Drop Episodes Overview

About 20% of individuals with CLS may experience Stimulus-induced drop episodes (SIDEs) starting in mid-childhood to the teenage years.  Unexpected tactile or auditory stimuli or excitement triggers a brief collapse, but no loss of consciousness.  If the individual is not injured by the fall, he or she is back to normal within seconds.

In some CLS individuals drop episodes closely resemble cataplexy. In others, there is brief hypertonus resembling hyperekplexia. Some patients have sound-provoked cataplexy or ‘cataplexy’ and hypertonus both brief and prolonged at different times and at different ages.  In some individuals, there have been true epileptic seizures.

Fryns et al. (1977) described frequent episodes of sudden, non-epileptic collapses with atonia in two CLS-affected brothers. These drop episodes were generally induced by a loud noise or excitement, and their severity worsened and frequency increased with age. Subsequently, those authors observed the same sudden collapse phenomenon in one additional male out of 20 CLS patients examined  (Fryns and Smeets, 1998). It is worth noting that these drop episode symptoms increased in frequency and severity in the two brothers initially described, together with progression of torsion scoliosis and muscle wasting, while they completely disappeared in the latter-described male after surgical correction of scoliosis.

As of June 2003, of the 258 individuals with CLS on the CLS Foundation database, 30 have reported drop attacks and 9 have been diagnosed with ‘seizures’, a total of at least 15%. Onset clustered at 4-7 years (range 4-17 years).

The occurrence of drop episodes in CLS differs between individuals and with time and age. The likelihood of having a drop episode seems to be related to the level of anxiety at the time, so that the fear of falling becomes self-fulfilling. The drop episodes increase in frequency and severity over time, often becoming debilitating as the individual is afraid to stand for fear of falling down. Many end up in a wheel chair  for their own safety.

Articles on Drop Episodes

Stimulus-Induced Drop Episodes in Coffin-Lowry Syndrome PEDIATRICS Vol. 111 No. 3 March 2003, pp. e197-e202 (Full Text)

Drop episodes in Coffin-Lowry syndrome: exaggerated startle responses treated with clonazepam. Pediatr Neurol 1998 Aug;19(2):148-50

Treatment of Drop Attacks in Coffin-Lowry Syndrome With the Use of Sodium Oxybate Navasuma Havaligi, MD, Chandra Matadeen-Ali, MD, Divya S. Khurana, MD, Harold Marks, MD, and Sanjeev V. Kothare, MD Pediatr Neurol 2007;37: 373-374. Full Text

Medications for Drop Episodes

Clonazepam or Clorazepate have both been shown to be partially effective in controlling drop episodes by reducing anxiety.  However, tolerance to the drugs usually develops which necessitates higher doses, and eventually the drugs lose their effectiveness. A regimen of three weeks on and one week off may mitigate this, or only giving one dose in the morning and none at night.

Lamictal (limotrigine) seems to be the most consistently effective drug found to date, sometimes resulting in 100% control of the drop episodes, however, it does not work for everyone. Occasionally, people who take Lamictal develop a potentially life-threatening rash, if treatment is not given within 24 hours or so.  If, however, you build up very gradually to the desired dose (12.5mg increase every two weeks until desired dose is reached), the likelihood of developing the rash is greatly reduced. 

Sodium Oxybate (GBH) has been shown to be 100% effective in one 2007 case study (See articles, above). Further study is necessary.

For a list of seizure medications, see 


For a list of anti-anxiety medications, see http://www.adaa.org/finding-help/treatment/medication 

For information on homeopathic anti-anxiety treatments, see http://www.holisticonline.com/Remedies/Anxiety/anx_homeopathy.htm  

Medications for Seizures and Anti-Anxiety

Startle Epilepsy