Thursday, 5 February 2026

B0260795 CWH

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Alright, 14-year-old, night-time full-body twitching with headache history, ADHD/autism, on methylphenidate (propranolol held). Normal basic bloods. Here are 3 solid differentials you’d be expected to think of:


1️⃣ Nocturnal seizures (esp. myoclonic or focal motor epilepsy)

Big one to rule out.

Why it fits

  • “Full body twitching” → could be generalised myoclonic jerks

  • Occurring at night → seizures often cluster in sleep / on waking

  • Adolescence = peak age for juvenile myoclonic epilepsy (JME)

  • Headaches → could be post-ictal or comorbid migraine

  • Neurodiversity slightly ↑ epilepsy risk

Clues to ask for

  • Tongue biting, incontinence

  • Confusion after episodes

  • Morning jerks dropping things

  • Family history of epilepsy

👉 Needs EEG ± sleep-deprived EEG


2️⃣ Functional neurological disorder (FND) / functional movement disorder

Already hinted in the note — and common in teens.

Why it fits

  • Adolescent girl (peak demographic)

  • Whole-body movements that may look dramatic

  • Occurs in bed but not clearly stereotyped like seizures

  • Normal investigations so far

  • Headache history (functional symptoms often cluster)

  • Autism/ADHD → higher FND prevalence

Suggestive features

  • Variable pattern between episodes

  • Eyes tightly shut during events

  • Stops with distraction or suggestion

  • No post-ictal phase

Diagnosis is positive, not exclusion-only.


3️⃣ Medication-related movement disorder (stimulant-induced)

Very relevant here.

Methylphenidate can cause:

  • Tics

  • Myoclonus

  • Exacerbation of underlying movement disorders

  • Sleep disruption → worsens physiological jerks

Why it fits

  • Known trigger

  • Night = when fatigue unmasks abnormal movements

  • ADHD/autism patients have higher baseline tic risk

Also consider:

  • Propranolol withdrawal tremor (if recently stopped)

  • Interaction between sleep deprivation + stimulant

Trial of dose review / drug holiday can be diagnostic.


🌙 Other good “honourable mentions” (less likely but exam points)

ConditionWhy
Hypnic jerksBenign sleep-onset jerks; usually brief, not repetitive
Periodic limb movement disorderRhythmic limb jerks in sleep
Migraine with brainstem auraRarely movement phenomena
Anxiety/panic nocturnal attacksCan mimic shaking

🚩 Red flags pushing toward epilepsy

  • Stereotyped episodes

  • Injury during events

  • Cyanosis/apnoea

  • Post-event sleepiness

  • Occurs from sleep repeatedly


🧠 Most likely trio in this case

  1. Nocturnal seizures (JME or focal motor epilepsy)

  2. Functional movement disorder (FND)

  3. Methylphenidate-related movement/tic disorder


If you want, I can give a quick “seizure vs FND” bedside comparison table — that’s usually what examiners love next.

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