If any Deep Tendon Reflexes (DTRs) are hyperreflexive, what should be tested next?

• A. Romberg test
• B. Gait evaluation
• C. Nystagmus observation
• D. Clonus

Answer: (D)

When reflexes are hyperactive, it signals involvement of the upper motor neurons and increased excitability of the stretch reflex. The next test to perform is clonus, because it is a classic, objective sign of sustained UMN dysfunction. To test for clonus, quickly dorsiflex the ankle (or strike the muscle with a brisk stretch) and hold the position; if rhythmic, repetitive beats or oscillations occur as the footmoves, that indicates clonus. The presence of clonus helps confirm UMN involvement and can reflect the severity of the lesion.

Romberg, gait evaluation, and nystagmus observation assess different systems—proprioception and dorsal columns, overall balance and walking, and vestibulo-ocular/cerebellar function, respectively. They don’t specifically indicate upper motor neuron hyperexcitability like clonus does, which is why clonus is the next key finding to check.