Case 34 Neurology

Recurrent ground-level falls

Work it one clue at a time. The diagnosis stays hidden until you reveal it.

Clue 1

A 72 year-old man presents to the clinic for recurring ground-level falls. There are no accompanying medical records. We start by evaluating his gait. What finding is present?

Clue 2

Additional exam confirms our suspicion.

Clue 3

Our patient has a “steppage” (or “equine”) gait from unilateral foot drop. Since he can’t dorsiflex his right foot normally, he must lift his leg higher than normal when walking to allow the foot to clear the ground.

What is the cause of weakened dorsiflexion? We consult our framework for weakness and decide to check his reflexes. He has hyporeflexia of the R Achilles tendon, which focuses our attention on the lower motor neurons.

Clue 4

As we consider the causes of unilateral LMN injury, we notice bony growths involving the DIP joints on our patient’s hands. How could this be connected to the foot drop?

Clue 5

The presence of Heberden’s nodes leads us to ask the patient a key question: “When was your hip replaced”? Our patient responds, “Well it was right before I started to have these falls !”

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