Clinical Diagnosis is made with Parkinson’s Disease society brain bank criteria. There are 3 steps in diagnosis;
STEP 1. Bradykinesia and one of:
- resting tremor,
- postural instability
STEP 2. Other possible causes for these symptoms need to be ruled out.
STEP 3. During the onset or evolution of the condition; need three of:
- Unilateral onset,
- Tremor at rest,
- Progression in time,
- Asymmetry of motor symptoms,
- Response to levodopa for at least five years,
- Clinical course of at least ten years
- Appearance of dyskinesia induced by the intake of excessive levodopa
Supportive evidence from radiology Imaging using CT or MRI may be used to illustrate other conditions that may mimic PD (eg; vascular disease) or to exclude tumours, where the diagnosis is unclear. Also other scans are being more widely used to assist diagnosis; such as SPECT scans and DAT scans which show a decreased uptake of labelled dopamine in PD.
Clinical diagnosis of PD is poorly specific, Parkinson’s has symptoms similar to other neurodegenerative conditions and as every case is unique, diagnosis is problematic , often repeated examinations over several years by specialists are needed before a confident diagnosis can be made. Studies show that GPs make false positive and negative diagnoses of PD. Thus if we suspect PD based on the above criteria we should refer quickly and untreated for specialist confirmation.
NICE Guidelines state patients should be seen by a specialist within 6 weeks of referral. They also state that diagnosis should be reviewed by an expert regularly (6-12 monthly) and reconsidered if atypical features develop. PD patients should have access to specialist nursing care. NICE also states that Physio, OT and speech and language therapy should be made available to PD patients. Finally the guidelines state PD patients and their carers should be given the opportunity to discuss end of life issues with appropriate healthcare or palliative professionals.