Teaching NeuroImage
VIDEO Alien hand syndrome
Patricio S. Espinosa, MD, MPH; Charles D. Smith, MD;
and Joseph R. Berger, MD
A 47-year-old right-handed man
presented with sudden onset of
left-sided weakness and incoor-
dination of his left hand. The pa-
tient stated that he was not able
to operate his left hand appropri-
ately (video E-1). On examina-
tion, he had mild weakness in his
left arm and leg. When asked to
perform tasks with his right
hand, his left hand would imitate
the other (video E-2). An MRI
showed acute ischemic strokes of
the right parietal area and ante-
rior corpus callosum (figure).
Alien hand syndrome (AHS) or
alien limb sign includes failure to
recognize ownership of one’s limb
when visual cues are removed, a
feeling that one body part is for-
eign, personification of the af-
fected body part, or autonomous
activity which is perceived as out-
side voluntary control.
1
Although
the hand is most frequently af-
fected, any limb or combination of
limbs may fulfill the alien limb
criteria.
1
Two types of AHS have been
described. Frontal AHS occurs in
the dominant hand and is associ-
ated with reflexive grasping,
groping, and compulsive manipu-
lation of tools. It is a result of
damage to the supplementary mo-
tor area, anterior cingulate gyrus,
and medial prefrontal cortex of
the dominant hemisphere and an-
terior corpus callosum. Callosal
AHS is characterized by inter-
manual conflict and requires only
an anterior callosal lesion. Cal-
losal AHS is best explained by
hemispheric disconnection mani-
fested during behaviors requiring
dominant hemisphere control.
2
We hypothesize that the alien
limb symptoms that our patient
demonstrated were secondary to
the lesion in the anterior corpus
callosum; however, some of his be-
havioral manifestations may have
been exacerbated by the concurrent
right parietal stroke. The latter
may be associated with hemispa-
tial neglect, typically characterized
by directional hypokinesia for ac-
tions into and toward contrale-
sional hemispace or failure to
respond to stimuli on the left side.
3
Anosognosia, or unawareness of
the neurologic deficit, is frequent
after right parietal lesions, and
may compound the disability deriv-
ing from the neglect itself,
3,4
al-
though no characteristic features of
neglect were observed in our patient.
References
1. Doody RS, Jankovic J. The alien hand and
related signs. J Neurol Neurosurg Psychiatry
1992;55:806–810.
2. Feinberg TE, Schindler RJ, Flanagan NG,
Haber LD. Two alien hand syndromes. Neu-
rology 1992;42:19–24.
3. Buxbaum LJ, Ferraro MK, Veramonti T, et al.
Hemispatial neglect: subtypes, neuroanatomy,
and disability. Neurology 2004;62:749–756.
4. Levine DN, Calvanio R, Rinn WE. The patho-
genesis of anosognosia for hemiplegia. Neu-
rology 1991;41:1770–1781.
Figure. MRI of the brain DWI and
FLAIR showing the acute stroke in the
right parietal lobe and anterior corpus
callosum (see file 1).
Disclosure: The authors report no conflicts of interest.
Address correspondence and reprint requests to Dr. Patricio S. Espinosa, Department of Neurology, Kentucky Clinic (Room L-445), Lexington, Kentucky
40536-0284; e-mail:psespi2@email.uky.edu
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