A Case of Pyruvate Dehydrogenase Deficiency with Low Density Areas in White Matter Noticed by CT Scan

Abstract

The patient was a 4-month-old boy, the first child of healthy, non-consanguineous patient. He was mildly asphyxiated at birth and developed severe convulsions at two days of age. At 4 months of age, he was referred to us because of infantile spasms and motor retardation. The EEG showed hypsarhythmia, ACTH and anticonvulsants were started, but his seizures were not controlled completely.
At 8 months of age, the CT scan demonstrated a cerebral atrophy with enlarged ventricles and a diffuse low density of cerebral white matter, and lactic acidosis was first noticed. The glucose, glucagon, fructose, and alanine tolerance tests revealed almost normal responses in blood glucose levels and elevation of lactate levels above the initial value. Enzyme studies revealed a severe deficiency of pyruvate dehydrogenase complex and pyruvate dehydrogenase (E₁), and a normal activity of pyruvate carboxylase in liver obtained by biopsy. In biopsied muscle, mitochondria appeared normal. Treatment with thiamine, lipoic acid and anticonvulsants was not effective.
The clinical picture of PDC deficiency has been correlated with the amount of the residual activity, and this case confirmed to the “severe” category. Several pathologic entities may be associated with PDHC deficiency, and CT findings in our case demonstrated the demyelinating condition. The precise relationship between the defect and the pathogenesis remains to be elucidated.