Stress and dementia: the role of the hypothalamicpituitary-adrenal axis.

Hippocampus plays a crucial role in learning and memory and, in spite of its remarkable plasticity, it is also particularly sensitive to stress hormones due to its high concentration of corticosteroid receptors. Indeed, adrenal steroids modulate hippocampal plasticity, acting on excitability and long term potentiation or depression. By a chronobiological approach, we studied the cortisol and DHEAS secretion in clinically healthy old subjects and in age-matched demented patients, including both the degenerative and the vascular type. When compared to young controls, both clinically healthy elderly subjects and demented patients, particularly those with AD, had significantly higher cortisol levels at night time, i.e. at the moment of the maximal sensitivity of HPA axis to stimulatory or inhibitory inputs. At the same time, a clear age- and disease-dependent reduction of DHEAS secretion was found. Thus the cortisol to DHEAS molar ratio was significantly higher in healthy old subjects, and even more in demented patients, when compared to young controls, and significantly linked to both age and cognitive impairment. Finally, the quantitative and qualitative changes of the adrenal secretory pattern were significantly correlated with the decline of hippocampal volumes, measured by MRI. In conclusion, several lines of evidence deal with a pathogenetic role of stress hormones in the occurrence and progression of cognitive disorders in elderly subjects. The consequent hippocampal neuronal impairment may in turn be responsible for the continuous activation of HPA axis and the increased hypothalamic expression of vasopressin and corticotropin releasing hormone.

Survival of 793 patients with amyotrophic lateral sclerosis diagnosed over a 28-year period.

We reviewed retrospectively 793 consecutive patients discharged with ALS diagnosis between 1971 and 1998 to identify survival predictors. Vital status in July 2001 was known for all patients. Mean age at onset was 56 (SD 11.7) years and mean age at diagnosis was 57.4 (SD 11.5) years. Onset symptoms were bulbar in 20.8% of patients. The median survival time from symptoms onset was 2.9 years (95% CI 2.7-3.1). Survival from onset was 93% after one, 48% after three and 24% after five years. Median survival was shorter in patients with time between onset and diagnosis <12 months than in those diagnosed> 23 months; (2.1 years vs. 5.9 years; P<0.001). Patients with onset after age 65 had a 4.2 times greater risk of death than patients less than 40 years. Bulbar onset was associated with 1.4 times greater risk of death than spinal onset. Patients diagnosed after 1990 had longer median survival (3.3 years) than those diagnosed in 1971-1979 (2.4 years) (P<0.001). As expected, age, bulbar onset and short time from onset to diagnosis were independent predictors of survival. We also found a significant increase in survival over time, probably due to improved comprehensive treatment of ALS patients in Italy.

Reliability of the El Escorial diagnostic criteria for amyotrophic lateral sclerosis.

BACKGROUND: The El Escorial diagnostic criteria are the most commonly used in clinical studies and therapeutic trials in patients with amyotrophic lateral sclerosis (ALS). The accuracy of the El Escorial criteria was tested in clinical practice, but the reliability is unknown when the diagnosis of ALS must be assessed on the basis of medical records. OBJECTIVE: To assess the reliability of the El Escorial criteria for the diagnosis of ALS in different settings. DESIGN AND METHODS: Semistructured forms were used to include the main diagnostic information on 20 patients with definite (n = 6), probable (n = 6), possible (n = 6), and suspected ALS (n = 2) and 19 patients with clinical conditions considered in the differential diagnosis. Agreement was tested by comparing the diagnosis made by the attending physician (the 'gold standard') with that of 4 raters with different backgrounds: a teaching neurologist with research and practical experience in the field of motor neuron disorders, a neurologist with specific interest in motor neuron disorders and neurophysiological background, a neurophysiologist, and a general neurologist with only occasional ALS patients. Sources of disagreement were discussed and the agreement was tested further on the medical records of 98 additional cases taken from an ongoing ALS registry. Eight additional cases (ALS: 4; other conditions: 4) were examined directly by the 4 raters. RESULTS: The interrater agreement on the medical records was poor (overall kappa 0.05-0.29). When the differential diagnosis was made between ALS (all diagnostic levels) and other conditions, interrater agreement was at best modest, with moderate variations when raters were compared in pairs (kappa 0.03-0.58) and when each rater was compared with the physician (kappa 0.27-0.51). Agreement was higher after direct examination of the patients (kappa 0.33-1) and increased significantly on the medical records after training (overall kappa 0.52-0.79). However, concordance was low (overall kappa 0.08-0.36), even after training, at the lowest diagnostic level (definite to suspected ALS vs. other conditions). CONCLUSIONS: The El Escorial criteria are a poor diagnostic indicator when patients' records are examined. Although medical education significantly improves the reliability of the criteria, concordance is still modest when the diagnosis includes suspected ALS.