Pyramidal tract involvement with absent ankle jerk is seen in :

Answer is A (Friedrich's ataxia): Absent deep tendon reflexes despite coicospinal tract involvement with an extensor plantar reflex is characteristic of Friedrich's ataxia. Pyramidal tract may be involved in Friedrich's ataxia or SACD amongst the options provided. Reflexes amongst these two conditions present the following picture Friedrich's ataxia SACD Deep tendon reflex are * Increased deep tendons reflexes / clonus characteristically absent Extensor planter * Planter response is extensr Thus although both Friedrich's ataxia and SACD may present with absent ankle jerk, this feature is more characteristic and consistent with Friedrich's ataxia and hence this is the answer of choice.