fournal of Computer Assisted Tomography
7(1):130- 131, February
(© 1983 Raven Press, New York

Case Report

The Operculum Syndrome

R. Sandyk and M. J. W. Brennan

Abstract: A 48-year-old man presented with signs of pseudobulbar palsy. On
computed tomography (CT) he was found to have extensive tissue loss in the
region of the sylvian fissure and insula bilaterally. This appearance on CT
represents the radiological correlate to anatomic descriptions of the operculum
syndrome, and is useful in distinguishing the condition from pseudobulbar
palsy. Index Terms: Operculum syndrome—Pseudobulbar palsy—Computed

tomography.

The term operculum denotes the small region of
the telencephalic mantle covering the insula Reili,
and is comprised of contributions from the frontal,
temporal, and parietal gyri. Opercular lesions pro-
duce a clinical picture similar to pseudobulbar palsy
from which differentiation may be difficult. Such
differentiation is necessary because the operculum
syndrome is not associated with mental impairment
or sphincteric incontinence, in contrast to pseu-

From the Department of Medicine, Hillbrow Hospital, Johan-
nesburg, South Africa (R. Sandyk) and Neurological Unit,
Boston City Hospital, Boston, MA (M. J. W. Brennan). Address
correspondence and reprint requests to Dr. Sandyk at Depart-
ment of Medicine, Hillbrow Hospital, Johannesburg 2001, South
Africa.

130

dobulbar palsy, and thus has a better prognosis.
We have seen a man who presented with signs
suggestive of pseudobulbar palsy in whom com-
puted tomography (CT) scan revealed exten-
sive tissue loss in the region of the sylvian fissure
and insula bilaterally. On the basis of this appear-
ance a definitive diagnosis of operculum syndrome
could be made.

CASE REPORT

A 48-year-old man presented with a | year history of
dysphagia, dysarthria, and dysphonia. He was known to
be hypertensive and had been on a variety of
antihypertensive agents for many years. Two years pre-

FIG. 1. CT scan without contrast
showing extensive loss of tissue in the
region of the sylvian fissures involving
the opercula and insulae bilaterally,
multiple smail infarcts in the frontal,
temporal, parietal, and occipital lobes,
and dilatation of the ventricular system.
OPERCULUM SYNDROME 131

viously he had suffered a cerebrovascular accident which
left him with a mild right-sided hemiparesis.

He had left ventricular hypertrophy on chest
roentgenogram and on electrocardiographic criteria and
had moderate hypertensive changes in the fundi. There
was pseudobulbar paralysis of the 5th, 7th, and 9th
through 12th cranial nerves in association with marked
automato-voluntary dissociation. Muscle tone was in-
creased on the right with brisk deep tendon reflexes and
Babinski sign in keeping with an old cerebrovascular ac-
cident. No dementia or sphincteric dysfunction were
found, but frontal lobe release signs were present bilater-
ally. Pathological crying or laughing were not observed.

Routine laboratory determinations and cerebrospinal
fluid analysis were normal. Computed tomography re-
vealed prominent basal cisterns, extensive tissue loss in
the region of the sylvian fissure involving the opercula
and insulae bilaterally and approximately symmetrically,
several small lucencies in the frontal, temporal, parietal,
and occipital regions, and moderate dilatation of the en-
tire ventricular system (Fig. 1).

DISCUSSION

The operculum syndrome is quite uncommon—
there are only about 30 cases on record—and the

only known cause is cerebrovascular accident (1).
This may be of embolic or thrombotic nature and
is usually related to hypertension. The arteries are
all branches of the medial cerebral artery, the orbito-
frontal, prerolandic, rolandic, and anterior parietal
branches (1). The clinical picture may resemble
pseudobulbar palsy to the extent that differentiation
may be very difficult. Since the symptoms of im-
paired deglutition (salivation, difficulty with eating)
tend to regress rapidly in operculum syndrome, in
contrast with pseudobulbar palsy, and since mental
changes and sphincteric dysfunction do not de-
velop, it is important from a prognostic aspect that
the distinction be made (1). The appearance noted
on CT in this patient makes the diagnosis of oper-
culum syndrome inescapable.

REFERENCE

1. Bruyn GW, Gathier JC. The operculum syndrome. In: Vin-
ken PJ, Bruyn GW, eds. Handbook of clinical neurology,
vol 2, Amsterdam: North-Holland Publishing Co,
1969:776— 83,

J Comput Assist Tomogr, Vol. 7, No. 1, 1983