Clinical trial NCT00069550: Independent Studies of Dextromethorphan and of Donepezil Hydrochloride for Rett Syndrome
Official title: Pathogenesis of Rett Syndrome: Natural History and Treatment
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE3
Conditions: Rett Syndrome
Keywords: Glutamate/NMDA receptors
Cholinergic upregulation
Dextromethorphan
Donepezil hydrochloride
Aricept
Lead sponsor: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Sponsor class: NIH
First posted: 2003-09-30
Enrollment: 90
Sex: ALL
Minimum age (years): 1
Maximum age (years): 15
Standard ages: CHILD
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Primary purpose: TREATMENT

Brief summary: Rett syndrome (RTT) is a disorder in which the nervous system does not develop properly. RTT generally affects girls, but there are some boys who have been diagnosed with RTT. Symptoms of RTT include small brain size, poor language skills, repetitive hand movements, and seizures. This study will evaluate the effectiveness of two drugs in treating the symptoms of RTT.

Detailed description: RTT is a neurodevelopmental disorder characterized by apparently normal early development followed by loss of purposeful hand use, distinctive hand stereotypies, slowed brain growth, loss of language, respiratory irregularities, GI disturbances, gait abnormalities, seizures, and mental retardation. These symptoms appear between ages 6 and 18 months (stage 2 of the disease) following apparently normal development (stage 1). Subsequently, there is gradual stabilization of severe mental retardation and motor compromise (stage 3). The majority (70% to 80%) of patients demonstrate mutations in the methyl-CpG-binding-protein-2 (MeCP2) gene, a transcription repressor located on chromosome Xq28. The disorder predominantly affects females, but a few males with mutations in MeCP2 have been identified, even though many of them do not have the classic symptoms recognized in females.

Recent studies demonstrate increased brain N-methyl-D-aspartate (NMDA) receptors in stages 2 and 3 of the disease. This age-specific increase in glutamate levels and their receptors contribute to brain damage. This first study will examine the effectiveness of dextromethorphan, an NMDA receptor antagonist, to ameliorate symptoms. Participants will be randomized to receive one of three doses of dextromethorphan. All participants will be admitted to the hospital for three days at the beginning of the study. During the hospitalization, participants will undergo physical exam, Dexascan, MRI, EEG, behavioral assessment, laboratory testing, and neuropsychological evaluations. Six months after baseline assessment, participants will be rehospitalized for 3 days for similar assessments.

Reduction in choline acetyltransferase activity in RTT patients may also contribute to disturbed cortical development and psychomotor retardation in RTT. Therefore, the second part of the study will evaluate the effect of donepezil hydrochloride, an inhibitor of acetylcholine-esterase, on acetylcholine levels. This portion of the study will not begin until pharmacokinetic data for donepezil in children is available.

Eligibility criteria: Inclusion Criteria

* Diagnosis of Rett syndrome
* Mutation in MeCP2 gene
* Typical EEG abnormalities (disorganized background, frontal central spikes, rhythmic theta)

Exclusion Criteria

* Features of Rett syndrome with absence of MeCP2 mutation
* Non-specific EEG changes

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: Baltimore
country: United States
facility: Kennedy Krieger Institute
state: Maryland
Study officials:
affiliation: Hugo W. Moser Research Institute at Kennedy Krieger, Inc.
name: SakkuBai R. Naidu, MD
role: PRINCIPAL_INVESTIGATOR
References: