The Diagnosis of Parkinsonism

The Diagnosis of Parkinsonism

Parkinsonism is simply a clincial syndrome (constellation of findings)

Cardinal Features: (Mnemonic = T-R-A-P)

T remor

R igidity

A kinesia / Bradykinesia

P ostural Instability

Should have 2 of the first 3 features for diagnosis of Parkinson's Disease (PD)

Tremor:

- classic 4- to 6-Hz resting tremor ("pill-rolling")

- may be absent in up to 25% of PD

- brought out when patient distracted (ask to close eyes & count backwards) or with stress / anxiety / fatigue

- can also have postural tremor (may be attenuated when actually moving to position)

- often begins in one hand and remains more severe on that side throughout

- may also affect chin / lips / tongue (but not usually head)

- often not a disabling feature (not interfere w/ purposeful movements)

NB: most common differential for tremor-dominant PD is essential tremor (ET)

- features useful to distinguish ET from PD tremor include:

1) Family History: autosomal dominant inheritance common w/ ET (uncommon in PD)

2) Postural tremor predominant in ET (but can occur at rest if severe, and PD can have postural component)

3) Bilateral: in ET, never unilateral, although often can be asymmetric

4) Associated head tremor in ET ('titubation') & vocal tremor

5) Absence of other features of parkinsonism: no true rigidity or bradykinesia

Rigidity:

- resistance to passive movement in both flexors & extensors throughout whole range of motion

- patients may complain of feeling of "muscle stiffness", weakness or fatigue

- reduction in arm swing during gait often early sign

- may also begin unilaterally (and remain asymmetric)

- may be brought out by augmentation maneuvers

(eg. Froment's - ask to open & close contralateral body hand)

Bradykinesia:

- slowness of movements

- speech becomes hypophonic & swallowing slowed (saliva pools, drooling)

- trouble with buttons & fine finger movements

- takes longer to get dressed or do ADLs

- micrographia

Akinesia:

- poverty of movement & trouble initiating movements

- facial = hypomimia / amimia (and decreased eye blinking) ddx depression

Posture & Gait:

- short, shuffling gait (bradykinesia & rigidity)

- stooped (simian) posture

- may appear to drag one leg if asymmetric

- decrease in arm swing

- hesitancy in initiating & freezing (e.g. going through a door)

- turning en bloc

- may festinate (centre of gravity forward so take short increasingly rapid steps to catch up)

- postural instability as disease progresses (falls, retropulsion)

Main Differential Diagnosis

Most of these diseases are diagnosed clinically

- no easily available, reliable, diagnostic tests for PD, PSP etc.

- rely on careful history taking & clinical examination

- 15-25% of cases are misclassified when compared to pathology / autopsy

- 24% of cases of PD undiagnosed in community door-to-door studies

1) Neurodegenerative Diseases:

- Idiopathic PD

- Progressive Supranuclear Palsy (PSP)

- Multiple System Atrophy (MSA-P) aka striatonigral degeneration

- Cortico-Basal Degeneration (CBD / CBGD)

- Diffuse Lewy Body Disease (DLBD)

2) Drug-Induced: (incl. tardive syndrome)

- Neuroleptics, Metoclopramide / Prochlorperazine

- Valproate

- Lithium

3) Vascular Parkinsonism

4) Familial / Early onset cases:

- Wilson's disease

- Huntington's disease (Westphal variant)

- Machado-Joseph disease

- Familial PD (parkin, alpha-synucelin, unidentified?)

5) Structural Lesions: (usually hemiparkinsonsim)

- Neoplasms, Vascular, Traumatic

6) Toxic:

- Manganese

- Organophosphates

- Carbon monoxide

- Methanol

- Carbon disulfide

- Cyanide

7) Infectious:

- CJD / Prion diseases

- HIV encephalitis

- Postencephalitic (von Economo's)

- SSPE

8) Other:

- NPH

Features suggesting atypical Parkinsonism:

1) Early dementia (seen in PSP, DLBD, CBD, AD-PD)

2) Early age of onset (MSA, CBD in 40's-50's, not PSP, can occur in PD)

3) Rapid progression (over 3-4 yrs; in MSA, PSP, CBD)

4) Eye movement abN (loss of vertical saccades & OKN = PSP)

5) Autonomic dysfunction (impotence, bladder dysfunction, orthostatic hypotension, temperature dysregulation, GI dysmotility) in MSA

6) Early postural instability (PSP, MSA)

7) Early dysarthria (PSP, MSA, Vascular)

8) Axial > Limb rigidity (PSP)

9) Pyramidal signs (PSP, MSA, CBD +/- structural lesions) or cerebellar findings (MSA / OCPA)

10) Lower body parkinsonism (shuffling gait, good arm swing = vascular, NPH)

11) Poor / non-sustained response to levo-dopa (MSA / PSP may respond initially)

12) Sensory dysfunction (especially parietal w/ apraxia, cortical sensory loss, stimulus-sensitive myoclonus, alien-limb phenomenon = CBD)

13) "Wheelchair sign" (early confinement) not usual in PD

14) Hemibody involvement (asymmetry more common in PD; also seen in CBD & hemiparkinsonism-hemiatrophy)

15) Prominent visual hallucinations (prior to treatment) in DLBD

(also fluctuating cognitive state & sensitivity to neuroleptic medications)

Other Common Manifestations of Parkinson's Disease:

Cognitive dysfuntion (Bradyphrenia - dementia in 30%)

Depression (30-40%)

Sleep disturbance (due to rigidity, tremor, dystonia [waking], restless legs, depression)

Sexual dysfunction

Sialorrhea (excessive salivation) ~ 75%

Olfactory hypofunction

Dysphagia / Dysarthria

Autonomic dysfunction (constipation, orthostatic hypotension, satiety, nausea)

Urinary dysfunction (detrusor hyperreflexia w/ urgency, frequency, nocturia)

Sensory: pain, cramps

Dystonia

Seborrheic dermatitis

Visual hallucinations / psychosis (especially due to dopaminergic Rx)

NB: many of these 'secondary' manifestations are not responsive to PD Rx

Hoehn and Yahr Scale:

Stage I - unilateral disease

Stage II - bilateral disease w/ preservation of postural reflexes

Stage III - bilateral disease w/ impaired postural reflexes but preserved ability to ambulate independently

Stage IV - severe disease, considerable assistance required

Stage V - end-stage disease (confined to bed or chair)

UPDRS (United Parkinson's Disease Rating Scale)

- validated tool for use in clinical trials to evaluate disease severity & response to treatment

- broken down into subsets: 1) cognitive; 2) ADLs; 3) motor exam; and 4) complications of Rx

References:

Med Clin N Am 1999; 83(2): 327-347

BMJ 1995; 310: 447-452.

NEJM 1998; 339: 1044-1053.

Last update: 2003-01-10

Reviewed by: Pending Review

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