Diagnostic difficulties in a patient with multiple sclerosis who presents with cranial nerve palsies: an unusual complication of dental work
- Jennifer Cathcart 1 , 2,
- Rebecca Caitlin Johnson 1 , 2,
- Nicholas Hughes 1 , 2 and
- Manish Patel 1 , 2
- 1 NHS Lanarkshire, Bothwell, UK
- 2 General Medicine, University Hospital Wishaw, Wishaw, UK
- Correspondence to Dr Jennifer Cathcart; jeni123@live.com
Abstract
A woman in her 60s with multiple sclerosis (MS) presented with right-sided ptosis, right sixth nerve palsy, right facial paraesthesia and signs of sepsis. She had a recent diagnosis of a dental abscess. Investigations revealed a right submasseter abscess leading to bacterial meningitis (Streptococcus intermedius) and a cavernous sinus thrombosis. She was managed in intensive care and underwent surgical drainage of the abscess. Anticoagulation for 6 months was planned. Cavernous sinus thrombosis is a very rare complication of a dental abscess, and even less frequently associated with submasseter abscesses. The case was complicated by a history of MS, to which the patient’s symptoms and signs were initially attributed to. This case highlights the diagnostic pitfalls, and aims to enhance learning around similar cases. To the best of our knowledge, this is the first case report of a masseter/submasseter abscess leading to cavernous sinus thrombosis.
Background
Cavernous sinus thrombosis is a serious condition which can be difficult to diagnose. The arrival at this diagnosis was further delayed as this patient’s presentation could have been a ‘flare’ of her multiple sclerosis (MS). We wish to present this case to highlight the importance of comprehensively investigating new focal neurology, even in patients with pre-existing neurological disorders, as there may be new pathology underlying the presentation. Furthermore, this case illustrates that dental abscesses can, in rare cases, precipitate cavernous sinus thrombosis, adding to a small number of reported cases.
Case presentation
The patient had a dental filling 5 weeks prior to admission. This procedure had been complicated by dental abscess, which did not improve despite three courses of different antibiotics. On admission, she reported a 1-day history of left facial droop, slurred speech, decreased mobility and a 2 to 3-week history of right facial numbness. She denied any headache. Cranial nerve examination revealed a complete right abducens nerve palsy and right ptosis, and subjectively reduced sensation involving all branches of the right trigeminal nerve. Limb tone was normal. Limb power with Medical Research Council grading was as follows: 5 in the right arm and 4 in the left; 4 in the right leg and 2 in the left. The left leg weakness was longstanding. She had up-going plantars bilaterally. Cardiac examination revealed a new soft systolic murmur with no other stigmata suggesting bacterial endocarditis. Respiratory and gastrointestinal examination were unremarkable. She was initially tachycardic but soon after admission developed a fever of 40°C. Her medical history consisted of MS and osteoporosis. She had never been treated with immunosuppressive therapy and had not taken any over-the-counter medication apart from paracetamol. There was no history of alcohol excess and she had never smoked. She lived alone and was functionally independent. Later in the admission, she developed swelling over the right parotid and trismus and reported a new headache.
Investigations
Blood test on admission showed a C reactive protein (CRP) of 263 mg/L; a white cell count (WCC) of 17.3×109/L; a haemoglobin of 10.6 g/L; and prothrombin time ratio of 1.6. Renal function was normal. Initial chest X-ray showed no abnormalities. A non-contrast CT of her head showed no acute pathology. Lumbar puncture was performed 3 days after her admission; this was delayed until her abnormal coagulation profile was corrected. Cerebrospinal fluid (CSF) examination showed a WCC of 115×109/L (polymorphs 10×109/L; lymphocytes 50×109/L; a protein level of 0.7 g/dL; and a glucose of 2.6 mmol/L compared with a serum glucose level of 5.7). CSF microscopy showed no organisms and no growth. Urine culture had no growth and four sets of paired blood cultures were negative initially. However, one set of blood cultures grew Streptococcus intermedius on day 6 of admission. Transthoracic echocardiography revealed a calcified mitral valve but no evidence of vegetations. A transoesophageal echocardiogram was considered but not performed as the cardiologist felt there was a low clinical suspicion of bacterial endocarditis. Blood-borne virus screening was negative. An orthopantomogram showed no evidence of bony destruction. Subsequent MRI with contrast on day 5 to look for a collection showed underlying severe periventricular and subcortical white matter changes consistent with demyelination. In addition, there was a 3×2×1 cm collection in the right submasseteric space region. There was thrombosis in the cavernous sinus and in the right internal jugular vein. MRI images were degraded by patient movement artefact, and so a CT head with contrast was arranged. This showed the right cavernous sinus thrombosis (figure 1) as well as thrombosis in the internal jugular vein extending to the C2 vertebral level and thrombus in the right sigmoid and transverse sinus. There was a large abscess in the submasseter space (figure 2) involving the muscles and retained root of the broken second upper right incisor (figure 3). The patient subsequently underwent surgery and microbiological samples taken during drainage of the abscess matched the organism grown in the blood cultures (S. intermedius).
Cavernous sinus thrombosis (furthest right arrow) and surrounding abscess (remaining arrows).
Right submasseter abscess with gas within pterygoid muscle (arrows).
Retained tooth (arrows).
Differential diagnosis
Due to the relative abrupt onset of symptoms and signs which were mainly unilateral, stroke was initially considered but felt less likely as the clinical picture emerged. A flare of the patient’s MS was considered in view of her new neurological findings, which could have been triggered by her dental infection. Steroids were not administered as this was not typical of the patient’s normal flare characteristics and it became apparent that sepsis was evolving. Endocarditis was also considered in view of the new systolic murmur and the history of recent dental work, but excluded after investigation. Subsequent stroke due to septic emboli was also considered as was basal meningitis after discussion with the neurology team. Investigations led to the diagnosis of right submasseter abscess leading to bacterial meningitis and cavernous sinus thrombosis.
Treatment
Initially, the patient received intravenous amoxicillin, metronidazole and gentamicin to cover sepsis of unknown origin. Intravenous acyclovir was added to cover central nervous system viral infection. She was moved to medical high dependency from the admission unit on day 2 of admission. Following persistently high temperature, antibiotics were changed to meropenum, gentamicin and amoxicillin after microbiology advice was sought. Neurologists were involved throughout and steroids were considered for treating MS but were withheld due to concern regarding basal meningitis. On day 4, she was also reviewed by maxillofacial surgeons who agreed that cavernous sinus thrombosis could be a possibility. After radiological confirmation, the patient was treated with low-molecular-weight heparin (LMWH; tinzaparin). After discussion with the maxillofacial surgeons, this was changed to intravenous unfractionated heparin to facilitate surgery. She was then transferred to the intensive care unit and underwent surgery to drain her right submasseteric abscess and remove the remaining carious tooth. Surgeons identified a potential further collection within her right anterior maxilla cystic area. Antibiotics were subsequently rationalised to co-amoxiclav based on sensitivities from the surgical specimens. On discharge, she was anticoagulated with warfarin for 6 months as it was felt the venous thromboembolic event was provoked by her infection.
Outcome and follow-up
Following surgery, the patient was generally weak and remained in hospital for a total of 54 days. Her CRP and fever decreased, and subsequent blood cultures were negative. Her ptosis partially resolved over the next few weeks. She required ongoing physiotherapy, which was continued at a rehabilitation unit where she continued to improve. She has been followed up on several occasions by the oral maxillofacial surgery team who are happy with her progress. She was also referred to outpatient ophthalmology to help with the management of her ongoing ptosis and sixth nerve palsy.
Discussion
Cavernous sinus thrombosis is a rare condition and as a consequence of low numbers, incidence rates are difficult to estimate. They are most commonly caused by infection but can be triggered by aseptic causes.1 Sinusitis, facial cellulitis, otitis media or mastoiditis can lead to thrombosis within the cavernous sinus. The cavernous sinus is a venous plexus situated around the pituitary gland. The cranial nerves III to V1+2 pass through it along with the internal carotid artery and internal carotid plexus. A constellation of clinical features may occur, including headache and fever, and focal neurological signs resulting from cranial nerve involvement, for example, ocular palsies.2 The abducens nerve (VI) controls the lateral rectus muscle and thus the ability of the eye to abduct. This was a key finding in this patient as well as ptosis indicating oculomotor nerve (III) involvement. Finally, she experienced trigeminal nerve (V) involvement, with right facial numbness. What makes the case more unusual is the trigger for patient’s cavernous sinus thrombosis. Our literature search yielded only a small number of case reports of cavernous sinus thrombosis originating from a dental infection. A literature review of cavernous sinus from dental origin over 15 years (1990–2015) found only 16 cases worldwide.3 Previous case reports record cavernous sinus thrombosis from dental infections leading to buccal mucosal laceration,4 facial abscess,5 septic embolic6 and bilateral mastoiditis.7 We found one more report following a tooth extraction.8 As far as we are aware, there are no previous case reports of a cavernous sinus thrombosis developing secondary to a massester/submasseter abscess, making this case unusual. Guidelines for the treatment of cavernous sinus thrombosis were updated in 2017 by the European Stroke Association. They recommend treatment with LMWH in the first instance but do not advise on the duration of anticoagulant therapy after the acute phase.9
The submasseteric space is a potential space between the three different insertions of the masseter muscle. This, along with the pterygomandibular and the superficial and deep temporal spaces, forms the masticator space. This potential space is ideal for the development of abscesses.10 Submasseter abscesses are rare and there are, thus far, limited case reports.10–13 All the case reports referenced are abscesses from a dental origin. Patients normally present with parotid swelling and trismus.13 These clinical signs were not initially apparent in our patient’s case, however, were noted later. The bacterium found in the abscess in this case was S. intermedius. Research has shown that this bacterium commonly causes abscesses,14 with the organism being a normal commensal of the mouth, intestine and upper respiratory tract.
The background history of MS in our patient did delay the eventual diagnosis as clinicians initially attributed our patient’s finding to a ‘flare’ of her MS. This is completely understandable given the presentation. A retrospective audit showed that isolated cranial nerve involvement occurs in 10% of patients with MS. Fifth nerve palsies were the most affected followed by seventh nerve palsies.15 Another case report illustrates a case in a similar-aged patient with multiple cranial nerve palsies due to MS.16 Initially, in our patient, it was felt that the neurological symptoms could be related to MS and the fever to the dental abscess. In hindsight, this may have delayed the diagnosis. We present this case to highlight this important pitfall. This cases also highlights that dental infections should never be dismissed as clinically insignificant as they can play a serious role in intracranial infections.
This was a complex case which required the input of many specialities before a diagnosis was reached and treatment was commenced. It highlights the benefit of involving different specialities early in the management to pull together a diagnosis and treatment. We are extremely grateful to the invaluable input from the maxillofacial surgeons, the neurology team and the radiologists who offered expert advice. We wish to highlight the importance of a multidisciplinary team (MDT) working in such complex cases. Without early MDT input, diagnosis and treatment would have been delayed further, which may have had long-lasting adverse consequences for the patient.
Learning points
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This case highlights some important medical pitfalls to learn from. It is important to remember to include other differentials for any patient with multiple sclerosis presenting with new focal neurology.
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The case adds to the literature surrounding dental abscess and submasseter abscesses as an origin of septic cavernous sinus thrombosis and highlights awareness of this complication.
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The case highlights the necessity of multidisciplinary working towards diagnosis and management in such complex cases.
Acknowledgments
Dr James Harper, consultant radiologist, was extremely helpful. Thank you.
Footnotes
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Contributors JC: discussion, presentation, treatment, outcome and follow-up and consenting patient. RCJ: investigations section and differential section. NH: summary and title. MP: finial edit, and review and planning of case report. All authors: reading and editing.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Patient consent for publication Obtained.
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Provenance and peer review Not commissioned; externally peer-reviewed.
- © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.
References
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