Unusual association of torticollis with Russell-Silver syndrome

Discussion

Russell syndrome was first described in 1953, is a well-recognised condition associated with prenatal and postnatal growth retardation. The syndrome was described by Silver and Russell who described a subset of children with low birth weight, postnatal short stature, characteristic facial features and body asymmetry. It is a genetically heterogeneous imprinting syndrome occurring in 1 in 50 000 births. This syndrome is characterised by intrauterine growth retardation followed by postnatal development deficiency.1 Paediatric tumours such as Ewing’s sarcoma are probabilities in such case.2

The syndrome manifests in various ways, some of them being typically short stature, normal head circumference, triangular faces (broadened forehead and narrow chin), limb length discrepancy due to hemihypertrophy. The five salient features of Russell-Silver syndrome is as follows:

1. Birth weight equal or less than −2 SD from population mean.

2. Poor postnatal growth equal or less than −2 SD from the mean value of diagnosis.

3. Preservation of occipitofrontal head circumference.

4. Classic facial features.

5. Skeletal asymmetry.3

Gastrointestinal symptoms such as refusal to feeding, gastro-oesophageal reflux, oesophagitis. Disruption methylation of 11p15 and maternal uniparental disomy for chromosome 7 is the most common genetic abnormality seen in these patients.

However, the molecular changes are seen in only two-thirds of the patients, and in the other cases with typical Russell-Silver syndrome remains unknown.4 The Netchine Harbison clinical scoring system which was proposed by Azzi et al, in which four out of six criteria were objective: protruding forehead and feeding difficulties are subjective but clear clinical definitions are given.5

As per the Netchine Harbison scoring system, the clinical diagnosis is considered if a patient scores four out of six criteria.6 If all the molecular tests are normal and differential diagnosis have been ruled out, patients scoring four out of six criteria including both prominent forehead and relative macrocephaly should be diagnosed as clinical Russell-Silver syndrome. Our patient satisfied four criteria out of six diagnostic criteria for Russell-Silver syndrome, including prominent forehead, body asymmetry, growth retardation and gastrointestinal disturbances. Torticollis was an additional prominent feature which was not a characteristic of Russell-Silver syndrome.

The term ‘torticollis’ derived from Latin word tortus means twisted and column means neck. It was first described by Tubby as ‘a deformity, congenital or acquired in origin, characterised by lateral inclination of the head to the shoulder, with torsion of the neck and deviation of the face’. Congenital muscular torticollis is a painless condition usually presenting during infancy.7 It is seen in 0.3%–1.9% of all births. The incidence can be as high as 1 in 250 births. It has a slight male preponderance (3:2), more common on the right side. It can be associated with other conditions such as hip dysplasia, craniofacial asymmetry, plagiocephaly and brachial plexus injury. The aetiopathogenesis are still unknown including birth trauma, and perinatal injury which causes trauma to sternocleidomastoid resulting in ischaemia and consequent fibrosis.8 Congenital torticollis is the result of unilateral shortening and thickening and excessive contraction of sternocleidomastoid. The basic abnormality is known as endomysial fibrosis with deposition of collagen and migration of collagen fibroblasts around individual muscle fibres. It leads to limitation of head movements in both rotation and lateral flexion and progressive degrees of contracture of neck.

Since the salient feature of our patient was torticollis, we considered differential diagnoses like Klippel-Feil syndrome which has a triad of short neck, low posterior hair line and limited cervical range of motion. Klippel-Feil syndrome was first described by Maurice Klippel and Andre Feil in 1912 in patient with congenital fusion of cervical vertebrae. This syndrome is associated with Sprengel deformity, high scapula, scoliosis, urinary tract anomalies, congenital heart defects and sensorineural hearing loss.9 Our patient did not have other salient features to be categorised into Klippel-Feil syndrome other than torticollis. Other syndromes such as Grisel’s syndrome, the cause of inflammatory torticollis was also ruled out. Grisel’s syndrome is due to non-inflammatory subluxation of atlantoaxial vertebrae secondary to infections of head and neck region. This was ruled out by clinical examination. There was no fusion of atlantoaxial vertebrae; trauma was excluded by history and through clinical examination.