A child with TSC2/PKD1 contiguous gene deletion syndrome successfully treated with tolvaptan for rapidly enlarging renal cysts.

Tolvaptan, a vasopressin receptor antagonist, has been shown to be effective in the treatment of renal cysts in ADPKD. However, tolvaptan is not indicated for pediatric patients, and reports of its use are rare, making its efficacy and adverse reactions unclear. Herein, we present the case of an 11-year-old girl who had vitiligo from birth. She was diagnosed with West syndrome at 6 months of age and tuberous sclerosis at 2 years of age. At the age of 6 years, an abdominal magnetic resonance imaging (MRI) revealed multiple bilateral renal cysts, and she was diagnosed with ADPKD. Abdominal MRI scans performed at 10 years and 11 years showed rapid renal cyst enlargement, and the renal prognosis was judged to be poor. The patient was treated with tolvaptan to delay cyst exacerbation. There were no apparent adverse events after the initiation of treatment, and the MRI performed 12 months after treatment initiation showed that renal cyst enlargement was suppressed. The results suggest that tolvaptan may be effective in pediatric patients with severe ADPKD who have rapidly enlarging renal cysts, although evaluation of renal cyst enlargement and side effects should be continued.

Restricted Diffusion in the Bilateral Subcortical Motor Areas Associated with Status Epilepticus in an Infant with Kawasaki Disease.

Status epilepticus (SE) often causes neuronal death in the cerebrum and consequent long-term sequelae. Acute encephalopathy with biphasic seizures and late reduced diffusion is clinically characterized by SE associated with fever and seizure clusters that occur 3-9 days after symptom onset. MRI reveals reduced diffusion in the frontal or frontoparietal subcortical white matter, with sparing of the perirolandic region following seizure clusters. Kawasaki disease (KD) is an acute self-limited vasculitis secondary to activation of the immune system; KD is rarely complicated by acute encephalopathy. We report the case of a male infant who developed SE associated with KD and showed late reduced diffusion in the subcortical white matter beneath the bilateral motor cortices (primary motor, premotor and supplementary motor areas) and the right frontal cortex. The patient had characteristic neurological sequelae in the chronic phase, including clumsiness of fingers and forearms, impaired discrimination of tactile sensation and position sense on digits in his hands and feet, corresponding to the lesions with reduced diffusion at the acute phase.