Spinocerebellar Ataxia with Axonal Neuropathy (SCAN1) S/S commonly include which finding?

• A. Absent reflexes
• B. Hyperreflexia
• C. Normal reflexes
• D. No neuropathy

Answer: (A)

The key idea is that peripheral nerve axonal damage dulls the reflex arc. In Spinocerebellar Ataxia with Axonal Neuropathy, the neuropathy component damages the axons of peripheral nerves, which disrupts the sensory input and motor output needed for a normal deep tendon reflex. This commonly results in reduced or absent reflexes, especially in the legs. Hyperreflexia would point to upper motor neuron involvement, which isn’t typical for this condition. Normal reflexes can occur with cerebellar-dominant disease or very mild neuropathy, but SCAN1 usually presents with decreased reflexes due to the neuropathy. No neuropathy contradicts the defining feature of SCAN1.