Clinical Question Regarding Patient Response to Botulinum Toxin Treatment

Patient description

The patient is a 60-year-old female in good general health. She is slim, presents with normal signs of aging, and has no known medical conditions. She is not currently taking any medications.

The patient last received botulinum toxin treatment approximately 10 years ago. At that time, she experienced similar adverse effects — a feeling of heaviness in the forehead and upper eyelids that affected her vision, which led her to avoid further treatments until now.

Case description

I have a clinical question regarding a patient who has now received botulinum toxin treatment four times. The first three times with different practitioners and the fourth time with me. In her previous treatments, three different brands were used: Xeomin, Dysport, and Vistabel. Each time, she experienced significant heaviness in the forehead and reported visual disturbances due to heavy upper eyelids.

Given her history, I opted for a very conservative approach. I used a low dose of Dysport and placed the injections high in the hairline to minimize diffusion affecting the frontalis inferiorly. I reconstituted 500 units of Dysport with 3 ml of NaCl to reduce concentration and administered only 10 units to the forehead. 

The outcome was that she lost all movement in the upper forehead, but retained movement in the lower part (from the mid-forehead downward). Despite this, she still experienced heaviness and visual discomfort. She says she followed every aftercare advice. 

In addition, I treated the glabellar complex with 50 units of Dysport:

• 10 units in the procerus (1 injection point)

• 40 units in the corrugator supercilii (10 units in each of 4 injection points)

• No product was injected into the depressor supercilii

I also placed 5 units of Dysport laterally in the orbicularis oculi bilaterally to achieve a subtle brow lift.

My questions are:

1. What could be causing the persistent heaviness, despite the minimal dosing and high placement of the injections?

2. What could I do differently in future treatments to avoid this complication?

Any insights would be greatly appreciated.