MotoGP champion Marc Marquez was sidelined for over four months during his previous episode of diplopia, during the winter of 2011-2012.
It’s now known that Marc Marquez won’t be on a MotoGP bike again this year after the ‘slight concussion’ initially reported following an off-road training accident on October 30 was revealed as being a ‘new episode of diplopia’ (double vision).
The diagnosis was made by Doctor Sánchez Dalmau, the same Ophthalmologist who successfully treated Marquez during his first diplopia ‘episode’, 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. Traumatic trochlear nerve palsies 𝗮𝗿𝗲 𝗮𝘀𝘀𝗼𝗰𝗶𝗮𝘁𝗲𝗱 𝘄𝗶𝘁𝗵 𝗺𝗼𝘁𝗼𝗿 𝘃𝗲𝗵𝗶𝗰𝗹𝗲 𝗮𝗰𝗰𝗶𝗱𝗲𝗻𝘁𝘀 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 constrained—like the trackball of a computer mouse—in such a way that only certain rotational movements are possible. Allowable movements for the superior oblique are (1) rotation in a vertical plane—looking 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 muscle… This fourth right nerve is the one that was already injured in 2011.”
The 2011 eye injury occurred during 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 Marquez’s rookie season in the intermediate class but confirmed Stefan Bradl – the rider now substituting for Marquez at Repsol Honda – as Moto2 world champion.
Marquez’s eye gradually recovered after the accident but, by mid-January 2012, had still not reached ‘the necessary level required by a professional rider.’
Surgery by Doctor Dalmau to treat ‘paralysis of the upper right oblique muscle, caused by trauma to the fourth right cranial nerve [at Sepang]’ 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, it’s confirmed that Marquez will miss the remainder of this year’s 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 year’s March 4-6 Qatar season opener.
The official MotoGP pre-season tests are scheduled for Sepang on February 5-6 then Mandalika 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 deadline for surgical intervention this time around.
“A conservative treatment with periodic updates has been chosen to follow with the clinical evolution,” was all Doctor Dalmau said of Marquez’s 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 year’s 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: ‘These are very hard moments, it seems that when it rains, it pours’.
But if the injury had happened early next year, it would have been more costly and the experience of Marquez’s 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 dominate the world championship, joining MotoGP the following year.