Call Me Ishmael

On board the Pequod, the great Nantucket whaling ship captained by a “grand, ungodly, god-like man”, were thirty crewmembers.

A pastime among them was attempting to understand their leader and his tyrannical descent into madness. For us to read Moby-Dick, the main cause is obvious; the mighty plot that drives the narrative. Captain Ahab, whose leg was cruelly swiped by a sperm whale, wants retribution, and he commandeers his crew for this long (very), heavily-detailed, and ultimately hellish quest for revenge. But was Ahab tortured by more than visions of the White Whale?

Stubb, the second mate from Cape Cod, relays a conversation about Ahab he had with Dough-boy (the anxious, pale, steward of the ship). “He ain’t in his bed now, either, more than three hours of the twenty-four; and he doesn’t sleep then. Didn’t that Dough-Boy […] tell me that of a morning he always finds the old man’s hammock clothes all rumpled and tumbled, and the sheets down at the foot, and the coverlid almost tied into knots, and the pillow a sort of frightful hot, as though a baked brick had been on it? A hot old man! I guess he’s got what some folks ashore call a conscience; it’s a kind of Tic-Dolly-row they say—worse nor a toothache. Well, well; I don’t know what it is but keep me from catching it.”

Tic-Dolly-Row is, of course, tic douloureux, otherwise known as trigeminal neuralgia, a condition often described as one of the most painful pathologies known to humanity, and untreated may have significant psychiatric sequelae, including depression, anxiety, and suicidality.

Treatments have advanced tremendously since Herman Melville’s time. No longer do we prescribe hemlock, exorcism, arsenic, tar on the face, hot pokers to the general vicinity, or a generous blood-letting. We have the MRI partly to thank for this.

As a recap of the condition, trigeminal neuralgia is neuropathic pain involving the fifth cranial nerve; lancinating in nature, although may become more prolonged and coalescent over time, triggered by sometimes trivial stimuli: brushing teeth, chewing, a light breeze. The pathological basis has only been recently understood, and involves localised compression of the trigeminal nerve. This results in focal myelin damage, and erratic, hyperactive nerve function. The nerve is also unable to shut-off pain once it fires in response to the stimulus. As time progresses, there is extension of the demyelination, involving more and more of the nerve, including into the eponymous Gasserian ganglion (Gasser the anatomist, not a generic anaesthetist), which runs in the more fabulously named Meckel’s cave (dedicated to another anatomist: Johann Friedrich Meckel, the Elder – names which we can still enjoy, despite how gauche and anachronistic eponyms now are). As a mildly interesting aside, the trigeminal ganglion is of vital importance to rodents, as this is the first part of the pathway from rat’s whiskers to their brain, and although I’d like to connect this with leaving a sinking ship, it may well be too long a bow to draw.

But where this REALLY gets interesting is the cause of the compression. For far too long, the (modern) treatment of trigeminal neuralgia has been throwing pharmaceuticals after the fact. A cauldron of anti-convulsants, muscle relaxants, anti-depressants, GABA modulators, all acting on dampening somewhere between the nerve firing and perception of pain, all with a not insubstantial side-effect profile. However, high quality MRI scans have shown the compression comes, in a high percentage of cases, from a vascular loop, often from the superior cerebellar artery. Where this as a cause is established, the surgical remedy is surprisingly minimally invasive, and currently consists of shifting the compressing blood vessels, while protecting the trigeminal nerve with Teflon gauze. The success rate for appropriately selected patients is very high.

Although it is a chronic condition, patients with trigeminal neuralgia DO present to the Emergency Department: sometimes as yet to be diagnosed, at the mercy of undertreated pain, suffering side effects from their cocktail of drugs, or simply at the end of their psychological tether. Appropriate imaging requests and neurosurgical referring may, indeed, be life-saving.

Poor Captain Ahab was never going to be recipient of any of this. Anyway, what sort of great American novel cures the protagonist of his torment? No, we need Ahab in anguish and misery, habitually clumping up and down the decks on his peg-leg through the dark nights in the black ocean-spray, plotting his revenge.