Painful Leg in a Toddler: Consider Idiopathic Neuralgic Amyotrophy

Case Report

Austin J Clin Neurol 2015;2(7): 1061.

Painful Leg in a Toddler: Consider Idiopathic Neuralgic Amyotrophy

Kliffen J7¹*, Niermeijer JMF² and Engelen M²

¹Department of Neurology, Sint Lucas Andreas Hospital, Netherlands

²Department of Pediatric Neurology, Academic Medical Center Amsterdam, Netherlands

*Corresponding author: Kliffen J, Department of Neurology Sint Lucas Andreas Hospital, PO Box 9243, 1006 AE, Amsterdam, Netherlands

Received: May 06, 2015; Accepted: June 21, 2015; Published: June 30, 2015


Idiopathic neuralgic amyotrophy (INA) is a plexopathy with acute onset of severe pain followed by loss of muscle strength and atrophy of the muscles innervated by the involved plexus. Involvement of the brachial plexus is characteristic but occasionally the lumbosacral plexus is involved. This is denominated as ‘idiopathic lumbosacral plexus neuropathy’. INA can occur at any age. This case illustrates the diagnostic course in a toddler with an ‘idiopathic lumbosacral plexus neuropathy’. Even as a recognizable clinical picture, INA remains a diagnosis by exclusion.

Keywords: Neuralgic amyotrophy; Pediatric; Plexopathy; Lumbosacral plexus


INA: Idiopathic Neuralgic Amyotrophy; CSF: Cerebrospinal Fluid; HNA: Hereditary Neuralgic Amyotrophy


Acute onset of severe pain in a limb, followed by loss of muscle strength and muscle atrophy gives suspicion of idiopathic neuralgic amyotrophy (INA). Our case illustrates that INA also involves the lumbosacral plexus and that it occurs at young age as well. This makes that INA is part of the differential diagnosis in a child with a painful lower limb. There are demonstrable clues towards the diagnosis.

Case Presentation

A 1 year and 8 months old girl was brought in the outpatient department with a painful right lower limb present since three weeks. The pain made it difficult to sleep at night. There was no previous history of trauma or infection. Developmental milestones and further medical history were unremarkable.

Neurological evaluation showed that she preferred to stand on the left leg. Her right foot was in an exorotation position on ambulation. Manipulation of the leg was painful. There was a flaccid paresis and atrophy of the proximal and distal muscles of the right leg. Patellar tendon reflex and ankle jerk were absent on the right leg. Sensory function could not be examined properly. She was also analyzed by an orthopedic surgeon, no other orthopedic abnormalities were found.

At the initial presentation symptoms and signs were interpreted as most compatible with a lumbosacral plexopathy. The muscle atrophy of the right leg was even visible on the X-ray of the pelvic area (Figure). To exclude treatable causes of plexopathy like inflammation, infection or space occupying lesions further investigations were done. Blood tests and MRI of the spine and lumbosacral plexus were unremarkable. Cerebrospinal fluid (CSF) cell count, protein, and glucose levels were normal. Limited electrophysiological studies, only nerve conduction velocity (the child was uncooperative), did not show any abnormalities.

Citation: Kliffen J, Niermeijer JMF and Engelen M. Painful Leg in a Toddler: Consider Idiopathic Neuralgic Amyotrophy. Austin J Clin Neurol 2015;2(7): 1061. ISSN : 2381-9154