Tuberculosis is regarded as a disease of vulnerable groups, including low socioeconomic status and fragile health conditions. Immune weakened patients, patients at extreme ages, diabetic patients, smokers, oncologic patients, and alcoholics are at increased risk (WHO, 2017). This is the younger case described of spine tuberculosis destruction syndrome, based in all the cases reported and indexed to PubMed and science direct.
Although elevated leukocyte, ESR, and CRP values have been observed in patients with both pulmonary and extrapulmonary tuberculosis, our patient presented a slightly elevation of the ESR of 28 mm/h. There have been described in the literature that up to 26% of patients with tuberculosis have a normal value of these parameters. Although they have a very high sensitivity, they are not highly specific parameters, which is why these are primarily used in monitoring disease activity and evaluating response to treatment [11].
Patients with spine pain should be kept under observation in an endemic region for tuberculosis and sequentially assessed with X-rays, every 4 to 6 weeks; in case of reduction of disc height they should be performed an MRI. Spinal tuberculosis lesions have been described as predominantly localized lesions in the thoracic region, mainly at the D6 level that can be confidently labeled as TB spine on MRI if the vertebrae show low signal in T1WI-weighted and hyper-intense signal in T2WI, suggestive of inflammation with a septate pre and paravertebral abscess and a contiguous vertebral body involvement with preserved intervertebral disc; these findings were similar to our patient helping us to evaluate the extension of the disease and start the treatment for the limitation of the spinal destruction [12].
The TB spine lesion in children causes more destruction as most of the vertebral bodies are cartilaginous [4, 5]. Our case was the youngest case of spinal tubercular disease that has been reported. The lack of information of the general population and the scarce symptoms that presents at the onset of the disease, usually delays diagnosis; if we add the aggressiveness of the disease in this age group, due to the innate characteristics of the disease, it causes to be diagnosed in advanced stages with high bone destruction. In a study carried out in a Mexican population, all the patients with Pott’s disease presented a deformity of the spine cord at the time of diagnosis, with an average time of diagnosis of 8 months with a range of 1 to 48 months [2]. Similarly, an UK cohort reported a median duration of symptoms before diagnosis of 7 months; whereas, the Taiwan cohort reported a median time of 2 months [13, 14].
Our patient did not presented constitutional tuberculosis symptoms, according to literature, only 20 to 30% of the patients with spinal TB have constitutional symptoms [1] making the initial approach to this type of patient even more difficult. Our patient presented neurological deficit at the time of the diagnosis; prevalence of these symptoms has been observed more than twofold times in developing countries; this is probably because of the lack of education of these syndromes around the population, as well as low economic resources that restrict the access to specialized studies for their diagnosis [1, 5]. In this type of patients, the neurological deficit depends proportionally to the size of the mass and the location, being the cervical and dorsal levels where it was presented in most of the patients [7, 15]. In order to get better outcomes in the developing countries, it is necessary to promote the dissemination of information in the population, in addition to carrying out an adequate approach in this type of patients.
It should be clarified that in Mexico since 1951, the BCG vaccine is part of the vaccination scheme, which is applied at birth, not recalled dose [16]. BCG vaccination is a highly cost-effective intervention against severe childhood tuberculosis [16]. Similar to our patient, multiple cases of bone tuberculosis have been described in children despite having the vaccine [17, 18]. This lack of protection must be assessed to reduce this catastrophic disease in this vulnerable group.
The base of the treatment is the antitubercular medication suggested for 12 months, starting during the first 2 months an intensive phase with isoniazid at 10–15 mg/kg, rifampicin 10–20 mg/kg, pyrazinamide 20–25 mg/kg, and ethambutol at 15–25 mg/kg. Subsequently, a support phase for the remaining 10 months based on isoniazid and rifampicin at the same previous doses in most of the patients, without surgery indications, responds to conservative treatment in 90–95% of the cases [10, 19,20,21].
The destruction of the vertebral body and endplate combined with the continuation of growth in the spine can cause deformity to progress. In 40%, the kyphosis worsens, 40% improves, and in 20% stays constant [3]. Consequently, surgery is indicated for complications such as deformity, neurological deficit, instability, huge abscess, diagnostic dilemma, and in suspected drug resistance to Mycobacterium tuberculosis. In our patient, the surgery was indicated for multiple complications as deformity, neurological deficit, and instability [5]. In children less than 7 years, that have 3 or more vertebral body involvement in a dorsal or dorso-lumbar spine, the deformity is severe and tends to progress further [5]. Our patient presented 2 of 3 clinical risk factors for developing progressive kyphosis, such as age less than 7 years, more than three vertebral body affection, only the lesion at distal dorsal, and dorso-lumbar junctional area was not present.
It should be noted that the growth potential is also disturbed when the disease focus is surgically approached. At the decompression of the spinal cord, the apophyseal ring is partially or completely damaged; consequently, the growth potential is partially or totally affected [1]. This suggests that posterior elements do contribute to growth and as far as possible anterior radical resection should be avoided in children [22, 23]
Therefore, an anterior decompression with total mass resection with corpectomy of vertebrae D7 and D8 was realized, with complete neurologic improvement. The “DiMeglio formula” states that for each vertebral segment, the person loss 0.7 mm/year of longitudinal growth after posterior arthrodesis [5]. For this reason, the posterior fusion of the thoracic spine to limit posterior vertebral growth and control the kyphosis deformity is pending.
In conclusion, spinal tuberculosis represents a huge challenge for its diagnosis because of its insidious clinical onset without specific clinical manifestations. However, this disease has been associated with catastrophic complications in pediatric age, due to the anatomical characteristics of the spine at this age, such as a severe deformity, an increased risk of vertebral collapse and neurological alterations. For this reason, a prompt diagnosis is necessary to limit the progression of this highly destructive disease. In addition, the fact of presenting at an early age produces hard making decisions for the adequate treatment of the disease and reduces the adverse effects of the procedures.
