Dados do Trabalho

Título

Subacute combined degeneration in a vegan young woman: the importance of a correct treatment.

RESUMO

Case report
A 31 year-old woman presented with numbness and complete loss of vibratory sensitivity and proprioception in her legs and arms, significantly decreased temperature and pain sensitivity at T12 level, as well as an ataxic gait and postural instability, which had been present for over a year. When the symptoms started, she sought medical care. Exams then revealed low levels of vitamin B12 and she received three doses of 5.000UI parenteral cyanocobalamin. However, the symptoms worsened over time and she was referred to our service. Electroneuromyography performed at admission showed pure sensitive axonal polyneuropathy; magnetic resonance imaging of her spine suggested subacute combined degeneration from C2 to T12; laboratory findings were normal, including vitamin B12 levels. Since the patient was vegan and had never taken vitamin supplements, the main hypothesis remained incorrectly treated vitamin B12 deficiency. Therefore, she was prescribed 5.000UI of intramuscular cyanocobalamin every week for four weeks and then one dose per month. The patient returned for a new evaluation two months after hospital discharge. Her gait had improved, along with proprioception and vibratory sensitivity in the lower limbs. Her neuropathic pain was well controlled with 150mg pregabalin. Results of her gastric endoscopy were normal and there was no evidence of autoimmune disease that could hamper vitamin B12 absorption.

Discussions
Vitamin B12 deficiency prevalence vary among different populations. Some conditions may be associated with it, like reduced intake of animal products and strict vegan diet. The clinical manifestations can range from hematological findings (anemia) to neuropsychiatric changes (mood fluctuations, insomnia, cognitive slowing, ataxia, sensitivity disturbances and weakness). The neurological findings can exist even without hematological alterations. Patients with neurological abnormalities may benefit from more aggressive cyanocobalamin replacement, starting with weekly parenteral replacement for at least four weeks and then once per month. It is important as well to investigate the ethology.

Conclusions
Despite being a common ethology for neurological abnormalities, this case report demonstrates how harmful vitamin B12 deficiency can be if not properly addressed.

Palavras Chave

Subacute combined degeneration; vegan; vitamin B12