New Study: HNPP, Brachial Plexopathy, Military Service or other exercise

I wanted to title this ‘New Study: with old results.’ I don’t think there’s anything new here, Brachial plexopathy has been reported as being a part of HNPP since the very earliest studies. I suppose it’s good that it is being highlighted again, and the association with exercise in military service being a contributary factor, which has also been reported before.

But it should be noted that it’s not just the military, I’ve heard many reports from people in the support groups who have had brachial plexopathy through all manner of exercise or activity. One very common provoking activity is decorating, ie painting and wallpapering the domestic home.  Other activity which is very common is any repetitive work where the arms are in an elevated position, shelf stacking for example. Other reported activities, and ones which have been notes in medical studies, are backpacking and parachuting, the straps of the backpack being responsible for providing the provoking pressure. Weight lifting has also been reported as a provoking activity, so it can be seen, if one has the time to listen to the people who actually have HNPP rather than the neurologists, that brachial plexopathy is not uncommon at all.

Another point I’d like to make is that some people, including some  neurologists and some doubting members (very few) of the support groups, believe HNPP can only really affect the hands and feet. I’m not sure where this idea comes from, possibly from the belief that HNPP is mild in comparison to CMT1a and therefore has only mild signs of the distal length dependent presentation that characterises CMT1a. If these people took the time to read the medical studies they should realise that HNPP is multi-focal, and can initially present with palsies other than those affecting hands and feet.

So, that’s enough of my views and opinions, here’s the abstract for the recent study.

1. J Neurol Sci. 2014 Aug 22. pii: S0022-510X(14)00550-4. doi:
10.1016/j.jns.2014.08.018. [Epub ahead of print]

Characteristic features of hereditary neuropathy with liability to pressure palsy
(HNPP) presenting with brachial plexopathy in soldiers.

Kim KE.

Author information:
Department of Rehabilitation Medicine, Armed Forces Capital Hospital, 81,
Saemaeul-ro 177beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do Zip code: 463-040,
Republic of Korea. Electronic address: reorle@gmail.com.

A brachial plexus lesion is not common in hereditary neuropathy with liability to
pressure palsy (HNPP). We report the clinical and electrodiagnostic features of
young soldiers with HNPP presenting with brachial plexopathy. By reviewing 2year
medical records from Korean military hospitals, we identified soldiers with
brachial plexus lesions. Among them, patients diagnosed with HNPP were determined
and clinical and electrophysiological findings were compared between HNPP and
non-HNPP patients with a brachial plexus lesion. Thirteen patients (6.8%) were
diagnosed with HNPP among 189 patients with a brachial plexus lesion. Push-ups,
as either a punishment or an exercise, was the most frequent preceding event in
HNPP patients (76.9%), whereas it was rare in non-HNPP patients. The distal motor
latency of the median nerve showed the highest sensitivity (90.9%) and
specificity (100%) for HNPP in patients with a brachial plexus lesion. In
conclusion, HNPP should be suspected in patients with brachial plexopathy if
brachial plexopathy develops after push-ups or if the distal motor latency of
median nerves is prolonged.

Copyright © 2014. Published by Elsevier B.V.

PMID: 25175852

 

Whilst I was looking for the text file of this abstract, I came across this other study on brachial plexopathy and sciatic nerve involvement, and in a child, thus exploding the distal, age related length dependent myth, in one study.

1. Brain Dev. 2005 Mar;27(2):152-4.

Hereditary neuropathy with liability to pressure palsies in childhood: report of
a case and a brief review.

Ichikawa K(1), Nezu A.

Author information:
(1)Department of Pediatrics, Yokohama City University Medical Center, 4-57
Urafune-cho, Minami-ku, Yokohama 232-0024, Japan. kazushi@cds.ne.jp

We present a 10-year-old female diagnosed having hereditary neuropathy with
liability to pressure palsies (HNPP). She had suffered from acute, recurrent
monoplegic episodes affecting both the sciatic nerves and the left brachial
plexus since the age of 7 years. The paresis seemed to be triggered by hiking and
athletic training. Electrophysiological studies showed a conduction block in the
proximal portions of affected nerves. The FISH method disclosed a deletion of the
peripheral myelin protein 22 gene. This school child having HNPP is considered to
be susceptible to the influence of abundant physical training, rather than minor
trauma or compression at sites of entrapment of peripheral nerves.

PMID: 15668057