Clinical assessment and treatment of carpal tunnel syndrome in the mucopolysaccharidoses.

The mucopolysaccharidoses (MPS) are a common cause of carpal tunnel syndrome (CTS) in children and adolescents. As the MPS diseases are progressive in nature, it is essential that CTS in these children is readily diagnosed and treated, before damage to the median nerve becomes irreversible. Currently, no standards for diagnosing and treating CTS associated with MPS exist. Proper diagnosis of CTS generally involves the assessment of clinical signs and symptoms, in combination with nerve conduction studies. As the clinical signs and symptoms of CTS described for adults are often absent in children with MPS, early diagnosis of CTS in these children requires recognition of subtle findings such as decreased sweating, nocturnal waking, gnawing of hands, and manual clumsiness. Sensory tests could also be useful for detecting early CTS when the integrity of the nerve is still relatively intact. Nerve conduction velocities, which are the gold standard for diagnosing CTS, can be difficult to perform in patients with MPS and should be adapted to the patients' clinical characteristics such as their abnormally small hands and young age. Ongoing monitoring for CTS is indicated for all MPS patients, including those treated with hematopoietic stem cell transplantation or enzyme replacement therapy.