Abstract
Abstract: :
Lacrimation evoked by gustatory stimulation (crocodile tears), is a frequent finding in patients with severe proximal VII nerve palsy. It results when fibers originally supplying salivary glands reinnervate the lacrimal gland. Case reports have shown, than botulinum toxin (BOTOX) injected in the palpebral lobe of the lacrimal gland, may be useful to decrease lacrimation in some patients. However, complete series and follow-up have not been previously reported. Additionally, reports lack to mention the duration of BOTOX effect in hyperlacrimation. Purpose: To provide clinical evidence of the lenght duration of BOTOX effect to decrease lacrimation in patients with crocodile tears. Methods: Consecutive patients with hyperlacrimation secondary to 7th nerve palsy were included. During a complete ophthalmological examination, other factors that could lead to lacrimation were ruled-out. A modified Schirmer test was used to quantify tearing with and without a chewing action, before treatment, at the first week, and at the first, third and sixth months. Treatment consisted of a single dose of 2.5 units of botulinum toxin injected into the palpebral lobe of the lacrimal gland. Results: Sixteen patients were included. Hyperlacrimation improved at the first week in 11 patients (68%)and was totally absent in all the patients at the first month (100%). Mean duration of the BOTOX effect was 18.3 weeks (range 11 to 25 weeks). Ten patients were re-treated between the fourth and the fifth months. In only five patients (30%), the Botox effect lasted more than 5 months. One patient, requiered a second application at the third month. All the patients were re-treated by the sixth month. Conclusion: Patients with crocodile tears may benefit with BOTOX application into the palpebral lobe of the lacrimal gland. Re-treatment is necessary at 18.3 weeks (11-25 weeks). Duration of BOTOX effect in the lacrimal gland seems to be longer than that reported for other pathologies. Further studies should determine if duration of effect is dose dependent.
Keywords: 452 lacrimal gland • 305 acetylcholine • 439 inhibitory neurotransmitters