Introduction: Ossification of the posterior longitudinal ligament of the spine is a rare cause medullar compression.
Observation: A 50-year-old man from Senegal was referred with recent-onset mechanical lumbar pain with proximal motor deficiency of the lower limbs and somatosensory disorders. Magnetic resonance imaging revealed layered medullar compression, due to anterior cervical and mixed anterior and posterior thoracic ossification. Corticosteroid treatment led to regression of the pain and neurological disorders within a few days.
Discussion: This case report of ossification of the posterior longitudinal ligament of the spine appears to be an idiopathic form corresponding to the "Japanese disease" initially thought to be limited to that population.