THE LANCET

Case report

Rapid recovery from left
hemiplegia
Achim Gass, Michael G Hennerici, Jochen Gaa,
Andreas Schwartz
A 56-year-old woman with diabetes mellitus, chronic
diabetic renal failure, and peripheral arterial disease was
admitted for surgery to overcome vascular insufficiency in
her left leg. Her neurological history was unremarkable.
She underwent left femoral bifurcation thromboendarterectomy and iliofemoral bypass surgery. The
following morning she had dialysis and in the early
afternoon she was noted to have a left hemiparesis and to
be inattentive. A cranial computed tomography (CT) scan
showed multiple subcortical hypodense areas that
suggested old lacunar lesions due to diabetic small-vessel
disease but no evidence of acute ischaemia. When reviewed
by a neurologist, she was somnolent and disoriented in
place and time. There was continuous deviation of gaze to
the right and left-sided hemiplegia. Reflexes on the left
were absent with an extensor plantar response; those on the
right were present and unremarkable. Pain perception in
the left arm appeared greatly diminished. On the basis of
the severe neurological deficit and the reduced level of
consciousness, stroke due to infarction of the right middle
cerebral artery infarction was suspected. Magnetic
resonance imaging (MRI) for acute stroke including
diffusion-weighted (DWI) sequences (EchoPlanarSpinEcho ∞/TE123 ms, b=300/1200 s/mm2) was done.1-3
Conventional MRI (proton density, T2, and T1 weighted)
showed no further structural changes than the CT scan.
DWI showed no infarction of the right middle cerebral
artery, but 13 small areas of high signal intensity in both
hemispheres, all at the junction of white matter and cortex.
The largest (0·5⫻1·0 cm2) was in the arm field of the
motor strip in the right precentral gyrus (figure). A
diagnosis of microembolic stroke was suggested.
Echocardiography was normal and doppler studies of the
extracranial and intracranial arteries showed no
abnormalities.
Transoesophageal echocardiography showed a freely
moving thrombus 1·2 cm in length with a calcified base
adherent to the intimal wall of the aortic arch. Oral
anticoagulation with warfarin was started. Over the next 4
days there was gradual resolution of symptoms resulting in
a mild residual hemiparesis and attention deficit. On repeat
MRI, 6 days later, DWI showed that the cortical lesion in
the precentral hand area and three other lesions were
unchanged but the remaining nine lesions were no longer
visible. Two further episodes of psychotic agitation and
disorientation occurred and DWI each time showed a new
small lesion (in the left optic radiation, and in the right
non-dominant
cerebral
peduncle).
Repeat
transoesophageal echocardiography showed a slight

DWI MRI of supratentorial brain
There are small hyperintense areas of ischaemia (small arrows)
suggestive of small embolic infarction. Bright signal in the splenium of
the corpus callosum is due to anisotropy effects (open arrow)

reduction in the size of thrombus in the aortic arch and,
later on, complete resolution. At discharge, 7 weeks after
the initial stroke, she had made an excellent recovery with a
discrete residual incoordination of her left hand and no
abnormality on formal neuropsychological testing.
The clinical assumption of an extensive middle cerebral
artery infarction was incorrect; multiple small emboli were
the likely explanation for the severe ischaemic deficit and
quick recovery. CT and conventional MRI failed to show
this pathogenesis but DWI demonstrated a pattern
indicating a thromboembolic source from the heart. After
conventional echocardiography failed to show any
abnormality, transoesophageal echocardiography, which is
superior to conventional echocardiography in identifying
sources of cerebral embolism (including paradoxical
embolism via a patent foramen ovale),4 identified a freely
moving thrombus in the aortic arch. This location has been
noted to represent a high risk for recurrent embolic brain
infarction.5 In this case, DWI findings led to an intensified
search for the thromboembolic source, and prophylactic
measures were taken early. In the presence of inconclusive
CT and conventional MRI, DWI is useful not only in the
early identification of cerebral ischaemia,2,3 but also to
disclose its nature more reliably.
References
1

2

Lancet 1997; 349: 772
Department of Neurology (A Gass MD, MC Hennerici MD,
A Schwartz MD) and Department of Radiology (J Gaa MD),
Klinikum Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer,
68137 Mannheim, Germany
Correspondence to: Dr Achim Gass
5

772

3

4

Le Bihan D, Breton E, Lallemand D, et al. MR imaging of intravoxel
incoherent motions: application to diffusion and perfusion in
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Warach S, Gaa J, Siewert B, et al. Acute human stroke studied by
whole brain echo planar diffusion-weighted MRI. Ann Neurol 1995; 37:
231–41.
Marks MP, Crespigny A, Lentz D. Acute and chronic stroke: navigated
spin-echo diffusion-weighted MR imaging. Radiology 1996; 199:
403–08.
DeRook FA, Comess KA, Albers GW, et al. Transoesophageal
echcardiography in the evaluation of stroke. Ann Intern Med 1992; 117:
922–32.

The French Study of Aortic Plaques in Stroke Group. Atherosclerotic
disease of the aortic arch as a risk factor for recurrent ischemic stroke.
N Engl J Med 1996; 334: 1216–21.

Vol 349 • March 15, 1997