MotoGP champion Marc Marquez was sidelinedย for over fourย months duringย his previous episode ofย diplopia, duringย the winter of 2011-2012.
Itโs now known thatย Marc Marquezย wonโt be on a MotoGP bike again this year after the โslight concussionโ initially reported following an off-road training accident on October 30 was revealed as being a โnew episode of diplopiaโ (double vision).
The diagnosis was made by Doctor Sรกnchez Dalmau, the same Ophthalmologist whoย successfully treated Marquez during his first diplopia โepisodeโ, in late 2011.
What is Diplopia?
The trochlear nerve, also called the fourth cranial nerve or CN IV, is a motor nerve that innervates just one muscle: the superior oblique muscle of the eye, which operates through the pulley-like trochlea.
Because of its fragility and extensive intracranial course, the trochlear nerve is especially vulnerable to trauma compared to most cranial nerves. Thus, the most common cause of an acquired defect of the trochlear nerve is trauma.[13] Traumatic trochlear nerve palsies ๐ฎ๐ฟ๐ฒ ๐ฎ๐๐๐ผ๐ฐ๐ถ๐ฎ๐๐ฒ๐ฑ ๐๐ถ๐๐ต ๐บ๐ผ๐๐ผ๐ฟ ๐๐ฒ๐ต๐ถ๐ฐ๐น๐ฒ ๐ฎ๐ฐ๐ฐ๐ถ๐ฑ๐ฒ๐ป๐๐ and boxing, as they involve rapid deceleration of the head. Because the trochlear nerve is so fragile, this can occur in minor head injuries that do not involve loss of consciousness or skull fracture. Shearing forces can result in disruption particularly at the superior orbital fissure, where the trochlear nerve enters the orbit.
Actions of the superior oblique muscle:
In order to understand the actions of the superior oblique muscle, it is useful to imagine the eyeball as a sphere that is constrainedโlike the trackball of a computer mouseโin such a way that only certain rotational movements are possible. Allowable movements for the superior oblique are (1) rotation in a vertical planeโlooking down and up (depression and elevation of the eyeball) and (2) rotation in the plane of the face (intorsion and extorsion of the eyeball).
Doctor Dalmau confirmed that Marquez now has "paralysis of the fourth right nerve with involvement of the right superior oblique muscleโฆ This fourth right nerve is the one that was already injured in 2011.โ
The 2011 eye injury occurred duringย an accident in opening Moto2 practice for the Malaysian Grand Prix, on October 21, when marshals failed to warn of a damp section of track.
The accident not only ended Marquezโs rookie season in the intermediate class but confirmedย Stefan Bradlย โ the rider now substituting for Marquez at Repsol Honda โ as Moto2 world champion.
Marquezโs eye gradually recovered after the accident but, by mid-January 2012, had still not reached โthe necessary level required by a professional rider.โ
Surgery by Doctor Dalmau to treat โparalysis of the upper right oblique muscle, caused by trauma to the fourth right cranial nerve [at Sepang]โ was thus required, taking place under local anaesthetic in Barcelona.
After some motocross training, Marquez made his return to a Moto2 bike during a private test at Alcarras on March 6.
In other words, he was off a Moto2 bike for four and a half months.
So far, itโs confirmed that Marquez will miss the remainder of this yearโs MotoGP action, meaning the Valencia finale and Jerez Test.
But if what sounds like a similar injury to 2011 results in a similar recovery timeline, Marquez would struggle to take part in any MotoGP pre-season testing before next yearโs March 4-6 Qatar season opener.
The official MotoGPย pre-season tests are scheduled for Sepangย on February 5-6 then Mandalikaย from February 11-13.
On the other hand, with the knowledge that rest alone was not enough to completely fix the eye issue in 2011, Marquez may set an earlier deadlineย forย surgical interventionย this time around.
โA conservative treatment with periodic updates has been chosen to follow with the clinical evolution,โ was all Doctor Dalmau said of Marquezโs current therapy.
Dogged by complications from a broken arm suffered at the start of the 2020 season, Marquez missed the opening two rounds of this yearโs world championship.
His slowly improving physical condition was roughly mirrored by technical progress made to the Honda, eventually allowing Marquez to win three races, including back-to-back victories at COTA and Misano just before the off-road accident.
Having overcome so much, the latest injury is a cruel blow for the eight-time world champion, who lamented on social media: โThese are very hard moments, it seems that when it rains, it poursโ.
But if the injury had happened early next year, it would have been more costly and the experience of Marquezโs previous injury at least suggests he should be on the grid for the start of the 2022 campaign, at the very least.
Marquez might also take some comfort from the fact that, despite missing two of the three pre-season tests in 2012, he went on to win the Qatar season-opener and dominateย the world championship, joining MotoGP the following year.