| Paroxysmal attack | |
|---|---|
| Other names | Paroxysms |
| Specialty | Neurology  |
Paroxysmal attacks orparoxysms are a sudden recurrence or intensification ofsymptoms, such as aspasm orseizure.[1] These short, frequent symptoms can be observed in various clinical conditions. They are usually associated withmultiple sclerosis orpertussis, but they may also be observed in otherdisorders such asencephalitis, headtrauma,stroke,autism,asthma,trigeminal neuralgia,breath-holding spells,epilepsy,malaria,tabes dorsalis,Behçet's disease, andparoxysmal nocturnal hemoglobinuria (PNH). It has also been noted as a symptom ofgratification disorder in children.[citation needed]
The wordparoxysm means 'sudden attack, outburst'[2] and comes from Greek παροξυσμός (paroxusmós) 'irritation, exasperation'.[3]
Paroxysmal attacks in various disorders have been reported extensively, andephaptic coupling ofdemyelinatednerves has been presumed as one of the underlying mechanisms of this phenomenon. This is supported by the presence of these attacks in multiple sclerosis and tabes dorsalis, which both involve demyelination of spinal cord neurons. Exercise, tactile stimuli, hot water, anxiety, and neck flexion may provoke paroxysmal attacks. Most reported paroxysmal attacks are painfultonicspasms,dysarthria andataxia,numbness, andhemiparesis. They are typically different from othertransient symptoms by their brevity (lasting no more than 2 minutes), frequency (from 1–2 times/day up to a few hundred times/day), stereotyped fashion, and excellent response to drugs (usuallycarbamazepine). Withdrawal of symptoms without any residualneurological finding is another key feature in their recognition.[citation needed]