The paroxysmal dyskinesias

Abstract

The clinical, pathophysiological and genetic features of some of the paroxysmal movement disorders are reviewed. Paroxysmal kinesigenic choreoathetosis/dyskinesias (PKC/PKD) is a condition in which brief and frequent dyskinetic attacks are provoked by sudden movement. PKC is more common in men and can be idiopathic (commonly familial) or due to a variety of causes. The pathophysiology of PKC is uncertain but it could be an ion-channel disorder. Antiepileptic drugs particularly carbamazepine are very helpful in a large proportion of cases. Paroxysmal exercise induced dystonia (PED) is a rare disorder manifesting as episodes of dystonia mostly affecting the feet induced by continuous exercise like walking or running. Although the initial cases were familial, there is a higher proportion of sporadic cases. The pathophysiology of PED is unknown and antiepileptic drugs are generally unhelpful. In paroxysmal dystonic choreoathetosis/non-kinesigenic dyskinesias (PDC/PNKD) the attacks are of long duration and induced by variety of factors including coffee, tea, alcohol and fatigue but not by sudden movement. PDC can be idiopathic (familial or sporadic) or symptomatic due to a variety of causes. The gene for familial PDC has been linked in 2 families to chromosome 2 q close to a cluster of ion channel genes again suggesting that this disorder may also be a channelopathy. Other paroxysmal disorders include paroxysmal nocturnal dyskinesia, a form of frontal lobe epilepsy in some cases which may be familial with autosomal dominant inheritance (ADNFLE). The gene for ADNFLE in one family has been found to be a mutation in the neuronal acetylcholine receptor gene (CHRNA4) on chromosome 20q. Tonic spasms in multiple sclerosis and Sandiffers syndrome producing intermittent torticollis in infants and children are other paroxysmal movement disorders.

The thalamic ultrastructural abnormalities in paroxysmal kinesigenic choreoathetosis: a diffusion tensor imaging study

“…The mean age at initial onset was 11.7 ± 3.1 (range [8][9][10][11][12][13][14][15][16][17] years, and the mean disease duration was 6.9 ± 5.1 (range [1][2][3][4][5][6][7][8][9][10][11][12][13][14] years. The confirmation of PKC was based on the diagnostic criteria of Kertesz [14].…”

“…Paroxysmal dyskinesias are a group of movement disorders characterized by transient attacks of choreoathetosis or dystonia that recur in brief episodes [1]. Paroxysmal kinesigenic choreoathetosis (PKC) is a term used to describe one of the paroxysmal dyskinesias and is a relatively rare neurological condition that is characterised by sudden, brief (seconds to 5 min) attacks of involuntary movements that are precipitated by sudden voluntary movement [2].…”

Excellent response to acetazolamide in a case of paroxysmal dyskinesias due to GLUT1-deficiency

“…Most patients have permanent or paroxysmal movement disorders, and paroxysmal exerciseinduced dyskinesias (PED) or paroxysmal non-kinesigenic dyskinesia (PNKD) is sometimes the main motor manifestation [3,4,6]. Acetazolamide can reduce the frequency and severity of paroxysmal episodes in episodic ataxia type 2 (EA2), but its effect on paroxysmal dyskinesia (PDysk) is controversial [1,2,4].…”

“…Acetazolamide has been reported both to improve [1,4] and to worsen [2] PED. How this carbonic anhydrase inhibitor suppresses ataxic attacks in EA2 is unknown.…”

Understanding dystonia: diagnostic issues and how to overcome them

“…Alcohol, caffeine and stress can also trigger symptoms. Improvement with acetazolamide is reported in some patients 54 . There is genetic heterogeneity in kinesigenic dystonia, with many patients testing negative for currently known genes.…”