Cutaneous sympathetic dysfunction in patients with Machado-Joseph disease

Area of Science:

• Neurology
• Autonomic Nervous System Research
• Clinical Neuroscience

Background:

• Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3, presents with diverse clinical symptoms.
• Autonomic nervous system dysfunction, particularly cutaneous sympathetic dysfunction, is understudied in MJD.
• Cutaneous vasomotor function in MJD patients has not been previously reported.

Purpose of the Study:

• To investigate the impact of Machado-Joseph disease on cutaneous sympathetic nervous system function.
• To evaluate both sudomotor and vasomotor responses in MJD patients.

Main Methods:

• Assessed cutaneous vasomotor and sudomotor responses in the palms of 15 genetically diagnosed MJD patients and 15 healthy controls.
• Stimuli included mental stress (mental arithmetic) and physiological challenges.
• Compared response amplitudes and presence/absence of responses between groups.

Main Results:

• 67% of MJD patients showed absent sweat response; mean sweat response amplitude was significantly lower in MJD patients (p<0.0001).
• 20% of MJD patients had absent vasoconstrictive response, but no significant difference in mean vasoconstrictive amplitude was observed between groups.
• MJD patients exhibited significantly reduced sudomotor function and mildly affected vasomotor function.

Conclusions:

• Machado-Joseph disease is associated with significant impairment of cutaneous sympathetic sudomotor function.
• Vasomotor function is also affected, though to a lesser extent than sudomotor function, in MJD patients.
• These findings highlight the autonomic nervous system's involvement in MJD pathophysiology.