What is Brown-Vialetto-Van Laere syndrome?
BVVL is a
rare, progressive, neurodegenerative motor neuron disorder that
specifically includes palsies (paralysis) of the cranial nerves, and is
sometimes referred to as “bulbar palsy.” The name Brown-Vialetto-Van
Laere comes from physicians and researchers who described some of the
first reported cases (Brown, 1894; Vialetto, 1936; and Van Laere,
1966), all of which also include sensorineural hearing loss. Though sensorineural hearing loss is a primary component of the syndrome, it may not be discovered until late in children due to the mildness of the hearing loss or the more obvious symptoms that manifest first. Progressive bulbar palsy without hearing loss is referred to as Fazio-Londe syndrome.
of symptoms varies from infancy to the third decade. In many cases,
children lead a normal life developmentally, disease-free, for years
before developing symptoms. Typically, the first symptom is
sensorineural deafness. Other
examples of nerve degeneration include vocal cord paralysis, ptosis
(droopy eyelids), facial weakness, slurred speech, dysphagia
(difficulty swallowing), visual difficulty secondary to optic atrophy,
neck and shoulder weakness, limb weakness, autonomic dysfunction, and
The course of the disease is variable as
some affected individuals gradually get worse while others may have
plateaus of stable disease throughout their course; however, all cases
reported are fatal, and only one-third of all individuals affected with
Brown-Vialetto-Van Laere have survived for longer than ten years.
What is the cause of BVVL?
As of March 4, 2010, at least one gene
has been linked as the cause of BVVL, as an autosomal recessive pattern of inheritance. The remaining cases that have yet to be linked to this gene are being further investigated for hopeful future genetic findings.
How common is BVVL?
the past century, only 59 cases of Brown-Vialetto-Van Laere have been
reported in the literature, and those numbers are growing; however, as we continue to have families and/or their physicians contact us through this web site, we are learning that BVVL is not near as rare as the literature purports. Unfortunately, only one of the more than a dozen cases that we have come across in one year's span has been reported, and BVVL International has been able to garner much from these unreported cases, far surpassing the information that is available from the literature.
How is BVVL diagnosed?
presentation of hearing loss, other cranial nerve palsies, and lower
motor neuron limb involvement raises the possibility of BVVL. However,
it is important to be evaluated by a pediatric neurologist who can also
test for treatable metabolic conditions which may present similarly.
It is also important to seek a second opinion.
show sensorineural hearing loss, and brainstem auditory evoked
potentials (BAER) are abnormal. Magnetic resonance imaging (MRI) of
the brain may show hyperintensities, especially in the brainstem, or
may show nothing at all. Muscle biopsy results are typically normal or
show groups of atrophic fibers suggesting denervation of muscles.
Neurophysiologic tests such as EMG and nerve conduction studies also
confirm denervation of muscles, both chronic and active. Cerebral
spinal fluid (CSF) analysis after lumbar puncture is typical normal or
only shows mildly elevated protein.
Although BVVL shares similar
features with a family of diseases known as spinal muscular atrophy
(SMA), affected individuals that have been tested and reported in the
literature were negative for SMA gene mutations.
To date, there
is at least one genetic test available to confirm the presence of BVVL, for the genetic mutation(s) on C20orf54.
Is there treatment?
is no certain effective treatment for Brown-Vialetto-Van Laere; however, as of 2011 there have been reports of stabilization or reversal of degeneration with the use of a new B2 Protocol
. This is not always the case, though, as some patients report no improvement with B2. In
some case reports, steroids and intravenous immunoglobulins (IVIg) have
been tried with little success, typically short periods of
stabilization before disease progression.
Supportive care and
symptomatic treatment such as tracheostomy, assisted ventilation, and
gastrostomy are typically offered to patients and their families.