Sialidosis is an inborn error of metabolism due to a defect in the NEU1 gene and manifests as two phenotypes: mild type I and severe type II. The cherry red spot (CRS) is a characteristic feature in both types of sialidosis; reports of sialidosis without a CRS are rare. We report two cases of genetically confirmed sialidosis type I with a typical presentation of progressive cortical myoclonus and ataxia but without the CRS. A previously reported homozygous pathogenic variant p.Arg294Cys was detected in the first case, and a novel homozygous pathogenic variant p.Arg305Pro was detected in the second case. Additionally, we reviewed the literature describing cases with similar mutations to find a genetic basis for the absence of a CRS. Milder mutation of both alleles detected in both patients may be the reason for the absence of a CRS.

Objective: Joubert syndrome (JS) is a rare syndrome characterized by ataxia and the molar tooth sign (MTS) on imaging. The present study aims to explore the clinical and radiological features in a cohort of patients with JS. Methods: This was a retrospective chart review of patients with JS evaluated by movement disorder specialists. Results: Nine patients were included in the study. All patients had facial dysmorphism and ocular abnormalities, and 4 patients had dystonia. Ocular tilt reaction and alternate skew deviation (66%) were the most common ocular abnormalities. Horizontally aligned superior cerebellar peduncles were observed in all four patients with diffusion tensor imaging, with a lack of decussation in three. Exome sequencing performed in four patients revealed novel variants in the MKS1, CPLANE1, and PIBF1 genes. Conclusion Facial dysmorphism, ocular abnormalities and classical imaging findings were observed in all patients with JS. Apart from ataxia, dystonia and myoclonus are other movement disorders observed in JS.

Objective: Joubert syndrome (JS) is a rare syndrome characterized by ataxia and the molar tooth sign (MTS) on imaging. The present study aims to explore the clinical and radiological features in a cohort of patients with JS. Methods: This was a retrospective chart review of patients with JS evaluated by movement disorder specialists. Results: Nine patients were included in the study. All patients had facial dysmorphism and ocular abnormalities, and 4 patients had dystonia. Ocular tilt reaction and alternate skew deviation (66%) were the most common ocular abnormalities. Horizontally aligned superior cerebellar peduncles were observed in all four patients with diffusion tensor imaging, with a lack of decussation in three. Exome sequencing performed in four patients revealed novel variants in the MKS1, CPLANE1, and PIBF1 genes. Conclusion Facial dysmorphism, ocular abnormalities and classical imaging findings were observed in all patients with JS. Apart from ataxia, dystonia and myoclonus are other movement disorders observed in JS.

Objective: The novel coronavirus disease (COVID-19) pandemic and public health measures to control it have resulted in unique challenges in the management of patients with deep brain stimulation (DBS). We report our experience with the management of acute worsening of symptoms due to battery exhaustion in 3 patients with DBS. Methods: Patients with DBS for movement disorders who visited the emergency room due to battery exhaustion during the nationwide lockdown from April to May 2020 were included. Results: Two patients with subthalamic nucleus-DBS for Parkinson’s disease (PD) and one with globus pallidus interna-DBS for generalized dystonia presented with acute worsening of symptoms due to battery exhaustion. Urgent battery replacement was performed in both patients with PD. The patient with generalized dystonia was managed with medication adjustment as he chose to defer battery replacement. Conclusion DBS battery replacement can be an emergency. Decisions regarding DBS battery replacement should be individualized during this COVID-19 pandemic.

Objective: With the use of next-generation sequencing in clinical practice, several genetic etiologies of dystonia have been identified. This study aimed to ascertain the utility of clinical exome sequencing (CES) in dystonia and factors suggestive of a genetic etiology. Methods: This study was a retrospective chart review of patients with dystonia who had undergone CES for the evaluation of dystonia. Results: Forty-eight patients (35 males, 46 families) with dystonia were studied, with a mean age at onset of 16.0 ± 14.1 (1–58) years. A pathogenic/likely pathogenic variant was found in 20 patients (41.7%) among which 14 patients (29.2%) carried a novel variant. CES was more likely to detect a genetic diagnosis in patients with an early age at onset, i.e., ≤ 20 years. Conclusion CES is a useful tool in the diagnostic evaluation of dystonia, with a yield of close to 40%. Patients with an earlier age at onset have a higher likelihood of having dystonia due to a genetic cause than those with a later age at onset.