Transtympanic Neurectomies for Control of Drooling

Auris' Nasus' Larynx (Tokyo) 11, 109-114 (1984)

TRANSTYMPANIC NEURECTOMIES FOR CONTROL OF DROOLING D. S.

GREWAL,

N. L.

HIRANANDANI,

and J. H.

SHEODE,

Z. A.

RANGWALLA,

M. D.

of Otolaryngology and Head and Neck Surgery, Gagalbhai Audiology and Speech Therapy School, Topiwala National Medical College and B. Y.L. Nair Charitable Hospital, Bombay, India

D~partment

Twenty patients of drooling were studied. Of the 20 patients studied, 8 patients underwent bilateral chorda tympani nerve section, and 12 patients underwent bilateral chorda tympani nerve along with bilateral tympanic nerve sections. Bilateral chorda tympani nerve section in combination with bilateral tympanic nerve section is a better and more effective procedure for control of drooling than bilateral tympanic nerve section alone. In both these methods there is immediate stoppage of drooling i.e. on 2nd postoperative day but chances of recurrence of drooling are less in chorda tympani nerve section in combination with tympanic nerve section (17 %) than chorda tympani nerve section alone (38%). Drooling is a common and troublesome problem in majority of the patients with cerebral palsy and mental retardation. It adds to the degree of physical and mental handicap of these patients because of following factors: i) It leads to reduction of body fluids and nutrition. ii) There is an increased risk for infection and in extreme cases it can even lead to aspiration pneumonia. iii) It leads to social, educational and hygienic problems. Drooling in a patient with brain damage with or without mental retardation may be due to one of the following causes: i) Poor head control and involuntary movements of the head interfere with transportation of saliva to the pharynx. ii) Dysfunction of pharnygo-esophageal sphincter mechanism (EKEDAHL, 1974). iii) Relaxed jaw, open mouthed posturing and mouth breathing may also Received for publication July 25, 1983 109

D. S. GREWAL et at.

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Table 1.

S.N.

1.

2. 3. 4.

Condition

Cerebral palsy Cerebral palsy with mental retardation Hemiplegia Dysarthria

No. of patients

8 10

C.T. nerve section

C.T. nerve and T. nerve section

Recurrence of drooling

No. of patients

No. of patients

No. of patients

4 4

4 6

1 3

C.T. nerve, chorda tympani nerve; T. nerve, tympanic nerve.

aggravate drooling. We have studied 20 patients of drooling in various conditions affecting the central nervous system (Table 1). In these patients, drooling was either treated by bilateral chorda tympani nerve section or by bilateral chorda tympani nerve section along with bilateral tympanic nerve sections. The results of these two procedures were compared by comparing the number of towels and handkerchieves required by the patients before and after the each surgical procedure. All the patients were regularly followed up for a period of 1-2 years and recurrence rate of drooling in both these procedures were studied and compared. MATERIAL AND METHODS

1. Our study comprised of 20 patients of drooling. Of these patients, 14 patients (70 %) were below the age of 10 years, 4 patients (20 %) were between 10-20 years and 2 patients (10%) were between 20-30 years of age. 2. All the patients with drooling fell in one of the following categories, i) Cerebral palsy-8 patients (40%), ii) Cerebral palsy with mental retardation-1O patients (50%), iii) Other central nervous system disorders viz.: hemiplegia, dysarthria-2 patients (IO %). 3 . Of the 20 patients studied, 8 patients (40 %) underwent bilateral chorda tympani nerve section and 12 patients (60 %) underwent bilateral chorda tympani nerve section in combination with bilateral tympanic nerve section. 4. Surgical procedures. i) Chorda tympani nerve section, ii) Tympanic nerve section. Both these procedures were done under general anaesthesia. 1-2 ml of saline adrenaline solution (10 drops of adrenaline in 10 cc normal saline) was infiltrated in the external auditory canal. Endomeatal incision was taken as for stapedectomy operation and flap was elevated. Posterior meatal wall bony overhang was removed by a curette. Chorda tympani nerve was traced and 2-3 mm

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TRANSTYMPANIC NEURECTOMIES FOR DROOLING Table 2. Comparison of chorda tympani nerve section with chorda tympani nerve section in combination with tympanic nerve section.

S.N.

Operation ----

I. 2.

Heaviness in the mouth

Loss of taste

Recurrence of drooling

No. of patients

No. of patients

No. of patients

8

6

2

3

12

7

5

2

Total No. of patients

-

Chorda tympani nerve section Chorda tympani and tympanic nerve sections

of its segment was cut and removed and the cut ends were cauterized. Tympanic nerve was also sectioned in 12 patients. The tympanic nerve was traced over the promontory anterior to the round window and approximately 2 mm of its segment was cut and removed, and the cut ends were cauterized. Wherever an additional branch of the tympanic nerve was present 1-2 mm of its segment was removed and cut ends of the nerve were cauterized. Endomeatal flap was replaced back in its original position. Gel-foam® soaked in Reverine® solution was placed over the tympanic membrane and a pack impregnated in Neosporin® ointment was kept in the external auditory canal. Same procedure was repeated on the other ear. Postoperatively systemic antibiotic was given for a period of 5-7 days. The packs from the external auditory canals were removed on the 4th postoperative day and patient was advised to put Neomycin with hydrocortisone ear drops. The Gel-foam® was removed on 7th postoperative day. Postoperatively all the patients and specially those with associated mental retardation were advised to undergo regular speech therapy for control of residual drooling. RESULTS (Tables 1 and 2)

a) If the neurectomy is successful, the results are immediate. b) All the patients were followed up regularly for a period of 1-2 years. The longest follow-up, we had, was of 3 years 6 months. c) Reduction of drooling was judged by a speech therapist by reduction in number of towels and handkerchieves required by the patients postoperatively as compared to pre-operative period. 1) Chorda tympani nerve section. It was done in 8 patients. They required about 6-8 towels or handkerchieves a day and after neurectomy only 4 patients (50 %) required one towel or handkerchief a day. Three patients (38 %) had recurrence of drooling after a period of 3-6 months and they required 3-4 towels or handkerchieves a day. However, they improved after speech therapy.

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2) Chorda tympani nerve section along with tympanic nerve section. It was done in 12 patients. They required 6-8 towels or handkerchieves a day and after neurectomies only 3 patients (25 %) required one towel or handkerchief a day. Two patients (17 %) had recurrence of drooling after a period of 4 and 6 months respectively and they required 2-3 towels or handkerchieves a day. However they improved after speech therapy. d) There was a considerable improvement in general condition and gain in weight in all the patients. e) Loss of taste was complained by 7 patients (35%) (of which 5 patients had undergone bilateral chorda tympani nerve section along with tympanic nerve section); while remaining 13 patients (65%) (of which 7 patients had undergone bilateral chorda tympani nerve section along with tympanic nerve section) complained of heaviness in the mouth. After a period of 6-8 months, these patients got adjusted to their complaints. f) Postoperatively none of the patients had perforation of tympanic membrane or xerostomia. DISCUSSION

The various methods for control of drooling can be discussed as follows: 1. Anticholinergic drugs. Atropine and atropine like drugs were tried for control of drooling but without any appreciable success. These drugs have many undesirable side effects like visual disturbances, headache, tachycardia, restlessness, urinary retention, constipation and dysphagia. Besides these, tolerance to these drugs develops after their prolonged use. 2. Irradiation of major salivary glands. Irradiation was used to bring about the parenchymatous atrophy of the major salivary glands (GOODE and SMITH, 1970). This mode of treatment is not advisable as there are chances of metaplastic changes in the salivary glands and oropharyngeal region, specially when used in patients of younger age group. Moreover there are individual variations to irradiation therapy. 3. Intensive speech therapy. In this the patient is made aware of collection of saliva in the mouth while sitting in front of the mirror. Then by temporarily closing the mouth and pinching the nose of patient, he is made to force to swallow in the saliva that has been collected in the mouth. Moreover by pouring drops of water in the lower anterior vestibule of the mouth with a dropper, the patient is made aware of the trickle of liquid on the lips and thus facilitate swallowing. Use of incentives like chocolates, lolipops, ice-cubes etc., help the patient to learn to suck in saliva and then swallow. MCCRACKEN (1978) believes that tongue thrust therapy helps to control the drooling but it is a very time consuming method. 4. Surgery 1) Extirpation of major salivary glands. GOODE and SMITH (1970) have ad-

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vocated excision of both parotid glands. Bilateral submandibular gland resection along with translocation of both parotid ducts into pharynx by a modified Wilkie's technique was reported by BRODY in 1977 with a success rate of 90 %. The disadvantage of these methods are that they involve a very major operation and the patients with brain damage are patients at poor risk. 2) Ligation of the major salivary glands ducts (GOODE and SMITH, 1970; DISHELL, 1971; EKEDAHL, 1974). These procedures are not recommended as they have to be combined with irradiation or anticholinergic drugs in order to induce atrophy of salivary glands. 3) Retropositioning of Stensen's or Wharton's duct. WILKIE (1967) performed the retropositioning of Stensen's duct into the tonsillar fossae after tonsillectomy. ENFORS and LUNDBERG (1968), LAAGE HELLMAN (1969) and EKEDAHL (1974) have reported the retropositioning of Wharton's duct. This type of surgery requires a lot of experience and has the following disadvantages: i) It can lead to salivary fistulae, stone formation or atresia of the salivary duct. ii) There is a increased risk of infection in the salivary gland due to kinking of its duct which may result after retropositioning. 4) Neurectomies. a) Bilateral auriculo-temporal nerve section combined with bilateral excision of the submandibular salivary ganglion-(YoEL and MARKHAM, 1963). This is a tedious operation which requires two stages. b) Tympanic nerve section by performing tympanotomy. This procedure was described by LEMPERT in 1946 for tinnitus and in 1962 GOLDING-WOOD reported tympanic nerve section along with chorda tympani nerve section to induce atrophy of parotid glands in cases of chronic parotitis. c) Chorda tympani nerve section by performing tympanotomy. FRIEDMAN, SWERDLOW and POMERICO in 1974 reported unilateral chorda tympani nerve section in combination with tympanic neurectomy while DIAMANT and KUMLIEN (1974) combined the chorda tympani nerve section with extirpation of submandibular salivary gland on the other side for control of drooling. d) Bilateral chorda tympani and tympanic nerve section was recommended by TOWNSEND, MORIMOTO and KRALEMANN (1973) and ARNOLD and GROSS (1977) for control of drooling. Mechanism of action of neurectomies. i) The chorda tympani nerve section cuts down secretions from submandibular and sublingual salivary glands which are viscid and mucoid and leads to loss of taste from anterior 2/3 of the tongue which further reduces the stimulation to salivation. In our opinion because the openings of the ducts of submandibular salivary glands are situated anteriorly and therefore they account for troublesome drooling in most of the patients and specially in those with the relaxed jaw. ii) The tympanic nerve section cuts down secretions from parotid glands which is serous and leads to loss of taste from the posterior 1/3 of the tongue which further reduces the stimulation to salivation.

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In our study we have come to the conclusion that bilateral chorda tympani nerve section in combination with bilateral tympanic nerve section is a better and more effective method for control of drooling, than bilateral chorda tympani nerve section alone. Both methods are safe and lead to immediate stoppage of drooling i.e. on 2nd postoperative day but the chances of recurrence of drooling are less in chorda tympani nerve section in combination with tympanic nerve section (17 %) than chorda tympani nerve section alone (38 %). We are grateful to our Dean, Dr. J. V. Bhatt for allowing us to publish this paper. REFERENCES ARNOLD, H. G., and GROSS, C. W.: Transtympanic neurectomy: A solution to drooling problems. Develop. Med. Child. Neurol. 19: 509-513, 1977. BRODY, G. S.: Control of drooling by translocation of parotid duct and extirpation of mandibular gland. Develop. Med. Child. Neurol. 19: 514-517, 1977. DIAMANT, H., and KUMLIEN, A.: A treatment of drooling in cerebral palsy. N. Y. J. Med. 13: 2419-2442, 1974. DISHELL, W. D.: Tympanic neurectomy in chronic parotitis. Arch. Otolaryngol. 94: 471-473, 1971. EKEDAHL, C.: Surgical treatment of drooling. Acta. Otolaryngol. (Stockholm) 77: 215-220, 1974. ENFORS, B., and LUNDBERG, A.: (1968) Cited by Toremalm N.G., and Bjerre, L.: Surgical elimination of drooling. Laryngoscope 86: 104-112, 1976. FRIEDMAN, W. H., SWERDLOW, R. S., and POMERICO, J. M.: Tympanic neurectomy: a review and an additional indication for this procedure. Laryngoscope 84: 568-577, 1974. GOLDING-WOOD, P. H.: Tympanic neurectomy. J. Laryngol 0101. 76: 683-693, 1962. GOODE, R. L., and SMITH, R. A.: The surgical management of sialorrhea. Laryngoscope 80: 1078-1089, 1970. LAAGE HELLMAN, J. E.: (1969) Cited by Toremalm, N. G., and Bjerre, I.. Surgical elimination of drooling. Laryngoscope 86: 104-112, 1976. LEMPERT, J.: Tympanosympathectomy. Arch. Otolaryngol. 43: 199-212, 1946. MCCRACKEN, A.: Drool control and tongue thrust therapy for mentally retarded. Am. J. Occup. Ther. 32: 79-85, 1978. TOWNSEND, G. L., MORIMOTO, A. M., and KRALEMANN, H.: Management of sialorrhea in mentally retarded patients by transtympanic neurectomy. Mayo. Clin. Proc. 48: 776-779, 1973. WILKIE, T. F.: The problem of drooling in cerebral palsy: a surgical approach, Canad. J. Surg. 10: 60-67, 1967. YOEL, J., and MARKHAM, I.: The surgical treatment of sialorrhea. J. Int. Coil. Surg. 39: 261267, 1963.

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Dr. D. S. Grewal, Reader in Otolaryngology and Head & Neck Surgery, T. N. Medical College and B. Y. L. Nair Charitable Hospital, Bombay-8, India