We reported the case of acute
encephalopathy related to colonic
acid treatment interruption in a 12-year-old female child presenting to our unit with episodes of
vomiting,
headache, irritability, acute
confusional state,
seizures, and left lower limb
hypotonia. Brain magnetic resonance imaging (MRI) showed signs of vasogenic and cytotoxic
edema at the cerebellar level bilaterally, and lesions at the temporo-occipito-parietal right level, temporomandibular left, and right thalamic with swelling of the convolutions and reduced differentiation between white and gray matter. The patient had suspended the
folinic acid treatment at least 6 months before the present admission. The relation between the clinical signs presented by the girl and
folic acid deficiency was confirmed by the result of laboratory assessment and by the answer to the notable clinical improvement with the renewal of
folinic acid treatment.
Dihydropteridine reductase (
DHPR) deficiency is a rare autosomal recessive
genetic disorder caused by the quinoid
dihydropteridine reductase (QDPR) gene mutations.
DHPR deficiency impairs the synthesis of the
tetrahydrobiopterin (BH4), an essential cofactor for the hydroxylation of the
aromatic amino acids phenylalanine,
tyrosine, and
tryptophan. When not precociously treated, the disorder may present whit severe neurologic impairment including developmental delay/intellective disability (DD/ID),
microcephaly,
seizures,
movement disorders,
cerebral palsy, and other neurological impairments. The clinical and neuroradiologic anomalies observed in our case were unusual, with signs previously unreported in patients with
folic acid deficiency. The present case shows that the clinical presentation and MRI anomalies of the cerebral
folic acid deficiency may be various and unusual compared with those reported in the literature, and it confirms the usefulness of the continuation of
folinic acid treatment during the course of the disorder in patients with
DHPR deficiency.