R Deepu^1*, A Venkateshwaran²

¹Assistant Professor, ²Professor And Head, Department of Radio Diagnosis, Karpaga, Vinayaga Institute of Medical Sciences and Research Centre, Maduranthakam, Chennai, Tamil Nadu- 603308, INDIA.

Email: drdeepurk@gmail.com

Table 1: National Society Consensus Guidelines for headache symptoms that warrant neuroimaging

Headache due to paranasl sinuses disease: Headaches resulting from disease of the nose or paranasal sinuses are usually associated with symptoms (congestion, fullness, discharge, obstruction) that point to the site of origin. Occasionally, however, nasal or sinus disease can be manifested solely as headache. In that circumstance, computed tomography (CT) scan of the sinuses may demonstrate an abnormality or disease of the nose or paranasal sinus.²⁵ Paranasal sinus causes of headache includes sinusitis (acute or chronic, bacterial or fungal), mucoceles, paranasal neoplasms. Whether or not nasal obstruction can lead to chronic headache is controversial. Paradoxically, sinus disease also tends to be under diagnosed, as sphenoid sinus infection frequently is missed.²⁶

Material and methods

This is a prospective study done in 200 cases with a primary complaint as headache undergoing Computed Tomography of the brain and limited paranasal sinus CT scan in Department of Radiodiagnosis at Karpaga Vinayaka Institute of Medical Sciences and Research Centre, Maduranthakam, Chennai, Tamil Nadu during the period from March 2020 to October 2020. The study was done using a SIEMENS Somatom emotion duo dual slice spiral CT scanner (Siemens Medical Systems, Germany). Computed tomography of the brain and limited paranasal sinus was performed with the patient in the supine position and the plane of the scan was taken parallel to the orbital-meatal plane at 10-25 degrees to Reid’s line. The limited PNS sections were acquired with the plane of section parallel to Reid’s line. Serial sections were taken with 4 mm slices supratentorial, 2.5 mm slices in the posterior fossa, and 5 mm through the paranasal sinuses. Intravenous iodinated contrast media was used for contrast study of the brain in selected patients with an average dose of 25 ml. Detailed clinical history of the patients were taken concerning the duration and severity of headache (subjective), diffuse/focal, sudden or insidious onset, presence of nausea and vomiting, photophobia/blurring of vision / red eye, neurological deficit, running nose, fever, etc. Associated systemic illnesses like hypertension, known extra CNS malignancies, etc were taken. The results were tabulated. The statistical analysis was then done for the diagnostic yield from imaging in patients with the only headache, headache with associated symptoms like nausea, vomiting, vision abnormality. Analysis of continuous variables like gender, analysis of diagnostic yield from imaging in patients with migraine, tension headache, chronic daily headache, and diagnostic yield in patients with known systemic illness was done. Inclusion Criteria: All patients (male and female) aged more than 12 years with headache (acute or chronic) with or without other neurological signs and symptoms. Exclusion Criteria: Headache due to ophthalmic cause, with the immediate history of trauma, known case of brain tumors or space-occupying lesion in the brain, and pregnant women with a headache.

RESULTS

Of these 200 patients studied, contrast enhanced CT (CECT) was done only in 8 patients and only plain CT of the brain was done for the rest of the patients. All patients had a limited study of the paranasal sinuses. A detailed clinical history of these patients was taken prior to including them in the study and included a history of the nature of the headache, onset (sudden or insidious), duration, associated symptoms like nausea, vomiting, blurring of vision, photophobia, fever, running nose, neurological deficits or any systemic illness. Of the 8 patients assessed with a CECT study, one had meningitis, two patients had metastases and two patients had cortical vein thrombosis. The age of the patients studied ranged from 12 years to 84 years. The patients involved in the study were divided into 7 age groups: less than 19,20-29,30-39,40-49,50-59,60-69 and greater than 70 years. There were 26 (13%) patients in the less than 19 years of age group, 52 (26 %) patients in the 20-29 years age group, 47 (23.5 %) patients in the 30-39 years age group, 33 (16.5 %) patients in the 40-49 years age group, 20 (10 %) patients in the 50-59 years age group, 17 (8.5 %) patients in the 60-69 years age group and 5 (2.5%) patients in the greater than 70 years age group. Significant abnormality was detected on imaging in the age group 50 -59 years (20 %), followed by 60-69 years (17.6 %). Imaging findings were least in the age group of under 19 years. Of the 200 patients studied, 93 (46.5%) patients were males and 107 (53.5%) patients were females. Among the 93 male patients studied significant abnormality was detected on imaging in 12 male patients. Significant abnormality was detected on imaging in only 10 female patients out of the 107 total female patients. Duration of headache varied from 2 days to 84 months with median duration being 6 months and were grouped in to 4 groups ie less than 1 month,1-3months,3-6months and greater than 6 months. The maximum number of the patients had a headache with duration of more than six months i.e 71 patients (35.5 %) followed by 51 patients (23.5%) with less than one month duration. Out of 51 patients with duration of headache less than one month significant abnormality was detected on imaging 15 patients. Among the 71 patients with headache duration of more than 6 months only 2 patients showed significant abnormality on imaging. Headache without any associated symptoms or neurological deficit was the main reason for referral of patients for neuroimaging (60.5 %) followed by headache with vomiting (22 %). Among the study group of 200 patients, 11 patients had migraine, 3 patients had tension headache, 38 patients had chronic daily headache, 8 patients had headache due to sinusitis, 2 patients had headache due to meningitis and in rest of the cases the headache did not fit into any of the diagnostic criteria and are labelled as others. One patient with migraine who had presented with sudden severe onset of headache showed an acute infarct in the right middle cerebral artery territory on imaging. One patient with chronic daily headache had sphenoid sinusitis. No abnormality was detected in patients with tension type of headache. Among the 8 patients suspected to have sinusitis, 4 had acute sinusitis on imaging. The rest of the group showed abnormality in 16 cases out of 138. Imaging findings were normal in 178 cases (89 %) of the study population and significant abnormality was detected in 22 cases (11 %). Among the 22 patients with abnormality on imaging, 13 had intracranial abnormality as the cause for headache and 9 patients had sinusitis as the cause for headache. Among the 9 patients with sinusitis, deviation of the nasal septum with sinusitis was seen in 4 patients. Overall, deviation of nasal septum was seen in 26 patients (13%). Among the 9 patients with sinusitis, 5 patients had acute onset of headache following runny nose and fever.Two patients had bilateral maxillary sinusitis, two had bilateral maxillary and ethmoid sinusitis, one had bilateral sphenoid sinusitis, one bilateral ethmoid and sphenoid sinusitis, one right frontal, one fronto-ethmoid and one pansinusitis. The yield of imaging in patients with only headache was low with positive likelihood ratio of less than 1. Among the 200 patients in the study group, 168 patients had diffuse headache with abnormality detected in 16 (9.7%) and 32 had focal headache with abnormality detected in 6 (16.7%). Most of these patients with focal headache had sinusitis on imaging. Headache with vision abnormality was seen in 22 patients. Significant abnormality in the brain CT was seen in 4 cases; 2 patients had acute infarct, 1 had metastasis to the cerebellum and 1 cortical vein thrombosis with a positive likelihood ratio of 2.3. Headache with nausea was seen in 22 patients and abnormality was detected on imaging in 2 patients. Both of them had sinusitis on imaging which could not explain the symptom. Headache with nausea had positive likelihood ratio 0.71. Headache with vomiting was seen in 44 patients and 13 of these patients showed significant abnormality on imaging i.e. 6 had a space occupying lesion in the brain, 2 acute infarcts, 1 SAH (subarachnoid haemorrhage), 4 CVT (cortical vein thrombosis) with positive likelihood ratio of 5.17. Headache with fever was seen in 16 patients. Of these patients 5 had sinusitis on imaging with an odds ratio of 3.3. Severe headache was seen in 14 patients. No grading scale was used for grading the degree of headache and it was purely subjective. Of these 14 patients, 7 had abnormality on imaging with odds ratio of 6.2. Sudden onset of headache was seen in 19 patients and 12 patients showed an abnormality on imaging with a positive likelihood ratio of 4.4. Systemic illness was present in 21 patients, most of them being hypertensive (15 patients). Of these, significant abnormality was seen in 5 (23.8%). SAH was seen in one patient who had come with a history of sudden onset of severe headache and accelerated hypertension, two known cases of carcinoma of cervix had posterior fossa metastasis, one known case of chronic myeloid leukemia had subdural deposits and one known case of rheumatic heart disease with heart valve replacement had multiple acute infarcts. In this study 2 patients had acute infarct on imaging and both the patients had a risk factor for ischemic insult to the brain. One was a case of rheumatic heart disease and the other was a patient with migraine. Both the patients had sudden onset of severe headache with vomiting and blurring of vision. In this study, 4 patients had cortical vein thrombosis. All these patients had acute onset of severe headache associated with vomiting. Blurring of vision was seen in one patient. Superior sagittal sinus thrombosis was seen in 2 patients, 1 patient had transverse sinus thrombosis and 1 had combined transverse sinus and straight sinus thrombosis. None of the patients had parenchymal changes on imaging .Other incidental findings of limited paranasal sinus imaging in this study are presence of polyps / retention cysts. Maxillary sinus was the most common site for polyp / retention cyst formation.

Table 2: Frequency of distribution of abnormalities detected on imaging

Table 3: Likelihood ratio for detecting an abnormality on imaging

Table 4: Distribution of various abnormality detected on imaging in patients with different symptoms

            Image 1                                                                             Image 2

          Image 3                                   Image 4                                             Image 5

Legend

Image 1: (case 165): 38-year-old male with diffuse severe headache and vomiting showing hyperdense straight sinus suggestive of thrombosis; Image 2 (Case 46): 76-year-old female patient with accelerated hypertension and the worst headache of life showing diffuse subarachnoid hemorrhage; Image 3 (case 160): 36-year-old male patient with diffuse headache and vomiting showing extra-axial space occupying lesion proved to be a meningioma; Image 4 (case 36): 42-year-old female patient with migraine and sudden onset of severe headache with blurring of vision showing an acute infarct in the right middle cerebral artery territory; Image 5 (case 54): 45-year-old male patient with frontal headache and fever showing bilateral maxillary sinusitis.

DISCUSSION

Among the 200 patients studied, most number of patients with headache belonged to the younger age group of 30 to 39 years (23.5 %). Significant abnormality was detected on imaging in the age group 50 -59 years (20 %), followed by 60-69 years (17.6 %). Imaging findings were least in the age group of under 19 years. These findings were similar to studies done by Carrerra G. F et al.²³ and Aygun D et al.¹¹ which showed increasing age to be strongly associated with a significant abnormality. There was no significant gender difference in detecting abnormality on imaging. Most common reason for referral for neuroimaing was only headache without any associated symptoms. Significant abnormality was detected on imaging in patients with a duration of headache less than one month i.e 15 patients out of 51.These findings were in concordance to the study conducted by Ewans RW et al.⁵ where the significant abnormality was detected in patients with recent onset of headache .In our study a significant abnormality were noted in 22 patients, where 6 (3%) showed a space-occupying lesion in the brain (intra or extra-axial), 2 (1%) had acute infarcts, 1 (0.5%) had a subarachnoid hemorrhage, 4 (2%) had cortical venous thrombosis and 9 (4.5%) had sinusitis. The prevalence of space-occupying lesions in the brain was similar to the study conducted by Sherf M et al.²⁴Headache without any associated symptoms or neurological deficit was the main reason for referral of patients for neuroimaging (60.5 %) followed by headache with vomiting (22 %). These observations was similar to the study conducted by Sherf M et al., to evaluate the indications and results for brain CT by primary care physians.²⁴Among the study group of 200 patients, 11 patients had a migraine, 3 patients had a tension headache, 38 patients had a chronic daily headache, 8 patients had a headache due to sinusitis, 2 patients had a headache due to meningitis and in rest of the cases, the headache did not fit into any of the diagnostic criteria and are labeled as others.The yield from imaging in primary type of headache is low, which is similar to the study conducted by Evans RW et al.⁵ Ischemic episodes are a known entity in patients with migraine and is suspected when there was a change like a headache with or without associated neurological findings. In the present study, one patient with migraine had a sudden onset of a severe headache without any neurological findings.The rate of detecting an abnormality in migraine was 8% which was more than the earlier studies (0-3%). This high rate of detecting an abnormality on imaging in this study is due to a relatively low number of patients with migraine. Headache with nausea was seen in 22 patients and abnormality was detected on imaging in 2 patients. Both of them had sinusitis on imaging which could not explain the symptom. Headache with nausea had a positive likelihood ratio of 0.71 suggestive of the low probability of finding an abnormality on imaging in patients with nausea and these findings were similar to the study conducted by Mitchell et al.⁶ Severe headache was seen in 14 patients. No grading scale was used for grading the degree of headache and it was purely subjective. Of these 14 patients, 7 had an abnormality on imaging with an odds ratio of 6.2 with a high probability of finding an abnormality on imaging. These findings were in concordance with the study conducted by Mitchell et al.⁶ Among the 22 patients with abnormality on imaging, 13 had intracranial abnormality as the cause for headache and 9 patients had sinusitis as the cause for headache. Among 9 patients with sinusitis, deviation of the nasal septum with sinusitis was seen in 4 patients. Overall, deviation of nasal septum was seen in 26 patients (13%). Among the 9 patients with sinusitis, 5 patients had acute onset of headache following runny nose and fever. Two patients had bilateral maxillary sinusitis, two had bilateral maxillary and ethmoid sinusitis, one had bilateral sphenoid sinusitis, one bilateral ethmoid and sphenoid sinusitis, one right frontal, one fronto-ethmoid and one pansinusitis. The patient with sphenoid sinusitis had chronic on and off headache without any symptoms to suggest sinusitis on clinical evaluation. Sphenoid sinusitis is one of the commonly clinically missed sinusitis, often patients come with chronic headache. It is often missed on plain radiograph. Imaging plays an important role in these patients to identify the cause for headache. Since most of the sinus headache have clinical feature suggestive of either intracranial or paranasal abnormality, cross sectional imaging modality is the choice to differentiate sinus headache from intracranial cause of headache in difficult situations. Acquisition of limited PNS sections along with the CT brain increases the yield as seen in this study. Other advantages of acquiring limited PNS sections are to differentiate paranasal sinus cause of headache from intracranial causes and reduces the cost arising from dedicated CT PNS imaging. The yield of CT brain and limited paranasal sinus imaging together was 22 (11%) were as CT brain alone would have been 13 (6.5%). Other incidental findings of limited paranasal sinus imaging in this study are presence of polyps / retention cysts. Maxillary sinus was the most common site for polyp / retention cyst formation. Significant number of patients presenting with headache had etiology attributed to both the paranasal sinus causes and intracranial causes. Thus additional acquisition of limited paranasal sinus along with brain increases yield with cost reduction, facilitation of better management of patient and reducing the patient apprehension. In comparison with MRI as a screening modality, availability of MRI machine, the cost of imaging, time of acquisition make CT the initial and preferred screening modality in a patient with headache. Perceived disadvantages of CT as screening modality will be in the evaluation of sellar and parasellar causes of headache, posterior fossa lesions, characterization of lesions and radiation exposure.

CONCLUSION

Screening in headache with CT not only helps in identifying an abnormality but also helps to rule out structural causes for headache thereby reducing patient apprehension. Additional acquisition of limited PNS sections increases the yield from imaging, reduces the cost from dedicated PNS imaging, and helps to differentiate paranasal sinus cause of headache from the intracranial cause. Diagnostic yield from CT is better in patients with severe headache or headache of sudden onset or headache associated with vomiting, fever, runny nose, or neurological deficits.

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