BEDSIDE TEST FOR DEFICIENT PERIPHERAL WARMTH PERCEPTION: A COMMON AND EARLY SIGN IN FABRY DISEASE

B NEDANOVSKI1, A TALBOT1, K NICHOLLS1,2
1The Royal Melbourne Hospital Department of Nephrology, Melbourne, Australia, 2The University of Melbourne, Melbourne, Australia

Aims: To determine
1. Prevalence and severity of sensory neuropathy in Fabry patients using simple bedside examination
2. Effect of enzyme replacement therapy
Background: Fabry disease is an X-linked lysosomal storage disorder that is associated with early mortality. Patients typically present in the first two decades of life with acroparaesthesia and heat intolerance. Time to diagnosis can be up to 20 years. Increased warmth detection threshold is often overlooked, with course and response to enzyme replacement therapy (ERT) poorly documented.
Method: Patients undergo serial neurologic examination 6-12 monthly, comprising lower and upper limb (LL/UL) stimuli (pin prick/cotton wool/heat probe), touched to the knee/elbow as reference, then to distal extremities and moved proximally until perceived as equal to the reference. Analgesia level was arbitrarily scored: none=0, toetips/fingertips=1, interphalangeal joint toe/DIPJ=2 …knee/elbow=10.
Sealed water containers provided heat (700C).
t-testing was used for analysis.
Results: In 118 patients (68 females) at baseline, symmetrical LL deficit in warmth perception was commoner than light touch and pain (89%vs38%vs33%). Seven patients <20yrs demonstrated a similar pattern (86% vs29%vs0%). UL deficits were similar (79.7% vs 38%vs31%).
Deficit severity (mean+/-SEM) was
(LL 4.1±0.3vs0.96±0.2vs1.4±0.2, UL 2.4±0.2vs0.9±0.2vs1.1±0.2, p<0.0001). Over time, in 70 untreated patients (51 females), deficit in warmth perception progressed in all limbs (p<0.01 at 5-10yrs and >10yrs). In 24 patients (20 males) started on ERT, deficit improved at 0.5-1 years (p=0.01) and did not progress thereafter.
Conclusion: Heat perception deficit is common, often isolated, increases over time and responds to ERT. Bedside testing may flag young patients for Fabry screening.


Biography:
Graduated Science with Honours in 2010 from the University of Melbourne and Walter and Eliza Institute of Medical Research. Graduated Doctor of Medicine from the University of Melbourne in 2015. Is currently a physician trainee at the Royal Melbourne Hospital.

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