Is scan-negative cauda equina syndrome a functional neurological disorder? A pilot study

Area of Science:

• Neurosurgery
• Radiology
• Psychiatry

Background:

• Cauda Equina Syndrome (CES) is a critical neurosurgical emergency requiring prompt lumbar MRI.
• A significant number of patients with CES symptoms lack radiological evidence, suggesting potential functional aetiologies.
• Understanding the clinical characteristics and outcomes of these scan-negative (SN) patients is crucial.

Purpose of the Study:

• To investigate the clinical characteristics and outcomes of patients with suspected CES.
• To compare patients with confirmed CES, radiculopathy, and scan-negative (SN) findings.
• To evaluate the role of functional comorbidities and mental health in SN patients.

Main Methods:

• A retrospective analysis of 155 adult patients undergoing urgent lumbar MRI for suspected CES.
• Patients were categorized into CES (n=25), radiculopathy (n=68), and SN (n=62) groups.
• Follow-up included postal questionnaires assessing disability, pain, anxiety, and somatic symptoms up to 3 years post-discharge.

Main Results:

• No clinical symptoms reliably differentiated CES from SN patients.
• SN patients exhibited higher rates of functional comorbidities but similar mental health diagnosis frequencies.
• Postal questionnaires revealed high levels of pain and disability in all groups, with SN patients reporting higher self-rated mental health issues and somatic symptoms.

Conclusions:

• SN patients present with more functional comorbidities and inconsistent care pathways.
• Further research is warranted to explore mental illness and somatic symptoms in SN cases.
• Optimization of neuropsychiatric assessment and care pathways is recommended for SN patients, despite low response rates limiting generalizability.