Unusual presentation of HNPP

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J Brachial Plex Peripher Nerve Inj. 2008 Jan 24;3(1):2

Unusual presentation of hereditary neuropathy with liability to

pressure palsies.

Farooq MU, JH, Andary MT.

ABSTRACT:

BACKGROUND: Hereditary neuropathy with liability to pressure palsies

(HNPP) is an autosomal-dominant painless peripheral neuropathy

characterized by episodes of repeated focal pressure neuropathies at

sites of entrapment/compression, with a considerable variability in

the clinical course. Electrodiagnostic and genetic testing are

important in the diagnostic evaluation of these patients.

CASE PRESENTATION: We report an unusual HNPP phenotype, five

compression neuropathies in four nerves in a patient with bilateral

hand numbness. A 42-year-old female, presented with acute bilateral

paresthesias and weakness in her hands after starting yoga exercises

requiring hyperextension of her hands at the wrists. Her presentation

was complicated by: a) a remote history of acute onset foot drop and

subsequent improvement, previous diagnoses of demyelinating

peripheral neuropathy, possibly Charcot-Marie-Tooth disease, and c)

exposure to leprosy. Electrodiagnostic testing showed 5 separate

compression neuropathies in 4 nerves including: severe left and right

ulnar neuropathies at the wrist, left and right median neuropathies

at the wrist and left ulnar neuropathy at the elbow. There was a mild

generalized, primarily demyelinating, peripheral polyneuropathy.

Based on the clinical suspicion and electrodiagnostic findings,

consistent with profound demyelination in areas of compression,

genetic analysis was done which identified a deletion of the PMP-22

gene consistent with HNPP.

CONCLUSION: HNPP can present with unusual phenotypes, such as 5

separate mononeuropathies, bilateral ulnar and median neuropathies at

the wrists and ulnar neuropathy at the elbow with mild peripheral

demyelinating polyneuropathy associated with the PMP-22 gene deletion.