High prevalence of carpal tunnel syndrome in children with mucopolysaccharidosis type II (Hunter syndrome)

Abstract

Although carpal tunnel syndrome (CTS) is the most common compressive neuropathy seen in the upper extremity of adults, it is rarely seen in children. Several reports have shown that mucopolysaccharidosis type II (Hunter syndrome), a rare genetic disorder, is one of the causes of CTS in children. Usual symptoms of CTS are pain, weakness, and paresthesias in the hand and digits. However, the diagnosis of CTS in Hunter syndrome is often delayed or unrecognized because of atypical symptoms and cognitive impairment. Here, we report the prevalence, clinical manifestation, and nerve conduction profiles of CTS in 45 Hunter syndrome patients. The mean age of the study participants was 117.1 (74.9) months (range: 4-408 months); all patients were male. Forty-three (96.0%) of the 45 patients with Hunter syndrome had CTS. Bilateral CTS was observed in all patients; 73 (82.0%) of the patients' hands had severe degree of CTS. Intriguingly, in contrast with other nerve velocities, decreases in forearm conduction velocities of the median nerve were observed in 28 (31.5%) of 89 hands with CTS. There was a significant difference in age (P < 0.001) between hands with normal, mild, moderate, and severe grades of CTS. The compound muscle action potential and sensory nerve action potential amplitudes of the median nerves decreased with age (CMAP, r = -0.526, P < 0.001; SNAP, r = -0.564, P < 0.001). Early recognition and intervention to ameliorate the symptoms of CTS are important in improving the quality of life of Hunter syndrome patients.

Nerve ultrasound in clinical management of carpal tunnel syndrome in mucopolysaccharidosis

“…One of the problems in MPS is the high prevalence of carpal tunnel syndrome (CTS) in MPS subtypes I, II, and VI, [1][2][3][4] which -if not treated -often results in disabling, severe damage of the median nerve. Most MPS patients, however, do not report typical symptoms of CTS.…”

“…In 20 hands the changes were classified as moderate (1) and in 16 as prominent (2). The mean distal CSA was 14.0mm 2 (SD 12.2mm 2 , range 3-48mm 2 ).…”

“…Multiple organ involvement in the course of mucopolysaccharidoses (MPS) means that patients with this disease need frequent medical screening and followup, particularly for cardiac and pulmonary disease, orthopaedic complications, spinal cord compression, hydrocephalus, and vision and hearing impairment. One of the problems in MPS is the high prevalence of carpal tunnel syndrome (CTS) in MPS subtypes I, II, and VI, [1][2][3][4] whichif not treatedoften results in disabling, severe damage of the median nerve. Most MPS patients, however, do not report typical symptoms of CTS.…”

Ultrasonographic evaluation of the median nerve at the level of the carpal tunnel outlet and mid forearm in patients with type II Mucopolysaccharidosis

“…Studies that have already been published about the CTS in MPS II revealed a frequency of the syndrome as high as 96 % [9].…”

“…The few studies that have been made reveal a high frequency of the CTS in patients with MPS [8,9]. The diagnosis is usually established based on the clinical exam or nerve conduction studies.…”