| OCR Text |
Show Jou77Ul1 of C/ iniall Neuro- ophthalmology 10( 3); 2W- 214, 1990, © 1990 Raven Press, U ( ork Olivopontocerebellar Atrophy Presenting with Hemiparkinsonian Ocular Motor Signs Michael P. Merchut, M. D., and Mitchell Brigell, ph. D. A patient with olivopontocerebellar atrophy presented with an asymmetric parkinsonian syndrome consisting of right limb rigidity, bradykinesia, masked facies, and a hypophonic, monotonous voice. Right limb clumsiness suggested corticospinal tract involvement. Gait was slightly wide based, but no other cerebellar or brainstem signs were present. Eye movements were characteristic of parkinsonism with low- gain pursuit and hypometric rightward saccades. Saccadic velocity and the vestibular ocular reflex were within normal limits. There was no pathologic nystagmus or saccadic dysmetria. Magnetic resonance imaging showed cerebellar and lower brainstem atrophy virtually diagnostic of olivopontocerebellar atrophy. Olivopontocerebellar atrophy may present uncommonly with asymmetric parkinsonian features, including parkinsonian eye movement abnormalities. Key Words: Olivopontocerebellar atrophy- Eye movements--- Parkinsonism. From the Department of Neurology, Loyola University Medical Center, Maywood, Illinois. Address correspondence and reprint requests to Michael P. Merchut, M. D., Department of Neurology, Loyola University Medical Center, 2160 South First Avenue, Maywood, lL 60153, U. S. A. 210 Olivopontocerebellar atrophy ( OPCA) is a heterogeneous group of disorders first described by Dejerine and Thomas ( 1). In some families OPCA is present in an autosomal- dominant pattern, whereas others show a hereditary- recessive or sporadic pattern. A subgroup with deficient glutamate dehydrogenase has recently been identified ( 2). Most commonly, patients with OPCA present in the fourth decade of life with progressive difficulty walking. Gait is typically ataxic and broad based with limb dysmetria. Subsequently, slurred speech, parkinsonian rigidity, and mental deterioration may develop. Visual complications are common. Families with OPCA often have associated cone- rod degeneration ( 3,4). Ocular motor abnormalities are most often characterized by dramatic slowing of saccadic velocity ( 5), presumably due to degeneration of burst neurons in the parapontine reticular formation ( PPRF) ( 6). Smooth pursuit, when abnormal, is accompanied by vestibular ocular reflex abnormalities and gaze- evoked nystagmus, a constellation of eye movement abnormalities often seen with degeneration of Purkinje cells of the vestibulo- cerebellum ( 7,8). Radiographic evidence of atrophy of the cerebellar cortex, olives, middle cerebellar peduncles, and pons confirm the diagnosis. In this article we report a patient presenting with hemiparkinsonism and corticospinal tract signs, including parkinsonian eye movements, who has radiologic evidence of OPCA. CASE REPORT A 54- year- old plumber complained of progressive clumsiness of his right lower limb, resulting in trips and falls over the preceding 1- 2 years. He had trouble arising from chairs, felt dizzy when standing up, and noted slurred speech and a weak voice. There was no history of toxin or drug exposure, nor family history of neurologic disease. PARKINSONIAN EYE MOVEMENTS IN OPCA 211 On examination, the patient appeared bradykinetic with a masked facies, but no resting tremor. There was no orthostatic hypotension. Gait was slightly wide- based and small stepped, with dragging of the right leg and decreased right arm swing. Rigidity of the right limbs was present, with clumsiness out of proportion to weakness and increased tone. Passive rotation of the trunk revealed axial rigidity. Weakness and sensory loss in the right ulnar distribution were also present. There was no limb ataxia, deep tendon reflexes were normal, and plantar responses were flexor. Cranial nerves were intact. Speech was monotonous, hypophonic, and dysarthric. Range of eye movement was full without pathologic nystagmus, and saccades were normometric. Pursuit was characterized by saccadic intrusions. Eye movement recording was performed with a computer- based direct- current electroculographic system ( ICS Medical, Schaumburg, IL, U. S. A.). Saccadic eye movements were obtained to a red LED visual target that appeared at a random time interval at a random location up to 20° to the left or right in the horizontal meridian. A typical sample of saccade tracings, recorded from left and right lateral canthi, is shown in Fig. 1A. Nineteen of 47 ( 40%) rightward saccades were hypometric, with three to four saccades required in order to reach target location. Only four of 49 ( 8%) leftward saccades were hypometric. Saccadic velocities for one run of 59 saccades is graphically illustrated in Fig. lB. Velocities were within normal limits for 83% of all saccades. Two- channel recording from individual eyes ( outer canthus referred to inner canthus) showed saccades to be conjugate without evidence of infranuclear palsy, internuclear ophthalmoplegia, or dysmetria. Smooth pursuit was obtained to sinusoidal oscillation of a red LED over a 40° range at frequencies ranging from 0.2 to 0.7 Hz. Pursuit gain ( ratio of eye velocity to target velocity) was below normal limits at all frequencies, with the exception of 0.2 Hz leftward pursuit ( Fig. 2). R2i A lUi QI III Siii '. iii 0 ue- U8 I~! .~. ;.-,-,.-.-,- Ho, izonh I lot. E,," _. '~~~ i ,251 liS ,.. • Bie \ u .. o , .. v MORIIAL ( U~) " • I ~ • I • I ~ 1I~ j@~ K~~ fJJtJlt~~~ M~~~@ 1tr~~~ fHii: f~ i:~:;::~:;.~: l;: :..:.:':.::..:".:.:.~:.:-:.:.~_.:'.,.:.:.,.::.:._:._,:..:._.::..::,:_.::.:..~:.:.:'.:.:.':.:.:."_:.':":,:..:':..:.':.:.':.::.:. :::._.:~:;,:.::-.:.~.:::.:;:.:"'::'::'..-:.:~:.:'~.'.,:.::':.:_:':~:::..::.::.::.:.'~::.::.:.::..:.:..:_:.:~:_:.~,..:::.~."-._: ~.:.:;.:.:::.~:~.._:.:, l :~:~:_..•..:.:.:~.::~~.:.::~~.:.:::..:~:....~:_:.~.:..:...::~.::..: l!:~..:~:.:~.,:..~..:.~..:~..:.~:..:~:_:._.:~.:..:~.:.:~:._:.:~:~:..~..::.~:~._.!:.:..,.~'.~.:_}::~.:~.:.;:~:,~.:. l.:~:,._~ .:. f...:•.:~.:..~* N.:.:.~ .• :~:.~.:~.:.~~:~:.~:.,~.. :[.:~.;)•... :~::.~:.' . ?~ I:~~ J:~@~~ lfg~~ IrJ~~~ fI~~~:~ If. HwItn)~~ MfIn:~~;'~:: · ::....'.. '.. .:.: :". ':" :. '.~..'.' :.:~ .. .:~..:.~~~:: . P~~~~~~~~~~ r ...........==----~~~~~~~;:; t )- ,~, < te8 oo~ 288 x ~ z: -."-- 3S382528ESE8 ;- 85 II l~ ' 21253' 1""' » 4' UGKTIIARD AIiP nUOE (; DEC. RE£ S) LEFTIMIlD FIG. 1. Recording of saccadic eye movement. s. A: Four- secon~ . segm~ nt of eye m? ve~ ent recording. Smooth black line indicates target position and dotted hne shows eye position. Rlght~ a~ d mot. lon IS represented by up,,:, ard deflection. The hypometric rightward saccade shown he. re was. characteristic of rlght",: ar~ ~ accades obtained during recording. B: Saccade amplitude versus peak velocity profile. Black dots represent Ind. lVI~ ual saccades a~ d stippled area indicates abnormally slow saccades. Eighty- three percent of saccades are wIthin normal velocity limits. I Clin Neuro- ophthalmol, Vol. 10, No. 3, 1990 212 M. P. MERCHUT AND M. BRIGELL . O. J III U ~ U@ I ./ III , ,/ .:' .~ .' ,/ .... / / "" / .' :. \~ ,/ " r ,... I l' \ " / ....,. ~-:. l. i5 ES ~ lGH1W~ D ~ AiH l£ tTWMRD GRIN zr;; 1.8' · · · · · , 1. · · ,.,..'.~.~ __ .~ .., ~ ,_ · ,., i ~--, •••••• I · · · · · , ,.., , _-- , _-_ . "> A 7Ci • ~ .. ". . ~:: e. 7 e., 6 8.5 : 8.4 8.3 8.2 : 8.2 8.3 8.4 8.. 5 8.6 8.7 n:, EQllEHC'Y ( HZ) FIG. 2. Results of pursuit recording. A: Eight seconds of pursuit performance at target frequency of 0.30 Hz. Pursuit is decreased in gain with superimposed catch- up saccades. B: Graph of pursuit gain as a function of target frequency. Stippled area represents abnormally low gain. Black dots show mean gain for our patient. Catch- up saccades are apparent in the recordings. The slow- phase of optokinetic nystagmus was similarly decreased in gain, but the vestibular ocular reflex was normal. Magnetic resonance imaging ( MRI) ( Figs. 3 and 4) showed marked atrophy of the basis pontis, inferior olivary nuclei, cerebellar peduncles, and cerebellar hemispheres. The basal ganglia were unremarkable. Serum glutamate dehydrogenase level was normal. Electromyography confirmed a right ulnar neuropathy and the patient underwent an ulnar nerve transposition at the elbow. His parkinsonian symptoms failed to improve on Sinemet ( Merck Sharp & Dohme, West Point, PA, U. S. A.) or Eldepryl ( Somerset, Denville, NJ, U. S. A.) therapy. DISCUSSION Parkinsonian signs can be the manifestation of neuro- degenerative diseases other than idiopathic Parkinson's disease, such as striatonigral degeneration, idiopathic orthostatic hypotension ( ShyDrager disease), progressive supranuclear palsy ( Steele- Richardson- Olszewski syndrome), cortico- I Clin Nturo- ophthalmol, Vol. 10, No. 3, 1990 FIG. 3. T1- weighted axial MRI ( 1.5 Tesla) shows marked atrophy of basis pontis, middle cerebellar peduncles, and cerebellum. PARKINSONIAN EYE MOVEMENTS IN OPCA 213 FIG. 4. T1- weighted axial MRI showing atrophy of the lower brainstem. The arrow points to the inferior olives, which are exceptionally atrophic. basal degeneration ( 9), or OPCA. Patients with these Parkinsonlike syndromes respond poorly to dopaminergic therapy, in contrast to those with idiopathic Parkinson's disease. It is estimated that 5- 6% of patients with parkinsonism truly have some variant of OPCA ( 10). Our patient is an example of such a variant, with minimal signs of cerebellar dysfunction, no brainstem abnormalities, gait and eye movement disorders consistent with extrapyramidal and corticospinal tract involvement, and MRI indications of OPCA. Aside from the clinical significance of this variant of OPCA, there are several features of our case that are of interest regarding motor control. As mentioned above, patients with OPCA generally present with slowing of saccades. When pursuit abnormalities are present, they are generally accompanied by other ocular motor signs of dysfunction in the vestibulocerebellum. Despite MRI evidence of OPCA and no evidence of structural defects to the basal ganglia, the eye movement characteristics of our patient are stereotypical for disease of the basal ganglia as classically described by Smith ( 11). Patients with Parkinson's disease have normal or near normal ( within 1 SO) saccadic velocities ( 12- 16). Hypometric saccades are commonly observed in Parkinson's disease ( 12,13) and have been attributed to dysfunction in inhibitory input to pause cells ( 13). Low- gain " cog- wheel" pursuit is clinically the most commonly observed ocular motor abnormality in Parkinson's disease ( 13,17,18). The pursuit abnormality is generally found in the absence of other eye movement signs associated with abnormalities in the vestibulocerebellar pathways, although hypoactive vestibular ocular reflex has been reported in Parkinson's disease when quantified with caloric or rotational stimulation in darkness ( 19,20). Absence of cerebellar signs, gaze- evoked nystagmus, and saccadic dysmetria, with relatively intact saccadic velocity, in our patient suggests that the floccular Purkinje cells, dorsal vermis, and burst cells of the PPRF are relatively spared. Rather, it would appear that a pathway from the basal ganglia to the brainstem and cerebellar areas involved with gaze control is affected in our patient. Another unusual feature of this case of OPCA is its asymmetry. The patient appeared to have parkinsonian rigidity of the right limbs, with clumsiness from pyramidal dysfunction. Abnormalities of eye movements were similarly asymmetric, with hypometric rightward saccades and a more severe pursuit impairment for rightward pursuit. Asymmetric ocular motor disorders in hemiparkinsonism have recently been reported ( 16). These motor and eye movement features strongly suggest more prevalent dysfunction in pathways involving the left basal ganglia. Although hemiparkinsonism is a common feature of Parkinson's disease, the limb rigidity and eye movement abnormalities in OPCA have generally been described as symmetric. One patient with OPCA was reported to have " unsteadiness of gait particularly affecting the right leg" ( 21), and two unrelated patients have been reported with left arm rigidity, with or without cog- wheeling ( 2,22). To our knowledge, asymmetric eye movement abnormalities, such as those seen in our patient, have not previously been reported in OPCA. Parkinsonism was the initial symptom in only 9% of the OPCA cases reviewed by Berciano ( 23). Our patient has asymmetric parkinsonian impairment of limb and ocular movement, with clear MRI evidence of OPCA. This uncommon parkinsonian presentation of OPCA can be misleading, and MRI can be useful in its early diagnosis. REFERENCES 1. Dejerine J, Thomas A. L'atrophie olivo- pontocerebelleuse. Nouv lconogT Sa/ pelT 1900; 13: 330- 70. 2. Plaitakis A, Nicklas WJ, Desnick RJ. Glutamate dehydrogenase deficiency in three patients with spinocerebellar atrophy. Ann NeuTo/ 1980; 7: 297- 303. 3. Weiner LP, Konigsmark BW, Stoll J Jr, Magladery JW. He- J Clin Neuro- ophthalmol, Vol. 10, No. 3, 1990 214 M. P. MERCHUT AND M. BRlGELL re~ tary olivopontoce~ ebellar atrophy with retinal degeneration. Report of a family through six generations. Arch NeuroI1967; 16: 364- 76. 4. Walsh FB, Hoyt WF. Clinical neuro- ophthalmology. Baltimore, MD: Williams & Wilkins, 1969: 92~. 5. Leigh RI. Zee OS. The neurology of /? Ife movements. Philadelphia: FA Davis, 1983: 225. 6. Zee DS, Optican LM, Cook JD, Robinson DA, Engel WK. Slow saccades in spinocerebellar degeneration. Arch Neurol 1976; 33: 243- 51. 7. Baloh RW, Konrad HR, Honrubia V. Vestibulo- ocular function in patients with cerebellar atrophy. Neurology 1975; 25: 160- 8. 8. Zee DS, Yee RD, Cogan DC, Robinson DA, Engel WK. Ocular motor abnormalities in hereditary cerebellar ataxia. Brain 1976; 99: 207- 34. 9. Gibb WRG, Luthert PI. Marsden CD. Corticobasal degeneration. Brain 1989; 112: 1171- 92. 10. Duvoisin RC. An apology and an introduction to the olivopontocerebellar atrophies. Adv NeuroI1984; 41: 5- 12. 11. Smith JL. Optokinetic nystagmus: Its use in topical neuroophthalmologic diagnosis. Springfield IL Charles C. Thomas, 1963: 108- 13. 12. Melvill Jones G, Dejong JD. Dynamic characteristics of saccadic eye movements in Parkinson's disease. Exp Neurol 1971; 31: 17- 31. 13. Teravainen H, Caine DB. Studies of parkinsonian movement: 1. Programming and execution of eye movements. Acta Neurol Scand 1980; 62: 137- 48. J Clin Neuro- ophthalmol, Vol. 10, No. 3, 1990 14. White OB, Saint- Cyr JA, Tomlinson RD, Sharpe lA. Ocular motor deficits in Parkinson's disease II. Control of the saccadic and smooth pursuit systems. Brain 1983; 106: 571- 87. 15. Gibson JM, Pimlott R, Kennard C. Ocular motor and manual tracking in Parkinson's disease and the effect of treatment. / Neurol Neurosurg Psychiatr 1987; 50: 853- 60. 16. Rascol 0, Clanet M, Montastruc JL, Simonetta M, et al. Abnormal ocular movements in Parkinson's disease. Brain 1989; 112: 1193- 214. 17. Miller NR. Walsh & Hoyt's clinical neuro- aphthalmology. Vol. 2, 4th ed. Baltimore, MD: Williams & Wilkins, 1985: 733- 6. 18. Jung R, Komhuber HH. Results of electronystagmography in man: the value of optokinetic, vestibular, and spontaneous nystagmus for neurologic diagnosis and research. In: MB Bender, ed. The ocular motor system. New York: Harper & Row, 1964: 428- 82. 19. Reichert WH, Doolittle J, McDowell FH. Vestibular dysfunction in Parkinson's disease. Neurology 1981; 32: 1133- 8. 20. White OB, Saint- Cyr JA, Sharpe JA. Ocular motor deficits in Parkinson's disease. I. The horizontal vestibular ocular reflex and its regulation. Brain 1983; 106: 555-- 70. 21. Locke S, Foley JM. A case of cerebellar ataxia, with a discussion of classification. Arch NeuroI1960; 3: 279- 89. 22. Carter HR, Sukavajana C. Familial cerebello- olivary degeneration with late development of rigidity and dementia. NeuroI1956; 6: 876- 84. 23. Berciano J. Olivopontocerebellar atrophy. / Neurol Sci 1982; 53: 253- 72. |
