Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Nov 25:2:196-8.
doi: 10.1016/j.ebcr.2014.09.007. eCollection 2014.

Stimulus-induced myoclonus treated effectively with clonazepam in genetically confirmed Coffin-Lowry syndrome

Elif Acar Arslan  1 , Serdar Ceylaner  2 , Güzide Turanlı  3
Affiliations

Stimulus-induced myoclonus treated effectively with clonazepam in genetically confirmed Coffin-Lowry syndrome

Elif Acar Arslan et al. Epilepsy Behav Case Rep. .

Abstract

Purpose: Coffin-Lowry syndrome (CLS) is a rare X-linked semidominant syndromic genetic disorder that is characterized by typical facial and radiologic findings, psychomotor and growth retardation, and various skeletal anomalies. A distinctive paroxysmal disorder called stimulus-bound myoclonus is clinically heterogeneous and is generally characterized by a sudden loss of muscle tone that is regained within a few seconds and is induced by sudden auditory or tactile stimulus. As the pathophysiology of stimulus-induced drop episodes (SIDEs) is not well understood, there is no definite therapy for those episodes.

Methods: We report a 15-year-old female with stimulus-induced drop episodes occurring many times a day that resulted in failure to perform her daily activities. Because her SIDEs were misdiagnosed as atonic seizures, she was treated with several antiepileptic drugs, including valproic acid, levetiracetam, lamotrigine, primidone, carbamazepine, and clobazam.

Results: We realized that her clinical and radiological findings, together with SIDEs, are compatible with Coffin-Lowry syndrome. All of her medications were discontinued following the diagnosis of SIDE, and she was started on clonazepam. After treatment, she became more independent and was able to perform her daily activities. Subsequently, her episodes decreased from 3 times a day to 1-2 times a month. Sodium oxybate and fluoxetine were added to the treatment protocol without remarkable improvement. Her genetic analysis revealed a heterozygous variation of CLS.

Conclusion: We conclude that SIDE should be included in a differential diagnosis of epileptic seizures in patients with CLS and that clonazepam is an effective choice in the treatment of SIDEs.

Keywords: Clonazepam; Coffin–Lowry syndrome; Stimulus-induced myoclonus.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Photograph of the patient showing the thinning of the distal fingers.
Fig. 2
Fig. 2
X-ray showing a drumstick appearance.
Fig. 3
Fig. 3
A truncating mutation and frameshift variant are shown. All protein units after position 659 are defective. This variation causes damage to the functional protein kinase domain.
See this image and copyright information in PMC

References

    1. Coffin G.S., Siris E., Wegenkia L.C. Mental retardation with osteocartilaginous anomalies. Am. J. Dis. Child. 1966;112:205–213.
    1. Lowry B., Miller J.R., Fraser F.C. A new dominant gene mental retardation syndrome. Am. J. Dis. Child. 1971;121:496–500. - PubMed
    1. Temtamy S.A., Miller J.D., Hussels-Maumenee I. The Coffin–Lowry syndrome: an inherited faciodigital mental retardation syndrome. J Pediatr. 1975;86:724–731. - PubMed
    1. Pereira P.M., Schneider A., Pannetier S., Heron D., Hanauer A. Coffin Lowry syndrome. Eur. J. Hum. Genet. 2010;18:627–633. - PMC - PubMed
    1. Hahn J.S., Hanauer A. Stimulus-induced drop episodes in Coffin–Lowry syndrome. Eur J Med Genet. 2012;55:335–337. - PubMed

LinkOut - more resources