Neurometabolic diseases caused by genetic defects related to metabolism of the nervous system can be effectively treated with nanotheranostics, a combination of diagnosis and therapy through nanotechnology. Nanotheranostic platforms, such as nanoparticles, liposomes, dendrimers, and quantum dots, offer dual functionality: drug release and imaging techniques for looking at the effect of drugs in the body system. For instance, nanoparticles may be designed surface ligands that help them enter the brain by passing through the BBB while at the same time delivering the drugs to neuronal tissue without affecting other tissues. At the same time, these nanoparticles can also incorporate imaging, for instance, by carrying fluorophores or magnetic resonance imaging agents. Some of the advancements under development are stimuli-sensitive nanocarriers that release cargo in response to pH, temperature, or specific enzymes in the injured or pathologic nervous system to provide greater targeting. The current approaches to treating the disease are symptomatic; however, the potential for treating genetic neurometabolic disorders has expanded with the use of traditional gene editing tools like CRISPR/Cas9 combined with nanocarrier structures, which allow for the direct elimination of DNA mutations. In addition to this, Nanotheranostics also strengthens the value of for personalized medicine since the dynamic monitoring of disease pathways of distinct patients is possible. However, current literature shows that important issues such as nanoparticle biocompatibility, immune responses, and long-term safety profiles remain unsolved to allow broad clinical application of the referred platforms.