Objective: To describe a two cases of patients presenting with a PSP phenotype and genetic findings consisted with Huntington’s disease (HD) in one case and FXTAS in another.

Background: Huntington’s disease (HD) typically presents with a combination of hyperkinetic movements, cognitive impairment, and neuropsychiatric symptoms. Parkinsonism is a common feature in juvenile onset HD and can be a presenting feature at older ages. FXTAS is an adult onset neurodegenerative condition which has been associated with parkinsonism. Both conditions can be mimics of alternative diagnoses while co-pathology is also described.

Method: Case report.

Results: Case 1: A 58 year old right handed man presented with a one year history of cognitive impairment and parkinsonism. He described a deterioration in his memory and impairment of executive function. The patient’s mother had developed HD in her late 70s. Examination revealed frontalis overactivation, square wave jerks and slow vertical saccades. There was marked neck and axial rigidity. Examination of the gait revealed a “gunslinger” gait. There was no chorea. A DaTscan was abnormal, consistent with nigrostriatal degeneration. Treatment with levodopa was followed within five months by the emergence of oro-lingual dyskinesia.  Subsequent testing for HD confirmed a IT15 allele with a CAG repeat number of 41 +/- 1 repeat.

Case 2: A 77 year old man and presented with  symmetrical Parkinsonism, restricted vertical gaze, prominent nuchal rigidity and a tendency to fall backwards. MRI brain certainly does show prominent mid brain atrophy and a humming bird sign as well as prominent subcortical white matter change. Notably, there was hyperintensity of the MCP which was DWI positive. Genetic analysis demonstrated a pathogenic repeat expansion in the FMR1 gene.

Conclusion: Typical presentations of HD include chorea, dystonia, tics, neuropsychiatric disease, dementia, and gait abnormalities. The Westphal variant is associated with juvenile onset parkinsonism, however, later onset parkinsonian presentations are reported and can occasionally mimic the “atypical parkinsonisms”.FXTAS typically presents with ataxia and tremor, however Parkinsonism is also described. These cases constitute a diagnostic dilemma as it is unclear whether there is a single disease entity manifesting in an unusual manner, or multiple pathologies manifesting in the same patient.

References: 1. Westphal, A. (1883). Uber eine dem Bilde der cerebrospinalen grauen Degeneration ahniliche Erkrankung des centralen Nervensystem ohne anatomischen Befund, nebst einigen Bernerkungen uber parodoxe Contraction. Archiv fiir Psychiatric und Nervenkrankheiten, 14, 87-134.
2. Chaudhuri K Ray, Reuter I, Andrews T, et al. (1998) Late onset Huntington’s disease presenting with dopa-responsive parkinsonism and minimal chorea. A new phenotypic variant. Mov Disord 13 (suppl 2) 167.
3. Bittenbender JB, Quadfasel FA (1962) Rigid and akinetic forms of Huntington’s chorea. Arch Neurol 7:37-50.
4. 7. Bollen E, Reulen JP, Den Heyer JC, Van der Kamp W, Roos RA, Buruma OJ. Horizontal and vertical saccadic eye movement abnormalities in Huntington’s chorea. J Neurol Sci. 1986;74(1):11-22. doi:10.1016/0022-510x(86)90187-5.

« Back to 2022 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/mimics-or-multiplicity-two-patients-with-a-psp-phenotype-and-underlying-genetic-neurodegenerative-disorders/