Effect of Riluzole as a Symptomatic Approach in Patients With Chronic Cerebellar Ataxia

Summary

Cerebellar disorders are often disabling and symptomatic therapies are limited to few options that are partially effective. It seems therefore appropriate to search for additional approaches. Purkinje cells are the sole output of the cerebellar cortex: they project inhibitory signals to the deep cerebellar nuclei (DCN), which have a critical role in cerebellar function and motor performance. DCN neurons fire spontaneously in the absence of synaptic input from Purkinje neurons and modulation of the DCN response by Purkinje input is believed to be responsible for coordination of movement. Recent evidences support the notion that an increase in DCN excitability may be an important step in the development of cerebellar ataxia and point to the underlying molecular mechanisms: the inhibition of small-conductance calcium-activated potassium (SK) channels, that causes an increase of the firing frequency in DCN, correlates with cerebellar ataxia. The rationale of the present project is that SK channel openers, such as riluzole, may have a beneficial effect on cerebellar ataxia. The researchers propose to perform a pilot study investigating safety and efficacy of riluzole, an approved treatment for amyotrophic lateral sclerosis, as a symptomatic approach in patients with chronic cerebellar ataxia.

Timeline

Start

2005-06

Primary completion

2008-06

Completion

2008-08

Publications

• Background Shakkottai VG, Chou CH, Oddo S, Sailer CA, Knaus HG, Gutman GA, Barish ME, LaFerla FM, Chandy KG. Enhanced neuronal excitability in the absence of neurodegeneration induces cerebellar ataxia. J Clin Invest. 2004 Feb;113(4):582-90. doi: 10.1172/JCI20216.
• Background Aizenman CD, Huang EJ, Linden DJ. Morphological correlates of intrinsic electrical excitability in neurons of the deep cerebellar nuclei. J Neurophysiol. 2003 Apr;89(4):1738-47. doi: 10.1152/jn.01043.2002.
• Background Raman IM, Gustafson AE, Padgett D. Ionic currents and spontaneous firing in neurons isolated from the cerebellar nuclei. J Neurosci. 2000 Dec 15;20(24):9004-16. doi: 10.1523/JNEUROSCI.20-24-09004.2000.
• Background Cao YJ, Dreixler JC, Couey JJ, Houamed KM. Modulation of recombinant and native neuronal SK channels by the neuroprotective drug riluzole. Eur J Pharmacol. 2002 Aug 2;449(1-2):47-54. doi: 10.1016/s0014-2999(02)01987-8.
• Background Doble A. The pharmacology and mechanism of action of riluzole. Neurology. 1996 Dec;47(6 Suppl 4):S233-41. doi: 10.1212/wnl.47.6_suppl_4.233s.
• Background Trouillas P, Takayanagi T, Hallett M, Currier RD, Subramony SH, Wessel K, Bryer A, Diener HC, Massaquoi S, Gomez CM, Coutinho P, Ben Hamida M, Campanella G, Filla A, Schut L, Timann D, Honnorat J, Nighoghossian N, Manyam B. International Cooperative Ataxia Rating Scale for pharmacological assessment of the cerebellar syndrome. The Ataxia Neuropharmacology Committee of the World Federation of Neurology. J Neurol Sci. 1997 Feb 12;145(2):205-11. doi: 10.1016/s0022-510x(96)00231-6.

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