Becker's Muscular Dystrophy
Author:
Pediatric Oncall
Question
A 12 year old boy born of non consanguineous marriage presented with gradual weakness of all 4 limbs for 3 years. Weakness initially started in both legs with clumsiness of gait and frequent falls and inability to get up from sitting position. Now since the past 1 year, the child is not able to walk or stand and there is now weakness of upper limbs with inability to lift heavy objects. There is no similar complaint in family. He is 4th of 4 children and all the 3 elder siblings are girls and are asymptomatic.
On examination, he had pseudohypertrophy of calves with hypotonia. Power was 2/5 at the hip and at the shoulder joint and 3/5 at wrist, ankles, knees and elbows. He had absent reflexes with planters’ flexors. Investigations showed elevated CPK levels (CPK = 2906 IU/L). His blood analysis for Xp21 deletion proved a diagnosis of Becker’s muscular dystrophy (BMD).
What are the associated problems in this disease?
What are the associated problems in this disease?
Expert Opinion :
The associated problems with BMD are:
• Dilated cardiomyopathy
• Swallowing problems due to weakness of muscles of mastication
• Recurrent aspiration pneumonia from progressive dysphagia
• Constipation
• Muscle pain, prolonged fatigue and myoglobinuria on overuse of muscles.
• Progressive scoliosis and contracture formation
• Risk of malignant hyperthermia (especially with anesthesia)
• Restrictive lung disease due to weakness of muscles of respiration
Dilated cardiomyopathy with congestive heart failure manifests in men at age 20-40 years. Hence screening with echocardiography may be required yearly. Also regular physiotherapy to prevent contractures and deformities to maintain functional mobility and independent activities is necessary. Speech therapist should evaluate for dysphagia and specific food textures and liquids should be avoided to prevent aspiration. Anesthesia should be given with caution to prevent malignant hyperthermia. Expiratory volumes may be monitored by spirometry and decreasing volumes may need further evaluation by pulmonary function tests to determine need for ventilation.