# Pathology of the conus medullaris and cauda equina. Beyond the usual suspects

## TL;DR

This paper reviews the diagnostic challenges and imaging features of conus medullaris and cauda equina pathologies to improve accurate diagnosis.

## Contribution

The paper provides an educational review of both common and rare causes of conus medullaris and cauda equina lesions with a focus on imaging characteristics.

## Key findings

- Contrast-enhanced MRI is the gold standard for diagnosing conus medullaris and cauda equina lesions.
- Myxopapillary ependymomas and schwannomas are the most frequent neoplasms in these regions.
- Infections like tuberculous arachnoiditis and neurocysticercosis can mimic neoplastic processes.

## Abstract

Pathologies affecting the conus medullaris and cauda equina can present with overlapping clinical symptoms, making an accurate diagnosis essential. Conus medullaris syndrome results from damage at the T12–L2 level, while cauda equina syndrome arises from nerve root compression below the conus. Both conditions may cause motor deficits, sensory disturbances, and autonomic dysfunction, necessitating a detailed differential diagnosis.

This educational review highlights common and rare etiologies of conus medullaris and cauda equina lesions, emphasizing imaging characteristics and diagnostic considerations. A comprehensive review of tumors, infections, inflammatory, vascular, and degenerative conditions affecting these regions was performed. Contrast-enhanced MRI was identified as the gold standard for diagnosis.

Tumors: myxopapillary ependymomas and schwannomas are the most frequent neoplasms, while drop metastases and glioblastomas represent rarer entities.Infections: tuberculous arachnoiditis, bacterial radiculitis, schistosomiasis, and neurocysticercosis may mimic neoplastic processes.Inflammatory disorders: Guillain–Barré syndrome, neurosarcoidosis, and MOGAD may cause nerve root thickening and enhancement.Vascular lesions: spinal dural arteriovenous fistulas, infarcts, and arteriovenous malformations can produce conus and cauda equina symptoms.Miscellaneous causes: developmental anomalies like diastematomyelia and ventriculus terminalis, along with degenerative diseases, can mimic other conditions.

Tumors: myxopapillary ependymomas and schwannomas are the most frequent neoplasms, while drop metastases and glioblastomas represent rarer entities.

Infections: tuberculous arachnoiditis, bacterial radiculitis, schistosomiasis, and neurocysticercosis may mimic neoplastic processes.

Inflammatory disorders: Guillain–Barré syndrome, neurosarcoidosis, and MOGAD may cause nerve root thickening and enhancement.

Vascular lesions: spinal dural arteriovenous fistulas, infarcts, and arteriovenous malformations can produce conus and cauda equina symptoms.

Miscellaneous causes: developmental anomalies like diastematomyelia and ventriculus terminalis, along with degenerative diseases, can mimic other conditions.

Radiologists play a pivotal role in differentiating conus medullaris and cauda equina pathologies. A thorough understanding of imaging findings is essential for accurate diagnosis and effective management.

Conus medullaris and cauda lesions present with overlapping clinical symptoms but show some distinct imaging patterns. It is essential to recognize characteristic features that differentiate neoplastic from infectious or vascular etiologies.

Conus and cauda lesions have varied causes; MRI with contrast is vital for accurate diagnosis.Myxopapillary ependymomas cause vertebral scalloping; schwannomas may be cystic; intramedullary gliomas expand the cord.Conus medullaris and cauda lesions overlap clinically; imaging helps distinguish neoplastic from infectious or vascular causes.

Conus and cauda lesions have varied causes; MRI with contrast is vital for accurate diagnosis.

Myxopapillary ependymomas cause vertebral scalloping; schwannomas may be cystic; intramedullary gliomas expand the cord.

Conus medullaris and cauda lesions overlap clinically; imaging helps distinguish neoplastic from infectious or vascular causes.