functional movement disorder. When they went back to
the original genetic testing laboratory, they discovered
that the patient had doctored the form with the genetic
test results. The authors deemed it a case of Munchausen syndrome by genetics.
Neurologists should especially consider the possibility
of movement disorders caused by autoimmune disease,
infection, deficiency states, toxins, drugs, and treatable
inborn errors of metabolism because treatment may alter the natural history of the disease and patient outcomes in these cases, Dr. Lang said.
Treatment of metabolic disorders typically requires a
multidisciplinary team and may consist of substrate reduction, removal or enhanced clearance of toxic metabolites, replenishment of depleted metabolites, enzyme
therapy, cell or organ replacement, and gene therapy.
Certain patients require long-term screening and
follow-up to monitor for and prevent complications.
Avoiding infection, trauma, surgery, and vaccination
may be important for patients with defects of small mol-
ecules. Patients with McLeod syndrome are at risk of
transfusion reactions, and patients with ataxia-telangi-
ectasia mutated gene variants should avoid ionizing ra-
diation because of increased risk of malignancy. “If you
are following patients with any of these rare disorders,
you need to be aware of the long-term consequences,”
Dr. Lang said.
In addition, online resources can provide useful in-
formation for neurologists who are evaluating patients
with potentially rare movement disorders, including
OMIM, GeneReviews, Orphanet, Face2Gene, SimulCon-
sult, and MDSGene, Dr. Lang said. NR
Gupta A, Lang AE. Psychogenic movement disorders. Curr Opin Neurol.
2009; 22( 4):430-436.
Sethi KD, Lang AE. Will new genetic techniques like exome sequencing obviate the need for clinical expertise? No. Mov Disord Clin Pract. 2017; 4( 1):
Ure RJ, Dhanju S, Lang AE, Fasano A. Unusual tremor syndromes: know in
order to recognise. J Neurol Neurosurg Psychiatry. 2016;87( 11):1191-1203.
Zittel S, Lohmann K, Bauer P, et al. Munchausen syndrome by genetics: Next-generation challenges for clinicians. Neurology. 2017;88( 10):
Neurology Reviews’ Epilepsy Resource Center, curated by leading epileptologists, is a central
portal for clinical information relevant to the state-of-the-art care of patients with epilepsy.
ThE EpilEpsy REsouRCE CEn TER fEaTuREs:
• Latest news on epilepsy research and recent literature summaries
• Current trends in epilepsy treatment, evidence-based medicine, guidelines, and patient care
• Conference coverage from high-profile medical conventions
• Case reports and diagnostic tools
• Expert interviews and other multimedia
• MD-IQ Quizzes to test your epilepsy knowledge