Case report: Chronic pain in a pediatric patient with late-onset pompe disease

Abstract

Pompe disease (PD) is a rare inherited metabolic disorder of deficient or absent acid alpha-glucosidase (GAA), resulting in defective lysosomal glycogen catabolism. Muscle weakness, respiratory deficiency and gastrointestinal symptoms are commonly monitored in PD. However, pain and associated psychological symptoms are less focused upon. A pediatric patient with late-onset Pompe disease (LOPD) comorbid with chronic pain is presented. Symptoms of pain in the feet were first reported between 6 and 7 years of age and were attributed to growing pains. Following progression of lower body pain, weakness, fatigue, and difficulties with ambulation, a thorough clinical assessment including genetic testing was performed, which led to a diagnosis of LOPD at 9 years of age. ERT with recombinant human alglucosidase alfa was subsequently started. The patient's clinical status is compounded by depressed mood, anxiety, and attention deficit hyperactivity disorder, which may further exacerbate pain. A multidisciplinary pain treatment approach consisting of orthopedics, physical therapy, and psychosocial therapy aimed at enhancing pain coping skills is described for this LOPD patient. This case highlights the need for a greater understanding of pain generation and identification of optimized pain treatment approaches in children with LOPD that can be implemented alongside ERT.

Keywords: ADHD; analgesia; depression; lysosomal storage disease; pain; pompe disease.

Figure 1

Clinical history and timeline.

Figure 2

Evaluation of psychological and physical factors: (A) the patient shows higher level of depression, stress, anxiety, and sleep disturbances, and reduced quality of peer relationships, physical functioning, cognitive functioning, and mobility compared to the general population when assessed by patient-reported outcomes measurement information system (PROMIS) questionnaires. (B) On the NIH Toolbox Cognition Battery, the Total Composite Score and Early Childhood Composite scores factor in the Fluid Composite and Crystalized Composite Score to assess general cognitive function. For NIH Toolbox, T scores were corrected for gender, age, ethnicity, and education level. (C) Assessment of motor functioning utilizing the NIH Toolbox Motor Battery, evaluating dominant and nondominant function where accessible. On the 4 m Walk Gait Test, the patient scored (0.98 m/s) slightly below the age and gender-corrected mean (1.05 m/s).