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Show f. Clin. Neuro-ophthalmol. 3: 133-136, 1983. Sustained Blepharoclonus Upon Eye Closure* AVINOAM B. SAFRAN, M.D., JOHN F. MOODY, M.B., B.5. GERARD GAUTHIER, M.D. Abstract A unique case of sustained, rhythmical contractions of both orbicularis oculi induced by voluntary eye closure is described. It was observed in a 25-year-old man who had suffered a severe head trauma. The lid phenomenon was synchronous with macro squarewave jerks. Sustained blepharoclonus upon eye closure is likely to be related to dysfunction in the cerebellar system. The term blepharoclonus refers to myoclonus of the orbicularis oculi, I i.e., unpatterned, more or less repetitive contraction of the muscle/ of sufficient magnitude to cause a visible jerk.3 We describe a case of sustained blepharoclonus induced by eye closure. It was observed in a patient who had a severe head trauma, and who also exhibited macro square-wave jerks. Ocular oscillations were synchronous with rhythmical lid contractions. To the best of our knowledge, this lid phenomenon has not been described previously. Case Report A 25-year-old man suffered a severe head trauma and remained comatose for 5 weeks. He was later transferred to Geneva University Hospital for rehabilitation, and we examined him 13 months after the accident. The patient showed bilateral facial weakness, paralysis of the right vocal cord, and spastic paralysis of the right upper and lower limbs, with increased deep reflexes and extensor plantar response on that side. The soft palate and the left vocal cord were in continual rhythmical myoclonus. Speech was slow and slurred, with irregular articulatory breakdown. There was dysmetria and intention tremor of the left upper and From the Department of Ophthalmology (ABSl. the Electromyography Unit (JFM), and the Department of Neurology (GGl. Hopital Cantonal Universitaire, Geneva, Switzerland. • This study was presented at the 4th Meeting of the International Society of Neuro-Ophthalmology, Hamilton. Bermuda, June 12-17,1982. June 1983 lower limbs and truncal tremor was evident when the patient was seated. Neuro-ophthalmological examination disclosed to-and-fro saccadic oscillations and pronounced saccadic overshoot dysmetria upon either horizontal or vertical centripetal saccades. As long as the eyelids were kept closed voluntarily, rhythmical contractions of both orbicularis oculi occurred. Synchronously with these, horizontal ocular oscillations could be observed under closed upper lids. Orbicularis contractions were absent during sleep. Attempts to squeeze the lids together did not prevent the appearance of either the ocular oscillations or the blepharoclonus. Forced lid closure did not elicit any distinctive tonic lateral deviation of the eyes. Horizontal eye movements were recorded by means of AC electro-oculography, using a 6-second time constant. Electrodes were fixed at the outer and inner canthi of each eye. When the eyes were open, traces demonstrated a unidirectional saccadic instability of fixation (Fig. 1). The eyes abruptly moved off the target to the right with a saccade of 4_9 0 amplitude, and foveation was quickly reestablished by a second saccade to the left. The time interval from termination of the initial rightward saccade to the beginning of the corrective leftward saccade was 50-170 mseconds. Ocular oscillations occurred at a rate of about 2 to 3 counts/second (cps). Saccadic overshoot dysmetria was present with both rightward and leftward 150 centripetal refixation saccades. Simultaneous electromyographic recordings of the left lateral rectus and left inferior pretarsal orbicularis oculi were performed using single concentric needle recording electrodes. Regardless of whether the eyes were open or closed, left lateral rectus traces showed the repetitive occurrence of the following four successive phases (Fig. 2): 1) a period of steady tonic discharge, lasting from 160 to 350 mseconds, 2) a period of inhibition of muscle activity lasting from 40 to 160 mseconds, 3) a new period of tonic discharge lasting from 50 to 180 mseconds, and 4) a burst of intense motor activity lasting from 30 to 170 mseconds. The electromyographic recording of the orbicularis oculi per- 133 Sustained Blepharoclonus Upon Eye Closure RE -l\..J\.I\'J\..f\L1'J\J'J\J\.JU""'UU~c.J'U IJ50 LE J\..f\J1fu 1 sec Figure 1. Electro-oculography recordings, with eyes open. The upper tracing is from the right eye and the lower tracing from the left eye. Rightward ocular movements are indicated by an upwMd deflection of the tracings, and leftward movements by a downward deflection. The traces show fixation instability, with conjugate rightward saccades followed, after a short latency, by a corrective leftward saccade. formed while the eyes were open was unremarkable. During eye closure, it showed regularly alternating phases of weak and more intense activity, occurring at a rate of 2-3 cps. Periods of enhanced orbicularis activity lasted from 200 to 300 mseconds and regularly started from 60 to ISO mseconds before an inhibition phase in the lateral rectus activity. Skull x-rays were unremarkable. Brain computerized tomography demonstrated diffuse atrophy of the brain stem with pronounced enlargement of the fourth ventricle and the perimesencephalic and peripontine cisterns. The patient refused to undergo palatal electromyography and electroencephalography. Discussion Neurological findings in our patient included: 1) palatal and left vocal cord myoclonus, 2) cerebellar dysfunction of speech as well as of limb and trunk motor control, 3) saccadic overshoot dysmetria, 4) ocular oscillations, and 5) sustained blepharoclonus upon eye closure. When the eyes were open, electro-oculographic recordings showed that ocular oscillations were classical macro square-wave jerks.4 Upon eye closure, rhythmical contractions of the lids caused artifacts on the electro-oculographic traces. However, electromyographic recordings of the left lateral rectus and orbicularis oculi activity permitted the analysis of the horizontal ocular movements behind the closed lids as well as the time relation between ocular oscillations and rhythmical lid contractions. Electromyographic traces from the left lateral rectus were consistent with the occurrence of macro square-wave jerks: tonic discharges indicated steady positioning of the eye in the intersaccadic periods, while bursts of intense activity indicated leftward saccades and inhibition phases indicated rightward saccades.5 Recordings demonstrated that macro square-wave jerks were also present when the eyes were closed. In addition, they showed that ocular oscillations were synchronous with rhythmical orbicularis oculi contractions induced by eye closure and that rightward saccades occurred during the last two-thirds of the orbicularis contraction periods. A O..:5nN OJ sec 134 Figure 2. Electromyography recordings, with closed eyes. The upper tracing is from the left lateral fl'du5 (LLR) ,)TId the lower tracing from the left orbicularis oculi (lOO). A and C indicate steady tonIC dlschMg(', B 5hows onhlblted muscle activity and D points to a burst of intense motor activity in l,ltPr,l1 rectus .. The recording from the orbicularis oculi demonstrates periods of weak activity (I) ,lll('rnating WIth phases of more Intense discharge (II). Interrupted lines show the time-relation between inhibition phJses in lateral rectus and periods of enhanced activity in orbicularis oculi. Journal of Clinical Neuro-ophthalmo)ogy The sustained blepharoclonus induced by eye closure seems to be a clinical entity. Although various patterns of repetitive contractions of the orbicularis oculi have been reported in a number of neurological conditions,1.6-9 they are not identical to those described here. Rhythmical contractions in the palatal myoclonus syndrome can involve orbicularis oculi muscles when the disorder is widespread.6 Our patient showed palatal myoclonus and it would have been plausible to consider his lid disorder to be related to this condition. In the palatal myoclonus syndrome, ocular oscillations can be induced or enhanced by eye closure, and lid movement has occasionally been reported to occur with ocular myoclonus. lO However, our patient did not demonstrate the pendular ocular oscillation described repeatedly in palatal myoclonus syndrome, 11.12 but showed macro square-wave jerks. Furthermore, since the blepharoclonus and the macro square-wave jerks were synchronous, it can be assumed that they were related phenomena and independent of palatal myoclonus. Blepharoclonus induced by eye closure bears some similarities with action myoclonus, which is a condition characterized by a movement-induced jerking of the muscles involved in any given action. I., Nevertheless, unlike the blepharoclonus described here, jerks in action myoclonus are not rhythmical and occur mostly in bursts at the beginning or at the end of the action. I:) In photosensitive patients, eye closure with forced upward deviation of the eyes has been reported to induce epileptic seizures, sometimes associated with repeated slow eye closure movements.~ These, however, are paroxysmal phenomena, and are, therefore, distinct from the sustained blepharoclonus upon eye closure. Lid tremor occurs also with parkinsonism upon gentle lid closure. 7 It differs, however, from the condition of our patient in that tremor sometimes disappears with complete relaxation, and is apparently prevented by the slightest volitional effort to squeeze the lids closed. In addition, the tremor rate in parkinsonian subject is about 10-12 cps/ while in our patient the frequency of the lid movement was only about 2-3 cps. The blepharoclonus described here has a closer resemblance to the tremor seen in cerebellar patients. Both phenomena have been found to occur during intention movements or tonic maintenance, and their frequency to be about 2-3 CpS.14. IS Our patient showed evidence of marked cerebellar system dysfunction in speech as well as in motor control of the trunk and limbs. In addition, he demonstrated saccadic overshoot dysmetria and macro square-wave jerks, both of which are considered to be signs of changes in the cerebellar system.4. 16 Since sustained blepharoclonus upon eye closure and macro square-wave jerks were June 1983 Safran, Moody, Gauthier time-related, it is likely that they were induced by the same lesion in the cerebellar system. Synchronism of orbicularis oculi contractions and ocular oscillations could be caused either by an oculopalpebral synkinetic mechanism or by a lesion which alters separately eyelid and ocular motor control. Physiological synkinesis of eyelid and ocular movements has been demonstrated. A blink at times initiates ocular refixation movements, 17 and forceful closure of the eyelids evokes a conjugate lateral deviation of the eyes in some subjects.l~ Blepharoclonus upon eye closure might be interpreted as an enhanced physiological synkinesis. This, however, is not likely because when eyes were open, contractions of the orbicularis oculi were not evident on electromyographic traces in association with macro square-wave jerks. In addition, forced lid closure did not elicit any distinctive lateral deviation of the eyes. References 1. Keane, J.R.: Gaze evoked blepharoclonus. Ann. Neurol. 3: 243-245, 1978. 2. Young, R.R., and Shahani, B.T.: Clinical neurophysiological aspects of post-hypoxic intention myoclonus. Adv. Neurol. 26: 85-105,1979. 3 Kelly, J.]" Sharbrough, F.W., and Daube, J.R.: A clinical and electrophysiological evaluation of myoclonus. Neurology 31: 581-589,1981. 4. Dell'Osso, L.F., Abel, L.A., and Darof£, R.B.: "Inverse latent" macro square-wave jerks and macro saccadic oscillations. Ann. Neurol. 2: 57-60, 1977. 5. Tamler, E., Marg, E., Jampolsky, A., and Nawratzki, I.: Electromyography of human saccadic eye movements. Arch. Ophthalmol. 62: 657-661, 1959. b. Bender, M.B., Nathanson, M., and Gordon, GG: Myoclonus of muscles of the eye, face and throat. Arch. Neurol. Psychiatry 67: 44-58, 1952. 7. Loeffler, J.D., Slatt, B., and Hoyt, W.F.: Motor abnormalities of the eyelids in Parkinson's disease. Arch. Ophthalmol. 76: 178-185, 1966. 8. Binnie, CD., Darby, CE., De Korte, R.A., and Wilkins, A.J.: Self-induction of epileptic seizures by eye closure: Incidence and recognition. /. Neurol. Neurosurg. Psychiatry 43: 386-389, 1980. 9. Cogan, D.G, Schulman, J., Porter, R.J., and Mudd, S.H.: Epileptiform ocular movements with methylmalonic aciduria and homocystinuria. Am. /. Ophthalmol. 90: 251-253, 1980. 10. Stacy, CB.: Continuous vertical ocular flutter, asvnchronous palatal myoclonus, and alpha co~a. Neuro-ophthalmol 2: 147-15b, 1982. 11. Chokroverty, 5., and Barron, K.D.: Palatal myoclonus and rhythmic ocular movements: A polygraphic study. Neurology 19: 975-982, 19b9. 12. Darof£, R.B., Troost, BT, and Dell'Osso, L.F.: Nystagmus and related ocular oscillations. In Neuroophthalmology, J.S. Glaser, Ed. Harper & Row, Hagerstown, 1978, pp. 219-240. 13. Lance, J.W., and Adams, R.D.: The syndrome of intention or action myoclonus as a sequel to hypoxic encephalopathy. Brain 86: 111-136, 1963. 14. Conrad, B., and Brooks, V.B.: Cerebellare Bewe- 135 Sustained Blepharoclonus Upon Eye Closure gungsstorungen im Tierversuch. f. Neurol. 209: 165179, 1975. 15. Rondol, P., Jedynak, c. P., and Ferrey, G: Physiological tremors: Nosological correlates. In Physiological Tremor, Pathological Tremors and Clonus. Progress in Clinical Neurophvsiology, Vol. 5, I.E. Desmedt, Ed. Karger, Basel, 1978, pp. 95-113. lb. Selhorst, J.B., Stark, L., Ochs, A.l., and Hoyt, W.F.: Disorders in cerebellar ocular motor control. I. Saccadic overshoot dysmetria: An oculographic, control system, and clinico-anatomic analysis. Brain 99: 497- 136 508, 1976. 17. Kennard, D.W., and Glaser, GH.: An analysis of eyelid movements. f. Nerv. Ment. Dis. 39: 31-48, 1964. 18. Cogan, D.G: Neurologic significance of lateral conjugate deviation of the eyes on forced closure of the lids. Arch. Ophthalmol. 39: 37-42, 1948. Write for reprints to: Avinoam B. Safran, M.D., CIinigue d'Ophtalmologie, HopitaJ Cantonal Universitaire, CH-1211 Geneva 4, Switzerland. Journal of Clinical Neuro-ophthalmology |
