Isolated sphenoid sinus disease - an overlooked cause of headaches
November 04 2015
Isolated sphenoid sinus disease is rare with an estimated incidence of 1-3 % amongst patients presenting with paranasal sinus disease, it is frequently misdiagnosed. Studies have indicated that the common presenting symptom of isolated sphenoid disease (ISD) is atypical headache - unresponsive to analgesics and and made worse by head movement. Localisation of the headache is very variable. Around 10% of ISD cases sre caused by fungal infection especially Aspergillus species.
Celenk et al ( 2015) have just published a study of 21 consecutive patients who underwent endoscopic sphenoidotomy for ISD. Diagnosis of isolated sphenoid sinusitis was based on history, physical examination, and radiologic evaluation. The most common initial symptom in all cases was headache in various localisations with the most common location being the vertex (24%). Nasal obstruction and discharge were secondary to headache.
The study also analysed the impact of sphenoid sinus surgery on headache intensity.The preoperative and postoperative mean VAS scores for headache were 8.24 ± 0.94 and 2.67 ± 1.49, respectively (p < 0.01). therefore surgery produced a statistically significant improvement.
The data suggests that sphenoid sinus disease should be considered as a diagnosis of patients presenting with sub-acute or chronic headache and endoscopic sphenoidotomy can relieve this condition.
CT scan showing blockage of left sphenoid sinus (source RIT radiology)
In 1983 a good review of 30 patients with infectious ISD was published in NEJM by Lew et al. Of the 15 chronic cases and 15 acute -the most prominent presenting symptom was severe frontal, temporal or retro- orbital headache. In acute cases purulent exudate was often seen in the middle and superior nasal turbinates.. Streptococcus pneumoniae( 41%) Staphylococcus aureus ( 29%) were the predominant organisms detected in acute cases - whilst in chronic cases gram negative bacilli were found in 43% and staphylococcal species in 24%. Notably aspergillus infection was found in 3/15 chronic ISD patients. In all cases an early and aggressive treatment regime was required to prevent often fatal complications.
When there is fungal involvement in this disease, the common process is a slow chronic but invasive and destructive process, often affecting the sphenoid and ethmoid sinuses. This is most often seen in the context of diabetes, corticosteroid use and in AIDS. Aspergillus fumigatus is the most common fungi isolated. Fungal infection should also be investigated in all these cases and treated rapidly when detected. A full description of fungal rhinosinusitis can be viewed in Chakrabarti 2009.