RESUMEN
Neurologic alterations form part of the classical manifestations of megaloblastic anemias, with pernicious anemia being the prototype. Subacute combined degeneration of the spinal cord with involvement of the posterior and lateral columns, axonal or demyelinating sensorimotor neuropathy, Lhermitte's syndrome, neuropsychiatric manifestations and degeneration of the autonomic innervation of the bladder and the Auerbach and Meissner plexuses being among the most important features. Of great importance is the possible absence of macrocytosis or even anemia in cases of neurologic manifestations. Otherwise, the multisegmentation of neutrophils may be an important indication for the correct diagnosis, particularly when the serum levels of vitamin B12 and methylmalonic acid are not available.