Infantile tremor syndrome secondary to peroral vitamin B12 replacement therapy: a report of two cases with myoclonus

Abstract

Background. Abnormal movements such as tremors and myoclonus may be observed during both treatment and deficiency of vitamin B12, particularly in infants. Infantile tremor syndrome (ITS) is defined by the tetrad of pallor, developmental delay/regression, skin pigmentation, and brown scanty scalp hair.Case. In this report, two cases with ITS aged less than one year who had myoclonic movements during vitamin peroral B12 treatment are discussed based on hematologic, neurological, and magnetic resonance images (MRI) findings, one of whom developed a whole-body tremor and rhythmic myoclonic movements, titubation, and restlessness in the hands and feet as well as diffuse cerebral atrophy on brain MRI. Conclusion.The infants of mothers with nutritional vitamin B12 deficiency may develop sudden abnormal movements following peroral vitamin B12 therapy and that the differential diagnosis of these disorders is highly important for the prevention of long-term neurological sequela by treatment.

Vomiting as a Presenting Symptom of Infantile Vitamin B12 Deficiency

“…More commonly described in various case reports of deficient infants is a transient movement disorder during the initiation of supplementation, although this was not observed in our patient. Several cases have reported variable movements without epileptiform discharges, despite potentially appearing epileptic in nature, with some even evolving over time [ 2 , 13 - 15 ]. Similar to neurologic symptoms related to deficiency, this resolves spontaneously within weeks, and its etiology remains unclear [ 2 , 14 - 16 ].…”

Tremors in Infantile Tremor Syndrome Mimicking Epilepsia Partialis Continua

“…4 Myoclonus has been reported in ITS and may worsen with vitamin B12 therapy. 1,4,7 In the index case, it appears that the patient has a combination of tremor with dystonia and myoclonus with predominant focal presentation.The onset of tremor is usually focal with intermittent nature and then rapidly progresses to a generalized involvement that may be asymmetrical and multifocal. 1,5,6 The tremors disappear during sleep but may be persistent at low intensity in severe cases.…”