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Spontaneous and Reflex Activity of Facial Muscles in Dystonia

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Spontaneous and Reflex Activity of Facial Muscles in Dystonia J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.64.3.320 on 1 March 1998. Downloaded from 320 J Neurol Neurosurg Psychiatry 1998;64:320–324 Spontaneous and reflex activity of facial muscles in dystonia, Parkinson’s disease, and in normal subjects Günther Deuschl, Christof Goddemeier Abstract darkness or blindness change blink rate only to Objective—The blink rate is an index a limited extent.1 However, physiological fac- which can be easily obtained during the tors related to the subjects’ general status clinical examination, but it has not yet including attention seem to be much more been properly standardised. The present important.12 study was undertaken to collect data on From the neurological point of view central the age dependent development of this regulation of the blink rate is of special interest index and on possible abnormalities in as diVerent pathological conditions can modu- Parkinson’s disease and dystonia. late the blink rate. Reduction of the blink rate Methods—The blink rate and the rate of has been found in Parkinson’s disease,3 in pro- perioral movements were measured in 156 gressive supranuclear palsy,4 and in subjects normal controls, 51 patients with Parkin- taking dopamine receptor blockers.5 This son’s disease, 48 patients with spasmodic reduction is considered to be such a well torticollis, 14 patients with generalised defined feature of Parkinson’s disease that it is dystonia, and 12 patients with focal hand even part of an item of the unified Parkinson’s or leg dystonias and have been correlated disease rating scale.6 An increase of the blink with the results of testing the orbicularis rate has not yet been established as a diagnos- oculi reflex, the palmomental reflex, and tic sign although it has been found in some the perioral reflex. patients with Huntington’s disease7 or Results—No age related eVects were found blepharospasm.2 7–10 for the blink rate and perioral movements The anatomical pathways and physiological but all the reflexes showed age dependent connections involved in the central control of variations. It is suYcient to measure the blinking have been reviewed recently.11 The blink rate for one minute, provided stand- parapontine reticular formation and the lateral ardised conditions are applied. Blink rate geniculum are known to facilitate eye and perioral movement rate were posi- blinking.212 The cerebellum seems to inhibit tively correlated in patients and controls. blinking27because the removal of the cerebel- The blink rate was significantly increased lum increases blink rate in rats.7 The basal gan- in spasmodic torticollis and decreased in glia play an important part in regulating the http://jnnp.bmj.com/ Parkinson’s disease. In generalised dysto- frequency of the eye blinks13 but further and nia the blink rate was increased but in more complex aspects of levator palpebrae and hand and leg dystonia the blink rate was orbicularis oculi interaction such as their normal. The reflex tests did not signifi- mutual reciprocal inhibition and especially the cantly diVer between the subject groups levator palpebrae inhibition814 are under con- except for the orbicularis oculi reflex, trol of basal ganglia circuits. which was hyperexitable in Parkinson’s Little is known about age related changes in disease. blink rate. The blink rate of newborn humans is on September 24, 2021 by guest. Protected copyright. Conclusion—Measuring the blink rate can below the values of adults15 and slowly assist the diagnosis of extrapyramidal dis- increases until the age of 20 years. The blink orders as a soft sign, but is not very sensi- rate seems to be modulated significantly by the Department of tive. The group diVerences found indicate testing paradigms: It is lower during reading Neurology, University a decrease of the blink rate and perioral 16 of Kiel, Germany than during a relaxed conversation. The movements in hypokinetic and an increase available data suggest that a protocol for blink G Deuschl in hyperkinetic extrapyramidal disorders C Goddemeier reflex measurements has to be standardised such as spasmodic torticollis and general- first before more extended measurements in ised dystonias. This may be of interest for Correspondence to: patients seem to be valuable. Thus we selected Professor Günther Deuschl, future pathophysiological studies. Department of Neurology, our testing paradigms in a methodological pilot Christian-Albrechts study before the normative study was started. Universität Kiel, (J Neurol Neurosurg Psychiatry 1998;64:320–324) Niemannsweg 147, 24105 The normative study assessed the blink rate in Kiel, Germany. Telephone a large group of normal subjects with special 0049 431/597 2610; fax Keywords: blink rate; orbicularis oculi reflex; primitive 0049 431/597 2712; email: reflexes; spasmodic torticollis; Parkinson’s disease emphasis on elderly people. Finally, blink rate g.deuschl@neurologie. was measured in a group of patients with uni-kiel.de hypokinetic (Parkinson’s disease) and a group Received 18 April 1997 and Blinking protects the conjunctiva from drying with hyperkinetic (focal and generalised in final revised form 10 and other possible injuries. Several external dystonia) movement disorders. Some addi- September 1997 Accepted 17 September conditions such as humidity and smoking fume tional clinical indices such as the number of 1997 content increase the blink rate.12 Complete perioral movements and some facial reflexes J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.64.3.320 on 1 March 1998. Downloaded from Blink rate 321 Controls AB Spasmodic torticollis Parkinson's disease 20 10 Blinks/min Figure 1 Symbols used to fixate used in the present study 0 displayed at a distance of about 50 cm. (A) point with an 50 70 90 110 130 original size of 2 cm. (B) open cross with an edge size of Time (segments of 10 s) 9.5 cm. Figure 3 Blink rate measured over intervals of between 60 (palmomental reflex, orbicularis-oculi reflex, and 120 s in five normal subjects, five patients with Parkinson’s disease, and five patients with spasmodic and perioral reflexes) were included because torticollis. The blink rate was already stable after 60 seconds they are known to be related to normal aging or of measurement. damage of central nervous functions.17 PALMOMENTAL REFLEX The palmomental reflex was considered posi- Patients and methods tive when a sudden twinge to the thenar BLINK RATE eminence caused a contraction of the ipsilateral A blink was defined as any visible, bilateral . contraction of the orbicularis muscles—no M triangularis matter if the eyes were completely closed. Two PERIORAL REFLEXES blinks were considered as separate, if they Perioral reflexes were considered to be positive could be separated visually from each other. if a sudden finger tap to the upper lip caused a Blink rate was expressed as blinks/minute. visible contraction of the orbicularis oris mus- cle. PERIORAL MOVEMENTS Any visible perioral movement (mainly involv- TESTING CONDITIONS ing the lips) was rated as a perioral movement After a pilot phase (see below) the blink rate and two were considered separate if there was a and the perioral movements were always meas- pause between both. Perioral movements were ured under the following conditions: The rated as perioral movements/minute. blinks and perioral movements were measured in a relaxed atmosphere either in a quiet place ORBICULARIS OCULI REFLEX 17 in the hospital or in the subject’s home. The The definitions of Jensen et al were used. subjects had to stare at an open cross with 9.5 Briefly, adaptation was considered present cm×9.5 cm side length for two minutes (fig 1). (reflex negative) if the blinking was reduced or The subjects were told that their facial expres- http://jnnp.bmj.com/ absent after 15 taps to the glabella. Any other sion would be noted. The light was not stand- response was considered as lacking adaptation ardised. Blink rate and perioral movements (reflex positive). It was considered grade 1 if were measured during this time. Subsequently the adaptation was lacking only for the glabel- the reflexes were tested. All the assessments lar portion; grade 2 if adaptation was also lack- were made by one of us (CG). ing for the skin over the eyebrows; and grade 3 if the adaptation was lacking over the eyebrows METHODOLOGICAL STANDARDISATION until the hair boundaries. In an attempt to standardise the measurement on September 24, 2021 by guest. Protected copyright. Cross of blink rate and perioral movements for clini- Point cal bedside testing, three conditions were 20 Waldo Normal Parkinson's disease 14 12 10 10 Blinks/min 8 6 Blinks/min 4 0 0 100 200 2 Time (segments of 10 s) 0 Figure 2 Blink rate measured over intervals between 60 s 08 00 10 00 12 00 14 00 16 00 18 00 20 00 and 180 s in five normal subjects when fixating a searching Time of measurement (h) task (Waldo),the point (task I), or the cross (task II) (displayed in fig 1). The blink rate is higher when fixating Figure 4 Blink rate measured three times a day in five cross or point compared with the searching task. No fatigue patients with Parkinson’s disease and five normal subjects. eVects were found during the observation period. No consistent daytime variations were found. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.64.3.320 on 1 March 1998. Downloaded from 322 Deuschl, Goddemeier 3.5 B n = 18 20 n = 18 A 3 17.5 n = 18 n = 19 2.5 n = 19 15 n = 19 n = 19 n = 19 n = 19 n = 23 n = 19 n = 21 n = 19 n = 21 12.5 n = 23 2 n = 18 10 1.5 7.5 Blinks/min 1 5 0.5 2.5 Period movements/min 0 0 20–29 30–39 40–49 50–59 60–69 70–79 80–85 86–93 20–29 30–39 40–49 50–59 60–69 70–79 80–85 86–93 Age groups Age groups Figure 5 Blink rate (A) and rate of perioral movements (B) in 156 normal subjects displayed in age classes of 10 or 5 years respectively.
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