Anterior Thalamic Stimulation Induced Relapsing Encephalitis.

Deep brain stimulation of the anterior thalamic nucleus is one of the promising therapeutic options for epilepsy. Several studies are still under way to further strengthen and clarify the mechanism, efficacy, and complications. Contrary to hardware-related and operation-related events, the stimulation-related adverse effect is mild, target-dependent, and adjustable. We present a case of relapsing herpes simplex encephalitis (HSE) as a newly reported and potentially fatal stimulation-related adverse effect following stimulation of the anterior thalamic nucleus (ANT-DBS) accompanied by fever, confusion, and cognitive impairment in a 32-year-old epileptic patient with a history of herpes meningoencephalitis 31 years earlier. The T2-weighted/FLAIR high-signal intensity in the temporal lobe developed at a "distance" from the stimulation target. The positive polymerase chain reaction of herpes virus deoxyribonucleic acid in the cerebrospinal fluid confirmed the diagnosis. The condition improved partially on acyclovir and stimulation stopped. Seizures disappeared and then returned after few months. The unique case report presents a rationale for considering history of herpes encephalitis as a relative contraindication for ANT-DBS, and HSE relapse should be suspected in patients with post-stimulation fever and/or altered consciousness.

Delayed-onset Friedreich's ataxia revisited.

BACKGROUND: Friedreich's ataxia usually occurs before the age of 25. Rare variants have been described, such as late-onset Friedreich's ataxia and very-late-onset Friedreich's ataxia, occurring after 25 and 40 years, respectively. We describe the clinical, functional, and molecular findings from a large series of late-onset Friedreich's ataxia and very-late-onset Friedreich's ataxia and compare them with typical-onset Friedreich's ataxia. METHODS: Phenotypic and genotypic comparison of 44 late-onset Friedreich's ataxia, 30 very late-onset Friedreich's ataxia, and 180 typical Friedreich's ataxia was undertaken. RESULTS: Delayed-onset Friedreich's ataxia (late-onset Friedreich's ataxia and very-late-onset Friedreich's ataxia) had less frequently dysarthria, abolished tendon reflexes, extensor plantar reflexes, weakness, amyotrophy, ganglionopathy, cerebellar atrophy, scoliosis, and cardiomyopathy than typical-onset Friedreich's ataxia, along with less severe functional disability and shorter GAA expansion on the smaller allele (P < 0.001). Delayed-onset Friedreich's ataxia had lower scale for the assessment and rating of ataxia and spinocerebellar degeneration functional scores and longer disease duration before wheelchair confinement (P < 0.001). Both GAA expansions were negatively correlated to age at disease onset (P < 0.001), but the smaller GAA expansion accounted for 62.9% of age at onset variation and the larger GAA expansion for 15.6%. In this comparative study of late-onset Friedreich's ataxia and very-late-onset Friedreich's ataxia, no differences between these phenotypes were demonstrated. CONCLUSION: Typical- and delayed-onset Friedreich's ataxia are different and Friedreich's ataxia is heterogeneous. Late-onset Friedreich's ataxia and very-late-onset Friedreich's ataxia appear to belong to the same clinical and molecular continuum and should be considered together as "delayed-onset Friedreich's ataxia." As the most frequently inherited ataxia, Friedreich's ataxia should be considered facing compatible pictures, including atypical phenotypes (spastic ataxia, retained reflexes, lack of dysarthria, and lack of extraneurological signs), delayed disease onset (even after 60 years of age), and/or slow disease progression.