Journal of Neuro-Ophthalmology, June 1986, Volume 6, Issue 2

Peripheral ophthalmoplegia as the only sign of late-onset fibrous dysplasia of the skull.

A 49-year-old woman presented with a left eye abduction-elevation defect and a bilateral internal rectus palsy of peripheral origin. Thyroid function, cranial computed tomographic scan, and cerebrospinal fluid examination were normal, as were the prostigmine test for myasthenia gravis and the guanidine hydrochloride test for myasthenic syndrome. Skull radiography showed osteosclerotic and osteolytic areas, with slight orbital distortion, and there was hyperactivity in an isotopic scan. A skill biopsy showed fibrous dysplasia. This case is an unusual example of fibrous dysplasia of the skull with neuro-ophthalmological symptoms but without ptosis, exophthalmos, or visual loss.

/ollrnol of Clinical N~lIro-0I'''tJrallllol08.v 6(2}: 109--112. 1986. <; 1986 Raven Press. New York Peripheral Ophthalmoplegia as the Only Sign of Late-Onset Fibrous Dysplasia of the Skull F. Barontini, S. Maurri, and D. Sita A 49-year-old woman presented with a left eye abduc­lion- elevation defect and a bilateral internal rectus palsy of peripheral origin. Thyroid function, cranial computed tomographic scan, and cerebrospinal fluid examination were normal. as were the prostigmine test for myasthe­nia gravis and the guanidine hydrochloride test for myasthenic syndrome. Skull radiography showed os­teosclerotic and osteolytic areas, with slight orbital dis­tortion, and there was hyperactivity in an isotopic scan. A skill biopsy showed fibrous dysplasia. This case is an unusual example of fibrous dysplasia of the skull with neur<rophthalmological symptoms but without ptosis, exophthalmos, or visual loss. From the Neurological Clinic I, University of Florence, Italy. Address correspondence and reprint requests to Prof. F. Barontini at First Neurological Clinic, Vie Morgagni 85, 50134 Firenze, Italy. 109 Diplopia in a pati~nt over 40 years of age often presents diagnostic difficulties, particularly when the more common causes, thyroid myopathy and myasthenia gravis, have been excluded. In the case described, the diplopia was due to a slight deformation of the orbital cavity caused by the fibrous dysplasia, which had previously been asymptomatic. This rare condition, which gave some diagnostic difficulty because of the absence of exophthalmos and visual defect, should be con­sidered a further cause of "orbital pseudo­tumor" (1). CASE REPORT A 49-year-old woman was admitted on April 2/ 1984/ with a 3-month history of first transient and then persistent double vision. Two years before, on July 27, 1982, she had had a slight head injury. The general examination was unremarkable. Abnormalities on the neurological examination were confined to oculomotor function, with a de­fect in abduction and elevation of the left eye and a slight bilateral internal rectus palsy (Fig. 1). A chest x-ray film, EKG, electroencephalogram, blood and urine examination, blood sugar curve, and estimation of thyroid function were all normal. A skull x-ray examination 2 years before had shown slight osteosclerotic changes in the left parietal bone. We repeated this test and it showed increased osteosclerotic changes in the fronto-or­bital regions and fronto-ethmoidal sinuses and also osteolytic areas in the frontobasal and parietal regions (Fig. 2). A skull computed tomographic (CT) scan confirmed these findings (Fig. 3). An in­tracranial CT scan with contrast enhancement gave a normal result, and a total body gallium ci­trate isotopic bone scan showed increased activity in discrete areas of the skull (Fig. 4). The Tre­ponema pallidum hemoagglutination test was nega­tive. 110 F. BARONTINI ET AL. FIG. 1. Defect in abduction and elevation of left eye and slight bilateral internal rectus palsy. The Lancaster red-green test and a synopto­metric examination showed a weakness of the left inferior oblique muscle together with a bilateral internal rectus palsy on attempted horizontal gaze in either direction, suggesting a bilateral internu­clear ophthalmoplegia. Pupil diameters were 4 mm on the right and 3 mm on the left, but reac­tions to light and accommodation were normal. Visual acuity was 20/20 in both eyes. The optic fundi, visual fields, color vision, and light inten­sity examinations were aU normal. Lumbar puncture revealed a clear cerebrospinal fluid (CSF) under normal pressure, cell count of 5/mm3, protein level of 63 mg/dl, glucose level of 59 mg/dl, and chloride level of 123 mg/dl. Electro­phoresis of the CSF showed no oligoclonal bands in the gammaglobulin fraction and Link's index was normal. Visual-evoked potentials showed normal findings in both eyes. FIG. 2. Skull radiograph showing osteosclerotic changes in the fronto-orbital regions and fronto-eth­moidal sinuses. as well as osteolytic areas in the fron­tobasal and parietal regions. I Oiu Nrllro-ophlltnlmol. Vol. 6. No.2. /986 A test with prostigmine (1 mg i.m.) as well as 10 mg tensilon i. v. was negative. Dexamethasone, 8 mg daily for a week, did not alter the ophthalmo­plegia. The otoneurological examination showed absence of spontaneous evoked vestibular signs and the visuo- and vestibulo-oculomotor tests gave normal results. Serum protein, alkaline phosphatase, acid phos­phatase, and calcium levels were all normal. Bence Jones protein was absent in the urine and 24-h uri­nary calcium and phosphate excretion was normal. Multiple myeloma was thus excluded. Radiographic and echographic examinations re­vealed no evidence of neoplastic disease. Guani­dine hydrochloride, 500 mg b.i.d., for a week had no effect. A skull biopsy was performed with the permis­sion of the patient after a few months. Histological examination of the specimen from the right pari­etal bone, where the isotopic scan had shown in­creased activity, revealed cellular fibrous tissue with irregular bone formation and infrequent os- FIG.~. vomputea tomographic scan of skull confirms findings described in Fig. 2. PERIPHERAL OPHTHALMOPLEGIA III FIG. 4. Total·body gallium ci­trate isotopic bone scan shows increased activity in discrete areas of the skulL Left: left anterior. Right: whole body posterior. teoblastic rimming of the bony trabeculae- the characteristic findings of fibrous dysplasia (Fig. 5). The patient still complains of diplopia and shows a complex peripheral ophthalmoplegia, with alternating prevalence of the bilateral adduc­tion defect and the abduction-elevation defect of the left eye. Exophthalmos is still absent, both in the cr scan and on examination with the Hertel exophthalmometer (right eye, 22 mm; left eye, 24 mm). DISCUSSION In the case we describe, radiography of the skull showed multiple osteolytic areas, the pathological nature of which had to be explained. The appro­priate investigations had excluded myelomatosis and metastases, and the possibilities of localized Paget's disease, eosinophilic granuloma (2), and sarcoidosis (3) were considered. However, biopsy of the bone from an area where scintigraphy had- FIG. 5. Histologic specimen from right parietal bone shows cellular fribrous tissue with irregular bone formation and infrequent osteoblastic rimming of the bony trabeculae-characteristic findings of fibrous dysplasia. f Clin Nturo-ophlhalmol. Vol. 6, No.2. 1986 1/2 F. BARONTINI ET AL. shown increased metabolic activity revealed fi­brous dysplasia. It is well known that fibrous dys­plasia of the skull, or focal areas of "fibrous osteo­dystrophy," shows histologically a proliferation of intraosseous cellular fibrous tissue (4). In spite of the fact that the condition usually affects patients under the age of 30 years, it has been found in patients over the age of 60 (4). The fibrous dyspla ia may be disseminated or localized, and multiple foci in the skull and in the fronto-orbital regions, as in our case, are not un­usual. The most common signs are progressive cranial enlargement and deformity, with distor­tion of the orbits and exophthalmos. Visual im­pairment is also common, because of compression of the optic nerve or ophthalmic artery (4,5). Cases have also been described that began with unilat­eral cranial nerve compression (6) or with involve­ment of the orbital roof (7) associated with ptosis and loss of visual acuity (6-8). ]n our patient, the first sign was a weakness of adduction, but without papilledema, visual loss, ptosis, or exophthalmos. These signs can be ex­plained by the downward and lateral displace­ment of the eyeballs by the dysplasia, which, al­though not excessive, involved the inner side of the left orbit and the fronto-orbital region bilater­ally enough to deform the orbital contours. The prognosis of fibrous dysplasia is usually , (/"• .\!,·un'·"l'lothallllol. Vol. 6. No.2. 1986 good, but rarely (0.4%) it may undergo malignant transformation (4,7). Progression is said to be un­usual after 20-30 years (4). ]n some cases men­tioned in the literature, fibrous dysplasia followed a head injury, but we are doubtful of this cause in our patient. REFERENCES J. Glaser, J. 5.: l'kurO-"l'lIthallllolo!(I(. Harper & Row, New York. 1978. 2. Khan, A., Fulco. J. D.. Shendo. A.. Rosenthal. A.• and Marc, J. A.: Focal hi tiocytosis X of the parietal lobe. f· ,'l/rO'lIrg. 52: 431 -433. 1980. 3. Rohatgi, P. K.. and Archutowska-Kempka, M.: Combined calvilrial and CNS ~arcuidosjs. Report of two cases. Arch. N,'urol. 38: 261-262. 191:11. 4. Derome. P. J.. and Vi ot. A: La d~'splasie fibreuse cra­nienne. Nt'lIrtldlirllr~it'29 (suppJ. I): 1983. 5. Sas in, J. Foo i1nd Ro ..nberg. R. '.: Neurological complica­tions of fibrous dysplasia of the skull. Arlit. Nellro/. 18: 363, 1968. 6. Fernand..z. E.. Culavita. K. Muschini. Moo and Fileni, A.: "Fibrous dy~pla~la" of the kull with complete unilateral craniill nen'l' inn,h·..menl. I. .\"'11 "',ur-:. 52: .w4-406, 1980. 7. Silvino, 5.. Fiumt'. Doo DeBia e, L. A.: and Colacecchi. C; Sindrome dello i1pICt! orbitario da displasia fibrosa del cranio ad t!\'oluzionl' maligna. A,'la .\'<'''Ttl/. 6: 340-346, 1984. 8. Deland heer. E., Arnoll, G.. Clarisse. Joo Hache, J. C. Dhell..mmes, P.. Pellerin. Poo Kriso\'ic. L. Viaud. Ch.• and Courle\·ille-Dt'lamarre. \I.: Amblyopie et diplopie intermit­t~ ntt? r~n?lat~ct' a dngt ans d' inten·alle. d' une dysplasie flbrt'us" Isolee du squelette crimien. Rt"'. OloJlt'uroopll. tnlll",l. 53: 255-263. 1981.