The literature on cortical excitability, inhibitory and facilitatory properties of the brain in patients with primary dystonia is not well elucidated. We aimed to study the changes in these neurophysiological parameters in patients with dystonia using transcranial magnetic stimulation (TMS).

Patients with primary dystonia of presumed genetic etiology (n = 36) and an equal number of healthy controls (HC) (n = 36) were recruited from May 2021 to September 2022. TMS was done using single and paired pulse paradigms. The left motor cortex was stimulated, and responses were recorded from the contralateral first dorsal interosseus muscle. Resting motor threshold (RMT), central motor conduction time, contralateral silent period (cSP), ipsilateral silent period (iSP), short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were recorded. All patients underwent whole exome sequencing.

The mean age of patients was 36.6 ± 13.5 years. There was a significant reduction of cSP (79.5 ± 33.8 vs 97.5 ± 25.4, p = 0.02) and iSP (42.3 ± 13.5 vs 53.8 ± 20.8, p = 0.003) in patients compared to HC. SICI was significantly enhanced in patients (0.38 ± 0.23) compared to HC (0.51 ± 0.24, p = 0.006). RMT was higher (42.1 ± 7.9 vs 37.1 ± 6.4%, p = 0.032) with enhanced SICI (0.36 ± 0.21 vs 0.56 ± 0.25, p = 0.004) in patients with generalized dystonia (n = 20) compared to HC. The genetically determined subgroup (n = 13) had significantly enhanced SICI compared to HC (0.23 ± 0.15 vs 0.51 ± 0.23, p = 0.001).

Patients with primary dystonia have altered cortical excitability and inhibition with significantly reduced silent period and enhanced intracortical inhibition suggestive of impaired GABAergic neurotransmission.

PRKN-related parkinsonism represents one of the most common types of genetically determined Parkinson’s disease (PD). However, the literature among the Asian ethnicity, particularly in the Indian context, is limited.

To study the clinico-genetic profile of patients with PRKN-related parkinsonism and to review the previously reported cases of PRKN-related parkinsonism from Asia.

A retrospective chart review from a tertiary neurology centre of patients with genetically confirmed PRKN-related parkinsonism. Additionally, we consolidated the Asian cohort from a detailed systematic review of the literature. We utilised the Movement Disorders Society gene cohort for comparison with the world literature.

We recruited 16 cases (males = 10, Early onset Parkinson disease (21 to <50 years age at onset)) of PRKN-related parkinsonism with a median age at onset of 28.5 years (range 14–46). Symptoms included parkinsonism (n = 15), dystonia (n = 10), postural instability (n = 7), freezing of gait (n = 5) and non-motor symptoms (NMS) (n = 10). The commonest symptom at onset was tremors (n = 10). Levodopa responsiveness was observed in all cases with drug-induced dyskinesia in eight (50%). Thirteen cases were homozygous, while three were compound heterozygotes, resulting in 19 variants (novel = 5). Exon deletion was the most common (n = 12). The extended Asian cohort comprising 294 cases had a high prevalence of EOPD (n = 186/257, 72.4%) and familial cases (n = 166/252, 65.9%). Deletion/duplication was the common mutation detected (n = 215, 73.1%). The presumed familial cases had a significantly higher frequency of rest tremors, bradykinesia, postural instability, NMS, dyskinesia and sleep disorders.

This largest single-centre study from India adds 16 new cases and five novel variants to PRKN literature. In addition, it consolidates the Asian cohort of PRKN elucidating its unique attributes.

Warthin's tumours are the second most common benign parotid tumours in the UK. The World Health Organization states that 5–14 per cent of patients have bilateral Warthin's tumours. This study aimed to: assess the presence of contralateral Warthin's tumours in patients who underwent surgery over the past 16 years at a head and neck unit in England, and perform the first systematic literature review on bilateral Warthin's tumours.

A retrospective analysis was conducted on patients diagnosed with Warthin's tumour based on histology between 2005 and 2020. Additionally, a systematic review (International Prospective Register of Systematic Reviews (‘PROSPERO’) registration number: CRD42022326846) was performed using PubMed and the Cochrane Library.

Among 290 patients diagnosed with Warthin's tumours based on histology following surgery, 24.5 per cent had bilateral Warthin's tumours. The systematic review identified 157 papers, with 14 meeting the inclusion criteria.

This study revealed that 24.5 per cent of patients had bilateral Warthin's tumours, deviating from the suggested range. These findings are of interest to surgeons discussing the disease with patients.