Senile non-ataxic postural instability

Specialty: Geriatrics.

• increased postural sway
• senile static instability
• postural oscillation of the elderly
• loss of balance without cerebellar signs

Why it occurs

• Proprioceptive dysfunction of the lower extremities secondary to large fiber peripheral neuropathy (diabetes mellitus, vitamin B12 deficiency)
• Age-related decrease in peripheral vestibular sensitivity and function (presbyvestibulopathy) combined with presbyopia
• Loss of ankle mobility ("ineffective ankle strategy") due to tibiotarsal osteoarthritis or Achilles tendon stiffness
• Subclinical orthostatic hypotension or rapid hemodynamic fluctuations induced by autonomic dysautonomia
• Degenerative cervical canal stenosis (cervical spondylotic myelopathy) with compression of the pathways of conscious proprioception

Initial workup

Romberg test and evaluation of the righting reflex using the posterior push test (Push Test); analysis of walking speed over a 4-meter distance; serum levels of Vitamin B12, folates, fasting blood glucose and glycated hemoglobin (HbA1c); Magnetic Resonance (MRI) of the cervical spine in case of suspicion of progressive cervical myelopathy (hyperreflexia, positive Babinski or Hoffman signs); Complete ophthalmological and auditory examination to evaluate the correction of peripheral sensory deficits.

Standard management

• Suspension or progressive reduction of doses of antihypertensive drugs if a systolic blood pressure less than 110 mmHg is documented in the frail elderly, which compromises cerebral perfusion
• Pregabalin — very low doses of 25 mg at night if peripheral neuropathic pain that alters proprioception coexists, monitoring for increased instability due to drowsiness
• Folic acid (5 mg orally per day if vitamin deficiency associated with megaloblastic peripheral neuropathy is confirmed).