Sleep Medicine 4 (2003) 247–249
www.elsevier.com/locate/sleep

Case report

Sleep disorder in alien hand syndrome
J.J. Ortega-Albása,*, M. de Entrambasaguasa, F.J. Montoyaa, A.L. Serranoa, D. Geffnerb
a

Sleep Unit, Department of Clinical Neurophysiology, Hospital General de Castellón, Avenida de Benicàssim s/n, E-12004 Castellón, Spain
b
Department of Neurology, Hospital General de Castellón, Avenida de Benicàssim s/n, E-12004 Castellón, Spain
Received 19 June 2002; received in revised form 19 September 2002; accepted 25 September 2002

Abstract
A 63-year-old right-handed woman developed an alien hand syndrome (AHS) after an acute infarction in the territory of the left anterior
cerebral artery. The uncontrolled hand movements were present during the daytime and eventually disturbed sleep. Polysomnography
revealed that these motor actions only appeared when the patient was awake. These awakenings emerged mostly from NREM sleep stage 2
during the first half of the night. There was no evidence of any epileptiform activity, dyssomnia or parasomnia. These movements were
controlled making her wear an oven mitt during sleep. The temporal distribution of this motor activity seems to follow the progressive
hyperpolarization of anterior horn neurons that occurs when sleep deepens. The accommodation of the grasp reflex in AHS probably helps
control this unwanted motor activity.
q 2003 Elsevier Science B.V. All rights reserved.
Keywords: Abnormal movements; Alien hand; Electroencephalogram; Polysomnography; Sleep; Stroke

1. Introduction
The alien hand syndrome (AHS) [1] is a motor
phenomenon in which one hand performs seemingly
purposeful actions that are beyond the patient’s voluntary
control. This rare condition has been related to a variety of
lesions of the corpus callosum, sometimes involving the
supplementary motor areas as well, or affecting posterior
brain territories [2 – 4]. Stroke is the most frequent cause. In
AHS the contralateral hand to the brain lesion performs
annoying free movements like grasping or groping; the
patient feels forced to grab it with the other hand in order to
control them. These motor actions can be very disturbing,
particularly at night, when the alien hand can continuously
disrupt sleep [3,5].

2. Clinical case
A 63-year-old right-handed woman with a previous
history of diabetes mellitus, hypertension and obesity
presented with a mild right hemiparesis and a self-limited
speech disorder. Magnetic resonance imaging (including
* Corresponding author. Tel.: þ 34-964-21-1000; fax: þ34-964-25-2345.
E-mail address: ortega_jua@gva.es (J.J. Ortega-Albás).

diffusion-weighted and vascular sequences) revealed a
6 £ 2 cm acute infarction in the territory of the left anterior
cerebral artery. Single photon emission computed tomography showed significant low blood flow in the left frontal and
anterior parietal cortex, as well as frontal and parietal
parasagital cortex. Computed tomography added no further
information. A couple of days after admission she
complained that her right hand had started moving around
in an uncontrolled, spontaneous fashion, crawling around
her head and grasping her bed sheets and clothes, so that she
had to grab it with her left hand in order to hold it.
Electroencephalogram (EEG) showed high voltage delta
waves on the left frontal and temporal-parietal regions,
suggestive of lesion, with a normal background activity, but
no epileptiform discharges. Her husband later reported that
he had witnessed an increase of these involuntary movements during the night. A nocturnal polysomnogram was
subsequently performed. EEG was recorded from surface
electrodes placed at Fp1, Fp2, C3, C4, A2, O1 and O2,
according to the international 10– 20 system. Electroculogram and submental electromyogram (EMG) were recorded
for sleep stage scoring, which followed common standards
[6]. Surface EMG was recorded from bilateral flexor carpi
radialis and extensor digitorum communis, and right deltoid
muscles. Electrocardiogram was also recorded. Bed time
was 7 h 17 min, with a total sleep time of 3 h 7 min. Sleep

1389-9457/03/$ - see front matter q 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S1389-9457(02)00236-8

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J.J. Ortega-Albás et al. / Sleep Medicine 4 (2003) 247–249

Fig. 1. Recording shows how the alien hand starts moving (right arrow) after the patient has awakened (left arrow). EEG prior to awakening corresponds to
NREM sleep stage 2. EEG electrodes nomenclature according to 10/20 international system. EOG, electroculogram; EMG, electromyogram; EKG,
electrocardiogram; FCR, flexor carpi radialis muscle; EDC, extensor digitorum communis muscle; R, right; and L, left.

latency was almost 17 min. NREM stage 1 sleep time was
32.5 min (17.4%), stage 2 was 63.5 min (34%), and stages
3 –4 were 47.5 min (25.5%). REM sleep time was 43 min
(23.1%), with two complete REM/NREM cycles. Eighteen
awakenings were recorded, each of them followed by a long
period of wakefulness. Total awakening time was 4 h 10
min, resulting in a low sleep efficiency of 43%. Awakenings
arose from NREM stages 1 (22.2%) and 2 (77.8%). Sleep
was reasonably continuous when present, with few stage
changes. Arousal index was under 5 per hour of sleep.
Video-EEG recording showed a nearly continuous right
hand movement, but only when the patient was awake (Fig.
1). This activity was more frequent in the first awakenings
than later on. The patient said she was afraid of falling
asleep in case her right hand clutched her neck and
suffocated her during sleep. Three weeks later, with no
subsidence of her hand’s movements, a second polysomnography was performed. Oral/nasal airflow, thoracic and
abdominal ventilatory effort, arterial oxyhemoglobin saturation (SaO2) and pulse rate were recorded in addition to
previous standards. Surface EMG was limited to bilateral
extensor digitorum communis and right tibialis anterior
muscles. On this occasion the patient wore an oven mitt on
her right hand. No spontaneous hand movements were
recorded; the patient slept all night long, and sleep
architecture was completely normal. An obstructive sleep
apnea syndrome was ruled out since no apneic episodes
were recorded. SaO2 was not under 97%. No periodic limb

movements were noted. Previous EEG lesional findings had
already disappeared.
So far, this patient is able to sleep quietly wearing her
oven mitt, and only suffers from AHS when her hand
receives tactile stimuli during the daytime.

3. Conclusion
Three forms of AHS have previously been described [4,
7]. Our patient presented the frontal form, which results
from damage to the supplementary motor area, anterior
cingulate gyrus, and medial prefrontal cortex of the
dominant cerebral hemisphere and anterior corpus callosum
and occurs in the dominant hand. Callosal AHS results from
an isolated anterior callosal lesion and is manifested by
intermanual conflict. The third form involves lesion of
posterior cortical or subcortical areas. It has been proposed
that the grasping in AHS is a cutaneous reflex mediated at a
subcortical or spinal cord level [8]. An alien hand-like
syndrome has also been described in the context of a partial
status epilepticus, with spike activity on the EEGs [9].
Alien hand motor activity may disturb the continuity of
sleep at night. We have only found two published cases of
AHS disturbing sleep. Both were frontal and clinically
similar to ours, but did not include any reference to
polysomnographic studies [3,5]. Ours showed that the alien
hand movements only occurred during wakefulness

J.J. Ortega-Albás et al. / Sleep Medicine 4 (2003) 247–249

emerging from superficial sleep, particularly stage 2, and
that these movements were more frequent early at night than
later on. These findings may express the normal gradual
hyperpolarization of anterior horn cells that occurs when
sleep deepens from superficial stages to slow and REM
sleep, causing a progressive decline in motor activity.
Habituation of cutaneous reflex to scant afferent stimuli
after some time in bed may also contribute to this temporal
distribution. An oven mitt probably controls alien hand
movements because it provides enough sensory stimulation
to the spinal grasp reflex to reach a level of accommodation
that stops the unwanted motor activity. Our study indicated
that the sleep disturbance in AHS might also arise from the
patient’s fear of being attacked by her hand while asleep,
rather than solely from its motor activity. Accordingly, AHS
can benefit from some psychological assurance.

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