Ganaxolone for treating intractable infantile spasms: a multicenter, open-label, add-on trial

This is a multicenter, open-label, add-on trial, investigating the safety and efficacy of ganaxolone (GNX) in a population of children with refractory infantile spasms, or with continuing seizures after a prior history of infantile spasms. A total of 20 children aged 7 months to 7 years were enrolled in this dose-escalation study, after baseline seizure frequencies were established. Concomitant antiepilepsy drugs were maintained throughout the study period. The dose of GNX was progressively increased to 36 mg/kg/d (or to the maximally tolerated dose) over a period of 4 weeks, then maintained for 8 weeks before tapering and discontinuation. Seizure diaries were maintained by the families, and spasm frequency was compared with the baseline period. The occurrence of adverse events was clinically monitored, and global evaluations of seizure severity and response to treatment were obtained. A total of 16 of the 20 subjects completed the study, 15 of whom had refractory infantile spasms at the time of study enrollment. Spasm frequency was reduced by at least 50% in 33% of these subjects, with an additional 33% experiencing some improvement (25-50% reduction in spasm frequency). Ganaxolone was well tolerated, and adverse events attributed to GNX were generally mild. Ganaxolone was safe and effective in treating this group of refractory infantile spasms patients in an open-label, add-on trial. Further investigation with randomized, controlled study design is warranted.

Clinical heterogeneity associated with the mitochondrial DNA T8993C point mutation

The mitochondrial DNA (mtDNA) point mutation T8993G has been associated with maternally inherited Leigh syndrome (MILS) when very abundant (> 95%). MILS patients are usually severely affected and die in early infancy. In 1993, a novel T8993C point mutation was described in a juvenile form of Leigh syndrome (LS) characterized by a less aggressive clinical course. We describe four unrelated T8993C patients who had diverse, relatively mild, clinical manifestations. Polymerase chain reaction-restriction fragment length polymphorphism analysis showed that the heteroplasmic T8993C point mutation was very abundant in several tissues from all four patients (94.2 +/- 1.5%) but was less copious in blood from 20 maternal relatives. ATP production in mitochondria isolated from skin fibroblasts in three patients was normal, whereas in one patient it was decreased to 20-35% of controls. These findings suggest that the T8993C mutation is less severe than the more common T8993G mutation.

Oto-palatal-digital syndrome type II with X-linked cerebellar hypoplasia/hydrocephalus

We describe an infant with clinically apparent oto-palatal-digital syndrome Type II (OPD II), who, in addition, also has hydrocephalus and cerebellar hypoplasia. This second X-linked disorder has not been reported previously to occur in association with OPD II. This patient had 2 maternal uncles who died neonatally with congenital hydrocephalus and digital abnormalities consistent with OPD II. We suggest that these 2 entities may be located near one another on the X chromosome, and that both loci are affected in this family.

Use of botulinum toxin to treat blepharospasm in a 16-year-old with a dystonic syndrome

A 16-year-old boy with generalized dystonia had continuous, severe blepharospasm and facial grimacing. Local intradermal injections of botulinum A toxin greatly reduced the spasms and improved function. No side effects were observed. Local botulinum A toxin injections may be useful in the treatment of eyelid and facial spasms in patients with generalized dystonias.