cryptogenic oculomotor nerve palsies in children
TRANSCRIPT
Cryptogenic Oculomotor Nerve Palsies in Children
Thomas R. Mizen, M.D., Ronald M. Burde, M.D., and Terence G. Klingele, M.D.
We examined two cases of isolated, acquired,unremitting oculomotor palsies in children. Theresults of systemic, neurologic, and neuroradiologicinvestigations were normal. Both children were observed for more than two years and showed noadditional signs or symptoms. Acquired isolatedoculomotor palsies in some cases are not necessarilya harbinger of serious disease.
ISOLATED OCULOMOTOR NERVE PALSIES that occur inchildren usually are classified as either congenital(present at birth) or acquired. Whereas oculomotornerve palsies are not uncommon in adults, in children they are rare.' The largest reported series ofoculomotor nerve palsies in children are by Miller!and Harley. 2 Approximately 40% of these cases werecongenital in nature, and, of those acquired palsies,Harley" has stated: "With few exceptions, acquiredthird nerve palsy in children is an ominous sign."Two patients with acquired, unremitting, cryptogenic third nerve palsies are the subject of this report.
Case Reports
Case 1A 51f2-year-old girl was in good health until No
vember 1982, when her parents noted that her righteye began to turn out. Ophthalmologic examinationsperformed in November and December 1982 whenshe was 4% years old were remarkable only for avisual acuity of 20/20 in both eyes, pupils of normalsize and reactivity, a right exotropia with medialrectus muscle underaction, and mild proptosis. The
From the Departments of Ophthalmology (Drs. Mizen, Burde,and Klingele) and Neurology and Neurological Surgery (Dr.Burde), Washington University School of Medicine, St. Louis,Missouri. This study was supported in part by an unrestrictedgrant from Research to Prevent Blindness, Inc., New York, NewYork.
Reprint requests to Ronald M. Burde, M.D., Department ofOphthalmology, Box 8096, 660 S. Euclid Ave., St. Louis, MO63110.
proptosis was believed to be more noticeable inDecember, and orbital roentgenograms were reported to be normal. An examination in May 1983 disclosed visual acuities of R.E.: 20/100 and L.E.: 20/30.The right pupil was now dilated and reacted slowlycompared with the left pupil; no afferent pupillarydefect was noted. A right exotropia and right adduction weakness were seen, along with 1 mm of blepharoptosis and slight psoptosis. The results of theremainder of the ocular examination were normal.Historically, the parents reported that the patient'spupils were dilated at the time of examination inDecember 1982, and the right pupil never returned toits preexamination size. The patient was referred to aneurosurgeon. A computed tomographic scan andarteriography were performed and results were reported to be normal.
In June 1983, an examination disclosed visual acuities of R.E.: 20/80 and L.E.: 20/30. Mild right proptosis was documented. The results of an extraocularmotility examination were unchanged from the previous visit, and the results of the remainder of theocular examination were normal. Bilateral orbitalbruits were recorded, and the patient was referred tothe Neuro-Ophthalmology Consult Office at Washington University Medical Center for examination.
An examination in June 1983 demonstrated visualacuities of R.E.: 20/80 and L.E.: 20/30. There was 3.5mm of right proptosis with equal retrodisplacementof both globes. A dilated, sluggishly reactive rightpupil without an afferent defect was seen. An extraocular motility examination showed an exotropia inthe primary gaze with adduction, supraduction, andinfraduction deficits. Hess screen testing documented a right third nerve palsy. A review of the previously obtained computed tomographic scans and anangiogram disclosed no abnormalities. Amblyopiatherapy (direct patching of the left eye) for the righteye was begun.
An examination in October 1983 demonstratedvisual acuities of R.E.: 20/30 to 20/40 and L.E.: 20/30.A dilated, poorly reactive right pupil without afferent defect was recorded. A slight proptosis and 1 to 2mm of right blepharoptosis were also seen. The rightthird nerve palsy was unchanged. Intorsion wasseen on slit-lamp examination, implicating fourth-
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nerve function. Bilateral ocular bruits were recordedand were believed to be transmitted carotid sounds.Both A- and B-scan ultrasonography failed to disclose any mass or dilated retro-orbital vessels. Amblyopia therapy was continued.
During the next year, no progression, regression,or evolution of additional symptoms occurred. InOctober 1984, the patient was referred to a pediatricneurologist whose review of the case showed thattwo months before the onset of the ocular symptomsthe patient sustained a blow to the right side of theneck in an automobile accident. No loss of consciousness or any immediate sequelae were noted. Resultsof a complete neurologic examination were unremarkable. Results of laboratory studies performed atthe time of admission were normal, and cerebrospinal fluid testing disclosed normal values. Magneticresonance imaging of the head, with excellent images of the midbrain and region of the third nerve, wasperformed and results were normal. No clear explanation for an apparent static problem was offered.
Case 2A 6-year-old girl was the product of an uncompli
cated full-term delivery and was noted to havereached all developmental milestones appropriately.The parents first observed that the patient's rightpupil was larger than her left in December 1981 whenshe was 5 years old. No additional abnormalitieswere noted by the parents. In October 1981 thepatient fell to the ground and hit the back of her headwithout serious injury or loss of consciousness. Anexamination in April 1982 disclosed a partial rightthird nerve palsy involving the pupil. No blepharoptosis was observed. The patient's visual acuity wasreported to be normal and equal bilaterally. Suppression of the right eye was noted on the extraocularmotility examination. The patient was referred to aneurologist; a computed tomographic scan was obtained and was reported to be normal. The patientwas referred to the Neuro-Ophthalmology ConsultOffice at Washington University Medical Center inSeptember 1982.
An examination performed at this time demonstrated visual acuity of 20/30 in both eyes. Anisocoriawith a dilated but reactive right pupil was seen. Noblepharoptosis was present. An extraocular-motilityexamination disclosed adduction, supraduction, andinfraduction weakness, with adduction weaknessbeing greatest. Hess chart testing documented thethird nerve palsy. With appropriate head and eyeposition, bifoveal vision was recorded. The patientwas referred to a pediatric neurologist and wasadmitted to the hospital. Results of a neurologicexamination were unremarkable. High-resolutioncomputed tomographic scanning and angiography
failed to disclose any abnormality. The results ofcerebrospinal fluid testing were normal.
The results of an examination performed in January 1983 disclosed slightly improved adductionand supraduction; otherwise, no change was seen.In April 1983 no progression or regression was recorded.
In September 1983 an examination disclosed visualacuity of R.E.: 20/30 and L.E.: 20/15 with suppressionof the right eye on dissociated testing. An extraocular motility examination demonstrated a right thirdnerve paresis, with adduction being most involved.No blepharoptosis was seen. Anisocoria with rightpupillary dilatation was noted. In December 1983,restriction to the field of action of the right medialrectus muscle was seen. In January 1984 the patientunderwent strabismus surgery in the right eye withgood cosmetic and binocular results. Subsequently, no additional neurologic or ocular symptomsevolved.
Discussion
Oculomotor nerve palsies in children are classifiedas either congenital or acquired. Victor" reported 16cases of what was considered to be congenital oculomotor nerve palsy seen during a 21-year period from1954 to 1975. Congenital cases are those recognizedat birth without an additional history of illness ortrauma. Acquired oculomotor nerve palsies canoccur with a variety of processes that involve thenerve from its mesencephalic intraparenchymal origin through its intracranial course to the eye. Inflammatory, infectious, parainfectious, vascular, andcompressive lesions all are implicated. From thesame institution as Victor, Miller! subsequently reported a combined experience of 30 cases of solitaryoculomotor nerve palsy that were seen from 1951 to1976. All of the patients were younger than 20 yearsof age, with 13 patients younger than 10 years of age.In Miller's I series, the disease of 13 (43%) of 30patients was defined as congenital, and the remaining 17 (57%) of 30 patients had acquired palsies. Inthe congenital group, all of the patients had symptoms of oculomotor nerve palsy present at birth.Nine of 13 patients were without a history of trauma,and all had aberrant regeneration with pupillaryinvolvement. The remaining four patients had histories of birth trauma, with two patients having aberrant regeneration. In all of the patients, no otherneurologic abnormality was present other than theisolated cranial nerve involvement. Harley" reported32 cases of isolated oculomotor palsy seen between1968 and 1979. Fifteen of these cases were congenital,
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and all of them showed varying degrees of aberrantregeneration. Of the cases of acquired oculomotorpalsy, five were considered to be vascular (threeophthalmoplegic migraine and two subdural hematoma), three were inflammatory (one meningitis andtwo orbital cellulitis), four were traumatic, threewere neoplastic, and one each was considered to bemyasthenia gravis and postviral.
Acquired oculomotor nerve dysfunction in this agegroup represents slightly more than half of the reported cases.J" The three most frequent causes ofacquired oculomotor nerve palsy in children aretrauma (20%), inflammation (13%), and neoplasm(10%).1 It is interesting that the onset of oculomotorpalsy in adults is associated with minor head traumain patients harboring occult intracranial tumors, usually in the parachiasmal area." Marmor, Wertenbaker, and Berstein" reported the development ofprogressive ophthalmoplegia in an ll-year-old boytwo weeks after a severe head trauma. They statedthat the child subsequently was found to have anintracavernous aneurysm. Although both of our patients had histories of preceding minor head trauma,in both cases complete repeated neuroradiologicevaluations failed to demonstrate the presence ofeither an aneurysm or tumor.
In children, migraine is a known but rare cause ofrecurrent third nerve palsy." Ophthalmoplegic migraine is a periodic episodic syndrome consisting ofheadache or cyclic vomiting followed by oculomotorparesis. The oculomotor paresis is transient initially,but the patient may be left with an increasing residual deficit with recurrent attacks. A presumed variantof ophthalmoplegic migraine in two children withrecurrent painless oculomotor palsy has been reported.? Both of our patients had unremitting palsiesunassociated with headache, cyclic vomiting, or afamily history of migraine. Isolated oculomotornerve palsies are reported to occur after a variety ofsystemic infections, both viral and bacterial. In ourpatients there was no historical evidence of antecedent or concurrent infectious illness.
The cases reported herein represent acquired oculomotor nerve palsy, of as yet undetermined origin,in two children. Follow-ups of more than two years ineach case did not demonstrate the development ofany underlying systemic or neurologic deficit. Neuroradiologic and neurologic examinations, includingcerebrospinal fluid examination, did not yield anydefinitive diagnosis. If these patients were adults,the accepted diagnosis most certainly would have
been a vasculopathic nerve palsy. The lack of development of aberrant regeneration would strongly support such a postulate, although recovery, or partialrecovery, in such cases is the rule. This diagnosis in achild has been considered by most authors to beuntenable.t-v" Similarly, one could implicate thesepalsies as an initial sign of systemic lupus erythematOSUS,9 but again the lack of definitive laboratoryfindings and the subsequent failure of developmentof the disease process militates against such a diagnosis.
Is there a lesson to be learned from these caseswith respect to the treatment of infants who haveacquired total or partial third nerve palsies? Although Burde, Savino, and Trobe" have recommended that every patient younger than 40 years of agewho has a third-nerve palsy should undergo computed tomographic scanning and angiography, webelieve that if the third nerve dysfunction is trulyisolated (with no other evidence of intracranial disease), "watchful waiting" may be appropriate.
References
1. Miller, N. R.: Solitary oculomotor nerve palsy in childhood. Am. J. Ophthalmol. 83:106, 1977.
2. Harley, R. D.: Paralytic strabismus in children. Etiologic incidence and management of the third, fourth, andsixth nerve palsies. Ophthalmology 87:24, 1980.
3. Victor, D. 1.: The diagnosis of congenital unilateralthird nerve palsy. Brain 99:711, ,1976.
4. Eyster, E. F., Hoyt, W. F., and Wilson, e. B.: Oculomotor palsy from minor head trauma. An initial sign ofbasal intracranial tumor. J.A.M.A. 220:1083, 1972.
5. Marmor, M., Wertenbaker, C., and Berstein, L.: Delayed ophthalmoplegia following head trauma. Surv. Ophthalmol. 27:126, 1982.
6. Friedmann, A. P., and Merritt, H. H.: Ophthalmoplegic migraine. Arch. Neurol. 7:320, 1962.
7. Durkan, G. P., Troost, B. T., Slarnovits, T. L., Spoor,T. e., and Kennerdell, J. S.: Recurrent painless oculomotorpalsy in children. A variant of ophthalmoplegic migraine?Headache 21:58, 1981.
8. Burde, R. M., Savino, P. J., and Trobe, J. D.: Diplopia.In Burde, R. M., Savino, P. J., and Trobe, J. D. (eds.):Clinical Decisions in Neuro-Ophthalmology. St. Louis,e. V. Mosby, 1985, pp. 147-195.
9. Sedwick, L. A., and Burde, R. M.: Isolated sixth nervepalsy as initial manifestation of systemic lupus erythematosus. A case report. J. Clin. Neuro-ophthalmol, 3:109, 1983.