Ataxia‐telangiectasia: Somatosensory,‘brainstem Auditory. And Motor Evoked Potentials in Six Patients

Abstract

SUMMARY Six patients with ataxia‐telangiectasia were given neurophysiological examinations. The patients had progressive sensorimotor axonal neuropathy that had begun at about age eight years. Brainstem auditory evoked potentials (BAEPs) showed central alterations in two of four cases. Somatosensory (BAEPs) and motor evoked potentials (MEPs) were altered in four of five cases. In the advanced stage of the disease the neurophysiological findings, except BAEPs and MEPs, resembled those in Friedreich's ataxia. MEP and BAEP results may therefore be useful for differential diagnosis. RÉSUMÉ Ataxie‐télangiectasie: polentiels évoqués somatosensoriels, auditifs du tronc cérébral et moteurs chez six patients Des examens neurophysiologiques ont été pratiqués chez six patients avec ataxie‐télangiectasie. Les patients présentaient une neuropathie axonale sensorimotrice, ayant commencé vers l'âge de huit ans. Les potentiels évoqués auditifs du tronc cérébral (BAEPs) révélaient une atteinte centrale dans deux de quatre cas. Les potentiels évoqués somatosensoriels (BAEPs) et moteurs (MEPs) étaient altérés dans quatre de cinq cas. A un stade avancé de l'affection, les données neurophysiologiques, exceptés les BAEPs et les MEPs, resemblaient à celles d'une ataxie de Friedreich. Les résultats MEP et BAEP peuvent ainsi être utiles pour un diagnostic différentiel. ZUSAMMENFASSUNG Ataxia‐Telangiectasia: somatosensorisch‐, akiistisch‐ und inotorisch evozierte Potentiate bei seclis Patienten Sechs Patienten mit Ataxia‐Telangiectasia wurden neurophysiologisch untersucht. Die Patienten hatten eine progressive sensomotorische axonale Neuropathie, die im Alter von etwa acht Jahrcn begann. Bei zwei von vier Fällen zeigten die akustisch evozierten Hirnstammpotentiale (BAEPs) zentrale Veränderungen. Die somatosensorisch (BAEPs) und motorisch evozierten Potentiale (MEPs) waren in vier von fünf Fällen verändert. Im fortgeschrittenen Stadium der Erkrankung ähnelten die neurophysiologischen Befunde–außer BAEPs und MEPs–denen bei der Friedreich schen Ataxic MEP und BAEP Ergebnisse können daher für die Differentialdiagnose von Bedeutung sein. RESUMEN Ataxia‐telangiectasia: potenciales evocados somato‐sensoriales, audilivos del tronco cerebral motores, en seis pacientes Se exploraron neurofisiológicamente seis pacientes con ataxia telangiectasia. Los paciente tenían una neuropatía axonal sensorio‐motora progresiva que se inició hacia los ocho años de edad. Los potenciales evocados auditivos del tronco cerebral (BAEP) mostraron alteracioncs centrales en dos de los cuatro casos. Los potenciales evocados somatosensoriales (BAEP) y los motores (MEP) estaban alterados en cuatro de los seis casos. En la fase avanzada de la ehfermedad, los hallazgos neurofisiológicos, excepto los BAEP y los MEP, se asemejaban a los de la ataxia de Friedreich. Asi pues, los MEP y los BAEP peuden ser útiles para un diagnóstico diferencial.

Extracerebellar MRI—Lesions in Ataxia Telangiectasia Go Along with Deficiency of the GH/IGF-1 Axis, Markedly Reduced Body Weight, High Ataxia Scores and Advanced Age

“…The central nervous tissue abnormalities offer a plausible explanation for the extracerebellar disease signs detected in some AT patients upon bedside examination [10,11,[20][21][22]. The extrapyramidal motor deficits seen in two of our AT patients have been reported in case reports recently [23,24].…”

“…The above mentioned disease symptoms have been described recently [10,11]. They clearly point towards an affection of brainstem and basal ganglia neuronal cells in human AT.…”

Neurodegeneration in Ataxia Telangiectasia: What Is New? What Is Evident?

“…Authors therefore suspected clinically silent affections of the brainstem sensory, auditory, and visual system in younger patients and suggested to routinely perform evoked potentials in patients with AT to discover clinically silent lesions in time. [76][77][78][79] From a neuropathological point of view, progressive degeneration of the posterior columns as well as degeneration of brainstem nuclei and white matter tracts have been frequently reported. 61,66,69 MRI studies in younger patients with AT often do not show any sign of brainstem abnormalities or signal alterations.…”

Motor pathway degeneration in young ataxia telangiectasia patients: A diffusion tractography study

“…DTI and fiber tracking have been applied to study cerebellar–corticomotor networks in a number of ataxic conditions ( Habas and Cabanis, 2007 ; Kitamura et al, 2008 ; Pagani et al, 2010 ; Prodi et al, 2013 ; Rizzo et al, 2011 ; Solodkin et al, 2011 ; Ying et al, 2009 ; Yoon et al, 2006 ) other than A–T. Although histopathological evidence for collective atrophy in pontocerebellar pathways ( Verhagen et al, 2012 ), altered evoked potentials and myelinated fiber loss in spinal cord sensory pathways ( Aguilar et al, 1968 ; Boder and Sedgwick, 1958 ; De Leon et al, 1976 ; Dunn, 1973 ; Scarpini et al, 1996 ; Sourander et al, 1966 ; Stritch, 1966 ), and demyelination of corticospinal tracts (CST) has been reported in A–T ( Agamanolis and Greenstein, 1979 ; Verhagen et al, 2012 ), these findings relate to post-mortem studies, usually at the end stages of disease. dMRI studies that employ probabilistic tractography to analyze WM pathway integrity and connectivity to multiple brain regions is urgently required to fully understand the impact of the ATM gene mutation on A–T motor circuits.…”