Neuropathy, hereditary, with liability to pressure palsies

[MIM 162 500]

(HNPP,  tomaculous neuropathy, heterozygous microdeletion 17p11.2p12)

Rare: 1 to 9/100,000. Hereditary neuropathy. Autosomal dominant transmission. In 80% of cases, it is a deletion of the 17p11.2 region which includes the PMP22 gene (peripheral myelin). Abnormalities in the level of nodes of Ranvier could sensitize the nerves and lead to block conduction in case of compression or stretching. This region is instead duplicated in Charcot-Marie-Tooth disease type 1 disease (CMT1A) (see this topic).

Symptoms generally appears from the age of 20 years but pediatric cases are regularly reported: recurring and painless attacks of paralysis and  paresthesia in the territory of a nerve pathway. These attacks are generally secondary to minimal trauma or compression on a nerve pathway. Recovery is the rule in a few weeks in about 50% of cases, but relapses are frequent, in the same territory or elsewhere. In addition to damage to the ulnar, radial and external peroneal nerves, facial and laryngeal nerves palsies have been described. Sometimes cramps during exercise.

EMG: distal motor prolonged latencies (> 3.8 msec) at the level of the zones of compression as median or peroneal nerves.

Biopsy: images of segmental de- and remyelinisations; areas of thickening in the form of sausages (tomacula) of myelin.

Useful web site: hnpp.org


Anesthetic implications:

careful prevention of nerve compressions; secure the endotracheal tube on the middle of the mouth and not at the level of a commissure; mobilize the limbs every 15 minutes if the patient is asleep. Peripheral nerve blocks: echoguided  to use the minimum volume of local anesthetic agent and avoid compression on the trunks. Neuraxial blocks: low concentration of local anesthetic agent to limit the motor block. Avoid any tourniquet.


References:

-         Wijayasiri L, Batas D, Quiney N. 
Hereditary neuropathy with liability to pressure palsies and anaesthesia : perioperative nerve injury.  
Anaesthesia 2006; 61: 1004-6.

-         Horowitz SH, Spollen LE, Yu W. 
Hereditary neuropathy with liability to pressure palsy: fulminant development with axonal loss during military training
J Neurol Neurosurg Psychiatry 2004; 75: 1629-31.

-        Berdai S, Benhamou D, SOS ALR.
Anesthésie locorégionale chez une femme enceinte atteinte de neuropathie tomaculaire asymptomatique.
Ann Fr Anesth Réanim 2004 ; 23 : 1011-4.

-        Carassiti M, Doyle JD, Cataldo R, Mattei A, Galli B, Agro FE.
Regional anesthesia for a patient with hereditary neuropathy with liability to pressure palsies.
Can J Anesth 2007; 54: 325-6/.

-         van Paassen BW, van der Kooi AJ, van Spaendonck-Zwarts KY, Baas F, de Visser M. 
PMP22related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies. 
Orphanet J Rare Diseases 2014; 9:38

-        Ichikawa K, Nezu A.
Hereditary neuropathy with liability to pressure palsies in childhood: report of a case and a brief review.
Brain Dev 2005; 27: 152-4.

-        Bar C, Villéga F, Espil C, Husson M, Pedespan J-M, Rouanet M-F.
Neuropathie héréditaire par hypersensibilité à la pression : à propos de 3 observations chez lenfant.
Arch Pédiatr 2017 ; 24 : 260-2.


Updated: March 2017