Formulations and methods of use thereof for restoring neuronal, muscular (cardiac and striated) and/or retinal tissue function in children and adults afflicted with chronic neurodegenerative diseases, such as neurodegenerative movement disorders and ataxias, seizure disorders, motor neuron diseases, and inflammatory demyelinating disorders, are described herein. Examples of disorders include Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). The method involves administering a pharmaceutical composition containing an effective amount of a tetrahydrobenzathiazole, preferably a formulation consisting substantially of the R(+) enantiomer of pramipexole. R(+) pramipexole is generally administered in doses ranging from 0.1-300 mg/kg/daily, preferably 0.5-50 mg/kg/daily, and most preferably 1-10 mg/kg/daily for oral administration. Daily total doses administered orally are typically between 10 mg and 500 mg. Alternatively, R(+) pramipexole can be administered parenterally to humans with acute brain injury in single doses between 10 mg and 100 mg, and/or by continuous intravenous infusions between 10 mg/day and 500 mg/day.