Vestibular function in patients with Niemann-Pick type C disease

Area of Science:

• Neurology
• Neuroscience
• Genetics

Background:

• Niemann-Pick type C disease (NP-C) is a rare genetic disorder.
• Postural imbalance and falls are common in NP-C patients.
• The underlying cause of postural instability in NP-C remains unclear.

Purpose of the Study:

• To investigate the role of vestibular dysfunction in postural imbalance in NP-C patients.
• To differentiate between vestibular and cerebellar contributions to postural instability in NP-C.

Main Methods:

• Eight NP-C patients and 20 healthy controls underwent vestibular function tests (vHIT, caloric irrigation, o- and cVEMP, SVV).
• Static posturography and Romberg quotient (RQ) were used to assess postural control and visual dependence.
• Statistical analysis compared vestibular and postural measures between NP-C patients and controls.

Main Results:

• No significant differences were found in vestibular function (canal or otolith) between NP-C patients and controls.
• NP-C patients exhibited significantly higher postural sway (tSP, RMS) in multiple conditions.
• NP-C patients had a significantly lower Romberg quotient, indicating intact visual stabilization despite increased sway.

Conclusions:

• Vestibular dysfunction is not the primary cause of postural imbalance in NP-C.
• The findings suggest that cerebellar dysfunction is the likely cause of postural instability in NP-C.
• This study differentiates the etiology of postural imbalance in NP-C from other inherited metabolic disorders.