Parakinesia Brachialis Oscitans

1. A D E W I J A Y A , M D – J U L Y 2 0 2 2
Parakinesia Brachialis Oscitans

2. Terminology
Parakinesia
• An abnormal involuntary movement that acts as a
parasite, caricature or replacement of a normal
movement
Brachialis
• Arm
Oscitans
• Yawn
Chowdhury, A., Datta, A. K., Biswas, S., & Biswas, D. A. (2022). Parakinesia Brachialis Oscitans–a Rare Post-Stroke Phenomenon. Tremor and Other Hyperkinetic Movements, 12.
Walusinski O, Neau JP, Bogousslavsky J. Hand up! Yawn and raise your arm. Int J Stroke 2010; 5: 21–27.

3. Yawning
 A homeostatic process that appears when the
default-mode network is active and sleepiness
increases; yawning then disengages the default-
mode network to promote the attentional network
 Accelerates the circulation of cerebrospinal fluid,
increasing clearance of somnogens such as
adenosine, prostaglandin D2, VIP, prolactin and
anandamide, and reducing sleepiness
Walusinski O. How yawning switches the default-mode network to the attentional network by activating the cerebrospinal fluid flow. Clin Anat. 2014 Mar;27(2):201-9.

4. Pathophysiology
of Yawning
Collins GT, Eguibar JR. Neurophamacology of yawning. Front
Neurol Neurosci. 2010;28:90-106.

5. Introduction
 First described at 1844
 Term Parakinesia Brachialis Oscitans (PBO) first
coined by Walusinski in 2010
 Occurs during post-stroke recovery both flaccid and
spastic phase
 Onset: 1 day – 4 months after stroke
 Usually involving upper limb  shoulder abduction
 False alarm of hope
Lim, I. C. Z., & Neo, S. (2022). Parakinesia Brachialis Oscitans: Old Sign, New Findings. Stroke, 53(2), e60-e62.
Chowdhury, A., Datta, A. K., Biswas, S., & Biswas, D. A. (2022). Parakinesia Brachialis Oscitans–a Rare Post-Stroke Phenomenon. Tremor and Other Hyperkinetic Movements, 12.
Walusinski O, Neau JP, Bogousslavsky J. Hand up! Yawn and raise your arm. Int J Stroke 2010; 5: 21–27.

6. Movement Disorder
 Rare phenomenon of abnormal involuntary
movement
 Parakinesia
 Automatic-voluntary dissociation
Lim, I. C. Z., & Neo, S. (2022). Parakinesia Brachialis Oscitans: Old Sign, New Findings. Stroke, 53(2), e60-e62.

7. Emotional motor system Proprioceptive loop theory
 yawning is thought to
represent a somatic
manifestation of a
disinterested emotional state
 During a yawn, there is co-
activation of bulbar and
motor neurons in the brain
stem, resulting in stretching
movements in the upper limb
via intact reticulospinal tracts
 The theory proposes that the strong
contraction of respiratory muscles
during a yawn sends a proprioceptive
signal antidromically to the anterior
spinal horn, cerebellum, and finally
the lateral reticular nucleus in the
medulla via the ventral
spinocerebellar tract
 A motor signal from the lateral
reticular nucleus is then formulated
in response and travels through the
extrapyramidal pathways of the
cerebellum, back to the anterior horn
cell from C4 to C8, resulting in the
involuntary movement of the
paralyzed upper limb.
Pathophysiology
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.
Eur J Neurol. 2003; 10:495–499.
Walusinski O, Neau JP, Bogousslavsky J. Hand up! Yawn and raise your arm. Int J Stroke 2010; 5: 21–27.

8. Etiology
 Ischaemic stroke
 Hemorrhagic stroke
 Amyotrophic lateral sclerosis
 Brainstem tuberculoma
Li J-y, Wu L, Sun L.-qing, Xiong J.-mei. Clinical and radiological characteristics of hemiplegic arm raising related to yawning in stroke patient.PLMAJ Med J Chinese People’s LIberation
Army. 2018; 43

9. Summary
 Movement of the paretic arm with yawning poststroke
can occur in patients with lesions along the pyramidal
tract (most commonly in the internal capsule or the
pons)
 PBO is an example of an autonomic-voluntary
dissociation. The loss of cortical inhibition of the
cerebellum via the corticopontocerebellar pathway, while
the spinoarcheocerebellar pathway remains functional,
explains the phenomenon.
 This phenomenon fades as the patient progresses in their
motor recovery.

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