Multiple System AtrophyCerebellar AtaxiaOlivopontocerebellar AtrophiesShy-Drager SyndromeSupranuclear Palsy, ProgressiveAtrophyAtaxiaalpha-SynucleinSpinocerebellar DegenerationsAutonomic Nervous System DiseasesParkinson DiseasePutamenSynucleinsSpinocerebellar AtaxiasHypotension, OrthostaticSyndromeGait AtaxiaInclusion BodiesLewy Body DiseaseMidodrineThioninsParkinsonian DisordersFriedreich AtaxiaDiagnostic Techniques, NeurologicalStriatonigral DegenerationCerebellumParkinson Disease, SecondaryPure Autonomic FailureVocal Cord ParalysisLewy BodiesTonic PupilBrainMagnetic Resonance ImagingOligodendrogliaBrain StemExtrapyramidal TractsRecurrent Laryngeal NerveSweat Gland DiseasesAge of OnsetMuscular AtrophyREM Sleep Behavior DisorderCerebellar DiseasesAtaxia TelangiectasiaNerve Tissue ProteinsNeurologic ExaminationNeurodegenerative DiseasesOptic AtrophyNerve DegenerationLevodopaAutonomic Nervous SystemBasal GangliaLaryngoscopyStiff-Person SyndromePedigreeEphedrineGenes, RecessiveElectromyographyAntiparkinson AgentsDihydroxyphenylalanineMyoclonic Cerebellar DyssynergiaPonsSeverity of Illness IndexReflex, AbnormalPerineumUrodynamicsApraxiasSalicylamidesCaudate NucleusMachado-Joseph DiseaseNeuronsDeath, SuddenSubstantia Nigra