High cervical instability in adult patients with Down syndrome

Anterior atlantoaxial subluxation with Down syndrome and arthritis: case report

Down syndrome (DS) occurs when an individual has a full or partial extra copy of chromosome 21 and is the most common of all malformation syndromes. Associating with numerous pathologies like anterior atlantoaxial subluxation (AAAS) which is an increase in the space between the anterior arch of the first cervical vertebra (C1) and the odontoid process of the second vertebra (C2), most of the time its asymptomatic, only 1-2% to all the 30% who may have the AAAS and DS develop clinical symptoms. In this occasion, we present the case of a patient with SD and Juvenile chronic arthritis (JCA) who has atlantoaxial subluxation of approximately 11mm, basilar impression and platybasia with severe medullary compression in 2 points, requiring surgical management by the Neurological Surgery Service in Bucaramanga-Colombia.

Cervical myelopathy causing numbness and paresthesias in lower extremities: A case report identifying the cause of a false positive Sharp-Purser test

INTRODUCTION

The patient was referred to an outpatient physical therapy clinic for lumbar radiculopathy by a primary care physician and subsequently referred for imaging due to suspicion of cervical myelopathy. The case highlights the clinical reasoning of the physical therapist differentiating between lumbar stenosis, cervical myelopathy, and upper cervical instability. To the author's knowledge, this is the only case report in the literature to describe the mechanism that could underpin a false positive Sharp-Purser test (SPT). The case also highlights the importance of interpreting the outcomes of special tests cautiously.

CASE DESCRIPTION

A 55-year-old female was referred to outpatient physical therapy for lumbar radiculopathy. The patient's complaint was a one-year history of intermittent bilateral lower buttock paresthesias radiating to the bilateral posterior thighs. She reported a three-month history of bilateral anterior thigh numbness that would present after sitting for 30 minutes. Lumbar stenosis was initially suspected, however the patient's failure to improve but rather worsen with flexed postures suggested this diagnosis was improbable. The patient experienced bilateral anterior thigh numbness with active cervical flexion, and had a reduction in symptoms with the SPT.

OUTCOMES

Magnetic resonance imaging revealed multi-focal disc-osteophyte complexes with central canal stenosis from C4-7. The patient underwent an anterior cervical discectomy and fusion with a good outcome.

DISCUSSION

A large disc herniation causing central canal stenosis could underpin a false positive SPT. Special tests should always be used with caution, as they can lead to inaccurate diagnoses if there is a false positive.

Atlanto-Axial Instability in People with Down's Syndrome and its Impact on the Ability to Perform Sports Activities - A Review

Atlanto-axial instability (AAI) is a developmental anomaly often occurring in persons with Down’s syndrome (DS). According to various reports, AAI affects from 6.8 to 27% of the population with DS. The aim of this review was to illustrate the issue of AAI with regard to the progressively changing state of scientific knowledge. The extended distance between the rear surface of the frontal arcus of the C1 cervical vertebra and the anterior surface of C2 cervical vertebra dens (anterior atlanto-odontoid distance, AAOD) indicates the occurrence of AAI and is detectable through X-ray examination. Hypoplasia of the C2 dens, also detectable through X-ray examination, is another suggested risk factor for AAI. According to current data, the methodology of taking measurements is inconsistent, which leads to errors in interpretation. As research focusing on AAI was progressing, new data emerged from other studies on persons with DS, suggesting that neurological symptoms in persons with DS that indicated the occurrence of spinal cord compression were an important factor in medical imaging detection of AAI. One of the main arguments supporting this thesis is that in isolated cases spinal cord (SC) damage was noted during screening examinations conducted on a large population of subjects. Moreover, cases in which the neurological symptoms indicate spinal cord compression existed long before the occurrence of the actual damage also remain of significant importance. Therefore, it is necessary to promote neurological studies on persons with DS to enable early diagnosis of spinal cord compression and, at the same time, reduce the use of medical imaging in cases of neurological symptoms.