mise à jour du
8 mai 2010
Parkinson Rel Dis
2009;15(Supp 2):S154
Parakinesia Brachialis Oscitans
due Brainstem Stroke
Report of two cases
Hélio A. G. Teive, Nilson Becker, Renato P. Munhoz
Movement Disorders Unit, Neurology Service, Hospital de Clínicas, Federal University of Paraná, Curitiba, Pr, Brazil.


Tous les articles sur la parakinésie brachiale oscitante 
All articles about parakinsia brachialis oscitans
Background: Parakinesia Brachialis Oscitans (PBO) is a rare movement disorder described in some cases of hemiplegia, when the onset of yawing is associated with an involuntary raising of the paralysed arm (Walusinski et al, 2005).
Objective: To describe two patients who developed PBO after ischemic stroke in the brainstem.
Case 1- A 39-year-old man with severe systemic arterial hypertension, developed sudden dysartria, dysphagia, dysesthesia and incoordenation in the left lower limb. The neurological examination showed hyperreflexia in the left upper and lower limbs, left Babinski sign, gait ataxia, dysmetria and dysdiadochokinesia associated to alodynia in the left upper limb. When the patient had yawning his left upper and lower limbs had spasm associated to the involuntary elevation of the left upper limb. The brain MRI showed an infarct in the right side the pontine area. The work-up discovered an elevated level of homocysteine.
Case 2: A 55-year-old man presented a sudden vertigo when he turn left his head, when he was riding a bicycle, followed by weakness and paresthesias of the left lower limb. The neurological examination demonstrated left lower limb paresis, associated to spasticity and increased of the profound reflexes. There is also a tactil hyposthesia in the left lower limb. This patient described that when he had a yawning his left lower and upper limbs has dystonic posture and the left upper limb has an involuntary elevation. Brain MRI showed a small infarct in the right side of the medulla oblonga. The extensive work-up demonstrated the presence of patent foramen ovale, with microembolization.
Conclusion: The authors describe two patients with brainstem stroke who developed Parakinesia Brachialis Oscitans.
Discussion: In 2005, Walusinski et al coined the term "parakinesia brachialis oscitans (PBO) to describe four patients who developed hemiplegia due stroke, most often localized on the internal capsule. In these cases of hemiplegia, the onset of yawning was associated with an involuntary raising of the paralyzed arm. These authors proposed that the section of the cortico-neocerebellum tract of the extra-pyramidal system disinhibits the spino-archeocerebellum tract, enabling a motor stimulation of the arm by the lateral reticular nucleus, which harmonises central respiratory and locomotor rhythms.
In the last 150 years there are some descriptions of these phenomenon in the world literature, and probable Abercrombie and Gendrin published the first case of PBO in 1835(Abercrombie J, Gendrin A, 1835).
Töpper et al studied three patients with involuntary stretching during yawning, after pyramidal lesions. The authors discussed that yawning might be the somatomotor manifestation of a particular emotional state characterized by boredom and fatigue. They stated that involuntary movements of the plegic arm in patients with pyramidal tract lesions support the concept of the existence of an independent emotional motor system, which has an input to mononeurones in the brain stem and the spinal cord. On the other hand Blin et al published a single report of a hemiplegic arm stretching related to yawning. The authors performed further investigation using apomorphine administration.
1- Walusinski O, Quoirin E, Neau JP. La parakinésie brachiale oscitante. Rev Neurol (Paris) 2005;161:193-200.
2- Abercrombie J, Gendrin A. Des maladies de l´encéphale et de la moelle épinière, Germer-Baillère, Paris, France, 1835.
3- Blin O, Rascol O, Azulay JP, Serratrice G, Nieoullon A. A single report of hemiplegic arm stretching related to yawning: further investigation using apomorphine administration. J Neurol Sci 1994;126:225-227.
4- Töpper R, Mull M, Nacimiento W. Involuntary stretching during yawning in patients with pyramidal tract lesions: further evidence for the existence of an independent emotional motor system. European Journal of Neurology 2003; 10:495-499.
mise à jour du
8 mai 2010
Parkinsonism Relat Disord
Parakinesia Brachialis Oscitans
Report of three cases.
Plínio M. G. de Lima, Renato P. Munhoz, Nilson Becker
Hélio A. G. Teive
Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná.
The term parakinesia brachialis oscitans (PBO) was coined recently by Walusinsk et al.[1,2] to describe cases of hemiplegia in which the initiation of yawning caused involuntary raising of the affected upper limb, usually followed by its drop during expiration. The phenomenon is still rarely described and considered as a curiosity, probably because it is, in fact, under recognized.

Here we report three additional cases of PBO discussing the phenomenology and possible physiopathology of this phenomenon.

Case Reports:

Case 1: A 63-year-old right handed man was initially admitted to the hospital because of sudden onset of left disproportionate (upper limb predominant) hemiparesis and mild dysarthria. Brain CT scan on admission revealed a right middle cerebral artery territory infarct. Brain MRI disclosed a recent right cortical/subcortical fronto parietal stroke. Carotid ultrasound revealed a 30&endash;40% bilateral internal carotid artery stenosis. Transthoracic echocardiogram showed a mild left ventricle hypertrophy. His past medical history was positive for elevated blood pressure detected 5 years ago and treated regularly with enalapril 10mg bid. He was discharged after 4 days with partial improvement of lower limb function but remained with minimal left upper limb strength (grade 1 distal, 2 proximal). After six months he was seen at the outpatient clinic where he was now followed for secondary prevention of cerebrovascular disease, using clopidogrel 75mg qd, enalapril 10mg bid and simvastatin 20mg qd. His lower limb function showed additional improvement during this period and he was now able to walk unassisted. His upper limb remained completely dysfunctional and was now spastic assuming a position of partial flexion and pronation of the forearm. At this time, he spontaneously related that his paretic arm presented unexpected and involuntary abduction and lifting during yawning. This phenomenon was reproduced twice during the consultation, always triggered exclusively by yawning, the first time while sitting and another while standing. He could recall occasional episodes triggered by yawning while lying down, just before sleep. The movement started during inspiration leading to minimal extension of the forearm, but a relatively wide abduction and elevation of the whole upper limb, reaching an angle of about 60 degrees from his body. The movement lasted for almost 2 seconds and slowly returned to the resting position by the end of the yawning act. He first noticed the phenomenon two months after his cerebrovascular event. Although curious, he was not bothered by the involuntary movement, nor did he feel that it interfered negatively with functionality. Indeed he viewed it as a sign of potential functional improvement in the near future.

Case 2: A 39-year-old man with severe hypertension, presented with sudden dysarthria, dysphagia, dysesthesia and incoordenation in the left lower limb (LL). On neurological examination he also presented increased deep tendon reflexes in the UL and LL, a left extensor plantar reflex, gait ataxia, dysmetria and dysdiadochokinesia with sensory symptoms (alodynia) in the left UL. When he presented spontaneous yawning, his left UL presented with involuntary elevation (abduction and flexion), associated with short amplitude extension of the left LL. Brain MRI (Figure 1) showed a right wedge-shaped lesion in the pontine base extending from the basal surface to the deep basis pontis. Brain and cervical MRA showed no abnormalities. Cardiological evaluation was negative. Extensive work-up demonstrated normal results, except for elevated homocysteine levels. After four months, the patient was reassessed at the outpatient clinic, with complete remission of the abnormal involuntary movements, treated for secondary prevention of cerebrovascular disease, using folic acid 5 mg qd, vitamin B complex bid, clopidogrel 75mg qd, and anlodipine 5 mg / losartane 10 mg qd.

Case 3: A 55-year-old man presented with sudden onset of vertigo when he turned his head to the left, while riding his bicycle. That was followed immediately by weakness and paresthesias of the left LL. On neurological examination he had left LL paresis, with spasticity and increased deep tendon reflexes. Sensation was also abnormal with tactile hyposthesia in the left LL. He described that while yawning, his left LL and UL presented contractures, the UL elevating with the hand deviating to the direction of the opposite side of his chest. Brain MRI showed a infarct in the right rostral medulla oblongata (Figure 2). An extensive work-up, including brain and cervical MRA were normal, and trans-esophageal echocardiography demonstrated a patent foramen ovale. Trans-cranial doppler confirmed microembolization. In the follow-up, after 6 months, neurological examination demonstrated only pyramidal signs in the left LL.




The term synkinesis defines the occurrence of an involuntary muscle contractions accompanying voluntary movements, as seen, for example, in cases of facial synkinesia that occurs in patients with Bell`s palsy, in which smiling induces involuntary contraction of the orbicularis oculi muscle leading to partial eye closure.[3,4] In the case of a hemiparesis, synkinesias occur in the affected hemibody as voluntary movements are produced in non the side, including an exacerbation of the spastic posture of the paralyzed limb, movement of the affected synergistic muscles, and imitation synkinesis, when the affected limb attempts to perform a similar movement occurring in the non affected limb.[5] PBO, on the other hand, represents a phenomenon triggered by a reflex movement, not a voluntary one. Therefore, the term synkinesis does not apply in this case. Parakinesia, as defined by the authors who coined the term PBO, is defined as "an abnormal involuntary movement that acts as a parasite, caricature or replacement of a normal movement".[1,2] Oscitans means yawn in Latin.

We report three cases of PBO, all caused by vascular ischemic disorders located in the cerebral hemispheres, the pontine and bulbar areas. Among the few cases of PBO reported in the literature,[1,2,5-9] etiologies varied included cerebrovascular disease, either ischemic or hemorrhagic, amyotrophic lateral sclerosis (ALS), and brainstem tuberculoma. There was no preference for laterality and no correlation with dominance. Onset occurred after the acute insult or later during the spastic phase, in most cases within 6 months from the causing insult. The movement is typically evident in the upper limb and include abduction or adduction, and the movement occurs exclusively with onset of the yawning act, returning to the resting posture when the yawn is over.[1,2,6] Cases in which there is motor recovery, PBO tends to disappear.[1] The location of the lesion includes the territory irrigated by the middle cerebral artery territory, and a pontine infarction in cases related to vascular origin; a pontomedullary lesion with Millard-Gübler syndrome related to a tuberculoma, and a case of ALS with prominent bulbar involvement.[1,2,5-9]

From an anatomic standpoint, the hypothalamus, the medullary and pontine regions play important roles in yawning, as well as their connections to frontal and cervical spinal areas.[9,10] Also, it seems obvious that the muscles innervated by cranial nerves V, VII, IX, X, XI, XII, phrenic nerve and the dorsal nerves innervating the intercostals, play an accessory role. Although so far there have been no convincing hypotheses concerning the anatomical pathways responsible PBO, one of the possible physiological explanations for PBO is that during yawning, the strong contraction of respiratory muscles forms a proprioceptive signal that eventually leads to the stimulation of the anterior spinal horn from C4 to C8. [1,2,10] This mechanism, however, does not explain the short concomitant involuntary movements in the LL described in case 2 and 3 presented here. Additionally, these two cases may represent variants of classic PBO as they also broaden the phenomenological spectrum of PBO as in case 2 there was no hemiparesis at all, and in case 3 only the LL was paretic.

We agree with the conclusion of previous reviews, indicating the few cases of PBO reported in the literature may not mirror its true frequency.[1,2] The clinical relevance, complete phenomenology and physiological implications of PBO are subjects to be addressed in future case series and reviews.



[1]. Walusinski O, Quoirin E, Neau JP. Parakinesia brachialis oscitans. Rev Neurol 2005;161:193-200.

[2]. Walusinski O, Neau JP, Bogousslavsky J. Hand up! Yawn and raise your arm. Int J Stroke 2010;5:21-7.

[3]. Valls-Solé J, Montero J. Movement disorders in patients with peripheral facial palsy. Mov Disord 2003;18:1424-35.

[4]. Espay AJ. Motor excess during movement: Overflow, mirroring, and synkinesis. Clin Neurophysiol 2010;121:5-6.

[5]. Blin O, Rascol O, Azulay JP, Serratrice G. A single report of an hemiplegic arm stretching related to yawning. J Neuro Sci 1994;126:225-27

[6]. Lanari A, Delbono O. The yawning and stretching sign in hemiplegics. Medicina 1983;43;3:355-6

[7]. Louwerse E. Forced yawning as a pseudobulbar sign in amyotrophic lateral sclerosis. J Neuroscience Research 1998;12:s392

[8]. Töpper R, Mull M, Nacimento W. Involuntary stretching during yawning in patients with pyramidal tract lesions: further evidence for the existence of an independent emotional motor system. European J Neurology 2003;10:495-9

[9]. Wimalaratna HS, Capildeo R. Is yawning a brainstem phenomenon ? a stroke patient who stretched his hemiplegic arm during yawning. Lancet 1988;1:8580

[10]. Walusinski O. Can stroke localisation be used to map out the neural network for yawning behaviour? J Neurol Neurosurg Psychiatry 2007;78:1166.