This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
All are true about Huntington's disease except: 
Select and explain. 
A. Chorea, B. Behavioral disturbance, C. Early onset of memory loss, D. Cog-wheel rigidity.
C: Early onset of memory loss
Answer: C: Early onset of memory loss 
Explanation: Answer is C (Early onset memory loss): 'Memory loss is frequently not impaired until late in the disease' Memory loss is frequently not impaired until late in the disease, although attention judgement & executive functions may be seriously deficient at an early stage. Involvement of extrapyramidal system (caudate nucleus) may explain cog wheel rigidity.