Parkinson’s disease is the second most common neurodegenerative disease in neurology after Alzheimer’s disease, and its clinical diagnostic criteria are the British Brain Bank criteria published in 1997. However, with the continuous development of research in the past two decades, the old criteria are no longer suitable for clinical and research needs.
Recently, the International Movement Disorders Society (MDS) has published a revised version of the latest diagnostic criteria. Compared to the British Brain Bank criteria, the role of non-motor symptoms in the diagnosis has been added and the diagnostic certainty has been categorized (confirmed PD and likely PD).
The primary core criterion for diagnosis is definitive Parkinson’s syndrome, defined as the presence of motor bradycardia and at least one of the two primary signs of resting tremor or tonicity. Examination of all core principal signs must be performed as described in the MDS-Uniform Parkinson’s Disease Rating Scale (MDS-UPDRS).
Once a clear diagnosis of Parkinson’s syndrome is made, the diagnosis is made according to the following criteria.
A clinically confirmed diagnosis of Parkinson’s disease (PD) requires the presence of.
1, no absolute exclusion criteria are met
2, at least two supporting criteria, and
3. no warning signs (redflags)
A diagnosis of probable PD requires having.
1, not meeting absolute exclusion criteria.
2, If warning signs (redflags) are present need to be offset by supportive criteria.
If 1 warning sign is present, at least 1 supporting criterion must be required
If there are 2 warning signs, at least 2 supporting criteria must be required
Note: More than 2 warning signs are not allowed under this classification.
Explanation of several terms above.
1. supportive criteria
(1) A clear and significantly effective response to dopaminergic drug therapy. The patient’s function returns to normal or near normal levels during the initial treatment period. In the absence of a clear record, a significant response to initial treatment can be classified as either
a significant improvement in symptoms with increasing drug doses and significant worsening of symptoms with decreasing doses; minor changes are not included. The above changes are documented by objective scoring (improvement of more than 30% in UPDRS-III score after treatment) or subjectively (reliable patient or caregiver provides clear confirmation of the presence of significant change).
b Clear and significant “on/off” phase fluctuations; must include predictable end-of-dose phenomena to some degree.
(2) Presence of levodopa-induced allodynia
(3) Single limb resting tremor documented on clinical physical examination (previous or current examination)
(4) Presence of olfactory loss or cardiac desympathetic innervation as indicated by cardiac MIBG scintigraphy
2. Absolute exclusion criteria
The diagnosis of PD can be excluded by the presence of any of the following.
(1) Definite cerebellar abnormalities, such as cerebellar gait, limb ataxia, or cerebellar oculomotor abnormalities (nystagmus induced by sustained gaze, large square wave surge, supra-rhythmic sweep)
(2) Downward vertical supranuclear gaze paralysis, or selective downward vertical sweep slowing
(3) Diagnosis of probable behavioral variant frontotemporal dementia or primary progressive aphasia within the first 5 years of onset (based on consensus criteria published in 2011)
(4) Presentation of Parkinson’s syndrome that remains confined to the lower extremities for more than 3 years after onset
(5) Treatment with dopamine receptor blockers or dopamine depleting agents at a dose and time course consistent with drug-induced Parkinson’s syndrome
(6) Lack of observable therapeutic response to high-dose levodopa therapy despite at least moderate severity of disease
(7) Definite cortical sensory loss (e.g., skin writing and entity discrimination impairment with primary sensory organs intact), definite limb perceptual motor loss or progressive aphasia
(8) Normal neuroimaging of presynaptic dopaminergic system function
(9) Clearly documented Parkinson’s syndrome or other conditions suspected to be related to the patient’s symptoms, or other syndromes that, based on the overall diagnostic evaluation, the professional evaluator feels are likely to be other than PD
3. Warning signs (RedFlags)
(1) Rapidly progressive gait impairment within 5 years of onset and the need for regular wheelchair use
(2) No progression of motor signs or symptoms at all for 5 years or more after onset; unless the stability is treatment-related
(3) Early onset ballistic dysfunction: severe dysphonia or dysarthria (speech is difficult to understand most of the time) or severe dysphagia (requiring softer food, or nasogastric tube or gastrostomy feeding) within 5 years of onset
(4) Inspiratory respiratory dysfunction: daytime or nighttime inspiratory stridor or frequent inspiratory sighs
(5) Severe autonomic dysfunction within 5 years of onset, including
a postural hypotension – a drop in systolic blood pressure of at least 30 mmHg or diastolic blood pressure of at least 15 mmHg within 3 minutes of standing up, and the patient is not dehydrated, otherwise medicated, or with a condition that might explain the autonomic dysfunction
b Severe urinary retention or incontinence within 5 years of onset (excluding prolonged or minor stress incontinence in women) that is not simple functional incontinence. In male patients, urinary retention is not due to prostate disease and must be associated with erectile dysfunction.
(6) Recurrent (>1 fall/year) falls due to balance impairment within 3 years of onset
(7) Disproportionate anterior neck tilt (dystonia) or hand-foot contracture within 10 years of onset
(8) absence of any of the common non-motor symptoms, including sleep disorders (sleep retention disorder insomnia, excessive daytime sleepiness, rapid eye movement sleep behavior disorder), autonomic dysfunction (constipation, daytime urinary urgency, symptomatic postural hypotension), hyposmia, psychiatric disorders (depression, anxiety, or hallucinations), even after 5 years of disease onset
(9) Other unexplained pyramidal fasciculations, defined as pyramidal limb weakness or clear pathological reflex activation (including mild reflex asymmetry and isolated metatarsal response)
(10) Bilateral symmetrical Parkinson’s syndrome. The patient or caregiver reports a bilateral onset without any lateral dominance and no significant laterality is observed on objective physical examination
Application of criteria.
1. according to the MDS criteria, can the patient be diagnosed with Parkinson’s syndrome?
If the answer is no, neither likely PD nor clinically confirmed PD can be diagnosed.
If the answer is yes, proceed to the next step of the assessment.
2. are there any absolute exclusion criteria?
If the answer is yes, then neither probable PD nor clinically confirmed PD can be diagnosed.
If the answer is no, proceed to the next step of the assessment.
3. Review the presence of warning signs and supporting criteria as follows.
(1) Recording the number of warning signs present.
(2) Recording the number of supportive criteria.
(3) Are there at least 2 supportive criteria and no warning signs?
If the answer is yes, the patient meets the criteria for a clinically confirmed PD diagnosis.
If the answer is no, proceed to the next step of the assessment.
(4) Are there more than 2 warning signs?
If the answer is yes, a diagnosis of probable PD cannot be made.
If the answer is no, proceed to the next step of the assessment.
(5) Is the number of warning signs equal to or less than the number of supporting criteria?
If the answer is yes, then the patient meets the diagnostic criteria for likely PD