Motor evoked potentials from the external anal sphincter in patients with autosomal dominant pure spastic paraplegia linked to chromosome 2p

Hereditary spastic paraplegia (HSP) is the name given to a heterogeneous group of rare neurodegenerative disorders of the motor system characterised by slowly progressive spasticity and weakness of the lower limbs. About one third of patients with autosomal dominant pure spastic paraplegia (ADPSP) linked to chromosome 2p have lower urinary tract symptoms (LUTS) and additionally most of these patients also experience rectal urgency/urge incontinence (RUI) as well as sexual dysfunction.1 The direct motor pathway to the external anal sphincter may be studied by transcranial magnetic stimulation (TMS), evoking compound muscle action potentials (CMAPs) with cortical and sacral stimulation.2 3 This study was conducted to evaluate the motor evoked potentials (MEPs) from the external anal sphincter in patients with ADPSP linked to chromosome 2p and to obtain norminative data. After informed consent was obtained 11 definitely affected patients from six different families with ADPSP linked to chromosome 2p and 12 normal controls were included. The median age for the patients was 41 (range 20–64) years, and for the controls 40 (range 21–60) years. Six patients had LUTS and RUI, five of whom previously underwent urodynamic evaluation including measures of the bulbocavernosus reflex (patient numbers A2, C4, C6, K10, and L11 in Neerup Jensen et al 1). Five patients were without LUTS and RUI. Family details, clinical features, …