Discussion:
Chronic endemic fluorosis is a major health problem in some regions of the world, especially in India, Asia, and Africa (5).
SF occurs as an endemic disease in some regions of the south of Tunisia especially rural areas because of the consumption of well water having fluoride more than 4ppm, the poor socio-economic status and the hot climate (6). For our three patients, SF was diagnosed based on epidemiological data (endemic region, consumption of well water having high fluoride concentration) associated with radiographic findings (diffuse osteoncondensation, osteophytosis, ossification of ligaments, interosseous membranes and tendon attachments). The diagnosis of SF can be confirmed by the detection of excess fluorine in the blood, urine, or bone tissue. Blood fluorine values higher than 0.2 mg/l are associated with a high risk of SF (2).
SF is often asymptomatic but in the advance stages, it causes crippling deformities and neurological complications. Neurological manifestations of SF are predominantly those of radiculo-myelopathies, present in 10% and the majority of those involved the cervical region. Higher cerebral function defects or cranial nerve palsies are extremely rare (7,8). Radiculo-myelopathy arise primarily from mechanical compression of the spinal cord and nerve roots from osteophytosis, sclerosed vertebral column and ossified ligaments (8). In our cases, the spine cord compression revealed the chronic fluorosis and the compression was caused by posterior vertebral ligament calcification at the cervical region.
MRI with T2 sequences are useful when there is suspicion neurological complication because they demonstrate not only the ligamentous ossification but the degree of spinal cord compression (2,9,10). Decompressive laminectomy is recommended in selected cases of myelopathy caused by ossification of the ligamentum flavum and/or posterior longitudinal ligament. It is only possible in such of those early cases in which the compression is confined to a limited segment of the vertebral column (8).The surgical intervention must be well discussed, considering the surgical risk. In such instances, surgery is fraught with the possibility of complications, including difficulty in intubation because of the rigid cervical spine and high risk for postoperative respiratory complications because of restricted chest movementsĀ (9).