Ulnar nerveUlnar nerve

The effect of long distance The effect of long distance bicycling on ulnar and bicycling on ulnar and

median nervesmedian nerves

AcknowledgementsAcknowledgements

Venu Akuthota, MDVenu Akuthota, MD

Christopher Plastaras, Christopher Plastaras, MDMD

Kristin Lindberg, MDKristin Lindberg, MD

Joel Press, MDJoel Press, MD

Cyndi Garvan, PhDCyndi Garvan, PhD

OverviewOverview

Cyclist palsyCyclist palsy HistoryHistory AnatomyAnatomy ClassificationClassification EtiologyEtiology Other studies / Other studies /

reportsreports Our studyOur study

Electrodiagnostic Electrodiagnostic datadata

Cyclist palsy Cyclist palsy

Also known as ‘Handlebar Also known as ‘Handlebar palsy’palsy’

Compression or entrapment Compression or entrapment neuropathy of ulnar nerve at neuropathy of ulnar nerve at or distal to Guyon’s canal at or distal to Guyon’s canal at the wristthe wrist

Cyclist Palsy - HistoryCyclist Palsy - History

1896 - Destot1896 - Destot Ulnar neuropathy in cyclists Ulnar neuropathy in cyclists

first described first described Paris-Brest-Paris 1200 km Paris-Brest-Paris 1200 km

bicycling race.bicycling race.

European journals European journals

1970’s – American journals1970’s – American journals

Guyon’s CanalGuyon’s CanalAnatomy Anatomy

Ulnar BorderUlnar Border pisiform bone and FCU tendonpisiform bone and FCU tendon

Radial BorderRadial Border Hook of HamateHook of Hamate

FloorFloor Pisohamate ligament Pisohamate ligament

RoofRoof Palmer carpal ligamentPalmer carpal ligament Palmaris brevis musclePalmaris brevis muscle

Branches:Branches: Dorsal ulnar cutaneousDorsal ulnar cutaneous

Superficial Sensory Superficial Sensory branchbranch

Deep branchDeep branch Branch to hypothenars Branch to hypothenars

Deep motor branchDeep motor branch

AnatomyAnatomy

Location of Location of compression:compression:

Within Guyon’s Within Guyon’s canal canal

Distal to canalDistal to canal

Wu’s Classification –Wu’s Classification –Ulnar nerve compression at the Ulnar nerve compression at the

wristwristTypeType Fibers Fibers

AffectedAffectedLocationLocation

II MixedMixed Proximal to or within Guyon’s canalProximal to or within Guyon’s canal

IIII SensorySensory At wrist, just distal to branch to At wrist, just distal to branch to palmaris brevis musclepalmaris brevis muscle

IIIIII MotorMotor Proximal to the branch to the Proximal to the branch to the hypothenar muscleshypothenar muscles

IVIV MotorMotor Distal to the branch to the hypothenar Distal to the branch to the hypothenar musclesmuscles

VV MotorMotor Proximal to the branches to the first Proximal to the branches to the first doral interosseous and adductor pollicis doral interosseous and adductor pollicis musclesmuscles

Etiology: Cyclist palsyEtiology: Cyclist palsy

Chronic repetitive Chronic repetitive traumatrauma

Chronic pressureChronic pressure

VibrationVibration

HyperextensionHyperextension

Cycling specific factorsCycling specific factors

Long biking excursions Long biking excursions

Hand positionHand position

Hyperextension of wristHyperextension of wrist

Forward weight shiftForward weight shift

SymptomsSymptoms PainPain

ParesthesiasParesthesias

NumbnessNumbness

WeaknessWeakness

BackgroundBackground Eckman – ’75 Eckman – ’75

3 case reports of ulnar neuropathy at the wrist in cyclists3 case reports of ulnar neuropathy at the wrist in cyclists

Jackson – ’89Jackson – ’89 20 long distance cyclists20 long distance cyclists 9 with symptoms9 with symptoms Normal NCS of median and ulnar sensory & motor studiesNormal NCS of median and ulnar sensory & motor studies

Wilmarth – ’88 Wilmarth – ’88 Ulnar sensory nerve conductions while within normal Ulnar sensory nerve conductions while within normal

limits in cyclists did vary signficantly compared to non-limits in cyclists did vary signficantly compared to non-cyclists.cyclists.

Patterson – ’03 Patterson – ’03 92% (23 out of 25) cyclists had either motor or sensory 92% (23 out of 25) cyclists had either motor or sensory

symptoms after a 600 km ride.symptoms after a 600 km ride.

The effect of long distance The effect of long distance bicycling on ulnar and median bicycling on ulnar and median

nerves:nerves:

An electrophysiologic evaluation of cyclist’s An electrophysiologic evaluation of cyclist’s palsypalsy

Objective:Objective: To objectively quantify To objectively quantify

changes in the ulnar and changes in the ulnar and median nerves associated median nerves associated with a long distance multi-with a long distance multi-day cycling event.day cycling event.

Design:Design: A prospective cohort studyA prospective cohort study

SubjectsSubjects

14 adult subjects14 adult subjects Total of 28 handsTotal of 28 hands Seven men, seven womenSeven men, seven women

Bike tour 6 day6 day 420 miles (Avg - 70 miles. 420 miles (Avg - 70 miles.

Max - 85.9 miles) Max - 85.9 miles) Flat and rolling terrain on Flat and rolling terrain on

asphalt & chip-coat roadsasphalt & chip-coat roads

Nerve Conduction StudiesNerve Conduction StudiesPre & Post RidePre & Post Ride

Ulnar motor (Dual Channeled) Ulnar motor (Dual Channeled) abductor digiti minimiabductor digiti minimi first dorsal interosseusfirst dorsal interosseus

Median motor Median motor abductor pollicis brevisabductor pollicis brevis

Ulnar sensory Ulnar sensory little fingerlittle finger

Median sensory Median sensory index fingerindex finger

QuestionnaireQuestionnaire Post ridePost ride

DemographicsDemographics

Experience levelExperience level

Hand positionsHand positions

Symptoms Symptoms experienced during experienced during rideride

Onset motor latenciesOnset motor latencies

3.7

3.453.1

3.03.5

3.7

0.450.72

00.5

11.5

22.5

33.5

44.5

5

Median Ulnar toADM

Ulnar to FDI

FDI - ADM

BeforeAfter

p = 0.5020 p = 0.2357 p = 0.0044 p < 0.0001

Peak sensory latenciesPeak sensory latencies

3.33.15

3.23.1

0

0.51

1.52

2.53

3.54

4.55

Median Ulnar

BeforeAfter

p = 0.31 p = 0.6466

Ulnar nerve resultsUlnar nerve results

Motor StudiesMotor Studies FDI & ADM within normal FDI & ADM within normal

rangesranges

Comparison of Pre/PostComparison of Pre/Post Significant DifferencesSignificant Differences

FDI FDI FDI – ADM FDI – ADM

Median nerve resultsMedian nerve results

Median nerve palsy due to cycling is rare.Median nerve palsy due to cycling is rare.

No significant difference between the hands No significant difference between the hands before or after the ride for median motor or before or after the ride for median motor or sensory.sensory.

Pre-ride – 3/28 hands with onset > 4.2 msecPre-ride – 3/28 hands with onset > 4.2 msec

Post-ride – all three with increases of latencyPost-ride – all three with increases of latency

Post-ride – 1 hand with 3.9 msec to 4.8 msecPost-ride – 1 hand with 3.9 msec to 4.8 msec

DiscussionDiscussion

Changes occur in Changes occur in the deep branch of the deep branch of the ulnar nervethe ulnar nerve Despite usual Despite usual

preventative preventative measuresmeasures

Sub-clinical changesSub-clinical changes

Pre-existing nerve Pre-existing nerve abnormalities may abnormalities may be exacerbatedbe exacerbated

LimitationsLimitations

Small sample numberSmall sample number Lack of temperature Lack of temperature

measurementmeasurement Technical errorsTechnical errors

Submaximal stimulationSubmaximal stimulation Distance differencesDistance differences

Same electromyographer Same electromyographer performed all examinationsperformed all examinations

ConclusionsConclusions

• Cyclist palsy or handlebar palsy is a Cyclist palsy or handlebar palsy is a compressive neuropathy of the ulnar compressive neuropathy of the ulnar nerve seen in cyclistsnerve seen in cyclists

• Early recognition of symptoms & Early recognition of symptoms & intervention with rest & cessation of intervention with rest & cessation of biking, then modification of biking, then modification of equipment and alteration in riding equipment and alteration in riding style is important for the avoidance style is important for the avoidance of nerve damageof nerve damage

ConclusionsConclusions

• Significant changes can Significant changes can occur to the deep branch occur to the deep branch of the ulnar nerveof the ulnar nerve

• May cause or exacerbate May cause or exacerbate symptoms of carpal tunnel symptoms of carpal tunnel syndromesyndrome