Neurological symptoms of vitamin B12 deficiency: analysis of pediatric patients*

Vitamin B12 is one of the essential vitamins that affect various systems in the body, including the central nervous system. Vitamin B12 plays an important part in the metabolism of the nervous system, although its exact role under pathological conditions is not fully understood. The purpose of this study was to emphasize the importance of early diagnosis of vitamin B12 deficiency in the light of the characteristics of the patients enrolled. This retrospective, clinical study included 38 children with neurological symptoms of vitamin B12 deficiency. Records of 38 patients referred to a single center of the university hospital outpatient child neurology clinic due to neurological symptoms of vitamin B12 deficiency between February 2012 and December 2013 were evaluated retrospectively. Patients aged 0-18 years with symptoms including syncope, dizziness, convulsion, hypotonia, developmental retardation, tremor, ataxia, tingling sensations and paresthesia, blurring of vision, fatigue and concentration difficulty caused by vitamin B12 deficiency were included in the study. Patient neurological findings included syncope (n=6), dizziness (n=4), hypotonia (n=9), inability to sit or walk without support, or gait ataxia (n=2), convulsion (n=4), hand tremor (n=1), tingling sensations and paresthesia (n=3), vision blurring (n=1), fatigue and concentration difficulty (n=8). All patients with neurological symptoms of vitamin B12 deficiency recovered within one month after vitamin B12 supplementation. In conclusion, clinical characteristics of vitamin B12 deficiency are broad and nonspecific and may not be associated with anemia and increased mean corpuscular volume. Since different clinical characteristics can be seen without anemia, awareness and cautious approach are essential in order to avoid severe clinical disease, especially in children from underdeveloped countries.