Core Concept: Persistent difficulty in language comprehension (receptive) or production (expressive); nonverbal communication (eye contact, gestures, joint attention) remains intact.
High-Yield Milestones: Failure to say single words by 12–15 mo; <50 words or no 2-word combinations by 24 mo.
Initial Next Step in Workup: Formal audiological evaluation (mandatory to rule out sensory or conductive hearing loss in all pediatric language delays).
Autism Spectrum Disorder (ASD): Impaired social reciprocity, abnormal nonverbal communication (poor eye contact), and restricted/repetitive behaviors (absent in isolated language disorder).
Speech Sound Disorder: Impaired motor articulation/phonology; vocabulary and grammar comprehension are completely normal.
Selective Mutism: Speaks normally at home, refuses to speak in specific social settings (e.g., school); associated with social anxiety.
Landau-Kleffner Syndrome: Regression of previously acquired language in a child aged 3–7; confirmed with epileptiform discharges on sleep EEG.
Intellectual Disability (ID): Deficits across all domains (language, motor, nonverbal cognition, adaptive functioning); nonverbal IQ < 70.
Management:
Age <3 years: Immediate referral to state-sponsored Early Intervention Services (do not “wait and see”).
Age ≥3 years: School-district Individualized Education Program (IEP).
Ongoing targeted Speech-Language Therapy.
Tympanostomy tubes only if persistent bilateral otitis media with effusion (>3 mo) causing conductive hearing loss.
Marked discrepancy: Normal or above-average IQ with substantially impaired academic performance.
Symptoms present during early school years and cause significant academic/occupational impairment.
Subtypes:
Reading (Dyslexia): Most common (~80%); impaired word decoding, reading rate/fluency, and comprehension.
Written Expression (Dysgraphia): Deficits in spelling accuracy, grammar, punctuation, and text organization.
Mathematics (Dyscalculia): Deficits in number sense, calculation accuracy, and mathematical reasoning.
Diagnostic Workup:
Initial screen: Routine vision and hearing testing (rule out sensory impairments).
Confirmatory: Standardized psychoeducational/neuropsychological testing (cognitive IQ battery + academic achievement battery demonstrating a specific achievement gap).
High-Yield Differential Diagnosis:
ADHD: Inattention/hyperactivity occurs across multiple settings (home and school); executive dysfunction rather than specific learning defect (often comorbid in ~30–40%).
Intellectual Disability: Global impairment across intellectual domains (IQ < 70) with concurrent deficits in adaptive functioning.
Sensory/Environmental deficits: Lack of educational opportunity or language barrier (rapidly corrects with appropriate instruction).
Management:
Primary: Individualized Education Program (IEP) or 504 Plan with tailored remediation (e.g., phonics-based instruction for dyslexia, speech-to-text software for dysgraphia).