Background: The authors present a case of a family with hereditary neuropathy with liability to pressure palsies (HNPP) with autosomal dominant inheritance. In this disease, primary peripheral nerve damage is frequent
after insignificant injury. Recurrent, painless, in most cases reversible peripheral nerve lesions are the basic symptoms. The symptoms appear in the 1st-3rd decade of life. The prognosis is favorable.
Case Report: The authors describe two cases, father and his daughter, in whom there were recurrent, reversible palsies of flexor muscles of feet and reversible palsy of brachial plexus in the daughter after several days of rucksack carrying. In both cases, neurophysiological studies revealed typical, mostly focal peripheral nerve damages, first of all in so-called entrapment sites. The rest of investigations: laboratory, of cerebrospinal fluid, of endocrine glands function and cerebral MRI (daughter) were normal. In the daughter we demonstrated prolonged absolute latencies of visual evoked potentials. In both cases, we applied during the progression of clinical symptoms cholinesterase inhibitors, vitamins and physiotherapy with significant improvement.
Conclusions: Prolongation of visual evoked potential latencies in the daughter indicates second cranial nerve damage, which has not been described yet in HNPP.

Keywords: hereditary neuropathy with liability to pressure palsies