A rare case of pseudotumor cerebri in adult Lyme disease

Abstract It is important to recognize the rare manifestations of chronic Lyme disease to prevent permanent disabilities. We present an adult case of chronic Lyme disease, who developed pseudotumor cerebri and who needed supplementary surgical treatment. We compare it to the existing published literature, reviewed by a systematic approach.


| INTRODUCTION
The chronic phases of infection with the spirochete Borrelia burgdorferi (Bb), European Lyme disease, are characterized by the involvement of several organ systems. In the nervous system, neuroborreliosis can develop in untreated individuals within 2-6 weeks 1 and includes signs of meningeal irritation with nuchal tenderness, fatigue, nausea, and the two cardinal symptoms: painful meningoradiculitis and peripheral motor deficits (Bannwarths triad). 1 Chronic neuroborreliosis (duration >6 months) can have numerous presentations.
We here present a rare case of chronic neuroborreliosis seemingly presenting as idiopathic intracranial hypertension (IIH) or pseudotumor cerebri (PTC) in a previously healthy woman. A case needed both antibiotic and neurosurgical treatments.

| PRESENTATION
A 51-year-old woman with no previous medical history was admitted to our neurological clinic on suspicion of IIH. For about 1 year, she had experienced slowly progressive fluctuating headache, bilaterally located, throbbing, from low to moderate in intensity. Within the last 3 months, the headache had increased in intensity. Moreover, she described nausea, occasional vomiting, light dizziness, discrete tinnitus, and unintended weight loss of 10 kg. Five months prior to admission, she had started noticing a blurred disturbance of the visual field in her left eye. Due to the tinnitus and dizziness, an ear, nose, and throat (ENT) doctor booked her a magnetic resonance imaging (MRI) of cerebrum. This showed a partial empty sella, meningeal enhancement, and distended optical nerve sheaths, suggestive of increased intracranial pressure. Shortly after, she was evaluated at the ophthalmological clinic. Here, she was diagnosed with bilateral chronic papilledema, bilateral visual field impairment and on the left eye reduced color vision, and a visual acuity of 3/6. This caused a direct admission to our neurological department, where she could tell of a debut 1.5 years before of moderate neck pain and upper backpain, but no recollection of insect bite or rash.

| ASSESSMENT
On neurological examination, she had slight problems of walking in a straight line, but otherwise performed normally aside from the vision loss.

| DIAGNOSIS AND MANAGEMENT
A laboratory investigation, for example, complete blood cell count, C-reactive protein (CRP), electrolytes, liver enzymes, albumin, creatinine, lactate dehydrogenase, and thyroid-stimulating hormone, was within normal limits. A computed tomography (CT) scan of the cerebrum excluded sinus thrombosis, while a repeated MRI showed postcontrast leptomeningeal enhancement and a normal-sized ventricular system (Figure 1). A lumbar puncture (LP) was subsequently performed with an opening pressure of 500 mm H 2 O.
The patient was initially treated with intravenous (iv) Ceftriaxone daily and Acetazolamide.
After one week of treatment, the symptoms worsened, and therapeutic repeated LP was made with good symptom relief. The effect was though temporary, and consequently, about 3 weeks after admission, a ventricular peritoneal shunt (VPs) had to be implanted, which stopped the progression of the symptoms.
Six months after the ended 18 days of antibiotic treatment (AB), the head pain and neck pain, as well as nausea and vomiting, were gone. Subjectively, the visual acuity and visual field defects had improved, but objectively, a central scotoma, lack of color vision, and atrophy of the optic nerve were still present.

| COMMENT
We describe a rare presentation of adult neuroborreliosis.
Nord and Karter 3 describe in 2003 "the first case" of PTC as a complication to Lyme disease in adults, but already in a review 2 from 1986, Burgdorfer et al describe a case with positive Bb antibody titer with papilledema and increased opening pressure at LP.
ΡTC in children in relation to Lyme disease has been described as a rare entity (1a, 1b), yet the literature shows that the entity is even more rare (or underdiagnosed) in adults. Literature has suggested a different presentation of Lyme disease in children compared to adults in, for example, concern to the involvement of neurological symptoms, 1,7 but no study has proved the mechanism behind this. Thus, it remains a hypothesis.
Nonetheless, this article has chosen to go into detail with the adult cases published.
The presentation of pseudotumor cerebri is usually headache, transient or gradual visual loss, photophobia, diplopia (sometimes with 6th cranial nerve palsy), weight loss, nausea or vomiting, and with papilledema (unilateral or bilateral) often, but not always present.
The term used for the condition is previously discussed 3,6 : the reason being that the definition of PTC initially required a normal CSF. The presence of pleocytosis would therefore better suggest the term secondary intracranial hypertension. Though in all the 5 published cases, the term PTC is used and so will we in this article.
The mechanism remains unknown, which is suggested to be an inflammatory response to the chronic Bb meningitis, impairing the CSF reabsorption in the arachnoid villi. 3,8 In pediatric literature, corticosteroids, 9 therapeutic LP, VPs, 9 and acetazolamide 8

NØRRESLET GIMSING aNd LUNdE LaRSEN
The rationale behind the therapeutic LP and the VPs comes from the evidence and use of these methods in medication-resistant IIH patients. 12 Therefore, both were performed when AB did not work fast enough to avoid further symptom progression.
The many pediatric cases of Bb-induced PTC point to an overall good prognosis 10 once AB has been initiated, and the previously published adult cases (Table 1) show a similar pattern. The case presented here is the first adult case with a need for surgical intervention to decrease the intracranial pressure on top of the AB.
The combination of negative Bb IgM and positive IgG in CSF also points to a chronic infection in contrary to the other published cases. 1 The positive oligoclonal bands in CSF are an unspecific inflammatory biomarker for intrathecal synthesis of IgG, as thus by default does not differ between an infectious and a non-infectious etiology. Specific inflammatory and infectious diseases have been found to be more correlated to positive oligoclonal bands. In the case of neuroborreliosis, previous studies have shown that up to 74% had positive oligoclonal bands at a time of diagnosis. 13 The positive result of the test in our case, itself, did not give reason to rule out supplementary infectious or inflammatory diseases, for example, test for multiple sclerosis.
The patient ended up having permanent visual impairment despite treatment, which illustrates the importance of remembering this rare differential diagnosis of secondary intercranial hypertension/PTC to be able to initiate treatment as early as possible.