Pearls & Oy-sters: A Case Report of Holmes Tremor Due to Nigrostriatal Dopamine Disruption That Responded to Dopamine Replacement Therapy.

Holmes tremor (HT), also known as midbrain, rubral, or cerebellar pathway outflow tremor, occurs because of disturbances of the cerebellothalamic pathway. This tremor is usually related to lesions in the midbrain peduncular region involving the superior cerebellar peduncle, the red nucleus, and possibly the nigrostriatal circuitry. Common etiologies resulting in HT include tumor, ischemia, and demyelination. We report a case of progressive left-sided HT in an otherwise healthy man with additional symptoms of parkinsonism, hypoesthesia, right oculomotor nerve palsy, cognitive dysfunction, and hypersomnolence. Imaging investigations revealed a right-sided thalamic and midbrain glioma. Dopamine transport imaging demonstrated significant dopaminergic denervation in the right caudate and putamen. The degree of striatal dopamine transporter deficiency was more severe than expected in a patient with Parkinson disease. A trial of dopaminergic agent resulted in significant improvement of the tremor and associated symptoms. Interruption of the nigrostriatal pathway can occur in cases of HT because of midbrain peduncular lesion. The striatal dopaminergic function imaging may have a role in assessing presynaptic dopamine dysfunction and guiding treatment.

Intrinsic peripheral nerve and root tumor and pseudotumoral lesions at a tertiary care pediatric hospital.

PURPOSE: Tumors affecting peripheral nerves in children are rare. Accurate diagnosis ensures that management is appropriate and timely. A review of intrinsic nerve tumors was completed to differentiate common peripheral nerve lesions based on clinical characteristics and investigations. METHODS: A retrospective review was conducted for children (< 18 years old) diagnosed with an intrinsic tumor affecting peripheral nerve(s) or roots at the Children's Hospital of Eastern Ontario (CHEO) from 2009 to 2019. RESULTS: We report 14 children with perineurioma (N = 6), neurofibroma (N = 4), intraneural ganglion cyst (N = 2), or lipomatosis (N = 2). Mean age of symptom onset was 8.2 years (range 0.3 to 17.3 years). Presenting symptoms included muscle weakness (7/14), painless muscle wasting (2/14), contracture (1/14), pain (1/14), or the identification of a painless mass (3/14). Nerve conduction studies (NCS) or electromyography (EMG) were performed in 11/14 patients. MRI was useful at differentiating between these pediatric nerve tumors. Biopsies were performed in nine patients with additional surgical management pursued in four patients. CONCLUSION: The rare nature of peripheral nerve tumors in children can pose diagnostic challenges. NCS/EMG are important to assist with localization, and MRI is useful to distinguish more benign tumors. Key MRI, clinical, and NCS features can in some cases guide management, potentially avoiding the need for invasive procedures.

Improved care and management of paediatric neurological patients evaluated at a paediatric Rapid Access Neurology clinic: A pilot study.

AIM: Referral wait times for paediatric neurological patients are increasing, leading to an increased burden on the emergency department (ED). The paediatric Rapid Access Neurology (pRAN) clinic was created for paediatric patients who are clinically stable, but require an urgent paediatric neurology consultation. The objectives were to evaluate the pathways of referral, accuracy of referring diagnoses, adherence to clinic appointments, impact of clinic visitation on ED visits and patient satisfaction. METHODS: Data were collected from the pRAN clinic from March 2018 until April 2019. Information was obtained from patient charts including the referring and final diagnosis, management plan and the number of visits made to the ED before and after visiting the pRAN clinic. RESULTS: Of the 256 referred patients, 91 met inclusion criteria. The most frequent referral diagnosis was a seizure. Referring physicians and pRAN clinic neurologists differed significantly in the level of diagnostic agreement for patients <2 years of age (P = 0.03; 95% confidence interval (CI) -0.294, 0.373). There was a significant reduction in visits to the ED made by patients 3 months after the pRAN appointment compared with before the visit (P < 0.001; 95% CI -0.9070, -0.4088). The majority of patients felt that the clinic had high value and were satisfied with their follow-up plan. CONCLUSION: This pilot study showed that a pRAN clinic can improve the accuracy of neurological diagnoses and management, especially for children <2 years of age. In addition, pRAN clinic patients make fewer subsequent visits to the ED and express high satisfaction with their care.

Research Consent Models Used in Prospective Studies of Neurologically Deceased Organ Donors: A Systematic Review.

Research to inform the care of neurologically deceased organ donors is complicated by a lack of standards for research consent. In this systematic review, we aim to describe current practices of soliciting consent for participation in prospective studies of neurologically deceased donors, including the frequency and justification for these various models of consent. Among the 74 studies included, 14 did not report on any regulatory review, and 13 did not report on the study consent procedures. Of the remaining 47 studies, 24 utilized a waiver of research consent. The most common justification for a waiver of research consent related to the fact that neurologically deceased donors are not considered human subjects. In conclusion, among studies of neurologically deceased donors, research consent models vary and are inconsistently reported. Consensus and standardization in the application of research consent models will help to advance this emerging field of research.