Brent L Fogel, Susan Perlman
An approach to the patient with late-onset cerebellar ataxia.
Nat Clin Pract Neurol. 2006 Nov;2(11):629-35; quiz 1 p following 635. doi: 10.1038/ncpneuro0319.
Abstract/Text
BACKGROUND: An 83-year-old man presented with hypertension, hyperlipidemia, and a previous basal cell carcinoma, having developed progressive worsening of his balance and difficulty walking at the age of 78 years. He was initially diagnosed with stroke, but MRI revealed only isolated cerebellar atrophy. The patient then underwent multiple evaluations for an underlying paraneoplastic process, all of which were negative, but his symptoms progressed and he remained undiagnosed for several years.
INVESTIGATIONS: Neurological examination, laboratory blood tests, MRI, and directed genetic testing.
DIAGNOSIS: Five years after becoming symptomatic, the patient was re-evaluated for a possible genetic ataxia syndrome, which was subsequently confirmed by gene testing as spinocerebellar ataxia type 6 (SCA6).
MANAGEMENT: Symptomatic medical treatment and physical, occupational, and speech therapy.
Thomas Klockgether
Sporadic ataxia with adult onset: classification and diagnostic criteria.
Lancet Neurol. 2010 Jan;9(1):94-104. doi: 10.1016/S1474-4422(09)70305-9.
Abstract/Text
In most patients with adult-onset progressive ataxia, the condition manifests without an obvious familial background. The classification and correct diagnosis of such patients remain a challenge, because almost the entire spectrum of non-genetic and genetic causes of ataxia has to be considered. A wide range of potential causes of acquired ataxia exist, including chronic alcohol use, various other toxic agents, immune-mediated inflammation, vitamin deficiency, chronic leptomeningeal deposition of iron leading to superficial siderosis, and chronic CNS infection. Mutations in single genes can also underlie sporadic ataxia in adults. Finally, patients might have a sporadic degenerative disease, such as multiple system atrophy of cerebellar type or sporadic adult-onset ataxia of unknown aetiology. The definition of clinical criteria and delineation of characteristic MRI features have greatly facilitated the early and correct recognition of sporadic ataxias. In addition, specific serological and genetic markers are available that allow a definite diagnosis in many cases.
Copyright 2010 Elsevier Ltd. All rights reserved.
T Yokota, T Shiojiri, T Gotoda, M Arita, H Arai, T Ohga, T Kanda, J Suzuki, T Imai, H Matsumoto, S Harino, M Kiyosawa, H Mizusawa, K Inoue
Friedreich-like ataxia with retinitis pigmentosa caused by the His101Gln mutation of the alpha-tocopherol transfer protein gene.
Ann Neurol. 1997 Jun;41(6):826-32. doi: 10.1002/ana.410410621.
Abstract/Text
The alpha-tocopherol transfer protein (alpha-TTP) is a cytosolic liver protein that is presumed to function in the intracellular transport of alpha-tocopherol, the most biologically active form of vitamin E. We studied 4 unrelated patients with autosomal recessive Friedreich-like ataxia who had isolated vitamin E deficiency. A point mutation was identified in all of them at position 101 of the gene for alpha-TTP, where histidine (CAT) was replaced with glutamine (CAG). Three of the 4 patients developed retinitis pigmentosa subsequent to the onset of ataxia. Neurological symptoms included ataxia, dysarthria, hyporeflexia, and decreased proprioceptive and vibratory sensations. Electrophysiological and pathological examinations showed that the cardinal sites affected were the central axons of dorsal root ganglion cells and the retina, with minor involvement of the peripheral sensory nerve, optic nerve, and pyramidal tract. The vitamin E tolerance test performed showed that the absorption of vitamin E was normal but that its decrease from the serum was accelerated. Oral administration of vitamin E appeared to halt the progression of visual and neurological symptoms. We propose a new treatable syndrome of Friedreich-like ataxia and retinitis pigmentosa caused by a defect in the alpha-TTP gene.
I Fukuchi, T Asahi, K Kawashima, Y Kawashima, M Yamamura, Y Matsuoka, K Kinoshita
Effects of taltirelin hydrate (TA-0910), a novel thyrotropin-releasing hormone analog, on in vivo dopamine release and turnover in rat brain.
Arzneimittelforschung. 1998 Apr;48(4):353-9.
Abstract/Text
Effects of taltirelin hydrate (CAS 103300-74-9, TA-0910), a novel thyrotropin-releasing hormone (TRH) analog, on the cerebral monoamine systems, especially the release and turnover of dopamine (DA) in rat brain were compared with those of TRH by intraperitoneal administration. Taltirelin hydrate (1-10 mg/kg) increased the extracellular levels of DA and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the nucleus accumbens and corpus striatum for 3 h in a microdialysis study. TRH (30 mg/kg) also increased the levels of these substances, the potency of TRH being the same as that of taltirelin hydrate at doses of 1-3 mg/kg. Taltirelin hydrate (10 mg/kg) also caused an increase in 3-methoxytyramine (3-MT: DA metabolite) until 6 h after the treatment and L-3-dihydroxyphenylalanine (DOPA: precursor of DA and noradrenaline). Taltirelin hydrate also increased the 3-methoxy-4-hydroxyphenylglycol (MHPG: noradrenaline metabolite) level in the frontal cortex and hypothalamus, and 5-hydroxytryptophan (5-HTP: serotonin precursor) accumulation and 5-hydroxyindoleacetic acid (5-HIAA: serotonin metabolite) level in the nucleus accumbens or corpus striatum. These results suggest that taltirelin hydrate possesses not only an enhancing effect on DA release, but also a stimulating effect on the monoamine system. Moreover, these actions were 10-30 times stronger and also longer-lasting than those of TRH. In addition, the mechanisms of DA release induced by these drugs were different from those induced by methamphetamine.
Deborah A Hall, Rachael C Birch, Mathieu Anheim, Aia E Jønch, Elizabeth Pintado, Joanne O'Keefe, Julian N Trollor, Glenn T Stebbins, Randi J Hagerman, Stanley Fahn, Elizabeth Berry-Kravis, Maureen A Leehey
Emerging topics in FXTAS.
J Neurodev Disord. 2014;6(1):31. doi: 10.1186/1866-1955-6-31. Epub 2014 Jul 30.
Abstract/Text
This paper summarizes key emerging issues in fragile X-associated tremor/ataxia syndrome (FXTAS) as presented at the First International Conference on the FMR1 Premutation: Basic Mechanisms & Clinical Involvement in 2013.
Dimitri Renard, Genevieve Fourcade, Giovanni Castelnovo
Teaching NeuroImages: Corpus callosum splenium hyperintensity in fragile X-associated tremor ataxia syndrome.
Neurology. 2015 Jun 2;84(22):e194. doi: 10.1212/WNL.0000000000001652.
Abstract/Text
D J Szmulewicz, J A Waterston, G M Halmagyi, S Mossman, A M Chancellor, C A McLean, E Storey
Sensory neuropathy as part of the cerebellar ataxia neuropathy vestibular areflexia syndrome.
Neurology. 2011 May 31;76(22):1903-10. doi: 10.1212/WNL.0b013e31821d746e.
Abstract/Text
OBJECTIVE: The syndrome of cerebellar ataxia with bilateral vestibulopathy was delineated in 2004. Sensory neuropathy was mentioned in 3 of the 4 patients described. We aimed to characterize and estimate the frequency of neuropathy in this condition, and determine its typical MRI features.
METHODS: Retrospective review of 18 subjects (including 4 from the original description) who met the criteria for bilateral vestibulopathy with cerebellar ataxia.
RESULTS: The reported age at onset range was 39-71 years, and symptom duration was 3-38 years. The syndrome was identified in one sibling pair, suggesting that this may be a late-onset recessive disorder, although the other 16 cases were apparently sporadic. All 18 had sensory neuropathy with absent sensory nerve action potentials, although this was not apparent clinically in 2, and the presence of neuropathy was not a selection criterion. In 5, the loss of pinprick sensation was virtually global, mimicking a neuronopathy. However, findings in the other 11 with clinically manifest neuropathy suggested a length-dependent neuropathy. MRI scans showed cerebellar atrophy in 16, involving anterior and dorsal vermis, and hemispheric crus I, while 2 were normal. The inferior vermis and brainstem were spared.
CONCLUSIONS: Sensory neuropathy is an integral component of this syndrome. It may result in severe sensory loss, which contributes significantly to the disability. The MRI changes are nonspecific, but, coupled with loss of sensory nerve action potentials, may aid diagnosis. We propose a new name for the condition: cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS).
Andrea Cortese, Roberto Simone, Roisin Sullivan, Jana Vandrovcova, Huma Tariq, Wai Yan Yau, Jack Humphrey, Zane Jaunmuktane, Prasanth Sivakumar, James Polke, Muhammad Ilyas, Eloise Tribollet, Pedro J Tomaselli, Grazia Devigili, Ilaria Callegari, Maurizio Versino, Vincenzo Salpietro, Stephanie Efthymiou, Diego Kaski, Nick W Wood, Nadja S Andrade, Elena Buglo, Adriana Rebelo, Alexander M Rossor, Adolfo Bronstein, Pietro Fratta, Wilson J Marques, Stephan Züchner, Mary M Reilly, Henry Houlden
Biallelic expansion of an intronic repeat in RFC1 is a common cause of late-onset ataxia.
Nat Genet. 2019 Apr;51(4):649-658. doi: 10.1038/s41588-019-0372-4. Epub 2019 Mar 29.
Abstract/Text
Late-onset ataxia is common, often idiopathic, and can result from cerebellar, proprioceptive, or vestibular impairment; when in combination, it is also termed cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS). We used non-parametric linkage analysis and genome sequencing to identify a biallelic intronic AAGGG repeat expansion in the replication factor C subunit 1 (RFC1) gene as the cause of familial CANVAS and a frequent cause of late-onset ataxia, particularly if sensory neuronopathy and bilateral vestibular areflexia coexist. The expansion, which occurs in the poly(A) tail of an AluSx3 element and differs in both size and nucleotide sequence from the reference (AAAAG)11 allele, does not affect RFC1 expression in patient peripheral and brain tissue, suggesting no overt loss of function. These data, along with an expansion carrier frequency of 0.7% in Europeans, implies that biallelic AAGGG expansion in RFC1 is a frequent cause of late-onset ataxia.