Sporadic hyperekplexia presenting with an ataxic gait.
We describe a 62-year-old man with a sporadic form of hyperekplexia who presented with an unsteady gait, present since the age of 47. His clinical examination revealed an insecure broad-based gait and difficulty with tandem walking but no other abnormalities. For nearly a decade the patient was misdiagnosed with an idiopathic ataxia. A video electroencephalogram combined with an electromyogram during sudden auditory stimulus demonstrated an excessive startle response. An extensive work-up ruled out all the known causes of symptomatic hyperekplexia including anti-glycine receptor antibodies. Treatment with clonazepam markedly reduced the threshold and intensity of the startle response, enabling him to recover independence. Hyperekplexia is frequently associated with an awkward and hesitating gait, but these gait abnormalities might be confused with other causes of gait disorders if one is not aware of this disease. We report this patient to highlight that a correct diagnosis of hyperekplexia is crucial, because its treatment may change quality of life.
Neurology Service, Cruces University Hospital, Department of Neurosciences, University of the Basque Country, Plaza de Cruces, s/n., Baracaldo, Vizcaya CP 48993, Spain. Electronic address: idoia.rouco@gmail.com.
Idoia
I
Rouco
Neurology Service, Cruces University Hospital, Department of Neurosciences, University of the Basque Country, Plaza de Cruces, s/n., Baracaldo, Vizcaya CP 48993, Spain.
Iker
I
Bilbao
Neurology Service, Cruces University Hospital, Department of Neurosciences, University of the Basque Country, Plaza de Cruces, s/n., Baracaldo, Vizcaya CP 48993, Spain.
Jose
J
Losada
Neurophysiology Service, Cruces University Hospital, Vizcaya, Spain.
Iratxe
I
Maestro
Neurology Service, Cruces University Hospital, Department of Neurosciences, University of the Basque Country, Plaza de Cruces, s/n., Baracaldo, Vizcaya CP 48993, Spain.
Juan Jose
JJ
Zarranz
D002998:Clonazepam / Q000627:therapeutic use; D003937:Diagnosis, Differential; D004569:Electroencephalography; D004576:Electromyography; D018757:GABA Modulators / Q000627:therapeutic use; D020234:Gait Ataxia / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology; D016750:Stiff-Person Syndrome / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D016896:Treatment Outcome
D018757:GABA Modulators; D002998:Clonazepam
Clonazepam; Hyperekplexia; Sporadic hyperekplexia; Startle