In OSCE scenarios, you may be asked to perform a focused examination to determine the presence (or absence) of a certain condition. It is important to be able to confidently elicit the main diagnostic signs of the condition. In order to do this, you need to be comfortable with the relevant basic system examination (i.e. for a Parkinson’s disease examination you need to be comfortable with performing a full neurological examination).
Note: the instructions may not be specific, for example, the station instructions may say, ‘examine this patient with a tremor’.
Parkinson’s Disease Overview
Parkinsonism is a clinical syndrome characterised by bradykinesia, rigidity, tremor and posturalinstability.
Idiopathic Parkinson’s disease (PD) is the most common cause of parkinsonism.
Other primary (atypical) Parkinsonian disorders can closely mimic PD, which makes a correct clinical diagnosis challenging. These include Progressive Supranuclear Palsy (PSP), Multiple System Atrophy (MSA), Dementia with Lewy Bodies (DLB) and Corticobasal Syndrome (CBS).
Pathology of Parkinson’s disease
Loss of dopaminergic neurons from the pars compacta of the substantia nigra.
Presence of Lewy bodies(eosinophilic cytoplasmic inclusion bodies), containing tangles of α-synuclein and ubiquitin. Spreading from the brainstem to the midbrain and then to the cortex as the disease progresses.
Clinical features of Parkinson’s disease
Parkinson’s is not simply a disorder of movement. Other common features include:
REM-sleep behavioural disorder
Autonomic dysfunction: constipation, urinary frequency
Dementia (late feature, typically older patients)
Confirm the patient’s details (e.g. name and date of birth)
Explain the examination:
“Today I’m going to perform an examination which will involve me first of all having a general look at you and then asking you to do some movements.”
“Does everything I’ve said make sense?”
“Do you have any questions?”
“Are you happy for me to go ahead with the examination?”
You may like to ask the patient to expose their hands, wrists and elbows (watch this process, it can provide clues)
Ask if the patient currently has any pain
Parkinson’s disease can be a spot diagnosis– a lot of information can be gained from watching the patient walk into the room and sit down in the chair (we will explore these signs in more detail in the formal assessment of gait).
When the patient is sitting, pay close attention to:
Spontaneous movements and hand gestures – reduced spontaneous movements
Eyeblink – slow/less frequent
Facial expression – expressionless (hypomimia)
Tremor – asymmetrical tremor at rest – see below
Fidgeting – decreased
Speech – soft, indistinct (hypophonia)
Posture – flexed/stooped
A key, and easily observable sign, in Parkinson’s disease is a tremor, this is typically:
Hands – small tremor in the index finger and thumb (‘pill-rolling’), but can involve the lips, chin and legs
Note if an obvious visible tremor is present – if not, distract the patient by asking them to close their eyes and count back from 20.
Test for posturaltremor by asking the patient to raise their arms in front of their body and spread their fingers. Note: a resting tremor stops on initiation of movement. PD patients may have a re-emergent tremor that presents after a few seconds.
Action (kinetic) tremor
Test for action (kinetic) tremor by performing a finger-nose test – ask the patient to alternate between touching their nose with their finger and touching your finger.
Ensure the patient stretches their arm out fully
Slower movements can detect an action tremor more accurately
Keep your finger in a fixed position
Important differentialdiagnoses of tremor are:
Essential tremor – fast, postural and kinetic, improves with rest, head and neck involvement
Dystonic tremor – task-specific or task exacerbated, flurries, thumb extension
Inspect for evidence of tremor
Finger to nose test
Defined as: General slowness and the paucity of movement.
Test with rapid alternating movements– as big and fast as possible. Use at least 10-20 repetitions for each movement with one limb at a time.
Movements to assess include:
Finger tapping – ask the patient to oppose their thumb and forefinger
Hand grip – ask the patient to make a fist and then open their hand wide
Pronation/Supination – ask the patient to pronate and supinate their hand rapidly
Toe tap – ask the patient to keep their heel on the ground and tap their toes
Progressive reduction in speed
Progressive reduction in amplitude
Slowness of initiation
Extra tests to include:
Writing a sentence and drawing a spiral – asymmetric progressive micrographia
Undoing and doing up buttons – difficulty with buttons (functional deficit)
People with Parkinson’s typically have increased muscle tone – a.k.a rigidity. This is not velocity dependent – constant opposition to any passive movement – or direction dependent.
Perform a circular wrist movement while taking the weight of the patient’s arm – ask them to relax as much as possible (“let your arm be as floppy as possible while I take the weight”)
You can also perform circular elbow or ankle movements
Using an activation manoeuvre can accentuate subtle rigidity associated with early Parkinson’s – ask the patient to actively tap their thigh with their contralateral arm while you perform the movement.
Resistance to movement – sometimes referred to as lead pipe rigidity, although usually more subtle early on or if medicated
Cogwheel rigidity – resistance at several points in the movement. Due to tremor superimposed upon rigidity
Assess first the patient’s ability to stand from a seated position with arms across their chest.
Stand near and keep arm behind the patient to offer support if needed!
Ask them to walk up and down the room offering to walk with them if they seem unsteady.
Initiation – slow to start walking (failure of gait ignition) and hesitancy
Step length – reduced stride length, short steps, each step may get progressively smaller as the patient attempts to retain balance (Festinant gait)
Heel strike – asymmetrical (only one heel strikes) or symmetrical shuffling gait
Arm swing – reduced arm swing on one side or both
Posture – flexed trunk and neck, flexed elbows
Tremor – resting tremor can be observed when the patient is distracted by walking
Turning – impaired balance on turning or hesitancy, due to postural instability
Assess postural instability by performing the pull test.
Note: this may not be appropriate in an OSCE setting, so say to the examiner that you would like to perform this test.
To perform the pull test safely:
Ensure you are positioned closely behind the patient and between them and a wall (if the patient falls backwards you can support them while hitting the wall
Clearly explain the test – “I’m going to give you a quick tug on your shoulders and what I want you to do is to take one or two steps backwards to catch your balance. I will be behind you at all times and won’t let you fall.”
Perform a test by coaching and then tugging more gently
Quickly tug their shoulders backwards
If normal, patient corrects their balance in one or two quick steps
To complete the examination
Thank the patient
Wash your hands
Summarise your findings
“Today I performed a neurological examination on this 75-year-old gentleman to assess for the presence of Parkinson’s disease. On general inspection, he has reduced facial expressions, reduced spontaneous movements in his arms and a soft voice. An asymmetrical tremor was noted in his left hand at rest, involving his forefinger and thumb, which was more apparent when the patient was distracted. A re-emergent tremor in his left hand was elicited upon extension of both arms. Asymmetric bradykinesia was detected on the left side with progressive slowness and amplitude of rapid alternating movements. Assessment of tone revealed rigidity in the left wrist, elbow and ankle. Observation of the patient’s gait showed a flexed neck and left arm, with a reduced arm swing and an absent heel strike on the left side. He had a short stride length and was hesitant when turning. These findings are consistent with clinical features of parkinsonism.”