Journal of Korean Medical Science
Vol 4, No. 1, P 1-5, Mar. 1989

Mesencephalic Hemorrhage
—A Report of 3 Cases—

Seol Heui Han, M.D., Jae Kyu Roh, M.D., Ho-jin Myung, M.D.

Department of Neurology, College of Medicine, Seoul National University,

We studied three patients with spontaneous mesencephalic hemorrhages. All
presented with some degree of impaired consciousness and abnormal ocular
movements. One patient had a convergence-retraction nystagmus with a un-
ilateral hemorrhage contined to the dorsal midbrain. Another patient showed left
third nerve palsy due to a unilateral hemorrhage that involved ventral midbrain.
The third patient revealed left internuclear ophthalmoplegia with ataxia due to
a pinpoint hemorrhage in the tegmentum of the left midbrain. The patients
survived and major neurolgic deficits recovered, but abnormal ocular move-

ments persisted.

Key Words: Mesencephalic hemorrhage, Abnormal ocular movements, Impaired consciousness

INTRODUCTION
Spontaneous mesencephalic hemorrhage

is rare (Till, 1984), and this condition has not been
well recognized as a distinct clinical entity until re-
cently (Weisberg, 1986). Prior to the availability of the
CT, the prognosis of brainstem hemorrhage had
been held to be dismal. Since the advent of CT
more benign cases have been described. Although
the characteristic ocular findings could localize the
lesion to the midbrain tegmentum in our cases, there
were no useful symptoms or signs which would
allow confident separations of small brainstem hemor-
thages from ischemic brainstem lesions. Moreover it
is critically important to differentiate the hemorrhagic
condition from the ischemic processes in the mana-
gement of the patients with brainstem stroke at the
earliest stage. We report the clinical symptoms and
CT findings of three patients with primary mesen-
cephalic hemorrahge.

Address for Correspondence: Seo/ Heui Han, M.D. Depart-
ment of Neurology, College of Medicine, Seoul National
University, 28 Yunkun-Dong, Chongno-Ku, Seoul 110-744,
Korea (7601-2278)

CASE REPORTS

Case 1

A 40-year-old normotensive alcoholic man sud-
denly developed a headache and blurring of vision
while he was washing his hands. He became drowsy
and vomited several times over the next few hours.

On admission, he was slightly lethargic but easily
arousable and his blood pressure (BP) was 130/90
mmHg. Physical examination revealed some chronic
liver disease stigmata with palpable liver edge (two
finger breadth below right costal margin). Neurologi-
cal examination revealed no definite motor weakness
or signs of meningeal irritation. However, pain and
thermal sensations were decreased in the left side;
face was most densely involved and the arm was
slightly more affected than the leg. But the vibratory
sensation was intact. Tendon stretch reflexes were
normal. Ophthalmologic examination was remarkable
in that there were impaired upward gaze and con-
vergence-retraction nystagmus on attempted upward
gaze. The horizontal and downward gazes remained
intact. Although the light reflex was hardly demonstra-
ble, the near reflex was brisk. Both pupils were small
2

but isocoric.

The result of coagulation study and blood ammo-
nia level was normal. A computed tomographic (CT)
scan performed 4 days later disclosed a small non-
enhancing hematoma, approximately 1.5cm in size,
in the dorsolateral midbrain at the collicular level on
the right side (Fig. 1). During the subsequent week,

Fig. 1. CT demonstrates an area of hemorrhage in the
dorsal midbrain lateralized to the right.

he regained consciousness fully, but the gaze distur-
bance persisited. CT performed 2 weeks later showed
resolution of the hemorrhage.

Case 2
A 38-year-old hypertensive man was hospitalized

Fig. 2. Unenhanced CT reveals a high-density region in
the left tegmentum of midbrain adjacent to the posterior
third ventricle.

S.-H. Han, J.-K. Roh, H.-J. Myung

because of sudden onset of occipital headache and
visual disturbance. He had vomited several times but
did not complain of dizziness, weakness, or num-
bness.

On admission, his blood pressure was 150/110mmbHg.
He was well oriented, and memory was intact. The
right pupil was 3mm, the left 6mm; the right pupil
was briskly reactive to light, the left, fixed to light and
accomodation. Vertical gaze was restricted, more
marked on the left side. Although the horizontal gaze
of right eye was intact the left eye showed medial
gaze limitation and ptotic eyelid. The remainder of
neurological examination was unremarkable. CT rev-
ealed a high-density area in the mesencephalon at
the level of colliculus (Fig. 2). Magnetic Resonance
Imaging (MRI) performed 6 days after CT scan dis-
closed an area of abnormal signal intensity compati-
ble with hemorrhage in the upper midbrain. Four-
vessel cerebral angiography revealed no vascular
abnormality.

18 days later, CT showed resolution of the hemor-
rhage. 3 months after onset, the pupilary abnormality
was partially recovered.

Case 3

A 49-year-old normotensive man noted an abrupt
onset of diplopia, which was preceded by an occipital
headache. He then developed unsteady gait and
fluctuating somnolence.

On admission, his BP was 110/70mmHg. He was
somnolent but easily arousable. Speech was dysar-
thric. There was no motor or sensory deficit. Ocular
examination revealed a typical internuclear ophth-

Fig. 3. CT defines a pinpoint left lower tegmental mid-
brain hemorrhage.
Mesencephalic Hemorrhage

Table 1. Findings in three patients with mesencephalic hemorrhages

Case Age/Sex oes CT Risk Factor Angiography Outcome
1 40/M Convergence- Lt. dorsal Alcoholic ND Persisted
retraction midbrain chr. liver Ds EOM disturbance
2 38/M Lt. 3rd N Rt. upper HT Normal Partial recovery
palsy ventral of pupilary
midbrain abnormality
3 49/M INO Lt. lower (2) ND Persisted
ataxia midbrain EOM disturbance
tegmentum

INO: internuclear ophthalmoplegia, ND: not done

almoplegia (INO) on the left i.e., adduction of the left
eye was not feasible beyond the midline. The abduct-
ing right eye showed jerky nystagmus. The conver-
gence remained relatively intact. Pupils were isocoric,
briskly reactive to light. Finger to nose and heel-
knee-shin testing were definitely ataxic on the left.
The gait was wide based and ataxic. The remainder
of clinical examination was unremarkable. CT re-
vealed a tiny area of abnormal high density in the
left midbrain (Fig. 3). Over the ensuing week, gait
ataxia was slightly improved. A second CT scan
showed resolution of the hemorrhage.

When seen 6 months after the onset, gait ataxia
was almostly unnoticeable, but the INO persisited.

DISCUSSION

Spontaneous brainstem hemorrhage occurs most
commonly in the pons where the basis pontis and
tegmentum are usually involved (Silverstein, 1972).
Isolated, non-traumatic mesencephalic hemorrhages
have been only infrequently reported (Humphreys,
1978: Durward et al., 1982; Weisberg, 1986; Sand et
al. 1986).

Most patients with brainstem hemorrhage have a
grave prognosis and usually succumbed to death
within the first 24 hours after the acute event (Silver-
stein, 1972). However, widespread use of CT has led
to better recognition of non-fatal, relatively benign
cases of brainstem hemorrhage (Drury et al., 1984;
Del-Brutto et al., 1987).

All three patients in our series survived. Clinical
features and CT findings are summarized in the
table. Abnormal ocular movement was one of their
salient clinical features. One had typical convergence-
retraction nystagmus which was readily elicited by
attempted up-gaze. Another showed left third nerve
palsy. And the third patient revealed unilateral inter-
nuclear ophthalmoplegia (INO) which suggested the

involvement of medial longitudinal fasciculus (MLF).
The MLF consists of fibers, many of which carry a
conjugate horizontal eye movement command from
abducens internuclear neurons to the medial rectus
subdivision of the contralateral oculomotor nuclear
complex. Lesions of the MLF produce INO. When
the lesion is unilateral, the INO is characterized by
weakness of the adducting eye to ipsilateral to the
lesion and dissociated nystagmus of the abducting
eye to the lesion (Crane et al., 1983). The first two
patients showed somewhat limited vertical gaze es-
pecially on upward direction. These findings could
help in localizing the lesion to the midbrain tegmen-
tum (Christoff, 1974). Among the various abnormal
ocular movements the convergence-retraction nystag-
mus is characterized by quick phases that converge
and/or retract the eyes and it is usually caused by a
lesion near or within the dorsal mesencephalon
(Segara and Ojeman, 1961: Gay et al., 1969). It had
been concluded from electromyographic data that
this distinctive ocular movement results from syn-
chronous innervation and therefore simultaneous -
contraction of all rectus muscles during each quick
phase of nystagmus (Gay et al., 1969).

In addition to the visual disturbances, severe un-
usual headache of sudden onset with or without
vomiting was noted in all patients. The altered level
of consciousness such as fluctuating somnolence
was thought to be due to the involvement of peria-
queductal gray matter by hematoma itself and accom-
panied edema. But none of the patients showed
complete loss of consciousness. In patient 3 who
had an INO also showed left-sided limb ataxia. The
responsible lesion was thought to be located in the
dorsolateral portion of the mesencephalon, which
might affect the superior cerebellar peduncle by pres-
sure effect. Because the dentato-rubro-thalamic tract
passes via the superior cerebellar peduncle, any le-
sion near this structure may cause this type of limb
ataxia.
The etiology of these mesencephalic hemorrhages
was not determined. None had an evidence of trau-
ma or coagulation defects although one patient was
alcoholic and had a chronic liver disease. In one
patient (Case 2) whose four-vessel angiographic
study revealed no tumor stain, aneurysm or vascular
malformation, the lesion was thought to be either
due to rupture of a cryptic vascular malformation or
due to uncontrolled hypertension. Most midbrain vas-
cular malformations occur in dorsal mesencephalon,
are eccentric, but may cross the midsagittal line
(McCormick et al., 1968; Durward et al., 1982). In
our case 2 low field MRI demonstated distinct hema-
toma without further information about the nature of
the lesion. Recently Gomori et al (1986) demonstrat
ed characteristic appearance of occult cerebral vas-
cular malformations using the high-field MRI. These
lesions typically consists of central foci of high-in-
tensity signal, thought to be consistent with subacute
or chronic hemorrhage, surrounded by a peripheral
zone of low intensity, attributed most frequently due
to the paramagnetic effect of hemosiderin deposition.
They considered these findings as specific and virtu-
ally pathognomonic of cryptic vascular malformation.

The possible alternative causes of mesencephalic
hemorrhage are vascular disease consequent upon
chronic uncontrolled hypertension, or less likely, from
hemorrhage into a pre-existent brainstem tumor. In
our cases, except case 2, the patients were nor-
motensive. In general, hypertensive vascular changes
are rarely seen in the midbrain. The usual site of
microaneurysms within the brainstem is the pons,
hence the pons is the major site of spontaneous
brainstem hemorrhage. Furthermore follow-up CT
scans showed complete resorption of hematoma with
no residual abnormal high or low densities and con-
sequently brainstem tumor could be ruled-out. We
believe that high-field MRI might have been of great
help in elucidating further nature of hemorrahges in
our cases.

The clinical course of our patients was character-
ized by spontaneous improvement. None experieficed
neurological deterioration or needed surgical interven-
tion. Although some authors reported successful
surgical evacuation of mesencephalic hematoma
previously (La Torre et al., 1978; Humphreys, 1978),
decisions regarding the management of the patient
with a mesencephalic hemorrhage should be made
after careful evaluation of the clinical condition of the
patient. Unless impending brainstem compromise
that may result from expanding hematoma or from
hydrocephalus develops, treatment of patient with

S.-H. Han, J.-K. Roh, H.-J. Myung

mesencephalic hemorrhage should be conservative,
ie, supportive care, close clinical observation and
management of precipitating factors such as hyper-
tension and coagulation defects, should be in the
first place.

In our cases, the clinical outcome was excellent, in
that motor strength or coordination had eventually
recovered, but ocular problems such as gaze limita-
tion or pupillary abnormality did not resolve com-
pletely.

In summary all three patients showed typical me-
sencephalic localizing signs; upgaze limitation, con-
vergence-retraction nystagmus, sluggish light reflex
or INO with or without pupillary abnormality, and
some degree of altered consciousness. CT could
confirm the hemorrhages in the mesencephalon,
and all patients had good recovery with conservative
management.

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