Title:Aminopyridines and Acetyl-DL-leucine: New Therapies in Cerebellar Disorders
Volume: 17
Issue: 1
Author(s): Roger Kalla and Michael Strupp*
Affiliation:
- Department of Neurology, German Center for Vertigo and Balance Disorders, and Institute for Clinical Neurosciences, University Hospital Munich, Campus Grosshadern, Munich,Germany
Keywords:
Cerebellar ataxia, central vestibular disorders, aminopyridines, 4-aminopyridine, episodic ataxia type 2, downbeat
nystagmus, acetyl-DL-leucine.
Abstract: Cerebellar ataxia is a frequent and often disabling syndrome severely impairing motor
functioning and quality of life. Patients suffer from reduced mobility, and restricted autonomy, experiencing
an even lower quality of life than, e.g., stroke survivors. Aminopyridines have been
demonstrated viable for the symptomatic treatment of certain forms of cerebellar ataxia. This article
will give an outline of the present pharmacotherapy of different cerebellar disorders. As a current
key-therapy for the treatment of downbeat nystagmus 4-aminopyridine (4-AP) is suggested for the
treatment of downbeat nystagmus (5–10 mg Twice a day [TID]), a frequent type of persisting nystagmus,
due to a compromise of the vestibulo-cerebellum. Studies with animals have demonstrated,
that a nonselective blockage of voltage-gated potassium channels (mainly Kv1.5) increases Purkinje-
cell (PC) excitability. In episodic ataxia type 2 (EA2), which is frequently caused by mutations
of the PQ-calcium channel, the efficacy of 4-AP (5–10 mg TID) has been shown in a randomized
controlled trial (RCT). 4-AP was well tolerated in the recommended dosages. 4-AP was also effective
in elevating symptoms in cerebellar gait ataxia of different etiologies (2 case series).
A new treatment option for cerebellar disease is the amino-acid acetyl-DL-leucine, which has significantly
improved cerebellar symptoms in three case series. There are on-going randomized controlled
trials for cerebellar ataxia (acetyl-DL-leucine vs placebo; ALCAT), cerebellar gait disorders
(SR-form of 4-AP vs placebo; FACEG) and EA2 (sustained-release/SR-form of 4-AP vs acetazolamide
vs placebo; EAT2TREAT), which will provide new insights into the pharmacological treatment
of cerebellar disorders.