- Clinical science
Parkinson-plus syndromes (or atypical parkinsonism) are a group of neurodegenerative diseases that present with parkinsonism and a variety of additional features. Depending on the particular syndrome, a combination of basal ganglia, cerebral cortical, cerebellar, midbrain, and/or brainstem structures are affected. The prognosis is less favorable than in . Parkinson-plus syndromes should be considered if parkinsonism does not respond to levodopa treatment, if dementia progresses rapidly, or if gait instability occurs early in the course of the disease. In most cases, only symptomatic treatment is possible.
Parkinson-plus syndromes have a number of features that differentiate them from (PD):
- Poor response to levodopa
- Early involvement of the autonomic nervous system (orthostatic hypotension, impotence, incontinence, anhidrosis)
- Early onset of postural instability with frequent falls
- Visual hallucinations (usually a sign of Lewy-body disease)
- Signs of cerebellar involvement
- Pathological reflexes present (e.g., Babinski sign); enhanced proprioceptive reflexes
- Eating and swallowing disorders; pronounced dysarthria
- Supranuclear vertical gaze palsy
- Clinical presentation: The sequence of symptoms is more variable than in most other types of dementia.
- Prognosis: Median survival is approx. 10 years.
- Definition: Multiple system atrophy (MSA) is a rare, adult-onset, neurodegenerative disease characterized by neuronal degeneration in the substantia nigra.
- Pathology: Lewy bodies
- Motor abnormalities
- Autonomic dysfunction (e.g., orthostatic hypotension, urinary incontinence, erectile dysfunction)
- Cerebellar symptoms (e.g., ataxia, tremor, dysarthria)
- Additional symptoms
- IBZM-SPECT imaging :
Pure autonomic failure (PAF)
- Clinical features: orthostatic dysregulation with life-threatening drops in blood pressure
- Therapy: no causal therapy
- Definition: a neurodegenerative disease characterized by atrophy of the structures at the midbrain-diencephalic junction (e.g., superior colliculi, red nuclei, dentate nuclei, subthalamic nuclei, and globus pallidus) and mild cortical atrophy
- Epidemiology: peak incidence between 60–80 years
- Clinical features
- Diagnosis: MRI shows “hummingbird sign” (atrophy of midbrain structures with a relatively intact pons region)
- Prognosis: usually fatal within 5–10 years
- Clinical features
- Diagnosis: : asymmetric focal cortical atrophy and bilateral atrophy of the basal ganglia on MRI
|Differential diagnoses of Parkinson-plus syndromes|
|Multiple system atrophy (MSA)||Progressive supranuclear palsy (PSP)||Corticobasal degeneration (CBD)||Dementia with Lewy bodies (DLB)|