ABSTRACT
Fragile X-associated tremor ataxia syndrome (FXTAS) is a relatively recently described condition that is frequently misdiagnosed as essential tremor and then occasionally treated as such with deep brain stimulation (DBS) to the nucleus ventralis intermedius of the thalamus (Vim). Reports of ataxia worsening after bilateral Vim DBS in FXTAS patients are conflicting, and only five FXTAS patients treated with Vim DBS for intractable tremor have been reported in the literature, three of whom having undergone a bilateral procedure. We report a patient who underwent a staged Vim DBS procedure, with excellent contralateral hand tremor control and no worsening of ataxia after the first procedure, but immediate worsening of his ataxia after the second one, arguing in favor of a unilateral surgical approach for intractable tremor in FXTAS.
Subject(s)
Deep Brain Stimulation/methods , Tremor/therapy , Cerebellar Diseases/diagnosis , Cerebellar Diseases/therapy , Diagnosis, Differential , Essential Tremor/diagnosis , Hand , Humans , Male , Middle Aged , Treatment Outcome , Tremor/diagnosis , Tremor/etiology , Ventral Thalamic Nuclei/physiopathologyABSTRACT
Spinocerebellar ataxias are a group of rare and heterogeneous autosomal dominant disorders characterized by progressive ataxia and other features. Spinocerebellar ataxia 17 (SCA17) is one of the 32 subtypes described to date and is secondary to CAG/CAA repeat expansion in the gene coding for the TATA-box binding protein (TBP). SCA17 is clinically heterogeneous and typically presents with slowly evolving ataxia, dysarthria, dementia, depression, and other movement disorders such as chorea. More than 41 CAG/CAA repeats are considered diagnostic of SCA17, with more than 49 being associated with full penetrance. We report one patient presenting with isolated rapidly evolving ataxia who was found to have 44 CAG/CAA repeats in the TBP gene. This suggests that, while SCA17 typically slowly progresses over years, its repertoire of presentations should be expanded to include rapidly progressive isolated ataxia resembling paraneoplastic disorders or prion disease.
Subject(s)
Gait/physiology , Spinocerebellar Ataxias/diagnosis , Spinocerebellar Ataxias/physiopathology , Walking/physiology , Aged , Female , Humans , Time FactorsABSTRACT
BACKGROUND: Drug-induced parkinsonism (DIP) is the second commonest cause of akinetic-rigid syndrome in the western world. Differentiating DIP from Parkinson's disease (PD) may be a challenge to clinicians. One of the factors distinguishing DIP from PD is that discontinuation of the neuroleptic agent in DIP should relieve the symptoms of parkinsonism. The majority of the literature uses the 6-month timeframe between the neuroleptic withdrawal and resolution of the symptoms of parkinsonism. METHODS: We report two cases of DIP wherein the symptoms of parkinsonism persisted more than 6-months from withdrawal of the dopamine receptor blocking agent (DRBA) and the results of their ioflupane iodine-123 (DaT) single-photon emission computed tomography (SPECT) scan. DaT scan is a newly approved radiopharmaceutical in the United States indicated for striatal dopamine transporter visualization to assist in the evaluation of adult patients with suspected parkinsonian syndromes. RESULTS: The first case is a patient who developed parkinsonism from risperidone, while the second case developed parkinsonism from metoclopramide. In both cases, parkinsonism persisted 6 months after discontinuation of the DRBA, therefore DaT scan was obtained, showing normal striatal dopamine transporter uptake. Nine months after the discontinuation of the DRBA, parkinsonism was significantly improved in both patients but not completely resolved. CONCLUSION: Our two cases illustrate the possibility of persistent parkinsonism beyond 6-9 months from the time of neuroleptic withdrawal without evidence of presynaptic dopaminergic neuronal loss that would be suggestive of conversion to PD. We recommend that the official recommendation of the minimum time of neuroleptic withdrawal be modified to at least 1 year before entertaining the diagnosis of PD conversion in patients with exposure to DRBAs.
Subject(s)
Antipsychotic Agents/adverse effects , Parkinson Disease, Secondary/chemically induced , Parkinson Disease, Secondary/diagnosis , Parkinson Disease/diagnosis , Substance Withdrawal Syndrome/diagnosis , Aged , Aged, 80 and over , Female , Humans , Male , Parkinson Disease/complications , Parkinson Disease, Secondary/complications , Substance Withdrawal Syndrome/complications , Time FactorsABSTRACT
Impulse-control disorders (ICDs) are becoming more commonly recognized in the Parkinson disease (PD) population. To date, there are no definitive methods of treating dopamine dysregulation syndromes in PD patients. We sought to uncover an effective treatment option for future study. We report a series of 3 PD patients with ICDs who were effectively treated with valproate. Based on these encouraging preliminary observations, future controlled clinical trials investigating the efficacy of valproate for ICDs in PD are recommended.
