CNS DEGENERATIVE DISEASES CORTEX (dementias) BASAL GANGLIA and brain STEM (parkinsonian) SPINOCEREBELLAR(ataxias MOTOR NEURONS(muscle atrophy)CNS DEGENERATIVE DISEASES • CORTEX (dementias) • BASAL GANGLIA and BRAIN STEM (parkinsonian) • SPINOCEREBELLAR (ataxias) • MOTOR NEURONS (muscle atrophy)