Characteristic Clinical Features of Idiopathic Neuralgic Amyotrophy in Childhood

Sir,

we read with interest the article by van Alfen et al ([1]) reporting on two new cases of idiopathic neuralgic amyotrophy. Since this disease seems to be a rare condition in children a report of a further case with painless neuralgic amyotrophy may be of interest.

At the age of 2 years and 11 months our patient was admitted to a Spanish hospital after suffering from an upper airway infection and fever for two days. He appeared to be severely ill, and developed a flaccid paresis of his right arm within one hour after admission. While his cardiopulmonary situation was stable initially it deteriorated within the next hours and cardiopulmonary resuscitation became necessary. Chest X-ray showed signs of an adult respiratory distress syndrome. The patient's medical as well as family history were non-informative. Routine blood and cerebrospinal fluid investigations revealed no abnormalities. Virology and serology analyses for cytomegalovirus, influenza and parainfluenza virus, brucella, mycoplasma pneumoniae, legionella, coxiella burnetti and chlamydia pneumoniae were all negative. The only positive screening test in serum was for adenovirus. An encephalitis was suspected and the patient was treated with aciclovir and antibiotics. Assisted ventilation was maintained for 72 hours; after extubation no further cardiopulmonary problems occurred. The flaccid paresis of the right arm persisted. Four weeks after the acute episode, electromyography showed the signs of complete denervation in the infra- and supraspinate muscles, in the biceps and in the triceps. On follow-up investigations in our department 16 months later, the boy still showed an extensive peripheral paresis of his right shoulder girdle and arm muscles (Fig. [1]): trapezoid, deltoid, biceps, triceps and brachioradial muscle were completely paretic and atrophic, he also had areflexia in these areas. Extending movements in the right wrist were impossible as well as supination of the forearm. In the right hand signs of muscular atrophy were absent and motoric function was undisturbed. Sensory testing of the affected region was also normal. Magnetic resonance imaging of the brain, of the cervical spinal cord, and of the brachial plexus region were normal. Median nerves somatosensory evoked potentials revealed no abnormalities.

Fig. 1 Four-year-old boy 16 months after the onset of idiopathic neuralgic amyotrophy. He shows marked atrophy and paresis of the right trapezoid, deltoid, biceps, triceps and brachioradial muscles.

In summary, the clinical phenotype of our patient confirms the distinct clinical features of idiopathic neuralgic amyotrophy in childhood as pointed out by van Alfen et al (1): His sudden paretic symptoms were preceded by an upper respiratory infection, most likely of viral origin. He had no pain and showed no signs of recovery during a follow-up period of 16 months.

Reference

• 1 van Alfen N, Schuuring J, van Engelen B GM, Rotteveel J J, Gabreëls F JM. Idiopathic neuralgic amyotrophy in children. A distinct phenotype compared to the adult form.  Neuropediatrics. 2000;  31 328-332