Introduction

Disorders of the neuromuscular junction in children can be congenital or acquired. Acquired conditions include autoimmune disorders (myasthenia gravis, Lambert-Eaton myasthenic syndrome) and botulism.

Methods

Retrospective chart review of consecutive children with disorders of neuromuscular junction presenting to a north Indian tertiary care hospital over 8 years was done.

Results

Of 34 cases, 24 were acquired (all autoimmune myasthenia gravis). Median age at onset was 4years (Range:1.5-12years)  with almost equal sex distribution. Commonest presenting feature was ptosis(24; 21 asymmetric). Other associated features included ophthalmoparesis (14), facial weakness (8), bulbar weakness(4), axial weakness(7) and appendicular weakness(8). Anti acetyl cholinesterase anitbody was positive in 17 patients. Initially all patients responded to steroids and pyridostigmine. Antibody positive patients were put on azathioprine; one required rituximab.  Relapses were seen in 5 patients. Thymic hyperplasia was seen in 3 patients.

Amongst the 9 patients with congenital myasthenic syndrome (CMS), median age at presentation was 6years (Range:3-18years) with male preponderance. Commonest clinical features were fatiguability (9), ptosis (8), generalized weakness (8), facial weakness (6) and ophtalmoparesis (5). Three had positive family history. Repetetive nerve stimulation test showed presynaptic pattern in 1 with post synaptic involvement in rest. Six patients showed partial response to pyridostigmine and one to salbutamol. Genetic diagnosis was available in 5 patients (1 COLQ, 1 DPAGT1 and 3 CHRNE mutations).

Conclusion

Acquired disorders of neuromuscular junction are treatable disorders with a good prognosis. Early diagnosis of CMS is imperative for appropriate treatment, prognosis and genetic counseling.