This case indicates that watershed infarction is a
potential complication of acute hypereosinophilia.
Local thrombus formation is possible; however, microthromboembolic cause must be considered,
given the known predilection of small emboli for
watershed regions.3,7 Clinicians should be aware of
such complications of hyperviscous states.
From the Department of Pediatrics, Division of Neurology,
Children’s Hospital of Eastern Ontario, Ottawa, Canada
(H.J.M., A.D.); and Department of Pediatrics, Division of
Hematology-Oncology, Children’s Hospital of Eastern Ontario, Ottawa, ON Canada (D.L.J.).

Copyright © 2008 by AAN Enterprises, Inc.
1.

2.

3.
4.

5.

Disclosure: The authors report no conflicts of interest.
Received September 11, 2006. Accepted in final form April 6,
2007.
Address correspondence and reprint requests to Dr. A. Doja,
Children’s Hospital of Eastern Ontario, Division of Neurology, 401 Smyth Road, Ottawa, Ontario, Canada, K1H 8L1;
adoja@cheo.on.ca

H. Tanaka, MD
M. Arai, MD
T. Kadowaki, MD
H. Takekawa, MD
N. Kokubun, MD
K. Hirata, MD

PHANTOM ARM AND LEG AFTER PONTINE
HEMORRHAGE

The phantom limb appears not only after limb
amputation1 but also after brain damage (known
as supernumerary phantom limb [SPL]).2 A previous review1 on phantom limb following limb amputation proposed the remapping hypothesis of
topographic reorganization of somatosensory
cortex in which the referred sensation from the
neighboring receptive field to phantoms is one of
at least five possible sources for phantom sensation. On the other hand, the current theories of
SPL emphasize the dissociation between established sensorimotor limb representation and
marked changes in afferent and efferent signals in
brain–limb communication.3,4
There is little information about SPL in patients with brainstem damage,5 which has somewhat different characteristics from phantom
sensations following supratentorial cerebral lesions, as well as from phantoms following limb
amputation. Here we address the contribution of
the brainstem to SPL.
Case reports. A 47-year-old woman (Case 1) and
a 55-year-old man (Case 2) developed acute pontine hemorrhage (figure, A [a, b] and B [a, b]).
They survived a locked-in period with complete
paralysis except for vertical eye movements. The
neurologic examination including sensory system
was limited due to poor communication. One
month after the onset, once they started showing
some functional recovery, SPL was recognized.
Neurologic examination of both patients after recovery revealed left hemiplegia and hemianesthe-

82

Neurology 70

January 1, 2008

6.

7.

Moore PA, Harley JB, Fauci AS. Neurologic dysfunction in the idiopathic hypereosinophilic syndrome. Ann
Int Med 1985;102:109–114.
Chusid MJ, Dale DC, West BC, Wolff SM. The hypereosinophilic syndrome: analysis of fourteen cases with
review of the literature. Medicine 1975;54:1–27.
Torvic A. The pathogenesis of watershed infarcts in
the brain. Stroke 1984;15:221–223.
Schaar CG, Brouwer OF, Wondergem JHM. Watershed infarction after near drowining in a two year old
child. Clin Neurol Neurosurg 1991;93:159–161.
Yazdi R, Cote C. Watershed infarct in a case of polycythemia vera. Clin Nucl Med 1986;11:665–666.
Ishii T, Koide O, Hosoda Y, Takahashi R. Hypereosinophilic multiple thrombosis. Angiology 1977;28:361–
375.
Pollanen MS, Deck JH. The mechanism of embolic watershed infarction: experimental studies. Can J Neurol
Sci 1990;17:395–398.

sia. Cognition was intact, without left neglect or
anosognosia. Both patients acknowledged the existence of extra limbs, as described in detail here.
Case 1. The arm located on the left along the side of the
true arm diverging from the elbow was formed perfectly
with a palm-up hand and five fingers, shorter than the true
arm (figure, A [c]). The patient could move it voluntarily,
though she described occasional loss of control and feeling
strangulated by the phantom arm around the neck resembling anarchic limb6 although there was no antagonistic action in the right arm like alien limb. She regained motor
control again without rule. Unpleasant burning or freezing
sensation was experienced occasionally in the third arm,
which was not caused by any noticeable factor, but matched
similar sensations she experienced in the true left arm prior
to hemorrhage. She also perceived a motionless third leg medial to the true left leg (figure, A [c]). The third arm and leg
persisted for 6 months without telescoping perception, with
no remarkable changes in left hemiplegia or sensory loss.
Case 2. The arm was located on the left along the patient’s true arm, of equal length and morphology to the true
arm, diverging from the shoulder with a palm-up hand (figure, B [c]). He remembered the existence of the third arm
since the locked-in state. Although he could move it, the voluntary control was lost sometimes with the occurrence of a
squeezing pain that was not triggered by any noticeable
event, and regained motor control again without rule. The
pain was similar to a sensation felt in the true left arm prior
to hemorrhage. The third arm disappeared immediately
whenever he touched the true left arm with the right hand.
He also perceived a third leg on the right inner side of the
true left leg, which was of similar length and shape to the left
leg (figure, B [c]). He could control the movement of the
third leg. The third arm and leg gradually disappeared without telescoping perception within 1 week during the recovery
of left hemiplegia.
We studied the localization of light touch sensation to
check the remapping of receptive fields for the arm,1 but neither patient reported referred sensation especially from the
face both ipsilateral and contralateral to the third arm. We

Figure

Axial T1-weighted images

not elicit a referred sensation from the ipsilateral
neighboring receptive field (face) to SPL. According to a report of anosognosia for hemiplegia after pontine infarction,7 the pons is suggested as an
integral part of a complex system subserving
body perception and that pontine lesions cause
functional deactivation of frontal and parietal areas through the limbic system and the thalamus.
Our cases showed sensory deafferentation with
pontine transection of pyramidal tracts, probably
triggering the phantom limb image. The mechanism of early disappearance of SPL in Case 2
could be related to earlier motor recovery.
Although there are no reports of SPL in
locked-in patients, Case 2 suggests the possible
existence of such phenomenon. One should be
aware of this in locked-in patients, especially because they cannot provide details of SPL and it
may produce distress.
From the Department of Neurology (H. Tanaka, T.K., H.
Takekawa, N.K., K.H.), Dokkyo Medical University,
Tochigi; and the Department of Neurology (M.A.), Tokyo
Medical University, Kasumigaura Hospital, Ibaraki, Japan.
Disclosure: The authors report no conflicts of interest.
Received August 2, 2006. Accepted in final form May 10,
2007.
Address correspondence and reprint requests to Dr. Hideaki
Tanaka, Department of Neurology, Dokkyo Medical University, Kitakobayashi 880, Mibu, Tochigi 321-0293, Japan;
hide@dokkyomed.ac.jp
Copyright © 2008 by AAN Enterprises, Inc.
ACKNOWLEDGMENT
The authors thank M. Saito for technical support.
REFERENCES
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2.
(a, b) Axial T1-weighted images (repetition time: 150 msec [A: Case 1], 593 msec [B: Case 2],
echo time: 15 msec [A], 15 msec [B], obtained 43 [A] and 22 [B] days after the onset of
stroke). Note the relatively right lateralized hematoma in the anteromedial to dorsolateral
portion from middle to upper pons in both cases. (c) Illustration of the configuration of supernumerary upper and lower phantom limbs reported by Case 1 [A] and Case 2 [B]. See text for
further details.

did not test the remapping of the third leg; however, the patients did not report any phantom sensations when they were
bed bathed.

Discussion. Our cases do not fit the remapping
hypothesis because total hemianesthesia should

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Ramachandran VS, Hirstein W. The perception of
phantom limbs. The D.O. Hebb lecture. Brain 1998;
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Brugger P. Supernumerary phantoms: a comment on
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PHANTOM ARM AND LEG AFTER PONTINE HEMORRHAGE
H. Tanaka, M. Arai, T. Kadowaki, et al.
Neurology 2008;70;82-83
DOI 10.1212/01.wnl.0000265394.80360.b5
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