Branched oligonucleotides

A method of delivering double-stranded nucleic acids to one or both of the brain and spinal cord of a patient, comprising administering to the patient a branched oligonucleotide compound comprising two siRNA duplexes connected to one another by a linker,

• wherein each siRNA duplex comprises a sense strand of at least 15 contiguous nucleotides and an antisense strand of at least 15 contiguous nucleotides having complementarity to the sense strand,
• wherein each sense strand and each antisense strand has a 5′ end and a 3′ end, and
• wherein the branched oligonucleotide compound is administered to the patient by intrastriatal (IS) injection, intrathecal (IT) injection, or intracerebroventricular (ICV) injection, thereby delivering the double-stranded nucleic acids to the brain and/or spinal cord of the patient.