Magnetic Resonance Imaging, Vol. 8, pp. 647-650, 1990 0730-725x/94 $3.00 + .cNl

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l Case Report

CERVICOTHORACIC MYELOPATHY IN CONRADI-HUNERMANN DISEASE: MRI DIAGNOSIS

PHILIP GOODMAN AND RODRIGO DOMINGUEZ

Department of Radiology, University of Texas Medical School at Houston, Houston, Texas 77030, USA

A lo-year-old boy with Conradi-Hunermann disease diagnosed at birth who developed progressive myelopathy is presented. Despite the many descriptions of Conradi-Hunermann disease in infants and young children, long- term follow-up of this disease is rarely reported. Magnetic resonance imaging (MRI) played a critical role in the diagnosis of this patient’s rare neurological dysfunction by demonstrating bony deformity and associated cord compression at the cervicothoracic junction. This area is often difficult to evaluate by conventional radiographic techniques.

Keywords: Spine; MR studies; Bones, epiphyses; Spinal cord, compression.

INTRODUCTION

Conradi-Hunermann disease is a nonlethal form of chondrodysplasia punctata which is characterized by epiphyseal stippling.’ Although spinal abnormalities including hemivertebrae have been noted in this dis- ease, neurological symptoms are rarely reported.2 We describe a patient with Conradi-Hunermann disease who developed progressive neurological impairment secondary to cervical spinal cord compression. We also discuss the role of MRI in detecting bony anom- alies of the cervicothoracic junction.

CASE REPORT

A lo-year-old boy with Conradi-Hunermann disease presented with a several-month history of increasing urinary incontinence and decreasing motor function of his hands. He was born one month prematurely after an otherwise normal pregnancy and developed respi- ratory distress shortly after birth requiring intubation for 10 days.

At the time of birth, the patient was noted to have abnormalities of the fingers and toes and mid-face hypoplasia with flattening of the nasal bridge. Full ge-

netic screening including family histories and chromo- some studies of the infant and TORCH titers on cord blood screens were unremarkable. Radiographs of the extremities revealed epiphyseal stippling consistent with Conradi-Hunermann disease (Fig. 1).

The patient developed progressive spastic paraple- gia resulting in inability to walk by age five years. This was felt to represent cerebral palsy related to his pre- mature birth. At age seven, weakness and wasting of the small muscles of the hands, occasional urinary in- continence, and blindness of the right eye secondary to optic atrophy were noted. Radiographs of the tho- racic and lumbar spine showed only mild curvature and computed tomography (CT) of the brain revealed only slight ventricular enlargement.

Motor skills of the hands deteriorated sharply at age nine years and urinary incontinence increased, sug- gesting a C6 level myelopathy. Radiographs of the cervical spine showed no obvious abnormality but the cervicothoracic junction was obscured on the lateral film by the shoulders (Fig. 2). To better evaluate this area, MRI of the cervical spine was performed. This revealed marked deformity at the C6_7 level with ky- phosis, abnormal vertebral segmentations and hemi-

RECEIVED 2/27&O. Acknowledgments- We acknowledge the assistance of

Joel W. Yeakley, M.D., in the original evaluation of our patient.

Address all correspondence to Philip Goodman, M.D., Department of Radiology, University of Texas Medical Branch, Galveston, TX 77550, USA.

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648 Magnetic Resonance Imaging 0 Volume 8, Number 5, 1990

vertebrae as well as marked retropulsion of the hypoplastic body of C, and almost complete stenosis of the spinal canal at this level (Figs. 3(A) and (B)). Plain film tomograms confirmed the bony abnormal- ities seen on MRI.

B

Fig. 1. (A) Frontal radiograph of the right foot in infancy reveals stippling of the distal phalangeal epiphyses. (B) Lateral view at age four years shows two separate ossifica- tion centers of the calcaneus.

B

Fig. 2. (A) Frontal and (B) lateral plain films of the c ervi- cal spine. The C, and C, vertebrae are not well evaluated on these films.

Cervicothoracic myelopathy in Conradi-Hunermann disease 0 P. GOODMAN AND R. DOMINGUEZ 649

Fig. 3. (A) Proton-density-weighted and (B) T,-weighted sagittal images of the cervicothoracic junction demonstrate bony anomalies causing marked stenosis of the spinal canal and cord compression at the C6_, level.

DISCUSSION

Chondrodysplasia punctata is a disease of en- chondral bone formation characterized by epiphyseal stippling.’ Several forms of this disease have been recognized. The rhizomelic type has an autosomal recessive inheritance pattern and is associated with symmetrical shortening of the proximal long bones, severe mental retardation and death within the first one to two years of life.3 Conradi-Hunermann dis- ease is a milder form of chondrodysplasia punctata which may occur sporadically or by autosomal dom- inant inheritance. This is usually associated with a normal life span and the most common clinical feature is hypoplasia of the nose with a depressed nasal bridge and a shortened columella.4 Other clinical features are variable and include cataracts, contractures of large joints, various skin lesions, slightly decreased stature, and mild mental retardation.3-5 A third type of chon-

drodysplasia punctata with characteristic skin lesions has been reported only in females, suggesting an X- linked dominant mode of inheritance.6

Epiphyseal stippling of the long bones is visible ra- diographically only in the first few years of life but may result in epiphyseal dysplasia in older children. I Two ossification centers are often seen in the calca- neus with subsequent fusion resulting in a character- istic vertical cleft and shortening of the calcaneus.4 The differential diagnosis of stippled epiphyses includes trisomy 18 and 2 1, Smith-Lemli-Opitz syndrome, ce- rebrohepatorenal syndrome, mucopolysaccharidosis, GM-l gangliosidosis, intrauterine infections, and maternal prenatal use of anticoagulants.2

Although stippling is most commonly recognized in the extremities, the spinal column may also be affected due to its cartilaginous origin. This may result in defective ossification of vertebral bodies causing clefts, hemivertebrae, and scoliosis. l-5,’ However, reports of

650 Magnetic Resonance Imaging 0 Volume 8, Number 5, 1990

neurological symptoms in Conradi-Hunermann dis- ease are rare. A review of the English language liter- ature reveals a single patient with Conradi-Hunermann disease who had congenital flaccid paraparesis due to absence of the Ti2 vertebral body with associated ky- phosis and compression of a tethered spinal cord. These findings were easily demonstrated on plain films and myelography.* Two brothers with chondrodys- plasia punctata who developed neurological symptoms in infancy secondary to atlanto-axial dislocation have also been reported. 8

Although our patient’s progressive paraplegia, up- per extremity weakness and urinary incontinence were suspicious for myelopathy, routine plain films were not diagnostic since the cervicothoracic junction was obscured on the lateral film by the overlying shoul- ders. Spinal cord compression might also have been difficult to detect on myelography for the same rea- son. MRI prevented further delay in diagnosis by pro- viding excellent visualization of the cervicothoracic junction and allowing definitive evaluation of verte- bral anomalies and spinal cord compression in this area.

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REFERENCES

Silengo, M.C,; Luzzatti, L.; Silverman, EN. Clinical and genetic aspects of Conradi-Hunermann disease. A report of three familial cases and review of the literature. J. Pediatr. 97:911-917; 1980. Curless, R.G. Dominant chondrodysplasia punctata with neurologic symptoms. Neurology 33:1095-1097; 1983. Paltzik, R.L.; Ente, G.; Penzer, P.H.; Goldblum, L.M. Conradi-Hunermann disease. Case report and mini- review. Cutis 29:174-180; 1982. Sheffield, L.J.; Danks, D.M.; Mayne, V.; Hutchinson, L.A. Chondrodysplasia punctata-23 cases of a mild and relatively common variety. J. Pediatr. 89:916-923; 1976. Taybi, H. Radiology of syndromes and metabolic disor- ders, 2nd ed. Chicago: Year Book Medical Publishers; 1983. Happle, R. X-linked dominant chondrodysplasia punc- tata. Review of literature and report of a case. Hum. Ge- net. 53:65-73; 1979. Kozlowski, K. Chondrodysplasia punctata in a nine-year- old girl presenting as “unclassified multiple malformation syndrome.” Pediatr. Radiol. 9:236-238; 1980. Afshani, E.; Girdany, B.R. Atlanto-axial dislocation in chondrodysplasia punctata. Report of the findings in two brothers. Radiology 102:399-401; 1972.