Paroxysmal is a term that describes the way that some symptoms of multiple sclerosis come on very suddenly, last only a few seconds or minutes and then disappear just as quickly. Sometimes this cycle repeats a few times or, perhaps, many times in a day. Some people call them attacks, clusters, surges, episodes or intermittent symptoms. Your health professionals may call them episodic symptoms.
Many symptoms of MS can come and go in a paroxysmal way including pain, spasms and difficulties with vision.
What are paroxysmal symptoms?
Paroxysmal is a term for any MS symptoms that begin suddenly and only last for a few seconds or a few minutes at most. However, these symptoms may reappear a few times or many times a day in similar short bursts. They may be painful and disrupt your everyday activities or they can just be annoying. The attacks usually stop after a few months.
Many symptoms of MS can come on in a paroxysmal way including:
- trigeminal neuralgia which gives stabbing or burning sensations down the side of your face, usually on one side only
- altered sensations in your skin such as itching, numbness, tingling, burning or aching
- Lhermitte’s sign which feels like an electric shock down your neck and spine
- shooting pains in the arms or legs which can be very brief but still take your breath away
- spasms which may cause the sudden tightening of a limb, clawing of a hand, twitching or kicking out of a leg. Spasms may affect your trunk or your face muscles
- problems with vision including double vision (diplopia) and Uhthoff’s phenomenon which is the temporary worsening of symptoms caused by an increase in temperature
- swallowing difficulties (dysphagia)
- slurring of speech (dysarthria)
- weakness, usually in your legs or feet, which can cause unsteadiness or a fall
- lack of coordination (ataxia) which may cause you to stumble or drop things
- freezing of movement (akinesia) which is briefly being unable to move or only being able to move slowly or with extreme difficulty.
What causes paroxysmal symptoms?
Paroxysmal symptoms are due to sudden, inappropriate electrical signals in nerves that have already been damaged by MS. Attacks of paroxysmal symptoms are different from the seizures seen in epilepsy as the brain wave patterns are completely different although, confusingly, they may be treated with anti-epileptic drugs.
Paroxysmal symptoms can be triggered by movement, touch, fatigue, hyperventilation (breathing too quickly), temperature change or emotional stress.
How many people get paroxysmal symptoms?
A study in 2002 found that about 3 in every 100 people with MS experienced paroxysmal symptoms.
Paroxysmal symptoms tend to be associated with early stages of MS, but only rarely are they one of the first clinical signs of MS. As such, they are sometimes mis-diagnosed.
What can I do if I have paroxysmal symptoms?
If you are aware of any triggers for your paroxysmal symptoms, such as making a particular movement or getting too hot, you could try to avoid these. Keeping a symptom diary can be helpful in identifying triggers that you may not be aware of.
Information for managing each specific symptom which can appear in a paroxysmal way is available in the A to Z of MS entry for that symptom.
Paroxysmal symptoms are generally not a sign of a relapse unless they are accompanied by other continuous symptoms. However, if you think you may be having a relapse, you should let your MS nurse or neurologist know.
Paroxysmal symptoms can be unsettling as you never know when they may appear. Techniques like mindfulness that help you to live in the present moment rather than wondering about what might happen in the future, can be helpful.
How are paroxysmal symptoms treated?
Paroxysmal symptoms may be treated if they interfere significantly in your everyday life. Just because they are intermittent, doesn't mean they are less important. However, they can be difficult to treat because they appear without warning and each burst only lasts a short time. Also, they often stop after a few months so treatment may be unnecessary. Any treatment will depend, to a large extent, on the specific paroxysmal symptom that you are experiencing. Drug treatment may only be used for a few weeks or months to control your symptoms but then the dose may be decreased or stopped to see if you are now symptom-free.
If you are concerned about paroxysmal symptoms, contact your MS nurse, neurologist or GP.
Last updated: July 2018
Last reviewed: July 2018
This page will be reviewed within three years
- Multiple Sclerosis 2002;8(6):495-9. Summary Epileptic seizures, cranial neuralgias and paroxysmal symptoms in remitting and progressive multiple sclerosis.
- CNS Drugs 2008;22(4):291-324. Summary Current management of pain associated with multiple sclerosis.
- Multiple Sclerosis 2001;7(6): 402-404. Summary Paroxysmal attacks in multiple sclerosis.
- PLoS One. 2017; 12(7): e0181458. Full article Paroxysmal and unusual symptoms as first clinical manifestation of multiple sclerosis do not indicate benign prognosis—The PaSiMS II study