# Clinical Cases: Movement Disorders

## Case 1: Parkinson's Disease

### Patient Demographics
- **Age:** 67 years
- **Sex:** Male
- **Occupation:** Retired engineer

### Chief Complaint
"My hand shakes and I've been moving slower."

### History of Present Illness
The patient's wife first noticed his right hand trembling about 2 years ago, initially only at rest. Over time, she has observed that he moves more slowly - he takes longer to button his shirt, his handwriting has become smaller (micrographia), and he shuffles when walking. He has had several near-falls because his feet seem to "stick" to the floor when turning. His voice has become softer and monotone. He reports constipation for years and loss of sense of smell. He also has vivid dreams where he acts out (REM sleep behavior disorder). No family history of Parkinson's disease. No antipsychotic use.

### Neurological Examination Findings

**Mental Status:**
- Alert, oriented, cooperative
- Mildly reduced verbal fluency
- Hypomimia (masked facies) - reduced facial expression
- Hypophonia - soft, monotonous speech

**Cranial Nerves:**
- Reduced olfaction (CN I)
- Decreased blink rate
- Otherwise intact

**Motor Examination:**
- **Tremor:**
  - Right hand: 4-5 Hz rest tremor, "pill-rolling" quality
  - Tremor decreases with action, increases with distraction (counting backward)
  - Mild left hand tremor at rest
- **Rigidity:**
  - Right arm: Cogwheel rigidity at wrist and elbow
  - Left arm: Mild rigidity
  - Neck: Axial rigidity
- **Bradykinesia:**
  - Right finger taps: Slow, decremental amplitude
  - Right hand opening/closing: Slow, fatigues quickly
  - Left side: Mildly affected
- **Strength:** 5/5 throughout (rigidity is not weakness)

**Reflexes:**
- 2+ symmetric
- Plantar responses flexor bilaterally

**Postural Stability:**
- Positive pull test - retropulsion with several steps to recover

**Gait:**
- Stooped posture
- Reduced arm swing, more pronounced on right
- Short, shuffling steps
- Difficulty initiating gait (start hesitation)
- Festination (progressively faster, shorter steps)
- En bloc turning (takes 5+ steps to turn)

### Diagnostic Criteria
**UK Brain Bank Criteria for Parkinson's Disease:**
1. Bradykinesia PLUS at least one of: rigidity, rest tremor, postural instability (YES - all present)
2. Supportive features: Unilateral onset (YES), rest tremor (YES), progressive course (YES), asymmetric (YES), excellent response to levodopa (to be tested)
3. Exclusion criteria: No repeated strokes, head injury, encephalitis, neuroleptic use, MPTP exposure, cerebellar signs, early dementia, Babinski signs

### Neuro Workup
- **Clinical diagnosis** - imaging not required if classic presentation
- **MRI Brain:** Normal (rules out vascular parkinsonism, NPH)
- **DaTscan (dopamine transporter SPECT):** Reduced uptake in bilateral striatum, right > left (confirms nigrostriatal degeneration) - ordered if diagnosis uncertain

### Diagnosis
**Parkinson's Disease** - Hoehn and Yahr Stage 2.5 (bilateral involvement with mild postural instability)

### Management

**Pharmacological Treatment:**
1. **First-line:** Carbidopa/Levodopa (Sinemet) 25/100 TID
   - Most effective symptomatic treatment
   - Start low, titrate slowly
2. **Adjuncts:**
   - MAO-B inhibitor (rasagiline 1 mg daily) - mild symptomatic benefit, possibly disease-modifying
   - Dopamine agonist (pramipexole, ropinirole) - younger patients to delay motor complications
   - Anticholinergic (trihexyphenidyl) - for tremor-predominant, use cautiously in elderly

**Motor Complications (anticipate with long-term levodopa):**
- Wearing off - add COMT inhibitor (entacapone) or increase frequency
- Dyskinesias - reduce individual doses, add amantadine
- On-off fluctuations - consider extended-release formulations

**Non-Motor Symptom Management:**
1. Constipation: Fiber, hydration, polyethylene glycol
2. RBD: Melatonin, clonazepam (low dose)
3. Depression: SNRI, SSRI
4. Orthostatic hypotension: Compression stockings, fludrocortisone, midodrine

**Non-Pharmacological:**
1. Physical therapy - gait training, balance exercises
2. Occupational therapy - ADL modifications
3. Speech therapy - LSVT LOUD for hypophonia
4. Exercise - associated with improved outcomes

**Advanced Therapies (for motor fluctuations):**
1. Deep brain stimulation (STN or GPi)
2. Levodopa intestinal gel (Duopa)
3. Apomorphine continuous infusion

### Clinical Image
![Parkinson's Disease DaTscan](case_01_image.jpg)

**Image Description:** DaTscan (dopamine transporter SPECT) showing reduced tracer uptake in the bilateral putamen with a comma-shaped appearance, consistent with nigrostriatal degeneration in Parkinson's disease.

**Attribution:** Image from Radiopaedia.org, Case courtesy of Dr. Yuranga Weerakkody. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/parkinsons-disease-datscan

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## Case 2: Essential Tremor

### Patient Demographics
- **Age:** 55 years
- **Sex:** Female
- **Occupation:** Elementary school teacher

### Chief Complaint
"My hands shake when I try to write or drink from a cup."

### History of Present Illness
The patient has had tremor in both hands for approximately 15 years. Unlike at rest, the tremor appears when she reaches for objects or performs tasks. She has difficulty writing on the board and has had to switch to using a projector. She cannot carry a full cup of coffee without spilling. The tremor briefly improves after drinking alcohol (which she discovered accidentally). Her father and grandmother both had similar tremors. The tremor has gradually worsened but has not affected her walking or cognition. She denies any other neurological symptoms.

### Neurological Examination Findings

**Mental Status:**
- Alert, oriented, normal cognition
- Normal facial expression

**Cranial Nerves:**
- Mild head tremor (titubation) - "yes-yes" pattern
- No vocal tremor
- Otherwise intact

**Motor Examination:**
- **Tremor:**
  - Bilateral hand tremor, 6-8 Hz
  - **Action tremor:** Present during finger-to-nose testing (kinetic tremor)
  - **Postural tremor:** Present when arms extended forward
  - **Minimal at rest** - key distinguishing feature from Parkinson's
  - Amplitude similar bilaterally
- **Rigidity:** None
- **Bradykinesia:** None - finger taps normal speed and amplitude
- **Strength:** 5/5 throughout

**Writing Sample:**
- Large, tremulous handwriting (compare to micrographia in PD)
- Spiral drawing shows significant tremor

**Reflexes:**
- 2+ symmetric
- Plantar responses flexor

**Coordination:**
- Finger-to-nose: Tremor increases as approaching target (intention component)
- Heel-to-shin: Mild tremor
- No dysmetria

**Gait:**
- Normal, no rigidity or bradykinesia
- Normal arm swing
- Tandem gait: Normal

### Essential Tremor vs Parkinson's Disease

| Feature | This Patient (ET) | Parkinson's |
|---------|-------------------|-------------|
| Tremor type | Action/postural | Rest |
| Tremor frequency | 6-8 Hz | 4-5 Hz |
| Bilateral | Yes | Usually asymmetric at onset |
| Family history | Positive | Usually negative |
| Alcohol response | Improves | No effect |
| Bradykinesia | Absent | Present |
| Rigidity | Absent | Present |
| Handwriting | Large, tremulous | Micrographia |

### Neuro Workup
- **Clinical diagnosis** - no imaging required
- **Labs to exclude secondary causes:**
  - TSH: Normal (hyperthyroidism can cause tremor)
  - Comprehensive metabolic panel: Normal
- **DaTscan:** Normal (would be abnormal in Parkinson's) - only if diagnostic uncertainty

### Diagnosis
**Essential Tremor** - bilateral postural and kinetic tremor, positive family history, alcohol-responsive, no parkinsonian features

### Management

**Pharmacological Treatment:**
1. **First-line:** Propranolol 20-40 mg BID, titrate up to 120-320 mg/day
   - Beta-blocker reduces tremor amplitude
   - Avoid if asthma, bradycardia, heart block
2. **First-line alternative:** Primidone 25 mg at bedtime, titrate to 250 mg TID
   - Anticonvulsant with anti-tremor effect
   - Start low due to sedation, ataxia
3. **Second-line:** Topiramate, gabapentin, alprazolam

**PRN/Situational Treatment:**
1. Propranolol 20-40 mg before important events
2. Small amount of alcohol (patient declines)

**Non-Pharmacological:**
1. Weighted utensils for eating
2. Use two hands for cups
3. Adaptive writing tools (weighted pen, keyboard)
4. Avoid caffeine (may worsen)

**Surgical Options (for refractory cases):**
1. Deep brain stimulation (VIM nucleus of thalamus)
2. MRI-guided focused ultrasound thalamotomy
   - Indicated if: Medication failure or intolerance, significant functional impairment
   - Success rate: 70-90% tremor reduction

### Clinical Image
![Essential Tremor Spiral](case_02_image.jpg)

**Image Description:** Archimedes spiral drawing demonstrating the tremulous line quality characteristic of essential tremor, with large amplitude fluctuations throughout the drawing.

**Attribution:** Image from Wikipedia Commons, public domain. Source: https://commons.wikimedia.org/wiki/File:Essential_tremor_spiral.jpg

---

## Case 3: Huntington's Disease

### Patient Demographics
- **Age:** 42 years
- **Sex:** Male
- **Occupation:** Former sales manager (currently disabled)

### Chief Complaint
"I can't stop moving and my memory is getting worse."

### History of Present Illness
The patient's wife reports that over the past 3 years, he has developed involuntary, jerky movements of his limbs, face, and trunk that worsen with stress. He appears restless and fidgety. His speech has become slurred. Cognitively, he has had progressive difficulty with concentration, planning, and decision-making. He was fired from his job 18 months ago due to poor performance. He has become irritable, depressed, and occasionally paranoid. His father died at age 50 in a psychiatric facility with dementia and involuntary movements. Two paternal uncles had similar presentations.

### Neurological Examination Findings

**Mental Status:**
- Alert but distractible
- Impaired attention (serial 7s difficult)
- Executive dysfunction: Poor clock drawing, difficulty with alternating sequences
- Slowed processing speed
- Mild depression on questioning
- Irritable affect

**Cranial Nerves:**
- Oculomotor abnormalities: Difficulty initiating saccades, slowed saccades, cannot suppress reflexive glances
- Facial chorea - grimacing, tongue protrusion involuntary
- Dysarthria - speech slurred, irregular

**Motor Examination:**
- **Chorea:**
  - Continuous, random, flowing movements of all extremities
  - "Piano-playing" movements of fingers
  - Facial grimacing, tongue movements (serpentine)
  - Movements incorporated into voluntary acts ("parakinesia")
- **Motor impersistence:** Cannot maintain sustained tongue protrusion or hand grip
- **Tone:** Hypotonic (may become rigid in later stages)
- **Strength:** 5/5 throughout (weakness masked by chorea)

**Reflexes:**
- 2+ symmetric
- Plantar responses flexor

**Coordination:**
- Difficult to assess due to chorea
- No clear ataxia

**Gait:**
- Wide-based, irregular
- "Dancing" quality with chorea incorporated
- Sudden lurching movements

### Neuro Workup
- **MRI Brain:** Bilateral caudate atrophy with ex vacuo enlargement of frontal horns of lateral ventricles ("box-car" ventricles)
- **Genetic Testing:** HTT gene CAG repeat expansion - 45 repeats (normal <36; 40+ = full penetrance)
- **PET scan (research):** Decreased caudate glucose metabolism

### Diagnosis
**Huntington's Disease** - genetically confirmed
- Autosomal dominant inheritance
- CAG trinucleotide repeat expansion in huntingtin gene (chromosome 4)
- Anticipation: Earlier onset in successive generations

### Management

**Symptomatic Treatment of Chorea:**
1. **First-line:** Tetrabenazine 12.5 mg daily, titrate to 25 mg TID
   - VMAT2 inhibitor - depletes presynaptic dopamine
   - Side effects: Depression, parkinsonism, sedation
   - Screen for depression before initiating
2. **Alternative:** Deutetrabenazine (Austedo) - longer half-life, fewer daily doses
3. **Second-line:** Antipsychotics (risperidone, olanzapine) - also help behavioral symptoms
4. **Avoid:** Dopamine agonists, levodopa (worsen chorea)

**Psychiatric Management:**
1. Depression: SSRIs (sertraline, citalopram)
2. Irritability/aggression: Antipsychotics, mood stabilizers
3. Psychosis: Atypical antipsychotics
4. Apathy: No proven treatment; stimulants sometimes tried

**Cognitive Management:**
1. No disease-modifying treatment available
2. Cognitive rehabilitation
3. Structured routines, memory aids
4. Speech therapy for dysarthria and dysphagia

**Multidisciplinary Care:**
1. Neurology, psychiatry, social work, PT, OT, speech therapy
2. Genetic counseling for family members
   - At-risk individuals may pursue predictive testing (complex ethical considerations)
   - Reproductive counseling (IVF with PGD available)
3. Advance care planning early in disease course
4. Home safety evaluation
5. Huntington's Disease Society of America support

**Prognosis:**
- Average survival 15-20 years from symptom onset
- Death typically from aspiration pneumonia, falls, suicide

### Clinical Image
![Huntington's Disease MRI](case_03_image.jpg)

**Image Description:** Axial T2-weighted MRI showing bilateral caudate nucleus atrophy with characteristic widening of the frontal horns of the lateral ventricles in Huntington's disease.

**Attribution:** Image from Radiopaedia.org, Case courtesy of Dr. Matt Skalski. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/huntington-disease-8