M. Tijssen

The paroxysmal dyskinesias

The paroxysmal dyskinesias are a challenging group of movement disorders characterised by painless dystonic and/or choreiform movements. Lack of familiarity with their features and a normal neurological examination between attacks frequently cause diagnostic delays, or even the diagnosis of a non-organic disorder. They are classified by their mode of triggering, and also by the duration and frequency of attacks, effectiveness of medication, and any associated syndromes. Four subtypes are recognised: paroxysmal kinesigenic dyskinesia induced by sudden movement; paroxysmal non-kinesigenic dyskinesia precipitated by for instance alcohol or caffeine; paroxysmal exercise-induced dyskinesia triggered by longer lasting activity; and paroxysmal hypnogenic dyskinesia occurring during sleep. Here we will summarise the characteristics of the subtypes, discuss the differential diagnosis, genetic aspects and pathophysiology, and give practical advice on the diagnostic work-up and treatment.

P04. Intermuscular coherence and eye movement studies in two sisters with orthostatic tremor

and smooth pursuit. Peak saccade velocity (main sequence) and saccadic gain were calculated. In addition, video recordings were performed to evaluate OMA. Results: Oculomotor abnormalities ranged from a complete ophthalmoplegia to dysmetric saccades. Slowing of saccades was found in six out of the seven patients. Five out seven patients showed OMA. Interestingly, unlike her sister one of girl the monozygotic twin did not show any eye movement abnormality. Smooth pursuit was normal except for the patient with complete ophthalmoplegia. Conclusions: All observed eye movement abnormalities in the patient group with type 3 Gaucher disease are indicative for brainstem pathology. Particularly, the neural circuitry consisting of burst neurons and pause cells in the reticular formation is malfunctioning. Phenotype varied, even between monozygotic twins.

FC16.2 Brain activity in cortical and essential tremor during wrist flexion-extension movement and posture; a simultaneous EMG-fMRI study

was delivered on the tongue. Analysis was performed using peristimulus time histograms and cumulative sum plots. Results: Seventy-six SMUs were sampled from 11 subjects. Twenty-four SMUs were localized in the OOr region (activated by lip protrusion). Fifty-two SMUs were in the eccentric muscles region (activated by mouth opening). Cutaneous stimulation: 77% of SMUs from the eccentric muscles showed a clear SP without a preceding facilitatory peak. Twenty-nine percentage of SMUs from the OOr responded with a SP without a preceding excitatory peak. Intra-oral stimulation: 40% of SMUs from the eccentric muscles showed a SP not preceded by excitation. Eight percentage showed an early facilitatory peak and a following SP. Twelve percentage of the OOr SMUs showed an isolated SP and none showed a facilitatory peak. Discussion: These results show the presence of an inhibitory modulation on lower facial motor neurons by trigeminal afferents. Both stimulus modalities are effective in inducing an SP in both muscle groups, though the maximal effect was found in the eccentric muscles for cutaneous stimulation. The SP produced after cutaneous stimulation is not due to synchronization of motor unit discharge after a facilitatory discharge. The present data confirm the presence of a trigemino-facial inhibitory reflex in lower facial muscles.

P31.18 EMG recorded during fMRI scanning identifies motor activity

P31.16 The utility of diffusion tensor brain fiber tracking to evaluate diffuse axonal injury: Imaging potentially correlates with cognitive disorder K. Sugiyama , T. Kondo , M. Endo , H. Watanabe , K. Shindo , K. Nishijima , Y. Furusawa , T. Mori , S.I. Izumi 1 1 Tohoku University Graduate School of Medicine, Physical Medicine and Rehabilitation, Japan 2 Tohoku Kouseinenkin General Hospital, Neurology, Japan 3 Tohoku Kouseinenkin General Hospital, Physical Medicine and Rehabilitation, Japan