Treatable Leigh-like encephalopathy presenting in adolescence.

Wernicke's encephalopathy is a triad of ophthalmoplegia, ataxia and confusion seen in alcoholics with dietary vitamin B1 (thiamine) deficiency. A rare genetic defect of thiamine transporter-2 may lead to similar clinical features, biotin-thiamine responsive basal ganglia disease (BTBGD). A 15-year-old girl developed rapid onset ptosis and ophthalmoplegia evolving into a subacute encephalopathy. Neuroimaging demonstrated symmetrical basal ganglia and mid-brain lesions reminiscent of Leigh's subacute necrotising encephalomyelopathy. Oral biotin and thiamine were started, and symptoms improved dramatically the next day. The therapeutic response suggested SLC19A3, encoding thiamine transporter-2, as a strong candidate gene and Sanger sequencing revealed a novel homozygous c.517A>G;p.Asn173Asp mutation, which segregated with disease within the family. BTBGD is a potentially treatable neurological disorder and should be considered in the differential diagnosis of Leigh syndrome and Wernicke's encephalopathy. Since delayed treatment results in permanent neurological dysfunction or death, prompt diagnosis and early initiation of biotin and thiamine therapy are essential.

Severe cerebellitis following methadone poisoning.

We report a 3-year-old girl with an unusual presentation of cerebellitis following ingestion of methadone. CT showed diffuse symmetrical swelling and oedema of the cerebellum resulting in compression of the fourth ventricle and hydrocephalus. The changes were confirmed on MRI with the addition of watershed injuries. These findings represent a toxic encephalopathy and have been reported in previous cases of heroin intoxication by inhalation, but rarely following opioid ingestion. The aetiology of the watershed infarcts is discussed.