[Lesions of ponto-cerebellar and olivo-cerebellar afferents demonstrated by neurophysiologic analysis].
We describe a 52-year-old woman presenting a 2-year history of limb clumsiness and gait difficulties, characterized by progressive worsening. Neurological examination revealed cerebellar intention tremor, cerebellar dysmetria of all 4 limbs and ataxic gait. However, brain MRI was normal. Analysis of fast wrist flexion movements demonstrated hypometric movements, with decreased intensities of agonist EMG activities and increased durations of antagonist EMG activities. Such EMG abnormalities have been demonstrated in patients presenting lesions of the middle cerebellar peduncle, affecting the crossed cerebellopontine projections. Moreover, adaptation motor learning during a pinch task (isometric force) showed a severe inability to adapt motor programming, indicating a disruption of cerebellolivary and cerebellopontine afferent systems. We suggest that our patient presented an exceptional brainstem syndrome involving the function of cerebellar inflow tracts. Such electrophysiological findings are not encountered in patients presenting a cerebellar cortical degeneration or cerebellovlivopontine atrophy, and might have important implications in the treatment of cerebellar ataxia in the future.
Servizio di Neurologia, Universita La Sapienza II, Roma, Italia.
F
F
Setta
M U
MU
Manto
J
J
Jacquy
S
S
Dethy
J
J
Hildebrand
M
M
Baecke
M
M
Barthelémy
D000344:Afferent Pathways / Q000473:pathology* / Q000503:physiopathology; D002531:Cerebellum / Q000473:pathology* / Q000503:physiopathology; D004576:Electromyography; D005246:Feedback; D005260:Female; D005684:Gait; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009068:Movement / Q000502:physiology; D009069:Movement Disorders / Q000209:etiology / Q000503:physiopathology*; D011149:Pons / Q000473:pathology* / Q000503:physiopathology; D011597:Psychomotor Performance; D012016:Reference Values; D014202:Tremor / Q000209:etiology / Q000503:physiopathology*
Atteinte des afférences ponto-cérébelleuses et olivo-cérébelleuses mise en évidence par l'analyse neurophysiologique.