Idiopathic
occipital neuralgia vs compressive C2-3 cervical pathology:
A clinical dilemma - Case report
Rewati R Sharma, Sanjay J Pawar, Ebenezer J Dev, Ashok K Mahapatra, Pravin Kharangate,
Luke Marin Josephi
A clinical dilemma - Case report
Rewati R Sharma, Sanjay J Pawar, Ebenezer J Dev, Ashok K Mahapatra, Pravin Kharangate,
Luke Marin Josephi
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ABSTRACT
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Idiopathic occipital neuralgia and compression of upper cervical (C2
and/or C3) pathology, both, present with common features in their initial
clinical course. The former is almost always considered a benign condition
due to the disturbance of the occipital nerves in their course, usually
in the suboccipital triangle and warrants a deliberate conservative therapeutic
approach, unless it becomes intractable. Whereas C2 and/or C3 radiculopathy
invariably occurs due to a compressive pathology until proved otherwise
and merits a formal surgical approach. A clinical dilemma exists in initial
stages of their presentation.
Authors present an interesting and instructive rare case of an intradural
C2-3 schwannoma arising from the left C3 nerve root, which was initially
treated as a case of idiopathic occipital neuralgia until patient developed
quadriparesis. Timely neurosurgical referral and intervention restored
her to normalcy. Pertinent clinical features are presented and discussed
with a brief review of the literature.
Keywords: Idiopathic occipital neuralgia, compressive C2-3 radiculopathy,
occipital triangle, schwannoma, acute cervico-medullary compression, quadriparesis
and microsurgery
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INTRODUCTION
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One of the most common and often misled causes of headaches is idiopathic occipital neuralgia.7,8,10,11 In clinical practice, the patients presenting with episodic severe shooting/lancinating suboccipital pains, radiating towards the vertex, aggravated by neck movements and with a point or localised suboccipital tenderness are rather commonly diagnosed as cases of idiopathic occipital neuralgia.11 This is especially more so when a past medical history of a cervico-occipital trauma (even if subtle) is present. In the absence of neurological deficits, it is invariably considered as a benign condition due to the disturbance of one of the occipital nerves in their course, especially in the suboccipital triangle and a deliberate conservative therapy is routinely advised. Interestingly, although comparatively far less common, compressive upper cervical (C2 and/or C3) radiculopathy may also present in their initial course with similar clinical features. A compressive C2 or C3 radicular lesion if present in such a clinical setting will therefore be missed until it’s progression to an advanced stage with high risks of upper cervical cord compression.
Authors report a case of C2-3 cervical schwannoma, which was initially treated as a case of idiopathic occipital neuralgia until it progressed to quadriparesis at a peripheral hospital. However, the timely neurosurgical referral and intervention restored patient to normalcy. Pertinent clinico-radiological features are presented and discussed with a brief review of the literature.
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CASE
REPORT
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A 24-year-old female was initially seen at a peripheral hospital with chief complaints of episodic shooting/lancinating pains of short duration in the left suboccipital triangle radiating towards the vertex for a period of about three months. Her clinical examination was unremarkable except for a tender spot like a trigger point in the suboccipital region. Her cervical spine x-rays (antero-posterior and lateral views) were normal. She was diagnosed as a case of idiopathic occipital neuralgia and was being treated symptomatically for about six months; initially with analgesics and later with local injections. She also underwent traditional branding by a local healer but without any long-term benefit. Three days prior to the neurosurgical referral patient started complaining of acute onset and rapid progressive weakness of limbs and became quadriparetic. Retention of urine was relieved by catheterisation. A high cervical lesion was suspected and therefore the patient was referred to the Neurosurgical services. At the time of admission in the neurosurgical ward, she was confined to bed.
Her general physical examination showed a head tilt towards left due to the severe pain at the left suboccipital triangle. She had multiple café-au-lait spots over her body. She had quadriparesis with muscle power of about grade 2 all over. The deep tendon reflexes were exaggerated with extensor plantar responses. Sensory examination showed impairment of sensations over the left occipital region extending up over the vertex and below C5 dermatomal level bilaterally. She was not able to walk and had a urinary catheter. Her haematological and biochemical parameters were within normal limits. Plain x-rays of the cervical spine at this stage showed an enlargement of the left C2-3 intervertebral foramen. Magnetic resonance imaging (MRI) of the cervical spine (Fig. 1 and 2) lucidly revealed an intradural extramedullary lesion on the left side at the level of C2-3 extending on the left postero-lateral aspect of the spinal cord with severe compression and continuing into the dural sleeve of the left C3 nerve root. The radiological features were suggestive of a C2-3 schwannoma involving the left C3 nerve root.
Under general anaesthesia the patient underwent C1-C3 laminectomy along with microsurgical total excision of the tumour (severely compressing and thinning the cord), which was arising from the C3 nerve root on the left side and expanding the dural sleeve. The histopathological study confirmed the diagnosis of a typical schwannoma. This patient made progressive sensory motor and sphincteric recovery and within a period of three weeks was able to regain near normalcy with the help of intense physiotherapy schedule. Her post-operative MR scan (Fig. 3) was satisfactory showing total excision of the lesion. Six months after surgery at out-patient follow-up she was asymptomatic.
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| Figure 1a and B — T1-weighted left para-sagittal MR scan (Fig. 1a) and axial scan (Fig. 1b) showing a large hypointense mass lesion at C2-3 level on the left side compressing the spinal cord and pushing it on the right side. The mass lesion on the left C3 nerve root eroding the C2-3 intervertebral foramen. |
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| Figure 2a and B — T2-weighted left para-sagittal MR scan (Fig. 2a) and axial scan (Fig. 2b) showing a hyperintense mass lesion at C2-3 level with hypointense areas in the mass lesion and extension of the lesion along the left C3 nerve root |
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3 — T1-weighted sagittal MR scan following C1-3 laminectomy
and total extension of the mass lesion showing normal spinal cord
intensity and anatomy. |
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DISCUSSION
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Idiopathic occipital neuralgia, in the absence of an associated neurological deficit is almost always a benign condition and warrants a deliberate conservative therapeutic approach.11 Calm reassurance offered to the patient and family by the neurosurgeon to the effect that the condition is benign and self limiting, lessens the anxiety, reduces secondary cervical muscle spasm, tension headaches and the sense of urgency.
Compressive C2, C3 radiculopathy or radiculitis may simulate or be mistaken for idiopathic occipital neuralgia. Similarities in both conditions present a unique challenge to the treating physician, perplexing the situation as in both conditions there may not be any physical signs. Compressive upper cervical radiculopathy results due to cervical spine trauma, osteoarthritic spurs, benign neoplasms (C2 or C3 – meningioma or schwannoma) and congenital anomalies at the base of the skull (Arnold-Chiari malformation or cranio-vertebral junctional bony abnormalities)7,8,10 Our patient had a left C3 nerve root schwannoma.
Schwannomas of the upper cervical region are relatively rare.15 They constitute approximately 5-8% of all spinal schwannomas, and are generally included in series of cervical or spinal neurinomas (1/6th cases) or in series of foramen magnum tumours (1/3rd cases). Such tumours are more common in patients with Von Recklinghausen’s disease and therefore multiplicity is a particular feature of these schwannomas (1/6th of the cases). The rate of multiple schwannomas at any spinal level is reported to be at 4% in patients with neurofibromatosis. They present with symptoms of high cervical nerve root/cord compression and rarely as subarachnoid haemorrhage.3,4,9 Generally, the initial presenting symptoms are the motor deficits, reported in about one-third of the cases but on examination the motor signs are found in about 80% of the patients.15 The next most common symptom is paresthesia in the limbs, recorded in one-third of the cases, whereas on careful examination sensory deficits are picked up in about 60% of patients.3,4,9,15 Mild, dull cervico-occipital pain occurs in about one in four patients; however, a typical radicular pain (radiculalgia) akin to neuralgia occurs in about 5% of patients. In our case, typical occipital neuralgic pain was the presenting complaint of the patient until she worsened and developed quadriparesis. Neck stiffness, neck swelling, gait disturbance, sphincter disturbance and Lhermitte’s sign are usually coexisting with motor or sensory signs.
These tumours usually occur in adults.15 The mean age of presentation is 45 years.9,15 The delay between first symptom and diagnosis can occur between three months to 12 years. Plain x-rays of the cervical spine may show erosion of the posterior arch of C1, C2 lamina or lateral atlanto-axial joint.8 Subtle erosion in the area must have been missed in our case at the peripheral hospital. Computed tomography (CT), MRI and digital substraction angiography (DSA) are of paramount importance in arriving at the pre-operative diagnosis.3,4,8,11 CT scan may show a low attenuation or isoattenuation mass lesion enhancing on contrast infusion. Typically an MR scan shows hyperintense or isointense mass lesion enhancing after gadolinium injection, on T1-weighted images, whereas the mass becomes hyperintense on T2-weighted images. The DSA may reveal a tumour blush supplied by the vertebral artery. In our case at surgery multiple small vessels from the vertebral artery were supplying the tumour, which were effectively dealt with.
Involvement of the dura mater is uncommon and the tumour is placed laterally with an anterior or a posterior extension. These tumours are approached via a posterior, postero-lateral or antero-lateral approach. We used a postero-lateral approach for the extension of the intradural spinal tumour and excised the intraradicular tumour via the same dural opening overlying the spinal cord without opening the dural sleeve of the C3 nerve root. Usually the results of the microsurgical excision are excellent. The patient under discussion had recovered completely in her neurological deficits as well as the occipital neuralgia.
This case highlights the importance to differentiate the typical, idiopathic, occipital neuralgia from the episodic pains of upper cervical radiculpathy due to a compressive C3 nerve root pathology ie. meningioma or schwannoma. With the availability of the CT/MR scanning it is imperative to differentiate these conditions if a logical approach to the management of the pain syndrome in the occipital region is to be undertaken. It is illogical to attack a peripheral nerve such as greater/lesser occipital nerve when the source of pain is more proximal in the C2 and/or C3 nerve roots.1,2,5,6,12,13,14 Moreover, a tumourous lesion on these nerve roots such as in our case may cause serious neurological compromise.15 One should be aware of this dilemma so as to take an appropriate investigation and surgical management before the risk of acute cervico-medullary compression with disastrous consequences.
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CONCLUSION
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A rare compressive upper cervical (C2 and/or C3) radiculopathy may be construed as a more commonly occurring non-compressive pathology, such as idiopathic occipital neuralgia with higher risks of acute cervico-medullary compression with disastrous consequences. The patients who are diagnosed as cases of idiopathic occipital neuralgia should therefore be investigated first to exclude the possibility of a compressive upper cervical radiculopathy with MR or CT scanning before contemplating medical or surgical therapy for the greater or lesser occipital nerves in the suboccipital triangle.
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REFERENCE
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| 1. | Behrman S: Traumatic neuropathy of second cervical spinal nerves. Br Med J 1983, 286: 1312-1313 |
| 2. | Blume HG: Radiofrequency denaturation in occipital pain: a new approach in 114 cases. Adv Pains Res Ther 1976, 1: 691-698 |
| 3. | Boss L, Caffararri E: Neuralgia occipital ingravescente in un caso di ectasia dell’arteria vertebrale corrispondente. Studio clinico e radiologico. Minerva Radiol 1967, 12: 529-532 |
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| 5. | Chambers WR: Posterior rhizotomy of the second and third cervical nerves for occipital pain. JAMA 1954, 155: 431-432 |
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| 8. | Ehni G, Benner B: Occipital neuralgia and the C1-C2 arthrosis syndrome. J Neurosurg 1984, 61: 961-965 |
| 9. | George B, Lot G: Neurinomas of the first two cervical nerve roots: a series of 42 cases. J Neurosurg 1995, 82: 917-923 |
| 10. | Hunter CR, Mayfield FH: Role of the upper cervical roots in the production of pain in the head. Am J Surg 1949, 78: 743-751 |
| 11. | Maxwell RE: Craniofacial pain syndromes: An overview – In: Wilkins RH, Rengachary SS (Eds) Neurosurgery 2nd edition, Vol 111. New York, McGraw-Hill 1995 pp 3909-3919 |
| 12. | Murphy JP: Occipital neurectomy in the treatment of headache. Results in 30 cases. Maryland S Med J 1969, 18: 62-66 |
| 13. | Poletti CE: Proposed operation for occipital neuralgia: C2 and C3 root decompression. Case report. Neurosurg 1983, 12: 221-224 |
| 14. | Sharma RR, Parekh HC, Prabhu S, Gurusinghe NT, Bertolis G: Compression of the C2 root by a rare anomalous ectatic vertebral artery. J Neurosurg 1993, 78: 669-672 |
| 15. | Star MJ, Curd JG, Thorne RP: Atlanto-axial lateral mass osteoarthritis, a frequently overlooked cause of severe occipito–cervical pain. Spine 1992 17(Suppl 6): 571-576 |
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Correspondence: Dr. Rewati Raman Sharma, P O Box 397, Postal Code 118, Al-Harthy Complex, Muscat, Sultanate of Oman Tel: (968) 567 339 / 562 483 - Fax: (968) 567 339 - Email: rrsharma@omantel.net.om |
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