DOI: 10.36347/sjams.2020.v08i09.025

Pages: 2106-2112

Learning Disability is a type of neurodevelopmental disorder which affects nearly 5% of school-aged children globally. It affects acquisition, organization, retention, comprehension or use of both verbal and nonverbal information. Children with LD have average or above-average IQ. There are many types of LD. Classification of LD is based on (a) Information processing and (b) By function impairment. LD can be classified into four stages input, integration, storage and output based on information processing. By function impaired there are Dyslexia, Dysgraphia, Dyscalculia, Auditory and Visual Processing Disorder, Nonverbal LD, Dyspraxia and Dysphasia. LD is neurobiological in origin. Both Herditary and environmental factors contribute to its pathophysiology. Some possible risk factors include maternal illness, fetal exposure to alcohol, and use of toxic drugs during pregnancy, complicated pregnancy or delivery and neonatal problems. There are 5 models through which the etiology of LD can be explained namely Difference Model, Deficit Model, Delay Model, Disruption Model and Personal-Historical Model. These models are not mutually exclusive. Neurphysiological and Neuroanatomical studies of brain of dyslexic persons have shown malformations predominantly on the left cerebral cortex. Corticostriatal system disorder is proposed in pathogenesis of LD. Evaluation of a child with LD needs a multidisciplinary approach. Diagnostic evaluation of LD is a sequential process involving Speech and language, cognitive, educational, medical, and psychologic evaluations along with clinical assessment of LD criteria. NIMHANS has developed an index to assess children with LD. Understanding etiology and pathogenesis will help in early identification and early intervention.