Cervicothoracic (C₆, C₇ & T₁) spina bifida occulta – A case report

Abstract

Introduction

Spina bifida (SB), as one of the spine abnormalities, is caused by incomplete closure of the neural tube and generally includes two types: open and closed. This study aims to introduce one of the rare cases of closed SB.

Case presentation

A 34-year-old male patient was admitted to the hospital with neck pain. Radiographic and computed tomography (CT) imaging revealed bifid spinous processes from C₆ to T₁ vertebrae, indicative of a rare case of closed SB in the cervicothoracic region.

Clinical discussion

Closed SB, while often regarded as benign, can be associated with various pathologies that require follow-up.

Conclusion

Diagnosing this abnormality is crucial for addressing potential complications that may arise from it.

Highlights

• •Spina bifida is the most common non-fatal neural tube closure defect.
• •Spina bifida is generally located in the lumbar or sacral region and extends over 2 to 3 vertebrae.
• •Spina bifida is associated with maternal folic acid deficiency during the fetal period.

1. Introduction

Spina bifida is the most common non-fatal neural tube closure defect caused by incomplete closure of the neural tube between 22 and 32 weeks of pregnancy [1]. SB in humans has an incidence of approximately 0.5 per 1000 pregnancies worldwide. This disorder is generally classified into two subgroups: open or close [2].

1.1. Types of spina bifida

• •Spina bifida occulta: is mainly observed in lumbar-sacral vertebrae and occurs in L5 or S1 vertebrae in approximately 10 % of the population. This disorder can be seen as a mass of hair, a small dimple, a vascular mole, and a skin sinus.
• •Spina bifida cystica: This abnormality is due to the protrusion of a cyst bag, such as meningocele or spinal cord, through a defect in the vertebral arches, a severe type of SB. Direct exposure of nerve tissue to amniotic fluid can result in neurological disorders [[3], [4]].

Although considered benign, SB occulta has recently been associated with several pathologies, such as tethered cord syndrome, reproductive tract dysfunction, disc pathology, lumbar spondylolysis, intraspinal lipoma, leg deformities, and syringomyelia. SB is generally located in the lumbar or sacral region and extends over 2 to 3 vertebrae [5]. On the other hand, involvement of the cervical spine is often occult, where the defect is covered by skin and limited to bone [6].

2. Case presentation

The studied patient is a 34-year-old man who came to Hospital, with neck pain. The patient had no severe history of neck pain or chronic related problems. A plain cervical spine radiograph was requested in two frontal and lateral views. X-ray images showed bifurcated appendages in the C6 to T1 vertebrae (Fig. 1). CT-scan of the neck and thorax clearly shows closed SB in the C6 to T1 vertebrae, limited to the bony structure (Fig. 2). In the physical examination, no evidence of a hair cyst or the connection of the spinal cord or meninges with the skin's surface was observed. Upon reviewing the radiologist's X-ray and CT scan results, it was suggested that the patient may have SB occulta, a condition uncommonly confined to the lower cervical and upper thoracic vertebrae. After the diagnosis, anti-inflammatory drugs were prescribed to the patient, which along with physiotherapy can help relieve pain.

Fig. 1.

Cervical X ray A) AP B) Lateral view.

Fig. 2.

Bone reconstruction CT-scan of cervicothoracic region - Arrows show the location of the defect - A) 6th cervical vertebra B, C) 1th thoracic vertebra.

3. Discussion

Spinal congenital abnormalities are prevalent, with the majority occurring in the cervical and lumbar regions of the spine. Conversely, the localization of these abnormalities in the thoracic spine is rare [7]. At the end of the third week of pregnancy, somitomeres grow and form sclerotomes, myotomes, and dermatomes from the created somites. The vertebrae are obtained from the development of the sclerotomy, the closest part of the somites to the embryonic axis. Indeed, notochord cells induce the growth of vertebral bodies from the sclerotome, while the neural tube induces the differentiation of the sclerotome into components of the vertebral arch [7]. NTC disorders can lead to neural tube defects (NTDs), a common and severe birth defect. A basic tenet of neuroregulation is that axial surfaces of the body that undergo primary neurulation are predisposed to “open” NTDs (e.g., anencephaly, spina bifida aperta, and cranioschisis) and, in contrast, impairment of secondary neurulation forms “Package” carries spina bifida [8]. Neural tissue development is coordinated by signals from Bone Morphogenetic Proteins (BMPs), Sonic Hedgehog (Shh), Fibroblast growth factors (FGFs), Wnt, and cilia-related genes [[9], [10]]. Therefore, disruption of Shh signaling can lead to SB [5].

SB occulta results from the failed fusion of posterior vertebral elements without affecting the spinal cord or meninges. Closed SB affects the lumbosacral region and accounts for 10–15 % of spine malformations [11–2]. Its prevalence ranges from 0.6 % to 25 %. Genes that regulate folate one‑carbon metabolism and glucose metabolism, along with various vitamins and minerals, play a crucial role in NTC [8]. Several studies have found evidence that SB is associated with maternal folic acid deficiency during the fetal period [[12], [13], [14]]. Yoon et al. observed a spinous process fusion at T11 and T12 [15]. Only one paper was published in 1972 by Levy et al., who reported a single failure of T1 fusion in 47 of 5363 asymptomatic African patients who underwent X-ray examination (0.01 %) [16]. In 2016, Mementi et al. reported a rare case of fusion failure of the thoracic vertebrae at the T1 level, discovered incidentally through X-ray imaging [7]. Although SB occulta, which commonly occurs at L5, is not mainly associated with disc herniation, one study found a correlation between the SB occulta of the S1 segment and posterior disc herniation [2].

Although expensive and time-consuming, magnetic resonance imaging (MRI) has significant clinical value in the prenatal diagnosis of SB. However, recent studies used 2D ultrasound (US) together with 3D US to diagnose SB occulta [11]. The present report, as a rare case of SB occulta in three consecutive cervical and thoracic vertebrae, can be helpful for radiologists, orthopedists, neurologists, and neurosurgeons, providing insight into the unique characteristics and management of rare presentations of SB. Remarkably, the patient described in this report had no significant history of neck pain or movement limitation in various regions of the spine; he sought medical care solely due to a relatively short period of neck pain. After the diagnosis of this rare but benign case, anti-inflammatory analgesic drugs were considered as the first line of treatment, which led to the relief of the patient's pain. The work has been reported in line with the SCARE criteria [17].

4. Conclusion

The current report presents a rare case of SB occulta that did not have severe clinical symptoms or troublesome complications. An accurate diagnosis of spinal deformities, using clinical assessments and medical imaging, is crucial for distinguishing between various types of spinal deformities. This helps effective management and prevents potential complications.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

As this is only a clinical case report, there was no need to obtain an ethics code. However, we obtained written permission from the patient to present this case report and to include images in the article, a written copy of which is available for submission to the journal, if necessary.

Funding

None.

Author contribution

• 1.Soheil mirzaei - Conception and design, Acquisition of data, Writing the paper, Final approval of the version to be published.
• 2.Maryam Khoshkholghsima – Imaging report, Critical revision of the article, Final approval of the version to be published.
• 3.Amir sabaghzadeh - Acquisition of data, Critical revision of the article, Final approval of the version to be published.
• 4.Hoshmand Zarei Kurdkandi - Writing the paper, Final approval of the version to be published.

Guarantor

Corresponding author: E-mail address: mirzaei.soheil@yahoo.com (S. Mirzaei).

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Conflict of interest statement

None.