Dissecting pain processing in adolescents with Non-Suicidal Self Injury: Could suicide risk lurk among the electrodes?

BACKGROUND: Although non-suicidal self-injury (NSSI) disorder is highly prevalent in adolescents, its relationship with pain system function and suicidality is still controversial. The present study was designed to assess the function of the nociceptive afferent pathways and the endogenous pain modulation in adolescent patients with NSSI and to longitudinally register any suicide attempt, describe its frequency and find a possible association between suicide, neurophysiological measures and psychological measures. METHODS: We enrolled 30 adolescents suffering from NSSI and 20 age- and gender-matched healthy controls. Patients underwent a comprehensive psychological evaluation. Each participant underwent thermal pain thresholds of the quantitative sensory testing, laser-evoked potential recording to study the ascending nociceptive pathway and the conditioned pain modulation testing to test the endogenous pain modulation. RESULTS: We found that patients with NSSI had a reduced amplitude of the N2 component of laser-evoked potentials and an abnormal conditioned pain modulation. The amplitude of the N2 was associated with suicidal risk. CONCLUSIONS: The deficit of the endogenous pain modulation likely depends on a saturation due to continuous pain solicitation. The strong association of a reduced amplitude of the N2 component with suicide suggests that it may serve as a possible biomarker in self-harming adolescents. SIGNIFICANCE: The present study identifies the N2 component of laser-evoked potentials as a possible neurophysiological biomarker of suicidal risk in patients with non-suicidal self-injury, therefore, raising the possibility for a non-invasive test to identify subjects at higher risk of suicide among self-harming patients.

The outcome of white matter abnormalities in early treated phenylketonuric patients: A retrospective longitudinal long-term study.

BACKGROUND: Pathogenesis and clinical consequences of white matter abnormalities on magnetic resonance imaging (MRI) in phenylketonuric (PKU) patients are incompletely known. OBJECTIVE: To study white matter alterations progression and outcome and its relationships with phenylalanine levels and intelligence quotient (IQ) in early treated PKU subjects who underwent serial MRIs during a prolonged follow-up. METHODS: 47 early treated PKU patients (mean age 25.1 ± 5.6 years; range 12-37 years) have been enrolled when two or more consecutive brain MRIs, a complete biochemical history, and MRI-concurrent blood phenylalanine levels were available. The severity and extension of white matter abnormalities were expressed in a computed score. Consecutive IQ assessments were available in 24 patients. We analyzed intra- and interindividual white matter alterations variations and their relationship with quality of biochemical control and cognitive outcome. RESULTS: Early treated PKU patients showed a high rate of white matter alterations with a relevant increase in frequency/severity from the second decade of life onwards. Age and quality of dietary control before or between subsequent examinations showed an independent cumulative effect on white matter alterations outcome. No significant association was found between white matter alterations and cognitive outcome. A remarkable interindividual variability was found and several patients disclosed incongruity between the trajectory of white matter alterations and biochemical control. About 30% of white matter alterations variability remains unexplained by the disease-associated determinants. CONCLUSIONS: The evolution of white matter alterations is not significantly affected by intellectual outcome and is affected by aging, chronic exposure to phenylalanine, and unknown individual factors.