The corner table is ready, as always. This evening, Watson has chosen a bottle of Barolo: elegant, structured, with just enough edge to spark conversation. As his colleague pours carefully, he recalls their last conversation, “You were, let’s say, animated about the diagnostic criteria for cervicogenic headache (CGH) being established by non-musculoskeletal practitioners. I have looked at the criteria; is there one that is particularly exasperating?”
Watson laughs, “There is more than one!” After a reflective pause, Watson begins, “Tell me, why does everyone assume that a CGH must be side-locked?”
His colleague pauses mid-pour, eyebrows raised. “Because that’s what the criteria say. One side, fixed, unmoving.”
Watson smiles wryly. “Yes. It’s become doctrine. Yet in forty thousand hours of clinical practice, I’ve seen something different, again and again. It is very common for unilateral head pain to not only swap sides between episodes, but also within episodes. Furthermore, suppose neck symptoms typically accompany their episodes. In that case, they also mirror the head pain behaviour, and can you imagine the (patients’) excited bewilderment when unilateral head pain swaps sides within 5 minutes of an unambiguous intervention at the C2-3 segment, coupled with unmistakable and predictable rotation of C2.”
The Side-Shift Heresy
His colleague leans back. “That sounds almost heretical.”
“Perhaps,” Watson replies. “But it’s no more heretical than an alternating list. In the low back, we accept without question that a patient may present leaning left with right low back pain one day and leaning right with left low back pain the next, a hallmark of discogenic misbehaviour. No one calls it ‘bilateral back pain’. We understand that a single mechanical driver can express itself on alternating sides.”
His colleague nods slowly. “So you think the same principle applies at C2-3?”
“Exactly,” Watson says. “A single upper cervical source, capable of provoking the trigeminocervical complex, but expressing itself unilaterally, and capable of alternating sides.”
“Fascinating,” his colleague murmurs. “But the orthodox response would be, ‘Alternating? Then it must be migraine.’”
False Dichotomies
Watson exhales, half amusement, half frustration. “Yes. Because the classification says CGH is side-locked, and migraine can shift. So if it shifts, it must be migraine. But that logic assumes the classification is reality, not just a description.”
“Category error,” his colleague offers.
“Precisely,” says Watson. “We’ve accepted a rule of thumb for a law of nature.”
A Pattern Hidden in Plain Sight
Watson swirls his glass. “It’s there if you look. The patient experiences alternating headaches and medial scapular pain. The one whose neck pain alternates in perfect synchrony with their eye pain. Same pattern, different side. It’s not bilateral, it’s not diffuse, it’s not vague. It’s exquisitely unilateral, just not always the same unilateral.”
His colleague smiles slowly. “So, a ‘side-shifting’ headache is not diagnostic confusion… It’s a diagnostic clue.”
“Exactly,” Watson replies. “It’s the cervical spine behaving like the lumbar spine sometimes does, a local musculoskeletal disorder with a variable expression of laterality.”
A New Question
They sit quietly for a moment, letting the idea breathe like the Barolo.
“Then the real question,” his colleague says at last, “is not ‘Why does it change sides?’ but ‘Why have we assumed it shouldn’t?’”
Watson raises his glass. “Yes. We’ve mistaken consistency of side for proof of mechanism. Yet nature rarely plays by our classifications.”
His colleague leans in, eyes bright. “So, if alternating lateral shift is the calling card of lumbar disc derangement, perhaps unilateral alternating headache is the calling card of C2-3.”
Watson’s smile deepens. “Exactly. Not bilateral, not contralateral – just alternating. And unmistakably cervical – this is my experience.”
Watson’s colleague reflects, “Okay, so if C2-3 is the calling card, are you saying alternating or side-shifting headache is the C2-3 equivalent of an alternating lumbar list?”
“Yes, that is my hypothesis – discogenic misbehaviour at C2-3,” Watson replies confidently.
A Toast to Better Questions
“But you can’t extrapolate from lumbar to cervical discs – they’re structured differently.”
Watson smiles assuredly as they clink their glasses gently.
“To the end of dogma,” Watson says softly, “and to the beginning of better questions.”
“To the curious side-shifters,” his colleague adds, “who may yet change how we see headache.”
The Barolo lingers on the palate; complex, layered, and quietly subversive.
