Brachial multisegmental amyotrophy caused by cervical anterior horn cell disorder associated with a spinal CSF leak: a report of five cases

Common symptoms in patients with a spinal CSF leak include orthostatic headaches, neck stiffness, and hearing difficulties. The main outcome of this report was to introduce and characterize brachial multisegmental amyotrophy, a rare, but treatable symptom associated with a spinal CSF leak.

Between 2013 and 2017, five patients who developed progressive amyotrophy were referred to our hospital. A retrospective and prospective analysis of clinical, electrophysiological, and neuroimaging findings is presented. Data were analyzed between August 2013 and April 2019.

Amyotrophy was observed in the C5–C8 myotomes and was more prominent in the proximal muscles than in the distal muscles. Amyotrophy was unilateral in three patients and asymmetric bilateral in two. Electromyography revealed active and chronic denervation in the C5–C8 myotomes, particularly C5–6, of all patients. Although the clinical manifestations of these cases were similar to amyotrophic lateral sclerosis, unusual neuroimaging findings were observed: spinal T2-weighted MRI revealed high-signal-intensity lesions in the bilateral anterior horns at the C2–C4 spinal levels in all five cases; ventral epidural fluid collection was also observed. Thin-cut MRI or digital subtraction myelography showed ventral dural defects associated with CSF leaks at high thoracic levels in four patients; four underwent surgical dural repair, which attenuated or stabilized neurological symptoms, while upper limb weakness worsened in the other patient who did not undergo surgery.

A spinal dural defect may be the essential cause of brachial multisegmental amyotrophy. Surgical dural repair may alter the progressive course of this rare condition.