The value of elecromyography in infants + toddlers with CMT

[Guest guest]

Ann Phys Rehabil Med. 2009 Aug 18.

The value of elecromyography in the aetiological diagnosis of hypotonia in

infants and toddlers.

Cetin E, Cuisset JM, Tiffreau V, Vallée L, Hurtevent JF, Thevenon A.

Physical Medicine and Rehabilitation department, Lille University Hospital,

André-Verhaghe street, 59037 Lille cedex, France.

INTRODUCTION: During the first two years of life, hypotonia may be the only

symptom of a central or peripheral nervous system disorder. We propose to assess

the sensitivity of electroneuromyography (ENMG) in the aetiological diagnosis of

hypotonia of neuromuscular origin in infants and toddlers.

METHOD: This is a retrospective, single-centre study with revision of the files

of the 37 children aged between zero and 24 months who, between 1994 and 2006,

underwent an ENMG in the etiological approach of their hypotonia and had a final

diagnosis of neuromuscular disease.

RESULTS: All the 13 patients with spinal muscular atrophy or Charcot Marie-Tooth

disease displayed neurogenic alterations on the electromyography (EMG). Among

the 24 children ultimately diagnosed with myopathies, five only displayed

myogenic alterations when tested before the age of two. Sixteen had normal EMG

results and three showed neurogenic alterations.

DISCUSSION AND CONCLUSION: In infants presenting with hypotonia, ENMG is useful

for the diagnosis of peripheral neuropathy. Normal ENMG is relatively common for

confirmed muscle disorders in infants whereas myogenic alterations seem more

unusual, so that muscle biopsy appears unquestionable. In a few cases, early

onset myopathies may present with a neurogenic ENMG pattern. Such a result

should not invalidate the clinically presumed diagnosis of myopathy and would

indicate on the contrary the need for a muscle biopsy.