hipotonia

Hipotonia, or hypotonia, is a medical condition characterized by decreased muscle tone or tension. In infants it is commonly referred to as a floppy infant syndrome when present since birth. Hipotonia may be central (nervous system) or peripheral (muscle or nerve), and it can be congenital or acquired later in life. Central hipotonia reflects central nervous system dysfunction such as brain malformations, hypoxic injury, or neurodevelopmental disorders (for example cerebral palsy). Peripheral hipotonia arises from neuromuscular disorders, including muscular dystrophies, spinal muscular atrophy, congenital myopathies, or neuropathies, as well as metabolic or endocrine diseases.

Clinical features include reduced resistance to passive movement, poor head control, poor suck and swallow in infants, delayed motor milestones, and reduced reflexes depending on the cause. In central hipotonia reflexes may be normal or brisk, whereas peripheral etiologies more often show decreased or absent reflexes; muscle atrophy and fatigability may be present.

Evaluation involves a detailed history and exam, assessment of developmental milestones, and targeted tests such as EMG/NCS, genetic panels, metabolic workup, neuroimaging (MRI), and possibly muscle biopsy.

Management focuses on treating the underlying cause and supportive therapies: physical and occupational therapy to improve tone and motor skills, speech therapy if needed, nutritional support, assistive devices, and management of complications (respiratory therapy, scoliosis surveillance).

Prognosis varies with etiology and severity; some children show gradual improvement, while others have persistent hipotonia with lifelong needs.