Heart rate variability and sympathetic skin response for the assessment of autonomic dysfunction in leucine-rich repeat kinase 2 associated Parkinson's disease

Recognition and characterising non-motor profile in early onset Parkinson's disease (EOPD)

Early onset Parkinson's disease (EOPD) has been recently defined as a clinical entity with subjects presenting with Parkinson's disease (PD) between the ages of 21-50 and replaces the term Young Onset PD (YOPD). Presentations in this age group are somewhat different to the typical Late Onset sporadic PD (LOPD) and genetic basis may play an important role. The presentations are however, to be differentiated from other causes of juvenile onset or early onset parkinsonism, which are often driven by rare genetic, brain metal deposition, or metabolic progressive disorders with a levolevodopa unresponsive or poorly responsive phenotype. Specific genetic mutations can also underpin EOPD and include nonmotor symptoms of EOPD, which have not been studied extensively. However, some real-life comparator studies with LOPD suggest a nonmotor profile in EOPD dominated by neuropsychiatric symptoms (anxiety), pain, sexual dysfunction, and a higher risk of impulse control disorders and segregation to the recently described noradrenergic and Park-sleep nonmotor endophenotypes may occur. Awareness of the phenotypic variants and nonmotor expression will pave the way for future precision and personalised medicine.

Not myopathic, but autonomic changes in patients with long-COVID syndrome: a case series

INTRODUCTION

Neurological sequelae following SARS-CoV-2 infection still represent a serious concern both for neurologists and neuroscientists. In our paper, we investigated pain, myalgia, and fatigue as symptoms in long-COVID patients with an electrophysiological approach, comprising the evaluation of sympathetic skin responses (SSRs) and quantitative electromyography (qEMG).

MATERIALS AND METHODS

Twelve patients were enrolled (mean age, 47.7 ± 11.6 years), referred to our attention because of myalgia, pain, or muscle cramps, which persisted about 6 months after the diagnosis of SARS-CoV-2 infection. They underwent conventional electroneurography (ENG), needle electromyography (EMG), and SSRs; moreover, qEMG was performed by sampling at least 20 motor unit potentials (20-30 MUPs) during weak voluntary contraction in deltoid and tibialis anterior muscles. The mean duration, amplitude, and percentage of polyphasic potentials were assessed and compared with healthy and age-matched volunteers.

RESULTS

ENG did not disclose significant changes compared to healthy subjects; needle EMG did not reveal denervation activity. In addition, qEMG showed MUPs similar to those recorded in healthy volunteers in terms of polyphasia (deltoid: p = 0.24; TA: p = 0.35), MUP area (deltoid: p = 0.45; TA: p = 0.44), mean duration (deltoid: p = 0.06; TA: p = 0.45), and amplitude (deltoid: p = 0.27; TA: p = 0.63). SSRs were not recordable from lower limbs in seven patients (58%) and from the upper ones in three of them (25%).

CONCLUSION

Our data suggest an involvement of the autonomic system, with a focus on cholinergic efferent sympathetic activity, without any evidence of myopathic changes.