Laser evoked potentials in amyotrophic lateral sclerosis.

The pathophysiological mechanism of the pain in ALS is still unclear. The aim of the study was to evaluate the laser evoked potentials (LEPs) in ALS patients in relation to their clinical features. Twenty-four ALS patients were selected. Pain features were assessed and their intensity was measured by a 0-10 VAS. LEPs were recorded in all patients and in 23 healthy subjects. The dorsum of both hands was stimulated, at laser stimuli intensity of 7.5 W, with 10s inter-stimulus interval and 25 ms duration. Four electrodes were placed at Cz, T3, T4 and Fz positions, with the reference electrode at the nasion; T3 and T4 electrodes were referred off-line to Fz, in order to detect the N1 component. Latencies of N2, P2 and N1 waves were significantly higher in ALS than in controls. N1 amplitude was significantly increased in ALS patients compared to controls, with a similar trend for the N2-P2 complex. No correlation was found between LEP abnormalities, pain intensity and clinical features. A degeneration of subcortical structures may subtend a delay in the afferent input to the nociceptive cortex in ALS. On the other hand, an increase of pain processing at the cortical level may derive from a potential sensory compensation to motor cortex dysfunction.

Predictors of long survival in amyotrophic lateral sclerosis: a population-based study.

BACKGROUND: Although amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder, some ALS cases can survive beyond 10 years. However, the predictors of long survival in ALS patients remain uncertain. OBJECTIVE: To define clinical predictors of long survival in a cohort of ALS incident cases. METHODS: One hundred-thirty incidents cases, diagnosed in 1998--1999 and classified according to the El Escorial criteria (EEC), were enrolled from a prospective population-based registry established in Puglia, Italy. All but two cases were followed-up until death or November 30, 2006. RESULTS: Thirteen patients (high 10% of the survivors) were classified as long survivors (LS), 13 as short survivors (SS) (low 10%), and 102 as average survivors (AS). LS presented a lower frequency of bulbar onset (8% versus 29% of AS and 39% of SS; p=0.1) and a significantly longer time between symptom onset to diagnosis [(ODI): 13 months versus 10 and 6; p=0.0005]. In multivariate analysis, predictors of long survival were younger age at diagnosis (>65 compared to < or =45 years: odds ratio (OR):18.9; 95%CI: 1.8-194.7; p=0.04), longer interval onset-diagnosis (< or =9 months compared to >9 months, OR: 7.9; 95%CI: 1.3-47; p=0.02) and clinical features with predominant upper motor neuron signs (OR: 8.5; 95%CI: 1.1-64.2; p=0.04). CONCLUSIONS: In this population-based study, younger age, longer interval onset to diagnosis, and clinical features with predominance of upper motor signs predicted long survival, while EEC category at diagnosis did not.

Predictors of delay in the diagnosis and clinical trial entry of amyotrophic lateral sclerosis patients: a population-based study.

BACKGROUND: The El Escorial and the revised Airlie House diagnostic criteria for amyotrophic lateral sclerosis (ALS) were introduced to select patients for clinical trials. Heterogeneity of clinical presentation at onset and delay in diagnosis may decrease the likelihood for trial entry. OBJECTIVE: Identify risk factors for delay in the diagnosis and trial exclusion. METHODS: ALS incident cases were identified with El Escorial (EEC) and Airlie House criteria (AHC) through a population-based registry established in Puglia, Southern Italy, in the years 1998-99. RESULTS: 130 ALS incident cases were diagnosed with a median interval between onset of symptoms and diagnosis of 9.3 months and not different across both EEC and AHC categories. Twenty percent of cases were not eligible for clinical trials according to the AHC. About 5% of subjects in this series died with only lower motor neuron signs. Predictors for delay in the diagnosis were age between 65 and 75 years and spinal onset while fasciculations and cramps as first symptoms were predictors of exclusion from trials. CONCLUSIONS: In this population-based series, diagnostic delay was longer in subjects with spinal onset and age between 65 and 75 and fasciculation as first symptoms. About 80% of incident cases were trial eligible with AHC criteria. However, a significant number of subjects with ALS, characterized by a limited spread of signs, were not trial eligible while alive.