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 calciļ¬cation 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).