ABSTRACT:
Gout is a crystalline arthropathy frequent in the population, but gouty spondyloarthropathy,
also called axial gout, is uncommon. The current case report presents a rare case
of cervical myelopathy secondary to axial gout. A 50-year-old female patient, without
previous pathologies, presented with loss of strength, altered sensitivity, and pyramidal
release for 2 years. The computed tomography showed a lytic image in the spinous process
of C7, and signs of myelopathy with myelomalacia on magnetic resonance imaging of
the cervical spine. After the surgical procedure and biopsy of the material, the diagnosis
was gout, and treatment for the pathology was started, with complete improvement of
the condition. The diagnosis of axial gout should be included in the spectrum of the
differential diagnosis of diseases that affect the spine. Although gouty spondyloarthritis
(or spondylitis) is uncommon, there is an underestimated occurrence due to the lack
of investigation of the cases. The early diagnosis and treatment of the pathology
can prevent patients from presenting complications of the disease, as reported in
the present study.
Keywords: gout; spinal cord compression; paraparesis.
RESUMO:
A gota é uma artropatia cristalina frequente na população; entretanto, a espondiloartropatia
gotosa, também chamada de gota axial, é incomum. O presente relato de caso apresenta
um caso raro de mielopatia cervical secundária a gota axial. Uma paciente de 50 anos
de idade, sem patologias prévias, apresentou quadro de perda de força, alteração de
sensibilidade e liberação piramidal há 2 anos. A tomografia computadorizada evidenciou
imagem lítica no processo espinhoso de C7, e sinais de mielopatia com mielomalácia
foram observados na ressonância magnética da coluna cervical. Após o procedimento
cirúrgico e biópsia do material, o diagnóstico foi de gota, e o tratamento para a
patologia foi iniciado, com melhora completa do quadro. O diagnóstico de gota axial
deve ser incluído no espectro do diagnóstico diferencial das doenças que acometem
a coluna vertebral. Apesar de a espondiloartrite gotosa ser incomum, há uma ocorrência
subestimada devido a não investigação dos casos. O diagnóstico precoce e tratamento
da patologia pode evitar que pacientes apresentem complicações da doença, como a relatada
no presente estudo.
Palavras-chave: gota; compressão da medula espinal; paraparesia.
FIGURES
| Citation: Matos TD, Teixeira KO, Fleury RBC, Costa HRT, Pádua JDB, Defino HLA. Cervical Myelopathy Secondary to Gout: Case Report*. 55(6):796. doi:10.1055/s-0040-1708514 |
| Note: * Work developed at the Department of Orthopedics and Traumatology of Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. |
| Conflict of Interests The authors have no conflict of interests to declare. |
| Received: August 12 2019; Accepted: December 12 2019 |
INTRODUCTION
Gout is the most frequent crystalline arthropathy, with an overall prevalence of 0.08%, and it primarily affects males after the fifth decade of life. However, gouty spondyloarthropathy (GS) is uncommon and mimics a variety of diseases that affect the spine, representing a challenge for its diagnosis in clinical practice.1-3
Gouty spondyloarthropathy, also called axial gout or spinal gout, was described in 1950 by Kersley et al,4 and Kosoff et al. (1953) were the pioneers in reporting gout myelopathy.5 Axial gout is an uncommon manifestation of this disease, with a broad spectrum of clinical manifestation of the disease, ranging from asymptomatic to severe compression of nervous structures, with paraplegia or tetraparesis.1 The objective of the present clinical case report is to present the involvement of the spine in gout accompanied by information about this unusual manifestation of the disease, which should be considered in the differential diagnosis.
The study was approved by the institutional research ethics committee under the number CAAE 19635119.8.0000.5440.
CASE REPORT
A 50-year-old female patient was admitted complaining of cervical pain radiating to the upper limbs, and paresthesia in the C6 and C7 dermatome. She reported frequent falls and difficulty in walking for 2 years. Physical examination revealed bilateral weakness of the upper limbs with grade four muscle strength, according to the Medical Research Council (MRC) scale, and with greater involvement of the C6 and C7 myotomes. Hoffmann e Babinski signs were positive on both sides.
The laboratory exams of the preoperative routine showed no changes and no diagnostic hypothesis could be elaborated to clarify the lytic lesions of the posterior elements of C7 (Figure 1). The magnetic resonance exam of the cervical spine showed spinal canal stenosis, mainly in the C6 to C7 levels (Figure 2).
The posterior approach of the cervical spine was performed to allow the stabilization and posterior decompression of the cervical spine, and to allow access to the posterior elements of C7 to obtain the material for the anatomopathological examination. The C4 to T1 arthrodesis and posterior fixation were performed, associated with C5to C7 laminectomy. The spinous process and the C7 arch, which presented the lytic lesion, were referred for anatomopathological examination for diagnostic investigation (Figure 3).
In the postoperative period, the patient showed significant improvement in the cervical pain and neurological symptoms, with good evolution of the surgical wound, without general or specific complications related to the surgical procedure performed.
On macroscopic examination, the C7 lesion was composed of brownish and soft tissue, and the histological sections stained by hematoxylin and eosin (HE) showed that the bone tissue did not present histological changes. Furthermore, we observed an adjacent portion of synovial tissue with villous hyperplasia, mild lymphocytic inflammatory infiltrate, and urate deposits surrounded by histiocytes and giant foreign body cells, compatible with the diagnosis of gouty synovitis (Figure 4).
After the result of the anatomopathological exam indicating the diagnosis of gout, complementary exams specific for this disease were performed, and the treatment started with the administration of Allopurinol, 300 mg/day, associated with the appropriate diet. The patient had a good evolution of the pain symptoms related to gout, and the evolution of the results of the tests performed during the follow-up showed a decrease in the values of serum uric acid (Table 1).
| 1st collection | 2nd collection | 3rd collection | 4th collection | |
|---|---|---|---|---|
| Serum uric acid | 15.5 mg/dL | 8.2 mg/dL | 9.7 mg/dL | 3.2 mg/dL |
| Urea | 35.7 mg/dL | 35.8 mg/dL | 31.4 mg/dL | |
| Creatinine | 1.0 mg/dL | 1.1 mg/dL | 1.2 mg/dL | 1.0 mg/dL |
| GTO | 23 U/L | 23 U/L | ||
| GPT | 18 U/L | 19 U/L |
Abbreviations: GTO, glutamic-oxaloacetic transaminase; GPT, glutamic-pyruvic transaminase.
DISCUSSION
Axial gout is an unusual manifestation of gouty arthritis, but clinical case reports exceed the 100, indicating that its occurrence may be underestimated.1 The diagnosis of axial gout of the patient we are reporting was due to the neurological symptoms she had and to the anatomopathological examination, as there was no clinical evidence of the disease. Axial gout may be more frequent than we consider, and only patients with symptoms have been considered in case reports.1,6,7 Ninety-eight percent of the patients analyzed in an axial gout review article had neurological symptoms,1 and the prospective radiological study of patients with gout, showed erosive lesions in the spine in asymptomatic patients.8
Male patients with an average age around 60 years have been the most affected by axial gout,1 contrasting with the patient we report. However, the patient had an increase in uric acid, which is reported in about 69.6% of patients with gout.1
All segments of the spine have been affected by axial gout, with the lumbar spine being the most frequent (58.4%). The cervical location, which was observed in our patient, corresponds to the second segment in frequency and is reported in 24.8% of patients. Any spinal structure can be affected, as well as adjacent tissues.1
The neurological symptoms observed in this patient agree with most reports, in which 77.9% of the patients had neurological symptoms that were associated with pain in the affected segment of the spine. Radiculopathy is the most frequent symptom, reported in 34.5% of patients, followed by neurogenic claudication (20.4%).1
Radiological findings are compatible with changes in osteoarthritis.9 Although unclear, the mechanisms associated with axial gout have been considered similar to what occurs in the peripheral condition, in which pH, temperature, trauma, and degeneration of the joints are involved in the deposition of crystals.9 Radiological changes can vary from soft-tissue edema to bone-tissue erosion.9 The lytic lesion observed in our patient, with the characteristics of the computed tomography and magnetic resonance images, are typical in this patients with gout but do not allow the diagnosis to be made. These lesions allow only the presumption of the diagnosis, which can be confirmed only with the histopathological examination, as occurred with our patient. Histopathological examination is essential for the definitive diagnosis and exclusion of other diseases that may present a similar image.1 The collection of material for histopathological examination can be done through puncture or by direct excision during treatment in patients who have neurological deficits and need surgical treatment. However, a thorough clinical, laboratory and radiographic evaluation must precede this step.
The histological characteristic of gout is the deposits of sodium urate surrounded by a variable granulomatous reaction of foreign body type. Urate crystals, which are brown in color, are visible in tissues fixed in alcohol. Fixing in formalin combined with the use of routine aqueous dyes, however, dissolves the crystals, leaving only a typical amorphous protein matrix, grayish with discrete eosinophilic streaks.10
Vertebral involvement can be the initial manifestation of gout, and it should be included in the differential diagnosis, especially in patients who have lytic bone lesions with the characteristics previously described.
The clinical case we reported did not have a previous history of gout, and the disease was diagnosed by histopathological examination, resulting from the treatment performed to improve the neurological deficit, because the patient had no symptoms or previous diagnosis of gout.
The diagnosis of gout should be included in the spectrum of the differential diagnosis of diseases that affect the spine, and the treatment of the disease must be carried out together with the treatment of the disease of the spine to avoid the problems caused by gout.1,4,6,9
