Na-Yeon Jung, Bo-Young Ahn, Kyu-Hyun Park,
Chin-Sang Chung, Duk L. Eun-Joo Kim
Department of Neurology,
Pusan National University Hospital, Pusan
National University School of Medicine and
Medical Research Institute, Busan, Republic of
Korea
Department of Neurology,
Samsung Medical Center, Sungkyunkwan University
School of Medicine, Seoul, Republic of
Korea
There have been few described cases of
hemiplegia with involuntary elevation of
paralyzed arms while yawning, symptoms referred
to as parakinesia brachialis oscitans
[1-4]. Brain imaging shows that lesions
in the internal capsule or basal ganglia are
mainly associated with this movement
[1-4]. We report a patient of
parakinesia brachialis oscitans after acute
infarction involving the right motor cortex and
frontal subcortex.
2. Case report
A 59-year-old man presented with sudden
onset of left-sided weakness. On admission,
neurological examinations revealed an alert
mental state, left hemiplegia (MRC grade 2/5 in
the left upper limb, 3/5 in the left lower limb)
and mild dysarthria. The results of sensory exam
were unremarkable. Deep tendon reflexes were
asymmetrically brisk on the left upper and lower
extremities. Babinski's sign presented on the
left. The patient had medical histories of
hypertension for 1 year and head trauma 10 years
ago. Diffusion weighted magnetic resonance
imaging (MRI) demonstrated increased signal
intensities on the right precentral gyrus and
frontal subcortex (Fig. IA). T2-weighted images
showed encephalomalatic changes in the right
frontal lobe and temporal lobe which were
thought to be sequelae from the previous head
trauma (Fig. lB).
One day after the stroke, the patient's wife
reported that his left hemiplegic arm was
spontaneously elevated every time he yawned. The
left hemiplegic arm was involuntarily raised up
to the level of his chest with flexion of the
elbow for about 3 s during deep inspiration, and
fell soon after the patient closed his mouth
(Supplementary video). Otherwise no abnormal
movement was noted. Motor weakness recovered
with the MRC grade 3/5 in the left upper arm
during a 17-day admission period, however, this
peculiar phenomenon persisted. At the last
contact with the patient's family five years
after the stroke onset, his left hemiplegia
still continued with the MRC grade of about 3/5,
however, abnormal movement in his hemiplegic arm
during yawning disappeared. The patient's family
did not recall the exact date when his abnormal
movement ceased.
3. Discussion
Cases with parakinesia brachialis oscitans
have been rarely described [l-4]. In
most cases, the hemiplegic arm was raised with
adduction and flexion of the elbow
[2,3], or with abduction of the shoulder
and extension of the arm upon yawning
[4]. In two of the previously reported
cases, this abnormal movement disappeared as
motor function recovered the following I or 2
weeks after symptom onset [2]. The other
two cases, with severe hemiplegia until 1 year
or 3 years after the stroke, showed persistent
involuntary arm rising during yawning
[2]. In terms of cerebral lesions
associated with parakinesia brachialis oscitans,
isolated internal capsule was mainly involved
[2,3]. Other cases with various brain
lesions without involvement of the internal
capsule, such as the centrum semiovale,
lenticular nucleus, centrum semiovale combined
with caudate nucleus, or middle pons have been
reported 12,4]. Two cases with total MCA
infarction have been also described
[2,4]. Our case suffered an acute
ischemic stroke localized at the right
precentral gyrus and frontal subcortex, but
there was no direct damage to the internal
capsule and basal ganglia as frequently involved
in prior cases (Table 1).
The underlying mechanisms of these peculiar
phenomena have yet to be clarified, but there
are a few possibilities. First, subcortical
structures disinhibited by the cerebral cortical
damage may release the reticular brainstem
formation interconnected with motor pathways
which are paradoxically activated with emotional
stimuli or yawning [3]. Second, Topper
et al. asserted that involuntary movement of the
hemiplegic arm in a patient with pyramidal tract
lesion occurred due to the 'emotional motor
system' which is independent of the somatomotor
system within the brain stem (4]. This
emotional motor system may be activated by
yawning representing a specific emotional state,
such as boredom or drowsiness, and may
co-activate the bulbar and spinal motor neurons
in the brain stem responsible for the
stereotyped and repetitive behaviors
[4].
Finally, Walusinski et al. recently reported
six cases with parakinesia brachialis oscitans
and suggested that the proprioceptive signals
induced by contraction of the respiratory
muscles during yawning might lead to involuntary
limb movement secondary to the activated lateral
reticular nucleus which plays a key part in the
sensory-motor coordination of the limb in the
brain stem projecting to the extrapyramidal
motor controls of the cerebellum [2].
Since these theories based on prior cases are
not mutually exclusive and the nature of the
observed phenomenon of our case was almost
consistent with those of previously reported
cases, we may assume that our patient's
parakinesia brachialis oscitans associated with
the right frontal cortical and subcortical
damage could have resulted from all those kinds
of mechanisms described above.
Additional case reports and experimental
studies with functional or structural imaging
analysis are needed to define the exact neural
correlates and mechanism associated with
parakinesia brachialis oscitans.
[3] Blin
O, Rascol O, AzulayJ, Serratrice G, Nieoullon
A. A single report of hemiplegic arm
stretching related to yawning: further
investigation using apomorphine administration.
J Neurol Sci 1994;126(2):225-7.
[41 Topper
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(5): 495-9.
