Synopsis
Recognise the combination of progressive autonomic failure with poorly responsive parkinsonism or cerebellar ataxia, identify airway and syncope hazards and provide anticipatory multidisciplinary care.
- Multiple system atrophy is a progressive synucleinopathy combining autonomic failure with parkinsonism, cerebellar dysfunction or both; MSA-P and MSA-C describe the predominant motor pattern.
- Early urinary urgency, incontinence or retention, erectile dysfunction and neurogenic orthostatic hypotension are major clues when they are disproportionate to motor disability.
- Parkinsonism is commonly symmetrical or axial and responds poorly or only transiently to levodopa, although a supervised adequate trial remains worthwhile in many patients.
- Cerebellar gait and limb ataxia, dysarthria or oculomotor signs can dominate, especially in MSA-C, and are not expected features of uncomplicated Parkinson disease.
- Inspiratory stridor, nocturnal noisy breathing, sleep-disordered breathing and disproportionate antecollis are high-value warning signs that require specialist airway assessment.
- Pyramidal signs, cold discoloured hands or feet, emotional incontinence, REM sleep behaviour disorder and rapid progression can support the syndrome but are not individually diagnostic.
- MRI may show putaminal or pontocerebellar atrophy and a hot-cross-bun appearance; these are supportive findings and can be absent early or occur in other disease.
- Management is symptomatic: salt and fluid strategies where safe, compression, postural training, bladder emptying plans, levodopa trial, speech and swallowing care and falls prevention.
- Pressor therapy can worsen supine hypertension, and bladder antimuscarinics can worsen retention, cognition and postural symptoms; physiology and post-void residual guide treatment.
- Progression is usually faster than Parkinson disease, so early driving, work, communication, nutrition, carer, palliative and advance-care conversations are appropriate alongside active symptom treatment.
Key red flags
Standing produces light-headedness, dim vision, weakness, neck or shoulder ache and sometimes syncope, with a substantial pressure fall and an insufficient compensatory pulse rise after confounders are addressed.
Harsh inspiratory noise, nocturnal stridor, choking, abnormal sighing, obstructive or central sleep-disordered breathing and morning headache signal laryngeal or respiratory involvement.
Investigation priorities
Document orthostatic physiology, symptom correlation and competing medicine or volume effects.
Management branches
Progressive parkinsonism or ataxia occurs with prominent urinary, sexual or blood-pressure dysfunction.
- Build a dated timeline of erectile, bladder, bowel, sweating, blood-pressure, sleep, speech, swallowing and motor symptoms and reconcile medicines that could reproduce them.
- Examine standing physiology, eye movements, parkinsonism, cerebellar and pyramidal signs and gait; measure post-void residual and obtain MRI to exclude alternatives and seek supportive features.
- Refer to a movement-disorder specialist for criteria-based longitudinal diagnosis, an adequate levodopa trial and targeted autonomic, urological or genetic investigation.
Key medicines
Levodopa combination therapyUndertake an adequately dosed specialist trial, titrated to recorded functional targets and individual tolerance.May worsen orthostatic hypotension, hallucination and dyskinesia; do not withdraw abruptly, and judge benefit against gait, transfers and daily activities rather than examination alone.
MidodrineA common start is 2.5 mg three times daily while upright, titrated under specialist guidance.Avoid doses near bedtime and monitor supine hypertension, urinary retention, scalp itching and piloerection; heart, kidney and vascular contraindications require review.