Allan, a 72 year old man who lives alone, presents with a tremor in his right hand for about 6 months.  He reports it is better when he is actively trying to do something but intermittent otherwise.  He has high cholesterol, chronic mild anxiety, GERD and irritable bowel syndrome.  He takes somac, ezetemide regularly and prn metoclopramide.  He does not smoke.  He has no allergies.

What are the differentials for his tremor?  List 4

1. Parkinson’s Disease (2)
2. Benign Essential Tremor (2)
3. Anxiety disorder (2)
4. Drug induced parkinsonism from metoclopramide (2)
5. Hyperthyroidism (1)
6. Cerebral tumour (1)

Tip – cerebellar disease, alcohol withdrawal would gain 0 marks due to stem.

What are medications that can cause parkinsonism? List drug name only.  List 4

1. Metoclopramide
2. Olanazpaine
3. Risperidone
4. Haloperidol
5. Less frequently –
   • Lithium
   • Sertraline
   • quetiapine
   • valproate

Reference – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3325428/table/T1/

What further history do you want to obtain? List 8

1. Bradykinesia (PD)
2. Micrographia (PD)
3. Postural instability (PD)
4. Rigidity (PD)
5. Expressionless face (PD)
6. weight loss (hyperthyroid)
7. palpitations (hyperthyroid)
8. Does the tremor improve with alcohol (essential tremor)

Case continued:  You perform a full neurological examination checking cranial nerves, gait, muscle tone, power, co-ordination, reflexes and sensation.  He has a stopped posture and shuffling gait. On gait he fails to swing his arms normally.  He has bradykinesia and mild cog-wheeling in his right arm, and repetitive movement in his left arm makes the tremor worse. Glabellar tap is positive.  TFTs done in the last 3 months were normal, as were his general check up bloods.  You diagnose Allan with parkinson’s disease and decide to commence treatment.

What is your initial medication regime?

1. Combination of Levodopa with  50-100mg  + carbipoda 25mg  (or benserazide)  bd-tds PO

What are the medication options are there if this does not improve his symptoms? List4

1. Increase Levodopa/carbidopa (or benserazide) combination (titrate slow, maximum 200 mg of carbidopa and 2,000 mg of levodopa)
2. Dopamine agonists – e.g. Pramiprexole 0.125 mg tds PO, transdermal rotigotine once-daily patch 2 mg/24 hours
3. MAO B inhibitors – e.g. selegiline 2.5-5mg daly or bd PO
4. Anticholinergics – good for tremor but their use in older or demented individuals and those without tremor is strongly discouraged

What are common side effects of dopamine agonists? List 6

1. impulse control disorders
2. nausea
3. vomiting
4. sleepiness
5. orthostatic hypotension
6. confusion
7. hallucinations
8. Peripheral edema

Tip – Impulse control disorder includes – compulsive gambling, buying, sexual behavior, and eating – but only write one of them, do not overcode

What other management considerations are there? List 4

1. Driving assessment
2. MMSE
3. ACAT
4. Physiotherapy for PD +| falls risk prevention therapy program