Acute handlebar syndrome: Two extremes of a challenging diagnosis

Abstract

Background: Ulnar nerve mononeuropathy diagnosis can be challenging depending on where neural lesion is present. Repetitive trauma during cycling is a rare cause of ulnar neuropathy. Case Description: We describe two patients who developed the handlebar syndrome, an ulnar nerve palsy at Guyon’s canal after cycling. The first patient had the syndrome after a short-distance ride and she was treated surgically, while the second patient developed the classical syndrome after a long ride and received conservative treatment. Surgical treatment of the first patient led to functional recovery. Conclusion: Handlebar syndrome is a neuropathy caused by extrinsic repetitive compression of ulnar nerve at wrist. Increasing incidence of this disease can be expected after increasing popularity of cycling sports. Avoid of repetitive trauma is the main management goal, with surgical treatment reserved for failure of conservative treatment.

The Physiatrist’s Guide to Cyclist Palsy

“…The differential diagnosis for cyclist palsy is broad. Compressive structural pathology at Guyon canal should be considered, such as ganglion cysts, hamate fractures, vascular malformations, and lipomas 7,18 . Median nerve entrapment should also be considered as it has been demonstrated that cyclists can developed electrodiagnostic evidence of carpal tunnel syndrome after long-distance rides 19–21 .…”

“…In the setting of intrinsic hand weakness, magnetic resonance imaging of the cervical spine should be considered to rule out conditions such as cervical myelopathy and radiculopathy. However, once both neurologically catastrophic pathology and more common pathology have been ruled out adequately, then nerve conduction studies and electromyography may be pursued to best localize the presumed peripheral nerve lesion 7 …”

“…An original classification system was described by Gross and Gilberman 11 consisting of three injury zones. Zone 1 injuries, regarded as the most common subtype, occur at the proximal portion of Guyon canal, before the bifurcation of the ulnar nerve into its superficial and deep branches 7 . These injuries manifest as combined motor and sensory deficits.…”

“…These can be conceptualized based on cycling-related risk factors, such as sudden increases in training volume, compared with anatomical-related risk factors, such as previous orthopedic injuries. While prolonged cycling is intuitively a more common risk factor for cyclist palsy, there are reports of cyclist palsy developing after short distance rides as well 7,15 …”

“…Cyclists are at high risk for neuropathies across the hand and wrist given their positioning on the bicycle. The prevalence of ulnar and median compressive neuropathies in long-distance cycling exists somewhere between 10% and 70% 7 . While the true incidence and prevalence of cyclist palsy is unknown, clinicians may see a rise in patients developing this condition given the increase in at-home stationary bicycle use, combined with an increase in bicycle sales during the COVID-19 pandemic 8,9 …”