Parkinson's disease and the non-motor symptoms: hyposmia, weight loss, osteosarcopenia.

Non-motor symptoms (NMSs) are common in Parkinson's disease (PD) and can precede, sometimes for several years. NMSs include, other than gastrointestinal symptoms like constipation and dysphagia, also hyposmia, weight loss and osteosarcopenia. These three NMSs seem to be inter-related and affect patients' health and quality of life. Unfortunately, patients with these symptoms usually are not initially seen by a neurologist, and by the time they are consulted, nearly ~ 80% of the dopaminergic neurons in the substantia nigra have died. To date, no guidelines exist for screening, assessment and management of NMSs in general. A better understanding of these specific NMSs, likely in the context of others, will make it possible to approach and optimise the treatment of the motor symptoms thereby enhancing the welfare of PD patients. Identifying the NMSs could be very helpful, and among them, hyposmia, weight loss and osteosarcopenia may play an important role in solving the limitations in the diagnosis of PD. A strict collaboration between general practitioners, clinicians, geriatricians and neurologists can be one approach towards the diagnosis of pre-PD. Waiting until the motor symptoms develop and the patient is finally visited by the neurologist could be too late, considering the catastrophic prognosis of the disease.