title: Sensory Neuronopathy Revealing Severe Vitamin B12 Deficiency in a Patient with Anorexia Nervosa: An Often-Forgotten Reversible Cause.
abstract: Vitamin B12 (B12) deficiency is known to be associated with various neurological manifestations. Although central manifestations such as dementia or subacute combined degeneration are the most classic, neurological manifestations also include sensory neuropathies. However, B12 deficiency is still rarely integrated as a potential cause of sensory neuronopathy. Moreover, as many medical conditions can falsely normalize serum B12 levels even in the context of a real B12 deficiency, some cases may easily remain underdiagnosed. We report the illustrating case of an anorexic patient with sensory neuronopathy and consistently normal serum B12 levels. After all classical causes of sensory neuronopathy were ruled out, her clinical and electrophysiological conditions first worsened after folate administration, but finally improved dramatically after B12 administration. B12 deficiency should be systematically part of the etiologic workup of sensory neuronopathy, especially in a high risk context such as anorexia nervosa.
authors.affiliation: Hôpital de La Casamance, 13400 Aubagne, France. j.franques@hp-lacasamance.fr.|Service de Médecine Interne, Hôpital Européen, 13003 Marseille, France. j.franques@hp-lacasamance.fr.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Franques
authors.affiliation: Service de Médecine Interne, Hôpital Européen, 13003 Marseille, France. l.chiche@hopital-europeen.fr.
authors.forename: Laurent
authors.initials: L
authors.lastname: Chiche
authors.affiliation: Service de Neurologie, CHU Bordeaux 33000 Bordeaux, France. stephane.mathis@chu-bordeaux.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Mathis
mesh_terms: D000328:Adult; D000856:Anorexia Nervosa / Q000097:blood*; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood; D006801:Humans; D016472:Motor Neuron Disease / Q000097:blood* / Q000175:diagnosis; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood* / Q000175:diagnosis*; D014810:Vitamin E / Q000097:blood
chemical_list: D014810:Vitamin E; D005492:Folic Acid; D014805:Vitamin B 12
keywords: anorexia nervosa; cobalamin deficiency; sensory neuropathy; vitamin B12