Cauda equina syndrome due to lumbosacral arachnoid cysts in children.

We describe the clinical, neuroradiological and surgical aspects of two children in whom symptoms attributable to cauda equina compression were caused by spinal arachnoid cysts. The first patient presented with recurrent urinary tract infections due to neurogenic bladder dysfunction, absent deep tendon reflexes and sensory deficit in the lower limbs. The second child presented with unstable gait as a result of weakness and diminished sensation in the lower extremities. Spinal magnetic resonance imaging revealed a lumbosacral arachnoid cyst in both patients. During surgery the cysts were identified and excised. Two years after surgery, the sensory deficits of the first patient have disappeared and patellar and ankle reflexes can be elicited, but there is no improvement in bladder function. Neurological examination of the second patient was normal. We conclude that the diagnosis of cauda equina syndrome should prompt a vigorous search for its aetiology. Lumbosacral arachnoid cysts are a rare cause of cauda equina syndrome in children.