Neuroradiology (1999) 41: 356±357
Ó Springer-Verlag 1999

M. Nagao
K. Takeda
T. Komori
E. Isozaki
S. Hirai

Received: 10 September 1998
Accepted: 15 September 1998

)

M. Nagao ( ) × T. Komori × E. Isozaki ×
S. Hirai
Department of Neurology,
Tokyo Metropolitan Neurological
Hospital, 2-6-1, Musashidai, Fuchu,
Tokyo, 183-0042, Japan,
Tel.: + 81-4 23-23-51 10,
Fax: + 81-4 23-22-62 19

D IA G N O S T I C NE UR OR A DI O LO G Y

Apraxia of speech associated
with an infarct in the precentral gyrus
of the insula

Abstract It has been postulated
that the precentral gyrus in the left
insula is responsible for co-ordination of speech. We report a paitent
with this disturbance who showed an
acute infarct limited to this region.
Key words Speech, apraxia ×
Infarct, cerebral × Magnetic
resonance imaging

K. Takeda
Department of Neuropsychology,
Tokyo Metropolitan Institute
for Neuroscience, Tokyo, Japan

Introduction

Case report

Identification of regions which coordinate speech articulation is important, because speech is the most fundamental means of communication and its complexity
separates humans from other species [1]. Although the
left opercular region has been identified as coordinating
articulation of speech [2], the precise regions remain
unclear. Dronkers [3] reported that the region responsible is the left precentral gyrus of the insula, using
the overlay technique with images from 25 patients with
a stroke and in co-ordination of speech articulation (or
speech apraxia) and 19 patients without such deficits.
However, it is not known whether a lesion restricted to
this small gyrus impairs co-ordination of speech articulation. We saw a patient with speech apraxia and a cerebral infarct restricted to the left precentral gyrus of
the insula.

A 67-year-old woman with diabetes mellitus developed sudden
disturbance of speech. She was admitted to hospital 4 h after the
onset. Her blood pressure was 160/106 mm Hg, and serum glucose
was 130 mg/dl. She was alert but aphonic, showing oral and lingual
apraxia, but no weakness of muscles involved in articulation of
speech. She had showed intact writing skills and neurologically was
otherwise normal. Antithrombin therapy was started at once.
During the first 12 h of her admission, the oral and lingual apraxia
diminished, and she could speak. However, she showed difficulty in
initiating utterances and inconsistency in repeated production of
the same ones. She could perceive and recognise speech sounds,
including her own errors of articulation. Within 48 h, she recovered
fully. Fluid attenuated inversion recovery (FLAIR), T 2- and diffusion-weighted MRI showed a small high-signal area in the precentral gyrus of the insula (Fig. 1), diagnosed as a small infarct.

Discussion
This case clearly shows that the left precentral gyrus of
the insula coordinates articulation of speech. However,
oral apraxia accompanied speech apraxia in our case,

357

Fig. 1 FLAIR A and diffusionweighted B axial MRI show
high signal (arrows) restricted
to the left precentral gyrus of
the insula

and the relationship speech and oral apraxias is controversial. Oral apraxia has been thought to be related
to lesions in the left frontal, central opercular and anterior insular regions [1]. Dronkers [3] reported oral
apraxia in 48 % of patients with apraxia of speech. Co-

existence of oral and speech apraxias in our case suggests that regions coordinating speech articulation and
orofacial movement are adjacent or overlap. It remains
unproven whether the region identified is the only one
coordinating speech articulation.

References
1. Donnan GA, Darby DG, Saling MM
(1997) Identification of brain region for
coordinating speech articulation. Lancet
349: 221±222

2. Broca PP (1865) Sur la si›ge faculte du
langage articulØ. Bul Soc Anthropol
Paris 6: 493±494

3. Dronkers NF (1996) A new brain region
for coordinating speech articulation.
Nature 384: 159±161