has been largely modified by the identification of novel genes, the detection of gene mutations in apparently sporadic patients, and the discovery of the strict genetic and clinical relation between ALS and frontotemporal dementia (FTD). As a consequence, clinicians are increasingly facing the dilemma on how to handle genetic counselling and testing both for ALS patients and their relatives. On the basis of existing literature on genetics of ALS and of other late-onset life-threatening disorders, we propose clinical suggestions to enable neurologists to provide optimal clinical and genetic counselling to patients and families. Genetic testing should be offered to ALS patients who have a first-degree or second-degree relative with ALS, FTD or both, and should be discussed with, but not offered to, all other ALS patients, with special emphasis on its major uncertainties. Presently, genetic testing should not be proposed to asymptomatic at-risk subjects, unless they request it or are enrolled in research programmes. Genetic counselling in ALS should take into account the uncertainties about the pathogenicity and penetrance of some genetic mutations; the possible presence of mutations of different genes in the same individual; the poor genotypic/phenotypic correlation in most ALS genes; and the phenotypic pleiotropy of some genes. Though psychological, social and ethical implications of genetic testing are still relatively unexplored in ALS, we recommend multidisciplinary counselling that addresses all relevant issues, including disclosure of tests results to family members and the risk for genetic discrimination.

ALS clinical trials: do enrolled patients accurately represent the ALS population?

OBJECTIVE

To assess the effect of eligibility criteria in amyotrophic lateral sclerosis (ALS) clinical trials on the representativeness of the enrolled population.

METHODS

Patients enrolled in 8 placebo-controlled clinical trials in our ALS center from 2003 to 2008 were compared 1) to the patients included a prospective epidemiologic register (Piemonte and Valle d'Aosta register for ALS, PARALS) in the same period and 2) the subset of PARALS patients who met the usual criteria for inclusion in clinical trials (PARALS-ct) (definite, probable, probable laboratory-supported ALS; age between 18 and 75 years; disease duration <36 months; vital capacity at diagnosis ≥70%; score ≥3 at the items swallowing and respiratory insufficiency at the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised scale; riluzole therapy).

RESULTS

A total of 164 patients were enrolled in 8 different clinical trials. The PARALS cohort included 813 patients, of whom 539 (66.3%) met the entry criteria for clinical trials. Patients enrolled in clinical trials were different from both epidemiologic cohorts, since they were younger, had a longer diagnostic delay, and were more likely to have a spinal onset, and to be men. Tracheostomy-free survival was significantly longer in the group of patients enrolled in clinical trials (median survival time, trial patients, 3.9 years [95% confidence interval (CI) 3.4-4.4]; PARALS, 2.6 [2.4-2.8]; PARALS-ct, 2.9 [2.7-3.1]).

CONCLUSIONS

Patients enrolled in clinical trials do not satisfactorily represent the ALS population; consequently, the findings of ALS trials lack of external validity (generalizability). Efforts should be made to improve patients' recruitment in trials, particularly enrolling incident rather than prevalent cases.

Anxiety undermines quality of life in ALS patients and caregivers

BACKGROUND

Although depression has been widely studied in amyotrophic lateral sclerosis (ALS), there is little information on anxiety.

OBJECTIVE

To detect anxiety in patients with ALS and their caregivers, comparing the diagnostic and the follow-up phases of the disease and assessing its impact on quality of life (QoL).

METHODS

Anxiety has been evaluated with the State and Trait Anxiety Inventory in a series of 75 consecutive ALS patients and their primary caregivers. Anxiety has been related to depression, QoL, and satisfaction with life.

RESULTS

In patients, state anxiety was significantly higher during the diagnostic phase, whilst in caregivers it was similar in the two phases. Patients' state anxiety was related to depression, shorter disease duration and lower satisfaction with life. Caregivers' state anxiety was related to their trait anxiety. Whilst in patients QoL and satisfaction with life were similar in the two phases, in caregivers there was a significant decrease of satisfaction with life in the follow-up phase.

CONCLUSIONS

Treating neurologists should recognize that the diagnostic phase and the earlier period after the diagnosis is characterized by a high level of anxiety both in ALS patients and in their caregivers, and should propose pharmacological and psychological interventions to relieve this highly distressing disturbance.

ALS patients and caregivers communication preferences and information seeking behaviour

To evaluate information preferences and information seeking behaviour in ALS patients and caregivers. Sixty ALS patients and caregivers couples were interviewed using a structured questionnaire about the content of diagnosis communication and their information seeking behaviour. The patients (35 men and 25 women) had a mean age of 63.4 years (SD 9.5). The caregivers (21 men and 39 women) had a mean age of 53.3 years (SD 14.9). The overall satisfaction with bad news communication and the impression that the physician had understood their feelings were higher amongst patients. Both parties indicated that the most important aspects to be informed were current researches, disease-modifying therapies and ALS outcome. Approximately 55% of patients and 83.3% of caregivers searched for information from sources outside the healthcare system. The most frequently checked source was internet, although its reliability was rated low. The caring neurologist should better attune the content of communication to patients' and caregivers' preferences, trying to understand what they want to know and encouraging them to make precise questions. Health professionals should be aware that ALS patients and caregivers often use internet to obtain information and should help them to better sort-out and interpret the news they found.