- Werdnig-Hoffman disease
DiseaseDisorder infobox
Name = Werdnig-Hoffman disease
ICD10 = ICD10|G|12|0|g|10
ICD9 = ICD9|335.0
ICDO =
Caption =
OMIM = 253300
MedlinePlus = 000996 | eMedicineSubj = orthoped
eMedicineTopic = 304
DiseasesDB =
MeshID = D014897Werdnig-Hoffman disease (also known as "Severe infantile spinal muscular atrophy", or "spinal muscular atrophy type I") is an
autosomal recessive neuromuscular disease . It is the most severe form ofspinal muscular atrophy , which is one of a number of neuromuscular diseases classified as a type ofmuscular dystrophy .Werdnig-Hoffman affects the lower motor neurons only.
Causes
It has been linked to an abnormal
survival motor neuron (SMN) gene.Eponym
It is named for
Johann Hoffmann andGuido Werdnig . [WhoNamedIt|synd|1825] [J. Hoffmann. Weitere Beiträge zur Lehre von der progressiven neurotischen Muskeldystrophie. Deutsche Zeitschrift für Nervenheilkunde, Berlin, 1891, 1: 95-120.] [G. Werdnig. Zwei frühinfantile hereditäre Fälle von progressiver Muskelatrophie unter dem Bilde der Dystrophie, aber auf neurotischer Grundlage. Archiv für Psychiatrie und Nervenkrankheiten, Berlin, 1891, 22: 437-481]ymptoms
It is evident before birth or within the first few months of life. There may be a reduction in fetal movement in the final months of pregnancy. Affected children never sit or stand unassisted and will require respiratory support to survive before the age of 2. Other symptoms include:
*
Fasciculations (quivering) of the tongue
* MarkedHypotonia in legs, arms, rib, chest & bulbar muscles (Patient lies in a frog-leg position, i.e. hips abducted & knees flexed)
* Flaccid quadriplegia
*Difficulty breathing
*Poor feeding
*Weak cry
*Areflexive extremities Diagnosis
*
Electromyogram (EMG) will showfibrillation & muscle denervationFact|date=June 2008
*Serumcreatine kinase may be normal or increasedFact|date=June 2008Genetics
Werdnig-Hoffman disease is inherited in an
autosomal recessive pattern, which means the defective gene is located on anautosome , and two copies of the gene - one from each parent - are required to inherit the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but do not have the disorder.Treatment
Treatment is symptomatic and supportive and includes treating pneumonia, curvature of the spine and respiratory infections, if present. Also, physical therapy, orthotic supports, and rehabilitation are useful. For individuals who survive early childhood, assistive technology can be vital to providing access to work and entertainment. Genetic counseling is imperative.
Tracheostomy is often (but not always) a part of the treatment plan.cite journal |author=Bach JR, Niranjan V, Weaver B |title=Spinal muscular atrophy type 1: A noninvasive respiratory management approach |journal=Chest |volume=117 |issue=4 |pages=1100–5 |year=2000 |month=April |pmid=10767247 |doi= 10.1378/chest.117.4.1100|url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=10767247]Prognosis
Children with Werdnig-Hoffmann disease / SMA Type 1 face a difficult battle. The patient's condition tends to deteriorate over time, depending on the severity of the symptoms.
The child is constantly at risk of respiratory infection and pneumonia.
Poor chewing and swallowing may lead to malnutrition; supplemental tube feedings may be required through the nose or directly into the stomach.
Recurrent respiratory problems (the primary cause of morbidity in this condition)cite journal |author=Yuan N, Wang CH, Trela A, Albanese CT |title=Laparoscopic Nissen fundoplication during gastrostomy tube placement and noninvasive ventilation may improve survival in type I and severe type II spinal muscular atrophy |journal=J. Child Neurol. |volume=22 |issue=6 |pages=727–31 |year=2007 |month=June |pmid=17641258 |doi=10.1177/0883073807304009 |url=http://jcn.sagepub.com/cgi/pmidlookup?view=long&pmid=17641258] mean that mechanical support for breathing—usually initially in the form of
BiPAP and later often tracheostomy and ventilation—are necessary for the baby to have any chance of long-term survival.Affected children never sit or stand and usually die before the age of 2 without breathing support.
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