The etiology of pediatric hydrocephalus across Asia: a systematic review and meta-analysis.

OBJECTIVE: Despite the high prevalence and significant implications of pediatric hydrocephalus, the etiological distribution of pediatric hydrocephalus across the diverse Asian demographic is poorly understood. This study aimed to inform clinical guidelines and public health decisions by identifying the etiological distribution of pediatric hydrocephalus across Asia. METHODS: In this systematic review and meta-analysis, the authors searched EMBASE, MEDLINE, CENTRAL, Global Health, Global Index Medicus, and Scopus, with no language restriction, from inception to January 27, 2023. Observational or experimental studies with pediatric data on the causes of hydrocephalus in a country within Asia were included. Pooled proportions of postinfectious hydrocephalus, nonpostinfectious hydrocephalus, and hydrocephalus related to spinal dysraphism were calculated using a random-effects model. Subgroup analyses were performed on prespecified moderators. Methodological study quality was assessed using the modified Newcastle-Ottawa Score and Cochrane's risk-of-bias tool as per the registered protocol on PROSPERO. RESULTS: The search yielded 5110 results, for which 79 articles were included, with data on 11,529 children from 18 Asian countries. The pooled proportion of nonpostinfectious hydrocephalus was 29.0% (95% CI 22.9-35.5); postinfectious hydrocephalus was 10.7% (95% CI 7.7-14.1); and hydrocephalus secondary to dysraphism was 7.6% (95% CI 5.1-10.5). The pooled proportion of postinfectious hydrocephalus was greatest in lower-middle-income countries (19.2% [95% CI 12.8-26.3]). There was a negative association between the proportion of postinfectious hydrocephalus and Human Development Index (-1.45 [95% CI -2.21 to -0.69]; p < 0.001); urbanization of the country (-0.008 [95% CI -0.012 to -0.004]; p < 0.001); and increasing distance from the equator (-0.016 [95% CI -0.026 to -0.006]; p = 0.002). The pooled proportion of nonpostinfectious hydrocephalus was greatest in high-income countries (36.7% [95% CI 27.6-46.3]). Certain etiologies of pediatric hydrocephalus were more common in different cultural regions, with postinfectious hydrocephalus most common in South Asia (23.2% [95% CI 15.8-31.5]); nonpostinfectious in East Asia (38.3% [95% CI 26.6-50.7]); and dysraphism in West Asia (11.9% [95% CI 6.4-18.8]). CONCLUSIONS: Geographic and economic characteristics are associated with the etiological distribution of pediatric hydrocephalus in Asia, with implications for prevention and management strategies. The large proportion of hydrocephalus cases in which the etiology was unclear highlights the need for both improved diagnostics as well as clear and strict universal guidelines on the etiological classification of hydrocephalus.

Sodium-calcium exchanger-3 regulates pain "wind-up": From human psychophysics to spinal mechanisms.

Repeated application of noxious stimuli leads to a progressively increased pain perception; this temporal summation is enhanced in and predictive of clinical pain disorders. Its electrophysiological correlate is "wind-up," in which dorsal horn spinal neurons increase their response to repeated nociceptor stimulation. To understand the genetic basis of temporal summation, we undertook a GWAS of wind-up in healthy human volunteers and found significant association with SLC8A3 encoding sodium-calcium exchanger type 3 (NCX3). NCX3 was expressed in mouse dorsal horn neurons, and mice lacking NCX3 showed normal, acute pain but hypersensitivity to the second phase of the formalin test and chronic constriction injury. Dorsal horn neurons lacking NCX3 showed increased intracellular calcium following repetitive stimulation, slowed calcium clearance, and increased wind-up. Moreover, virally mediated enhanced spinal expression of NCX3 reduced central sensitization. Our study highlights Ca2+ efflux as a pathway underlying temporal summation and persistent pain, which may be amenable to therapeutic targeting.