Beevor's sign

Beevor's sign is a clinical sign that indicates a lesion or dysfunction in the lower part of the spinal cord, specifically at or below the level of the thoracoabdominal nerves (T7-T10). It is named after Charles Edward Beevor, a British neurologist who first described it in the late 19th century. Beevor's sign is observed during the attempt to flex the abdomen.

Presentation

When a patient with a positive Beevor's sign attempts to flex the abdominal muscles by lifting the head while lying flat on their back, the umbilicus moves upwards towards the head. This is due to the paralysis or weakness of the lower abdominal muscles, while the upper abdominal muscles remain intact and functional. In a healthy individual, the umbilicus remains stationary or moves slightly downwards due to the balanced action of the upper and lower abdominal muscles.

Pathophysiology

Beevor's sign indicates a dysfunction in the spinal cord, specifically affecting the innervation of the lower abdominal muscles. The thoracoabdominal nerves (T7-T10) supply the upper abdominal muscles, while the lower abdominal muscles are innervated by the lower thoracic and upper lumbar nerves (T10-L1). A lesion in the spinal cord at or below the T10 level can disrupt the neural pathways to the lower abdominal muscles, leading to their weakness or paralysis. This results in the unopposed action of the upper abdominal muscles during attempts to flex the abdomen, causing the characteristic upward movement of the umbilicus.

Clinical Significance

Beevor's sign is a useful clinical indicator for the localization of spinal cord lesions. It is particularly significant in cases where imaging studies are inconclusive or unavailable. The presence of Beevor's sign suggests a non-functioning or damaged lower thoracic or upper lumbar spinal cord. This can be due to various causes, including trauma, tumors, infections, or degenerative diseases affecting the spinal cord.

Diagnosis

The diagnosis of a positive Beevor's sign is primarily clinical, based on the observation of the abnormal movement of the umbilicus during abdominal flexion. Further diagnostic tests, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, may be required to identify the underlying cause of the spinal cord lesion.

Management

Management of a positive Beevor's sign involves addressing the underlying cause of the spinal cord lesion. This may include surgical intervention, radiation therapy, or pharmacological treatment, depending on the nature of the lesion. Rehabilitation and physical therapy may also be necessary to help improve muscle strength and function.

See Also

• Spinal cord injury
• Neurological examination
• Charles Edward Beevor