|Year : 1967 | Volume
| Issue : 4 | Page : 149-152
Paradoxical gustatory lacrimal reflex - crocodile tears
Military Hospital, Calcutta-27, India
|Date of Web Publication||21-Jan-2008|
N C Singhal
Military Hospital, Calcutta-27
|How to cite this article:|
Singhal N C. Paradoxical gustatory lacrimal reflex - crocodile tears. Indian J Ophthalmol 1967;15:149-52
Emotional lacrimation is usually associated with salivary secretion and is a normal physiological phenomenon but lacrimation during mastication is an example of anomolous weeping. Such anomolous weeping is called Paradoxical Gustatory Lacrimal Reflex and is also nicknamed as Crocodile Tears because it is said that this reptile sheds tears before devouring its victim.
The basic pathology is that the salivary secretory fibres destined for the salivary glands via the facial nerve are deviated to the lacrimal gland either during development or in life as a sequela of facial nerve palsy.
It is an extremely rare condition and very few cases have been reported in the literature. Following four cases are recorded because of extreme rarity and successful treatment by a simple surgical measure.
| Case Reports|| |
Case 1 : An Assamese young soldier aged 21 suffered from right sided facial nerve palsy in April 1963 and was treated in the usual way. The palsy gradually recovered but 32 months after the onset of the palsy one evening while taking his dinner he had lot of watering from his right eye only. Thereafter every time he took his meal, there was lacrimation from his right eye. Even taking of citrus fruits at odd times brought watering from the right eye.
Case 2 : A 49-year-old clergyman developed right sided facial nerve palsy without any discoverable cause and was, given a conventional medical treatment with which he made a progressive recovery within 6 weeks. He appeared after six months in April 64 with watering by the right eye only during mastication for the last one month. He was perturbed by social embarrassment.
Case 3 : An airman aged 23 attended the eye department for watering of the right eye for six months. On probing into the history he had a fall from a tree on his right side resulting into bruises and swelling on the right side of the face two years ago. The swelling and stiffness of the face lasted for more than a month. He did not know whether a diagnosis of facial palsy was made. He remained alright till December 65 when the lacrimation from the right eye started.
Case 4 : A child aged 8 years was brought to the eye department for watering by her left eye since early age. Watering was only present during taking of meals. No other congenital abnormality was detected. No such family history was present.
All the above four cases had normal vision, anterior segments, fundi and ocular movements. On syringing, the lacrimal passages were found patent, Investigations for facial nerve palsy including W R and Kahn were negative.
In all the above cases palpebral portion of the lacrimal gland on the affected side was removed through a small incision in the conjunctiva after everting the lid. All cases made an uneventful recovery in a week's time and watering was completely absent during the meals. Cases were followed from six months to two years without any recurrence of the symptom.
| Discussion|| |
To understand the basis of the anomalous weeping it is necessary to consider the anatomical aspects of the facial nerve. The nerve arises by a sensory and a motor root from the pons.
The secretomotor fibres to the submaxillary and the sublingual glands travel by the sensory root (Intermediate nerve of Wrisberg) through the geniculate ganglion, facial nerve, chorda tympanii nerve, lingual nerve and the submandibular ganglion. The secretomotor fibres derived from the IXth nerve reach the parotid gland by the tympanic nerve, tympanic plexus, lesser superficial petrosal nerve, the otic ganglion and the auriculo-temporal nerve. The secretory fibres for the lacrimal gland are transmitted by the sensory root to the geniculate ganglion from where they are conveyed by the greater petrosal nerve which enters the middle cranial fossa through a hiatus in the petrous part of the temporal bone. Here it is joined by a branch from the sympathetic plexus around the internal carotid artery to form the deep petrosal nerve. The nerve then passes through the pterygoid canal to reach the sphenopalatine ganglion. Post-ganglionic fibres are then conveyed by the zygomatico-temporal nerve which joins the lacrimal nerve to reach the lacrimal gland. [Figure - 1].
In the case of anomalous weeping the fibres destined to the submandibular salivary glands are deviated from the geniculate ganglion up the greater petrosal nerve to reach the lacrimal gland. The rare chance of such a crossing explains the rarity of the phenomenon. Such diversion may either occur during the developmental stage or during the process of regeneration following facial nerve palsy in the neighbourhood of the geniculate ganglion.
Viallefont (1934) described a case of anomalous weeping accompanied by pavadoxical closure of the homolateral eyelids and flushing of the cheek, the stimulus being gustatory applied to the anterior two-thirds of the same side of the tongue. Singer and Kellner (1930) described a case without facial palsy due to a syphilitic lesion at the geniculate ganglion.
Anomalous weeping has also been reported due to a lesion of the fibres derived from the IXth nerve. Boyer and Gardner (1949) reported two such cases. They were iatrogenic because an attempt was made to cut the greater petrosal nerve for headache but inadvertently lesser petrosal nerve was cut. On regeneration some of the secretory fibres to the parotid gland found their way into the geniculate ganglion and the greater petrosal nerve to reach the lacrimal gland.
The first two cases reported by me had a facial palsy of the lower motor neuron type. At the time of the onset they were believed to be cases of Bell's palsy but when they came with anomalous weeping it was conceded in retrospect that the lesion must have been in the vicinity of the geniculate ganglion. No history of hyperacousis was available. In a true Bell's palsy it is difficult to understand the retrograde travelling of the salivary fibres from the level of stylomastoid foramen to the geniculate ganglion. In case No. 3 perhaps during the concussion some injury had occurred to the facial nerve. The fact that there was stiffness of the right side of the face lasting for more than a month lends support to this conjecture. Case No. 4 is of developmental origin.
The condition can be a social embarrassment of varying degree depending upon the status of the person. Its relief is of utmost importance to the patient. The logical procedure as recommended in the literature is to cut the greater petrosal nerve, a very difficult and risky undertaking. In all the four cases, in an anxiety to relieve their suffering, I had removed the palpebral part of the lacrimal gland. The only contraindication to this operation would be fibrosis, partial or complete. of the conjunctiva due to trachoma, burns or fibrotic sequele of other diseases. The eye is kept moist by a basic secretion of the conjunctival glands and that from the lacrimal gland. The former is of prime importance. Complete fibrosis of the conjunctiva leads to the dry and xerotic conjunctiva even though the lacrimal secretion is present. It is very unlikely that a conjunctivitis sicca would occur after partial dacryo-adenectomy provided the basic secretion is intact.
| Summary|| |
Four cases of anomalous weeping (Crocodile tears) are presented. A simple surgical procedure (excision of the palpebral part of the lacrymal gland) is suggested, based on the successful result in these four cases. A diagramatic sketch of the anatomical aspect of the anomaly is given.
| References|| |
Duke Elder, Sir Stewart (1952), Text Book of Ophthalmology. Vol. V, 1st Edition: p. 5206, Henry Kimpton, London.
Gray's Anatomy (1958), 32nd Edition: P-1114, Longman. Green and Co.
Stallard, H. B. (1965). Eye Surgery, 4th Edition, p. 290, John Wright & Sons Ltd., Bristol.
[Figure - 1]