Correspondence Address:
Dr. Lokesh Saini
Pediatric Neurology Unit, Department of Pediatrics, Advanced Pediatric Centre, Post Graduate Institute of Medical Education and Research, Chandigarh.
India

Full Text



A 7-year-old boy presented with isolated motor development delay and toe-walking. He was born preterm (32 weeks), appropriate for gestational age and the rest of the antenatal and perinatal history was noncontributory. He could walk independently but had difficulty while running. He had no difficulty in getting up from the floor or climbing stairs. There was no history suggestive of involvement of neck, bulbar, facial, and proximal muscles of the upper limbs. Examination revealed normal head circumference, bilateral calf hypertrophy [Figure 1], and hyperreflexia at both knees with fixed contractures of bilateral ankles with an average intelligence quotient. He did not have an evident spasticity at joints (besides ankle with fixed contractures). A clinical diagnosis of spastic diplegia was confirmed. Neuroimaging revealed altered periventricular and peritrigonal white matter signal intensities suggestive of periventricular leukomalacia. Creatine kinase levels were within normal limits.{Figure 1}

Spastic cerebral palsy (CP) is a group of nonprogressive motor disorder resulting from an insult to the growing brain. Children with spastic diplegic CP have a reduced medial gastrocnemius volume, which contributes to muscle weakness and loss of motor function.[1],[2] However, in some children, the calf muscles might undergo hypertrophy.[3] The calf hypertrophy in children with spastic CP is due to the accumulation of hydroxyproline (aminoacid exclusive to collagen) in and around the perimysium and endomysium of the muscles.[3] The synthesis of collagen depends on the neuronal activity, which brings changes in the structural and skeletal architecture of the skeletal muscles in children with spastic diplegia. The amount of collagen deposited correlates well with the severity of the disorder and plays a role in the development of contractures by forming cross-links.[3],[4]

Bilateral calf hypertrophy (absolute/relative) has been typically described in neuromuscular disorders such as Duchenne and Becker muscular dystrophies, Spinal muscular atrophy (IIIa/IIIb), Pompe disease, sarcoglycanopathies, congenital muscular dystrophies, etc. It may rarely be seen in children with vitamin D deficiency, celiac disease, and autism spectrum disorders (secondary to habitual toe-walking) and as a physiological variant in athletic adolescents.[4] Illustration of calf hypertrophy is usually based on subjective visual assessment, and it largely relies on the clinician’s experience. Therefore, it should be interpreted meticulously with respect to history to give it real meaning. Clinicians should be aware of this fact and should not give undue importance to this finding in a child with gait difficulties and rather plan their subsequent investigations based on history and rest of the examination.

Author contribution

IH and BS: Involved in patient care, conducted the literature review, and prepared the initial draft of the article. LS: Involved in patient care, critically reviewed the article, and provided intellectual input. PM and MC: Involved in patient care and helped in literature review.

Ethics Approval

This article was approved by the Departmental Review Board.

Statistical analysis

Not applicable.

Acknowledgments

The authors thank the parents of the patient for pictures and for adding to the literature.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

None declared.

Conflicts of interest

There are no conflicts of interest.

References