USMLE Forums banner
1 - 2 of 3 Posts

· Registered
25 Posts
Discussion Starter · #3 ·
Because in vitamin B12 deficiency specifically, the condition known as subacute combined degeneration (SCD) affects both the dorsal columns and the corticospinal tract. A lesion in the dorsal columns will lead to loss of position sense, which is crucial to such tests as knee and ankle jerk tests. So, these tests will show areflexia. Additionally, a lesion in the corticospinal tract will lead to a positive Babiniski sign. It will not be able to induce hyperreflexia because the afferent of the reflex arc itself is affected by the lesion in the dorsal columns.
I thought before that babinski must not appear due to dorsal column involvement.

I think it has then nothing to do with sensation and dorsal column, and its all pure motor.

Thank you.
1 - 2 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.