Keywords
Natural Orifice Endoscopic Surgery - Video-Assisted Surgery - Headache
Introduction
The crista galli lies on the midline of the cribriform plate. The falx cerebri attaches
anteriorly tothis bone formation a thin posterior border and slightly curve , and
the anterior border is attached to the frontal bone completing the margin of the foramen
cecum. The crista galli is embryologically derived from the ethmoid bone[1]. Regarding pneumatization of the crista galli, 2 theories are valid: pneumatization
can originate from the ethmoid sinus or the frontal sinus. The oldest theory in which
the pneumatization result from the ethmoid sinus is based on the embryological origin
of the crista galli, the ethmoid bone, and states that the displacement of ethmoidal
air cells would lead to increased aeration of the crista galli[2]. In the theory explaining pneumatization by the frontal sinus, sinus extension is
likely to cause increased aeration beyond the normal margin of the frontal bone[3]. The incidence of crista galli pneumatization has been reported to be between 2.8%
and 14.1%, depending on the population studied[2]
[4]
[5]. The possibility of involvement of inflammatory and/or infectious processes in pneumatization
of the crista galli is a noteworthy finding; however, such involvement is very rare
since there are no reports of it in the literature.
Aim
The aim of this study was to describe 3 cases where crista galli pneumatization evolved
into inflammation and infection and was treated surgically by endoscopic techniques.
Case Study #1
A 57-year-old female patient sought advice from the Specialized Service in Otolaryngology
in June 2008, complaining of a frontal headache that had been present for the last
year. The patient reported previous drug treatments for sinusitis including azithromycin
for 5 days, amoxicillin for 10 days, and a combination of amoxicillin and clavulanate
potassium for 10 days. However, she always experienced recurrence and progressive
worsening of her symptoms. Examination with video-endoscopy showed hypertrophy of
the lower and middle turbinates bilaterally associated with septal deviation in the
left nasal cavity. A computed tomography (CT) scan of the paranasal sinuses and nasal
cavity in the axial, coronal, and sagittal planes with a bone window of 2500–3500
rads was requested, which identified pneumatization of the crista galli with mild
mucosal thickening in the interior ([Figure 1]). This finding indicated endoscopic surgery through the transseptal approach in
the left nasal cavity for drainage and cleaning of the pneumatized crista galli ([Figure 2]).
Figure 1. Preoperative coronal section CT scan showing crista galli pneumatization with mucosal
thickening.
Figure 2. Video-endoscopic visualization of the left nasal cavity showing the septal incision
site and opening of the bone wall of the pneumatized crista galli. SEPTO = nasal septum;
CM = middle turbinate; CI = inferior turbinate.
Case Study #2
A 35-year-old female patient sought advice from the Specialized Service in Otolaryngology
in August 2010, complaining of a localized headache, cacosmia, and nasal obstruction
with progressive worsening of her symptoms during the previous 6 months. Her symptoms
had remained after drug treatment with amoxicillin and clavulanate potassium for 10
days. Video-endoscopy showed a deviated septum and inferior turbinate hypertrophy.
A CT scan of the paranasal sinuses and nasal cavity in the axial, coronal, and sagittal
planes with a bone window of 2500–3500 rads was requested, which identified pneumatization
of the crista galli apophysis with signs of mucosal thickening and obliteration interiorly.
We introduced antibiotic treatment (levofloxacin at a dose of 500 mg/day) for 14 days,
corticosteroids (prednisone at a dose of 40 mg/day) for 7 days, and symptomatic analgesia.
The patient's symptoms improved temporarily, but 5 days after treatment with antibiotics
was stopped, recurrence of her symptoms occurred. A second CT scan of the paranasal
sinuses and nasal cavity showed the maintenance of mucosal thickening and obliteration
within the crista galli ([Figure 3]). Endoscopic surgery by a transseptal approach through the right nostril was indicated
for drainage and cleaning of the pneumatized crista galli ([Figures 4]
[5]
[6]
[7]).
Figure 3. Coronal CT section showing mucosal thickening and obliteration of the pneumatized
crista galli.
Figure 4. Intraoperative endoscopic visualization of the right nasal cavity showing septal
incision and detachment. SEPTO = nasal septum; CM = middle turbinate.
Figure 5. Intraoperative endoscopic visualization of the right nasal cavity demonstrating septal
resection to allow approach to the bone wall of the pneumatized crista galli. SEPTO = nasal
septum; CM = middle turbinate.
Figure 6. Intraoperative endoscopic visualization of the right nasal cavity showing transseptal
opening of the bone wall of the pneumatized crista galli. SEPTO = nasal septum; CM = middle
turbinate.
Figure 7. Intraoperative endoscopic visualization of the right nasal cavity demonstrating the
detail of opening of the pneumatized crista galli, the lining of which shows mucosal
thickening and edema.
Case Study #3
A 31-year-old male patient sought advice from the Specialized Service in Otolaryngology
in April 2012, with the complaint of chronic nasal obstruction that had been present
since childhood and was associated with the symptoms of congestion, rhinorrhea, and
facial pain localized in the frontal region for the last 3 months. He had shown no
improvement after 2 previous episodes of treatment with antibiotics (levofloxin and
amoxicillin lasting 10 days and 14 days, respectively). He also reported a history
of adenoidectomy surgery prior to the age of 5. Video-endoscopic examination identified
the presence of septal deviation in the left nasal cavity associated with mild inferior
and right middle turbinate hypertrophy as well as hypertrophy of lymphoid tissue in
the nasopharynx. A sinus and nasal cavity CT scan in the axial, coronal, and sagittal
planes was requested, which identified septal deviation with bone spur formation,
prominence of the soft parts of the cavum, and pneumatization of the crista galli
with significant mucosal thickening and fluid present within ([Figure 8]). The patient underwent surgical resection of the lymphoid tissue present in the
nasopharynx and transseptal endoscopic drainage of the pneumatized crista galli.
Figure 8. Coronal CT section showing mucosal thickening and fluid within the pneumatized crista
galli.
Discussion
Most studies on the crista galli in the literature are anatomical descriptions from
surveys of series of CT scans or findings obtained during access to the anterior skull
base using endoscopic surgery[1]
[2]
[3]
[4]
[5]. There is a predominance in the study of pneumatization of the crista galli in females,
with a ratio of 2 females:1 male between the ages of 31 and 57 years. However, reports
on pneumatization of the crista galli related to the complaint of headache were not
found in the literature, and neither was evidence of the possibility of infection
from such pneumatization.
In the present study, it was possible to access pneumatization of the crista galli
and confirm the findings of CT scans showing signs of inflammation and/or infection
in all 3 cases by using a transseptal endoscopic approach. In the first patient, mucosal
thickening and edema was identified, while the second and third cases were associated
with purulent drainage and identification of mucosal thickening and edema within the
pneumatized crista galli. There were no transoperative or postoperative complications.
However, it is important to note that good knowledge of the field of endoscopic technique
and the anatomy of this region is essential, especially areas near the crista galli
such as the cribriform plate and other structures of the anterior skull base. Patients
were discharged on the same day as surgery, about 8 hours after operation. Antibiotics
(oral levofloxacin at a dose of 500 mg/day for 10 days in the first case and oral
clindamycin at a dose of 900 mg/day for 10 days in the other cases) plus corticosteroids
(oral prednisone at a dose of 40 mg/day for 7 days) were administered. Postoperative
follow-ups were performed weekly during the first month and monthly for another 6
months thereafter. These follow-ups ensured maintenance of the patency of the crista
galli through video-endoscopic examinations. After 6 months, the patients were advised
to return annually or if there was a need.
The collected material was sent for bacterial and fungal culture, but the results
were inconclusive, which can be explained by use of antibiotics prior to surgery.
The use of different antibiotics prescribed based on clinical criteria for sinusitis
was common in the history of all the patients prior to surgery. However, the use of
antimicrobial agents was apparently unsuccessful in treating this condition, in view
of the maintenance or recurrence of symptoms in all patients.
The findings of video-endoscopy examinations were nonspecific and did not contribute
significantly to the diagnosis of these cases. The suspected inflammation and/or infection
within the pneumatized crista galli were only confirmed by CT scan.
In all cases, pathological results confirmed the presence of fragments of upper airway
tract mucosa that were lined by pseudostratified ciliated epithelium resting on corium
and contained a discrete amount of mononuclear inflammatory cells and eosinophils,
which is characteristic of chronic inflammation of the respiratory mucosa contained
inside the crista galli. Furthermore, pathological examination in the third patient
confirmed the presence of lymphoid tissue in the nasopharynx that had no signs of
malignancy and was compatible with pharyngeal tonsil.
The patients complained of transient postoperative nasal obstruction and hyposmia/anosmia,
but showed improvement of symptoms and had no recurrence during a clinical monitoring
period of 3 years in the first patient, 1 year and 6 months in the second patient,
and 6 months in the third patient.
Conclusion
Pneumatization of the crista galli may be complicated by inflammatory and/or infectious
processes simulating rhinosinusitis and shows little response to drug therapy, thus
requiring endoscopic surgical treatment. In the current cases, such treatment was
demonstrated to be safe and effective.
