Inherited focal, episodic neuropathies: hereditary neuropathy with liability to pressure palsies and hereditary neuralgic amyotrophy.

[neuralgic amyotrophy]

Hereditary neuropathy with liability to pressure palsies (HNPP ; also called tomaculous neuropathy ) is an autosomal-dominant disorder that produces a painless episodic , recurrent , focal demyelinating neuropathy . HNPP generally develops during adolescence , and may cause attacks of numbness , muscular weakness , and atrophy . Peroneal palsies , carpal tunnel syndrome , and other entrapment neuropathies may be frequent manifestations of HNPP . Motor and sensory nerve conduction velocities may be reduced in clinically affected patients , as well as in asymptomatic gene carriers . The histopathological changes observed in peripheral nerves of HNPP patients include segmental demyelination and tomaculous or "sausage-like " formations . Mild overlap of clinical features with Charcot-Marie -Tooth (CMT ) disease type 1 (CMT 1 ) may lead patients with HNPP to be misdiagnosed as having CMT 1 . HNPP and CMT 1 are both demyelinating neuropathies , however , their clinical , pathological , and electrophysiological features are quite distinct . HNPP is most frequently associated with a 1 .4 -Mb pair deletion on chromosome 17 p 12 . A duplication of the identical region leads to CMT 1 A . Both HNPP and CMT 1 A result from a dosage effect of the PMP 22 gene , which is contained within the deleted /duplicated region . This is reflected in reduced mRNA and protein levels in sural nerve biopsy samples from HNPP patients . Treatment for HNPP consists of preventative and symptom-easing measures . Hereditary neuralgic amyotrophy (HNA ; also called familial brachial plexus neuropathy ) is an autosomal-dominant disorder causing episodes of paralysis and muscle weakness initiated by severe pain . Individuals with HNA may suffer repeated episodes of intense pain , paralysis , and sensory disturbances in an affected limb . The onset of HNA is at birth or later in childhood with prognosis for recovery usually favorable ; however , persons with HNA may have permanent residual neurological dysfunction following attack (s ). Episodes are often triggered by infections , immunizations , the puerperium , and stress . Electrophysiological studies show normal or mildly prolonged motor nerve conduction velocities distal to the affected brachial plexus . Pathological studies have found axonal degeneration in nerves examined distal to the plexus abnormality . In some HNA pedigrees there are characteristic facial features , including hypotelorism . The prognosis for recovery of normal function of affected limbs in HNA is good , although recurrent episodes may cause residual deficits . HNA is genetically linked to chromosome 17 q 25 , where mutations in the septin-9 (SEPT 9 ) gene have been found .

Diseases
Validation

Diseases presenting "recurrent episodes" symptom

acute rheumatic fever

adrenomyeloneuropathy

benign recurrent intrahepatic cholestasis

child syndrome

cholangiocarcinoma

cystinuria

familial mediterranean fever

hydrocephalus with stenosis of the aqueduct of sylvius

kabuki syndrome

neuralgic amyotrophy

pyruvate dehydrogenase deficiency

systemic capillary leak syndrome

triple a syndrome

You can validate or delete this automatically detected symptom