CASE REPORT Intervertebral disc calcification in children AbstractKG MaJ!nus BSc(UCT), MBChB(UCT), MMed(RadD, Stell) Symptomatic cervical intervertebral disc calcification in children presents vvith characteristic signs and symptoms, and usually has a benign, self-limiting and predictable course. The radiological images of the spine likevvise have typical appearances, vvith a recognisable pattern and fof lovvirig a predetermined course. A case report of this uncommon condition in an 8-year-old boy i II ustrates most of the clinical and radiological findings in th is entity. Department of Paediatric Radiology, Red Cross War Memorial Children's Hospital, CapeTown Introduction Intervertebral disc calcification (IVDC) is uncommon in children.t'? First described by Baron in 1924,14 nu- merous articles have since appeared. Few of these reports have appeared in the radiological literature, and the majority of these have been published in paediatric radiology journals. The B SA JOURNAL OF RADIOLOGY. August 1998 aim of this article is to bring this un- common but important subject to the attention of all radiologists. Case report A lO-year-old boy presented at Red Cross Children's Hospital with a two-day history of an extremely pain- ful neck. The onset was spontaneous and was not associated with any in- jury. Dysphagia without regurgitation of food had been periodically experi- enced. No other symptoms were elic- ited from the patient. Examin ation revealed a well- grown, apyrexial boy with a marked torticollis. The patient's head was tilted and rotated to the left as a re- sult of severe left-sided sternocleido- mastoid muscle spasm. Any form of head or neck movement produced acute neck pain and consequently mobility was totally restricted. Both upper limbs were neurologically nor- mal, with no evidence of radiculopathy. An ear, nose and throat examination was normal. Plain x-rays of the cervical spine were performed at the time of the ini- tial consultation. The anteroposterior (AP) (Figure 1) and lateral (Figure 2) Figure 1: AP cervical spine x-ray. Chin tilted and rotated to the left. Scoliosis convex to the right. Dense, oval shaped, central calcified intervertebral disc (arrow) at C5/6 level. topageg Intervertebral disc calcification in children Figure 2: Lateral cervical spine x-ray. The slight rotation and scoliosis results in poor lateral positioning. Linear, layered, densely calcified C5/6 intervertebral disc (arrow). Anterior wedging of the C5 vertebral body also present. projections demonstrated scoliosis convex to the right, with tilting and rotation of the head towards the left, plus dense, irregular, layered calcifi- cation of the intervertebral disc at the CS/C6 level. Loss of height of the an- terior CS vertebral body was present, giving it a wedge shape. The paraverte- bral soft tissues plus the remainder of the cervical vertebral bodies and their posterior elements were normal in appearance. Computed tomog- raphy (CT) of the cer- vical spine followed the plain x-rays. CT confirmed the dense calcification in the nu- cleus pulposus of the CS/C6 intervertebral disc (Figure 3). Unsus- pected central posterior herniation of the calci- fied nucleus pulposus through the annulus fibrosis was present, with slight midline protrusion of the calcified material into the spi- nal canal. The subligamentous (ante- rior to the posterior longitudinal liga- ment) calcified disc herniation in- dented the dural sac without com- pressing the spinal cord. Sagittal re- construction confirmed the anterior wedging of the vertebral body of CS. The remainder of the vertebral bod- ies and their posterior elements, as well as the surrounding paraspinal soft tissue structures appeared normal. Scoliosis and rotation of the cervical spine were confirmed. N on -steroidal anti -inf amma tory drugs plus analgesic medication were instituted for a month. The patient's neck was immobilised in a soft cervi- cal collar. All vigorous activity was suspended. At the follow-up consul- tation two weeks later, the patient was totally pain-free and clinically normal in appearance. The patient remained symptom-free and normal on exami- nation at a further follow-up exami- nation three months later. Repeat AP (Figure 4) and lateral (Figure 5) cer- vical spine x-rays on this occasion showed normal alignment. The pre- viously noted dense calcification in of C5/6 disc space Central, posterior, subligamentous herniation of the densely calcified nucleus pulposus of the intervertebral disc. No spinal cord or nerve root compression. 9 SAJOURNAL OF RADIOLOGY. August 1998 Figure 4: AP cervical spine fol/ow-up x-ray. Normal alignment. Two, small, poorly visible calcifications (arrow) in the C5/6 intervertebral disc immediately to the right of the CS spinous process. Figure 5: Lateral cervical spine fol/ow-up view. Normal alignment. Multiple, poorly visible, small calcifications (arrow) scattered in the CS/6 Intervertebral disc. Anterior wedging of the CS vertebral body stil/ present. the CS/C6 intervertebral disc was 1 ss easily visible, with multiple, small, poorly seen residual calcifications evi- dent The anterior wedging of the ver- tebral body of CS was unchanged af- ter three and a half months. The pa- tient was considered to have been adequately treated, and was dis- charged from further follow-up. to page 10 Intervertebral disc calcification in children frompage9 Discussion This case report is a good exam- ple of some of the characteristic clini- cal and imaging findings of sympto- matic IVDC in the cervical spine in a child. Few conditions can mimic this presentation.' The incidence of IVDC is greater in boys than it is in girls. I,9,12,15-18The affected age range varies from series to series - cervical IVDC has been de- scribed in young infants, I,2 including a premature newborn baby," with a maximum recorded age of 13 years.' 15,20 The peak age of presentation is be- tween 5 to 10 years.2,4,9,12,13,18 Clinically, the patient with symp- tomatic cervical IVDC is usually in good health generally, and presents with an acute onset of severe neck pain and torticollis, accompanied by limited neck and head movement.': 2. 4-7,9,Il, 12,15-17,21-25Some patients will have evidence of inflammation 1,2,4-7, 11,12,15,16,20,21,25with a low-grade fever at the onset of symptoms, possibly accompanied by a leucocytosis and raised ESR.I,2,4-7,12,15,16,20,25Dysphagia may be present.': 2,4 If anterior hernia- tion of the calcified disc occurs, it may be responsible for the dysphagia.l" 26 The history of dysphagia in our patient was not associated with anterior disc herniation, but may rather have been related to the painful neck muscle spasm. Posterior disc protrusion or her- niation can occur when the calcified nucleus pulposus herniates through the annulus fibrosis. The resultant disc de- formity may not impinge on the spinal cord or cervical roots, as was the case in this patient. Should this occur, the patient may present with a painful upper limb radiculopathy.'r-" 7,15,16,20- 22,25,27The incidence of associated disc protrusion or herniation with cervical IVDC is 30% to 38%.1,2,6,15,16,28It is postulated that the greater mobility of the cervical spine predisposes to disc calcification and herniation. I It is un- certain why the patients without disc herniation are symptomatic, but one explanation is that there may be a change in the hydrophilic properties of the calcified disc, raising intradiscal pressure and thereby producing symptoms.2,9,15 Patients with IVDC found co-inci- dentally on x-ray 2,4-7,9,15,16,20represent either an asymptomatic or dormant form of the disorder.2,5Curiously, patients with multiple levels of calcification are less likely to present with pain.? 18The in- cidence of asymptomatic patients is approximately 17 to 30%.6,13,16,20 IVDC has been associated with congenital malformations such as car- diac and bone anomalies, but this is the exception rather than the rule.2,9,18 In children, intervertebral disc cal- cification occurs within the nucleus pulposus, whereas in adults disc calci- fication occurs in the annulus fibrosis I, 2,6,9,16The aetiology of the calcifica- tion in children remains uncertain 1,2,4, 6-8,10,12,15,18,20,23Causes found in adults such as ochronosis, amyloidosis, ac- romegaly and metabolic defects such as chondrocalcinosis, hyperparathy- roidism, hypervitaminosis D, haemo- chromatosis, gout and pseudogout have not been implicated in children.': 2,4,6,9, 12,13,15,18,20Thirty to forty percent of symptomatic patients give a history of injury to the neck. I,2,4-6,15,20Vertebral body fractures in children are not asso- ciated with IVDC.1,5 The majority ofIVDCs occur in the cervical spine 1,2,4-6,12,13,15,16,20and most frequently in the C4 to C7 area.': 2,6,9, 10,15The calcification usually involves a single cervical disc, but multiple 10 SAJOURNAL OF RADIOLOGY. August 1998 calcified discs are recorded 1,2,5,6,9,12,13, 15,16,20,21with a prevalence which is es- timated to be 30 to 40% of all IVDC cases.' The thoracic and lumbar discs may occasionally calcify in children, but IVDC in these regions is usually asymp- tomatic and the calcifications are not absorbed, remaining unaltered for many years,': 2,4,9,12,24,29In the thoracic spine, disc protrusions are less likely to occur, possibly due to reduced thoracic mobility. In the lumbar spine, IVDC is found on the convex side of the curve in idiopathic scoliosis.' Plain radiographs, CT and Magnetic Resonance Imaging (MRI) are the imaging modalities of choice for this condition. All three examinations show the IVDC located in the nucleus pul- posus. The disc calcification usually occupies most of the disc space and has a round, oval 1,9,16or linear shape." Imaging may also demonstrate anterior wedging of the vertebral body adjacent to the calcified disc. 1,2,5,6,7,16,25Poste- rior wedging has also been docu- merited." CT and MR! are able to dem- onstrate the presence of calcified disc protrusion or herniation with or with- out spinal cord and/or nerve root in- volvement.':" Follow-up x-rays can be used to confirm the resolution of the calcification. A good case can be made for the use of plain x-rays alone to make the initial diagnosis,20,24and for CT to be restricted to investigating those patients with radiculopathy" Linear tomogra- phy of the spine is felt to be totally un- necessary. 20 IVDC in children is usually a self- limiting disease with an excellent prognosis.':" 6-8,10,11,15,16,18,20-24The clinical response to a regimen of non- steroidal anti-inflammatory drugs, analgesics and a cervical collar 1,2,4,9, 11,18,21,24is usually rapid, with the child becoming asymptomatic within days to page 11 Intervertebral disc c,-1lcificatiol1 in eh i ldre n from page 10 to weeks 2,4,6,9,11,12,IS, 16,18,21as oc- curred in this patient. Rarely, the pres- ence of the symptoms can be pro- longed and the clinical condition can persist for months or years." 9, 30 The disc calcification gradually disappears within weeks to months, with minor radiographic abnormalities remain- ing.': 2,4,6,12,15-17,18,20,21This is borne out in this patient, who showed al- most total disappearance of the C5/6 lVDC and the persistence of anterior wedging of the CS vertebral body, af- ter three and a half months. Some- times the IVDC can persist for years, but this is rare,2,5,6,12,16,15,18On occa- sion, neck traction is required to aid response to conservative therapy. Sur- gery for disc herniation with cord and/ or nerve root compression has been recorded, but is rare.l' 15,27The re- cent trend is to persevere with con- servative treatment, even with disc- related symptoms, There is increasing evidence that the clinical picture and radiculopathy in image-proven disc herniation with root or cord compres- sion resolve with medical treatment and immobilisation. Surgical decom- pression should be reserved for pa- tients who are refractory to conserva- tive treatment.v 4,6,7,28 The intermediate-term changes which are recorded with IVDC take the form of loss of vertebral body height adjacent to the disc calcifica- tion, disc space narrowing at the in- volved site, scoliosis and osteophyte development. 2,5,16The long term con- sequences of lVDC are poorly docu- mented, since patients are seldom closely followed into adulthood, References I. Ventura N, Huguet R, Salvador A, Terricabras L, Cabrera AM. Intervertebral disc calcification in childhood. 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