Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT): A Preventable Cerebellar Disorder.

We report a case study of a 60-year-old man with bipolar disorder on stable lithium treatment who developed severe toxicity while admitted to ICU with sepsis and multiorgan failure. Despite unchanged lithium administration, his serum levels escalated due to renal dysfunction, resulting in lithium toxicity. After regaining consciousness, he exhibited a cerebellar syndrome marked by ataxia, tremor, and scanning speech. MRI revealed cerebellar atrophy. Following discontinuation of lithium and hemodialysis, the patient's symptoms remained static. The patient was diagnosed with syndrome of irreversible lithium-effectuated neurotoxicity (SILENT), a chronic cerebellar disorder characterized by persistent ataxia, nystagmus, and gait abnormalities extending beyond two months post-lithium exposure. The disorder has a predilection for cerebellar and basal ganglia dysfunction. MRI findings include cerebellar gliosis and atrophy and leptomeningeal enhancement. This case report highlights that SILENT is both preventable and permanent, urging heightened awareness among clinicians to facilitate early detection and intervention. Patients on lithium with compromised renal function or fever necessitate vigilant lithium level monitoring, dose adjustment, or cessation, to forestall enduring morbidity. This case emphasizes the significance of recognizing and managing SILENT, particularly in critical care settings, to mitigate long-term cerebellar impairment and optimize patient outcomes.

Features in essential tremor and the development of Parkinson's disease vs. parkinsonism.

BACKGROUND: Patients with essential tremor (ET) are at higher risk to develop Parkinson's disease (PD). Recent studies suggest that propranolol (common treatment for ET) can augment pathologic expression of alpha-synuclein. We studied features associated with the development of Parkinson's disease with antecedant essential tremor (ET-PD) compared with ET-plus with parkinsonism (PK). DESIGN: Retrospective case series from a tertiary movement disorders center including patients with ET and PD, found to have ET-PD or ET-plus (PK). RESULTS: We analyzed two groups: (1) ET-plus (PK) (n = 33) and (2) ET-PD (n = 35). Constipation and anosmia were more common in the ET-PD group (73% and 48%) than in the ET-plus (PK) group (33% and 19%). The ET-plus (PK) group was more likely to undergo dopamine transporter (DAT) scans compared with the ET-PD group (73% vs. 34%) and less likely to receive levodopa trials (21% vs. 91%). There were no significant differences in self-reported REM sleep behavior disorders or beta-blocker use. Similar rates of depression, anxiety, cognitive complaints, and family history of tremor or PD were reported in both groups. CONCLUSION: ET-PD and ET-plus (PK) can be clinically difficult to differentiate as they have overlapping motor and non-motor features. Beta-blocker use did not predict development of ET-PD or ET-plus (PK); however, anosmia and constipation may be helpful non-motor distinguishing features. DAT scans and levodopa trials may be valuable in clarifying the diagnoses.

Treating the Neurologic Manifestations of Wilson's Disease With Liver Transplantation.

Wilson's Disease (WD) manifests with systemic and neuropsychiatric symptoms, caused by an ATP7B genetic mutation, leading to an accumulation of copper. Presentations are diverse and the diagnosis should be considered in anyone under 50 with a new onset movement disorder. Early recognition and treatment can limit morbidity. While liver transplantation (LT) is recommended in WD patients with hepatic failure, its use for pure neurologic indication remains controversial. We present a patient who failed medical management and underwent LT for pure neurologic indications. Subsequent neurologic symptom improvement supports the use of LT for patients with pure neurologic manifestations of WD.

Blepharoclonus in Parkinsonism.

Background and Objectives: In clinical practice, we have observed that patients with Parkinson disease (PD) often have blepharoclonus, but its prevalence is not well described in the literature. Understanding the relative frequencies of blepharoclonus in PD and atypical parkinsonian syndromes may shed light on the diagnostic utility of this clinical sign. We aimed to assess (1) the frequency of blepharoclonus in patients with PD in a single-center cohort; (2) the association of blepharoclonus with disease stage, tremor severity, and non-motor symptoms; and (3) the frequency of blepharoclonus in synucleinopathy vs non-synucleinopathy-associated parkinsonism. Methods: We prospectively enrolled 85 patients, 75 with PD and 10 with atypical parkinsonism. Blepharoclonus was considered present if eyelid fluttering was sustained for >5 seconds after gentle eye closure. For each patient, demographics were collected, and we completed selected questions from the MDS-UPDRS (Unified Parkinson's Disease Rating Scale) part 2, REM Sleep Behavior Disorder Questionnaire, and MDS-UPDRS part 3 tremor assessments and recorded the presence/absence of dyskinesia. Results: 63 of 75 patients with PD (84%) had blepharoclonus. Among the 10 patients with atypical parkinsonism, 5 had synucleinopathy syndromes. Blepharoclonus was present in 3 of 5 patients with synucleinopathy and 0 of 5 patients with non-synucleinopathy-associated parkinsonian syndromes. Discussion: Blepharoclonus is prevalent in our PD cohort, suggesting possible utility as a clinical marker for PD. The absence of blepharoclonus in a patient with parkinsonism may suggest a non-synucleinopathy (e.g., tauopathy). Analysis of a larger cohort of both PD and atypical parkinsonism would be needed to establish whether blepharoclonus distinguishes PD from atypical parkinsonism, or synucleinopathy from non-synucleinopathy.

Updated Perspectives on the Management of Drug-Induced Parkinsonism (DIP): Insights from the Clinic.

Parkinsonism refers to the clinical combination of bradykinesia, rigidity, tremor, and postural instability. Parkinsonism is often neurodegenerative, but it can be secondary or iatrogenic, as in drug-induced parkinsonism (DIP), which is the topic of this review. We review the pathophysiology of DIP, differentiate DIP and idiopathic Parkinson's disease (PD), list culprit medications in the development of DIP, discuss the diagnosis of DIP as well as the motor and nonmotor signs and symptoms that can help with differentiation of DIP and PD, and detail the management of DIP.

Amantadine Revisited: A Contender for Initial Treatment in Parkinson's Disease?

The best practice for the initiation of symptomatic motor treatment for Parkinson's disease is an ongoing topic of debate. Fueled by interpretation of the results of the LEAP and MED Parkinson's disease studies, many practitioners opt for early initiation of levodopa formulations, avoiding dopamine agonists to circumvent potential deleterious side effects, namely impulse control disorder. Compared with levodopa, monoamine oxidase inhibitors may lack necessary potency. Ignored in this academic debate is another therapeutic option for patients with Parkinson's disease requiring treatment initiation: amantadine. Amantadine was first reported effective in the treatment of Parkinson's disease in 1969 and several studies were published in the 1970s supporting its efficacy. Currently, amantadine is mainly utilized as an add-on therapy to mitigate levodopa-related dyskinesia and, more recently, new long-acting amantadine formulations have been developed, with new indications to treat motor fluctuations. Amantadine has not been reported to cause dyskinesia and is rarely implicated in impulse control disorder.