Infantile epileptic encephalopathy with a hyperkinetic movement disorder and hand stereotypies associated with a novel SCN1A mutation

We report a female patient who presented with intractable epileptic seizures, profound developmental delay since early infancy, and hyperkinetic movements with hand stereotypies. The patient initially developed focal seizures with multiple foci at 3 months of age. Thereafter, the seizures evolved to frequent episodes of hyperthermia‐induced status epilepticus. A novel de novo SCN1A mutation was identified by whole‐exome sequence analysis. This case demonstrates that SCN1A mutations may cause movement disorders as an atypical phenotype and the case history of this patient may expand our understanding of the clinical spectrum of SCN1A‐associated epileptic encephalopathy. [Published with video sequences]     

Clinical Course of Six Children With GNAO1 Mutations Causing a Severe and Distinctive Movement Disorder

ObjectivesMutations in GNAO1 have been described in 11 patients to date. Although most of these individuals had epileptic encephalopathy, four patients had a severe movement disorder as the prominent feature. We describe the largest series of patients with de novo GNAO1 mutations who have severe chorea, developmental delay, and hypotonia in the absence of epilepsy.MethodsSix patients with recurrent missense mutations in GNAO1 as detected by whole exome sequencing were identified at three institutions. We describe the presentation, clinical course, and response to treatment of these patients.ResultsAll six patients exhibited global developmental delay and hypotonia from infancy. Chorea developed by age four years in all but one patient, who developed chorea at 14 years. Treatments with neuroleptics and tetrabenazine were most effective in the baseline management of chorea. The chorea became gradually progressive and marked by episodes of severe, refractory ballismus requiring intensive care unit admissions in four of six patients. Exacerbations indirectly led to the death of two patients.ConclusionsPatients with GNAO1 mutations can present with a severe, progressive movement disorder in the absence of epilepsy. Exacerbations may be refractory to treatment and can result in life-threatening secondary complications. Early and aggressive treatment of these exacerbations with direct admission to intensive care units for treatment with anesthetic drips may prevent some secondary complications. However the chorea and ballismus can be refractory to maximum medical therapy.     

Tetrabenazine for hyperglycemic-induced hemichorea-hemiballismus.

We reported a 74-year-old woman with new-onset diabetes mellitus who presented with the sudden onset of mild left hemiparesis and marked left hemichorea-hemiballismus. Brain CT scan and MRI showed T1W, T2W, and DWI lesions in the right putamen and caudate, which have been previously reported in cases of hyperglycemic-induced hemichorea-hemiballismus (HIHH). The patient dramatically responded to tetrabenazine within a day. Subsequent dose reductions lead to a reemergence of symptoms. Tetrabenazine improves a variety of hyperkinetic movement disorders but, to our knowledge, its use has never been reported for HIHH.