A Functional Tremor After a Car Accident: What Medication Can and Can’t Treat
A tremor with no structural cause, and a patient who wants to know plainly whether medication has any real role in her treatment.
Jenna C., 34, was rear-ended on her commute home four months ago, hard enough to total her car but, by every scan and exam done in the emergency department that night and in the weeks since, without any structural injury to explain what happened next: within days, a tremor appeared in her right hand that comes and goes unpredictably, sometimes disappearing entirely for hours, and her gait has developed an odd, effortful, knee-buckling quality she's never had before, worse when she knows someone is watching her walk. She has no history of tremor or gait problems before the accident, normal brain and spine imaging, and a neurological exam notable specifically for signs that point toward, rather than away from, a functional rather than structural cause: her tremor's frequency shifts to match a rhythmic tapping task the examiner asked her to perform with her other hand — entrainment, a finding essentially never seen in tremor caused by structural neurological disease — and her leg weakness, absent on formal strength testing, reappears the moment she's asked to walk. She has a documented history of generalized anxiety, worse but not new since the accident, and describes recurring, intrusive replays of the collision itself.
Functional neurological disorder is now understood as a genuine disorder of how the brain's own networks connecting intention, self-monitoring, and motor output are functioning — visible on functional imaging as real, measurable network-level abnormality. The diagnosis now rests on positive signs like the ones she has — entrainment, give-way weakness — rather than on ruling everything else out, a shift formalized in the DSM-5 criteria, which dropped the older requirement that a psychological stressor be identified before the diagnosis could be made. It is not a diagnosis of exclusion meaning nothing is actually wrong, and not something Jenna is producing on purpose, a distinction her team has had to explain to her directly since her own first reaction to the diagnosis was that she was somehow imagining or faking it. What frustrates her most, in her own words, is that nobody has offered her anything to take — every conversation so far has been about physical therapy and psychology, not medication, and she wants to know plainly whether that's because nothing pharmacologic exists for this or because nobody has tried.
Clinic, four months post-accident
Functional neurological disorder is a real disorder of the brain's own intention, self-monitoring, and motor-output networks — not something Jenna is producing on purpose, and not a diagnosis of exclusion. Her entrainment finding and give-way weakness pattern are the actual positive signs that support it. But no medication treats that network-level dysfunction directly. What's actually shown to work is specialized physical therapy developed for functional movement disorders — the approach described by Nielsen and colleagues — combined with psychoeducation. I'd refer her there as the primary intervention.
I agree nothing pharmacologic treats the FND itself directly. But Jenna has a real, independently diagnosable generalized anxiety disorder that's worsened since the accident, plus recurring intrusive re-experiencing of the collision — symptoms that plausibly drive and sustain the functional symptoms through ongoing physiological arousal. Sertraline is first-line for both GAD and re-experiencing symptoms in their own right.
Framing 'no medication' as the complete answer to her actual clinical picture leaves a real, diagnosable, separately treatable condition unaddressed — her presentation includes more than the tremor alone.
I want to name something directly: Jenna has told us more than once that she's frustrated nobody's offered her anything to take, and how we handle that matters for whether she stays engaged with the treatment that actually works. I'd start sertraline today, explicitly and only for her anxiety and re-experiencing symptoms, and tell her plainly it isn't a tremor treatment — alongside a firm referral to FND-specific physical therapy, so she has something concrete and an honest explanation of what each part of the plan is actually treating.
Agreed: sertraline started explicitly for her anxiety and re-experiencing symptoms, explained to Jenna plainly as separate from tremor treatment, alongside referral to FND-specific physical therapy and psychoeducation.
Not agreed, and left open rather than smoothed over: whether treating her anxiety pharmacologically will, as the Psychiatrist hopes, meaningfully reduce the functional symptoms themselves through lowered physiological arousal, or whether the Neurologist is right that this is properly understood as two separate, only loosely connected treatment tracks running in parallel rather than one influencing the other — a question nobody in the room could resolve today, and one the team agreed to revisit only once she's had a real trial of both interventions rather than guessing now.