Cluster analysis of impairment measures to inform an evidence-based classification structure in RaceRunning, a new World Para Athletics event for athletes with hypertonia, ataxia or athetosis.

RaceRunning enables athletes with limited or no walking ability to propel themselves independently using a three-wheeled frame that has a saddle, handle bars and a chest plate. For RaceRunning to be included as a para athletics event, an evidence-based classification system is required. This study assessed the impact of trunk control and lower limb impairment measures on RaceRunning performance and evaluated whether cluster analysis of these impairment measures produces a valid classification structure for RaceRunning. The Trunk Control Measurement Scale (TCMS), Selective Control Assessment of the Lower Extremity (SCALE), the Australian Spasticity Assessment Scale (ASAS), and knee extension were recorded for 26 RaceRunning athletes. Thirteen male and 13 female athletes aged 24 (SD = 7) years participated. All impairment measures were significantly correlated with performance (rho = 0.55-0.74). Using ASAS, SCALE, TCMS and knee extension as cluster variables in a two-step cluster analysis resulted in two clusters of athletes. Race speed and the impairment measures were significantly different between the clusters (p < 0.001). The findings of this study provide evidence for the utility of the selected impairment measures in an evidence-based classification system for RaceRunning athletes.

[Non-epileptic paroxysmal movement disorders]. / Nichtepileptische paroxysmale Bewegungsstörungen.

Non-epileptic paroxysmal dyskinesias present with different forms of extrapyramidal hyperkinesias (dystonia, chorea, athetosis, ballism) in variable combinations and with cerebellar signs, respectively. They may be classified as: 1. paroxysmal dystonias/choreoathetoses (paroxysmal dystonic choreoathetosis = PDC), paroxysmal kinesigenic choreoathetosis = PKC, intermediate form) and 2. paroxysmal ataxias (PA) (PA with myokymia and neuromyotonia, azetazolamide-responsive PA). Nocturnal paroxysmal dystonia is now regarded as one form of nocturnal frontal lobe epilepsy. Research in molecular genetics has substantially contributed to the etiologic understanding of paroxysmal dyskinesias: In different families linkage has been successfully completed for PDC (chromosome 2q) and PA (chromosomes 12p, 19p). PA are now identified as channelopathies with mutations in the potassium channel (PA with myokymia and neuromyotonia) and the calcium channel gene (azetazolamide-responsive PA).

Paroxysmal choreoathetosis: an epileptic or non-epileptic disorder?

The pathophysiology of paroxysmal kinesigenic choreoathetosis (PKC) is controversial. Some classify it as a non-epileptic movement disorder, others consider PKC as a form of reflex-epilepsy but postulate that the epileptogenic source is within basal ganglia rather than in the cortex. An extensive invasive longterm monitoring in a girl with PKC demonstrated a consistent ictal discharge arising focally from the supplementary sensory-motor cortex (SMC), with a concomitant discharge recorded from the ipsilateral caudate nucleus, without significant spread to other neocortical areas. An hypothesis is presented to explain how a focal discharge within the supplementary motor cortex, demonstrated for the first time to occur in a patient with PKC, might cause phenomenologies distinct from the habitual SMC seizures and strongly suggesting a basal ganglia semeiology.

[Athetosis].

Athetosis is a peculiar involuntary movement resulting from pathologic involvement of the basal ganglia. Although mechanism of this movement is still far from established, athetosis is clinically differentiated from chorea and dystonia. The purpose of this article is to review and summarise the classification of this involuntary movement disorder. This movement disorder is classified into double athetosis, chorea-athetosis, unilateral athetosis and pseudo-athetosis. The double athetosis is featured by increased muscle tonus and irregular small amplitude movement, which appears the most frequently in patients of cerebral palsy. In chorea-athetosis, irregular abnormal movement is more prominent and larger than double athetosis. This type of movement appears commonly in patients other than cerebral palsy. Unilateral and pseudo-athetosis are derived not from disturbance of the basal ganglia but from impared sensory pathways of the deep sensation due to cerebro-vascular lesion. Stereotactic VL-thalamotomy is effective to relieve increased muscle tonus but not to decrease involuntary movement.

Typical and atypical forms of paroxysmal choreoathetosis.

Two children with clinical pictures of paroxysmal kinesinogenic choreoathetosis and paroxysmal dystonic choreoathetosis are described and compared with previous reports with regard to diagnostic procedures, therapeutic approach and prognosis. A third case, characterized by paroxysmal dyskinesia induced by exercise and associated with choreiform nonprogressive signs, is also described. Such an association has not been reported previously. This unusual clinical picture indicates the possibility of intermediate forms in the paroxysmal choreoathetosis group and suggests a relationship between paroxysmal motor disorders and benign familial chorea with early onset.

The nosology of extrapyramidal disorders.

The author presents a new classification of extrapyramidal diseases based on a clinical and genetic approach to the nosology. This classification is intended as a working frame for a reevaluation of the pathogenesis of many of the illnesses listed. A discussion of some theoretic possibilities derived from such a study concludes the paper.