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Solitary abducens palsy secondary to isolated sphenoid sinus
disease (ISSD) is rare and early management is important.
There is no report regarding the results of endoscopic sinus
surgery (ESS) for prolonged abducens palsy due to ISSD. We
present four cases of ISSD with solitary abducens palsy that
received ESS from 1995 through 2000. The interval between
onset of diplopia and ESS was longer than 96 hours (range,
4 days to 42 months). The sphenoid lesions were caused by
Aspergillosis in two patients and inflammation in two. Three
patients recovered completely from abducens palsy after 4-17
months and had no surgical complications. In conclusion, ESS
is a safe and effective treatment for ISSD with abducens palsy.
Recovery from abducens palsy is slow and progressive. Improvement
of extraocular movement is an early sign of recovery. (Chang
Gung Med J 2002;25:689-94)
Key words: isolated sphenoid sinus disease, abducens palsy,
endoscopic sinus surgery.
Isolated sphenoid sinus disease (ISSD) accounts for 1% to
3% of all sinus lesions.(1-3) Isolated sphenoid lesion is
easily misdiagnosed because of its subtle onset and vague
symptoms.(1-4) Since the 1990's, this disease has been well
documented and permanent cranial neuropathy and death have
been reported.(1-5) Therefore, early antimicrobial therapy
and/or surgical treatment are warranted.(2-4) For cases in
which the orbital complication resulted from sphenoethmoid
sinus, surgical drainage or decompression of sphenoethmoid
sinus and orbital suppuration are regarded as the quickest
methods of treatment.(6)
Involvement of the sixth cranial nerve in ISSD is unusual.(1)
Surgical intervention should be introduced as soon as possible
after medical therapy failed.(3,6) The role of endoscopic
sinus surgery (ESS) for prolonged abducens palsy resulting
from ISSD is still unclear. There have been no articles discussing
this condition in English literature. Herein, we present four
rare cases of ISSD with solitary abducens palsy that lasted
for more than 48 hours before ESS at Chang Gung Memorial Hospital
from February 1995 through May 2000. We also briefly discuss
a review of the literature about this disease.
CASE REPORT
Case 1
A 46-year-old healthy woman had suffered from intermittent
headaches and bilateral retroorbital pain since May 1997.
In June 1997, she presented with double vision for 2 days.
After neurological and ophthalmologic examinations, bilateral
abducens palsies were noted. Subsequently she was referred
to our clinic for further examination. Physical examination
revealed that a little mucopus had accumulated on the nasopharynx
but no tumor. A magnetic resonance image (MRI) with gadolinium
showed normal cerebrum and midbrain but abnormal enhancement
over bilateral sphenoid sinuses. Endoscopic sinus surgery
was performed under general anesthesia on the fourth day after
presentation of diplopia. The bilateral sphenoid sinuses were
filled with clay materials and a bony defect of the left sphenoid
roof was also noted. Aqueous better-iodine and isotonic sodium
chloride solutions were used for irrigation following aspiration
of pus. The wound was filled with gentamicin ointment. The
pathology showed Aspergillus infection and granulomatous inflammation
of the mucosa. Therefore, invasive aspergillosis of bilateral
sphenoid sinuses with bilateral abducens palsy was diagnosed.
The antimicrobial drug was subsequently switched from penicillin
G sodium to amphotericin B because the wound recovered slowly.
She received regular debridement and sinoscopic examination
at our clinic and the sphenoidal mucosa healed within 6 months.
Her extraocular movement (EOM) improved during the follow-up
period. The diplopia had completely resolved within 17 months.
Case 2
A 45-year-old man received a Caldwell-Luc operation for chronic
paranasal sinusitis in 1982. He had suffered from double vision
since April 1995. He visited our neurology and ophthalmology
outpatient clinic complaining of deteriorating diplopia in
May 1998. A physical examination showed normal findings except
for left sixth cranial nerve palsy. No preoperative medication
was given. A MRI showed abnormal signal intensity in the left
sphenoid sinus in both T1 and T2 weighted images as gray in
comparison with the brain. He was referred to our clinic and
neither nasopharyngeal tumors nor mucopus were noted. We performed
an ESS to explore the sphenoid sinus in June 1998 (42 months
after onset of diplopia). The redundant posterior end of the
middle turbinate was partially resected for a better view
of the sphenoethmoidal recess. We found mild edema and diffuse
fibrosis of sphenoidal mucosa after a left sphenoidotomy.
The pathology revealed chronic inflammation but no malignant
changes. Prophylactic antibiotic therapy (penicillin G sodium)
was prescribed. He also received regular debridement at our
clinic. Unfortunately, his diplopia did not resolve and an
ophthalmologic surgery was undertaken in September 1998 to
recess the left medial rectus muscle and to resect the left
lateral rectus muscle. His sphenoidal mucosa had healed within
6 months of the surgery.
Case 3
A healthy 67-year-old woman complained of intermittent headaches
over the left temporal and frontal areas and progressive exacerbation
of double vision since July 1998. She had taken acetaminophen
for relief of her headache. One month after taking the medication,
left abducens palsy and no other deficits were noted. She
was referred to our clinic for further evaluation. An MRI
showed an abnormal signal enhancement of the left sphenoid
sinus in T1- weighted and T2- weighted images (Fig. 1). Endoscopic
sinus surgery was performed under general anesthesia in October
1998 (3 months after the onset of diplopia). Fungal balls
were found in the sphenoid sinus. After removal of the materials
and diseased mucosa, the residual mucosa was clear and the
bony wall was intact. Then the sphenoid sinus was irrigated
with aqueous better-iodine and isotonic sodium chloride solutions,
and then filled with gentamicin cream. The pathology was diagnosed
as Aspergillus sphenoid sinusitis. Prophylactic antibiotics
with penicillin G sodium were given for 7 days and intensive
debridements were done. Her wound recovered well and no further
complications developed. Her mucosa healed within 1 month
and the left abducens palsy resolved completely within 6 months.
Case 4
A 69-year-old man received a Caldwell-Luc operation for chronic
paranasal sinusitis in 1982. In April 2000, he presented with
left intermittent retroorbital pain and progressive double
vision for 1 month. Neither exophthalmos nor periorbital infection
was found. The left sixth cranial nerve deficit was impressed.
His pain was relieved by acetaminophen. A computed tomography
(CT) scan showed moderate opacification of the left sphenoid
sinus (Fig. 2). He was subsequently referred to our clinic.
The nasopharyngeal mucosa was smooth. Endoscopic sinus surgery
was performed in May 2000 (2 months after the onset of diplopia)
and the left sphenoidotomy after ethmoidectomy was carried
out. The thick jelly-like pus in the sphenoid sinus was aspirated.
The inflamed mucosa was removed medially and inferiorly after
irrigation with better-iodine and isotonic sodium chloride
solutions. Pathology revealed chronic inflammation and no
malignant cells. He received antibiotic therapy with penicillin
G sodium for 3 days and regular debridements. The mucosa healed
within 3 months and the diplopia had disappeared within 4
months.
DISCUSSION
Sphenoid sinus disease is usually accompanied by an involvement
of the other sinuses and ISSD is rare. Direct spreading from
the ethmoid sinusitis, anatomic variation, or iatrogenic trauma
may change the function of drainage and predispose the area
to the disease.(3,4) Several researchers have demonstrated
that ISSD frequently occurs in middle aged (about 40 to 50
years old) and, as in our cases, elderly (mean age, 57 years
old) patients.(1,2,4) The etiologies of ISSD include inflammatory
diseases, neoplasms, fibrosseous disease, encephalocele and
internal carotid artery aneurysms.(1) In our report, inflammatory
disease resulted in their disorders (fungal infection: 2;
chronic inflammation: 2) and a previous sinus surgery seemed
to be a predisposing factor for this disease because two cases
had undergone Caldwell-Luc surgery (Table 1).
The presenting symptoms and signs in our cases were headache,
retro-orbital pain, and visual disturbance. The onset of symptoms
was subtle and the course progressed slowly. Therefore, patients
usually had a prolonged course.(4) In addition, indistinct
symptoms and signs made it difficult to diagnose this disease
earlier.(1-4) Lesions of the sphenoid sinus might involve
the adjacent structures including the optic, abducens,(1)
and oculomotor nerves.(2) We should note that an involvement
of the abducens nerve was more frequently associated with
malignancies because half of the neoplastic cases presented
with abducens palsy.(1) Endoscopic examination and MRI may
provide a better view of the soft tissue.
The possible mechanisms for the development of abducens palsy
from ISSD include 1) inflammation from sphenoidal sinusitis
to infect abducens nerve sheath and to result in nerve palsy,
2) the sphenoid mass expanding to the cavernous sinus or superior
orbital fissure and compressing the abducens nerve, and 3)
vasculitis or cavernous sinus thrombosis causing ischemic
infarction of the abducens nerve.(6) We think the dorsal clival
artery, which arises from the meningohypophyseal trunk and
supplies the proximal portion of the intracavernous abducens
nerve may play a significant role in the isolated abducens
palsy.(7)
The common pathogens isolated from acute sphenoid sinusitis
are Staphylococcus aureus, Streptococcus species, and Aspergillus.
Gram-negative and anaerobic organisms are more associated
with chronic sphenoid sinusitis.(2,3) Broad-spectrum antimicrobial
therapy is recommended as the fist-line treatment of ISSD.
However, surgical intervention should be performed when the
symptoms become worse, they are sustained for 24 to 48 hours
or complications appear.(2,3,6) Various surgical techniques
have been used to treat patients with ISSD. During the past
20 years, ESS is one choice of surgery for sphenoid sinus
lesion.(1-5) Endoscopic sinus surgery is safe and feasible
when performed by a well-trained otolaryngologist. As a rule
of thumb, ESS for sphenoid sinus diseases should avoid damaging
the nearby important structures, such as the optic nerve and
internal carotid artery.(8) Surgeons should clearly identify
these vital organs and refrain from over-manipulation.
We tried to resolve the prolonged diplopia secondary to sphenoid
lesions by ESS and antimicrobial therapy; the intervals between
onset of diplopia and sphenoidotomy were from 4 days to 42
months. Fortunately, the outcomes of our patients were good.
Three cases completely recovered within 4 to 17 months, however,
one had no improvement. We believed that the prolonged interval
between onset (42 months) in case 2 was probably the cause
for his irreversible neuropathy. As compared with the results
reported by Muneer et al, the recovery time of our patients
was longer (4 to 14 months versus 24 to 48 hours).(5) It seems
that the longer the diplopia persists, the longer the recovery
time of is needed. Certainly, the degree of severity and duration
of the cranial nerve deficit influenced the outcome. The course
of recovery from the prolonged diplopia is slow and long.
Therefore, this result accounts for the necessity of a long-term
follow-up. We also suggest regular and continued debridements
and sinoscopic examinations to prevent further inflammation.
In addition, an improvement of the EOM is a good sign for
recovery. Finally, bleeding, cerebrospinal fluid rhinorrhea,
and damage of nearby structures may also effect the prognosis.
In summary, although surgical interventions were delayed for
more than 48 hours, the chance of complete recovery still
existed after ESS. The course of recovery was slow and the
improvement of EOM was an early sign of recovery.
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