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Volume 14 No. 09
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Accepted Papers





Case Reports

Pseudo Status Cataplecticus in Narcolepsy Type 1

Candace N. Meinen, DO; Kelsey M. Smith, MD; Jan-Mendelt Tillema, MD; Suresh Kotagal, MD
Mayo Clinic, Rochester, Minnesota

ABSTRACT

The rare constellation of multiple episodes of cataplexy that are refractory to therapy is called status cataplecticus. We describe a young adult with known narcolepsy type 1 who reported a marked exacerbation of her symptoms that was initially suspicious for status cataplecticus. Neurological evaluation, polysomnography, and additional history revealed that the spells were not consistent with cataplexy, but rather with a somatoform disorder. The case highlights the importance of considering psychosomatic factors in narcolepsy type 1 when presumed cataplexy remains suboptimally controlled despite adequate dosing with appropriate medications.

Citation:

Meinen CN, Smith KM, Tillema JM, Kotagal S. Pseudo status cataplecticus in narcolepsy type 1. J Clin Sleep Med. 2018;14(9):1625–1627.


INTRODUCTION

Cataplexy is pathognomonic for narcolepsy type 1. It is characterized by episodic loss of extensor muscle tone and tendon reflexes due to intrusion of rapid eye movement (REM) sleep onto wakefulness.1 It is generally triggered by intense emotions such as laughter, surprise or by the anticipation of reward. Patients presenting with marked exacerbation of cataplexy (status cataplecticus) pose a management challenge. Psycho-genic mimics of status cataplecticus in a patient with known narcolepsy type 1 have not been reported. We describe a patient with narcolepsy type 1 who developed a psychological disturbance that mimicked cataplexy and became a diagnostic and management enigma

REPORT OF CASE

An 18-year-old college student with known narcolepsy type 1 presented with exacerbation of her daytime sleepiness and episodic muscle weakness. The onset of sleepiness and cataplexy had been around the age of 11 years. On presentation to our Sleep Clinic at the age of 16 years for a second opinion, she was very sleepy and scored 25/32 on the Pediatric Daytime Sleepiness Scale (reference value of 16 or less). She took multiple daytime naps with concurrent dream mentation and episodes of sleep paralysis. She described a feeling of her “knees becoming weak” especially with laughter or excitement, sometimes progressing to falls. On other occasions, she became “clumsy” upon laughing. There were also intermittent episodes during sleep at night in which she would violently strike out at her mother when she co-slept with her. Polysomnography demonstrated REM sleep without atonia, a minimally increased apnea-hypopnea index at 2 events/h and total sleep time of 435.5 minutes. A Multiple Sleep Latency Test (MSLT) demonstrated a mean sleep latency of 5.8 minutes with sleep-onset REM period (SOREMP) on naps 1 and 2. The association with cataplexy was consistent with narcolepsy type 1. She was started on modafinil, which was discontinued owing to potential side effects of emotional liability and suicidal thoughts. She was then switched to atomoxetine 80 mg once daily with improvement in daytime sleepiness. The cataplexy also improved but remained suboptimally controlled. Consequently, sodium oxybate (Xyrem) was started at 1 gram twice nightly. This was initially effective in alleviating the cataplexy. Over the subsequent 10 months, however, after an initial period of improvement, she developed an increasing number of falls that were suspicious for cataplexy. Sodium oxybate was uptitrated to 4 g twice nightly. Clomipramine was added and titrated to a dose of 25 mg every morning and 50 mg at night. Paradoxically, the presumed cataplexy increased to greater than 20 episodes/d and began to greatly interfere with her quality of life, participation in classroom activities and socialization with friends. The episodes were associated with head drop and bobbing, eye closure, and apparently preserved consciousness. There was a parental observation however that about one-fourth of the episodes of clumsiness were associated with clenching of the teeth. The episodes occurred both while sitting and standing. The duration of all episodes of motor incoordination, with or without teeth clenching was similar, between 10–30 seconds. She had multiple minor abrasions on bilateral knees related to falls from these episodes. The daytime sleepiness remained well controlled. The frequency of loss of muscle control increased to an estimated 60–90 episodes/d. Given the frequency of episodes, there was concern for status cataplecticus. Her mother started to notice periods of breath-holding during these episodes. This was atypical for cataplexy, hence a work-up was initiated to explore other possible causes such as seizures.

An awake and sleep electroencephalogram (EEG) captured multiple stereotyped episodes of head drop with nodding, twitching of the face, and tremulousness of the right upper extremity with no EEG correlates and normal background activity. Brief neurophysiologic monitoring in the daytime was obtained in the Sleep Lab using a MSLT montage, with recording of electro-oculogram, electroencephalogram, eye movements, and chin and arm electromyogram with ongoing video and clinical monitoring. Multiple episodes were captured during this recording session during which examination by one of the authors (SK) showed preserved and brisk tendon reflexes that is incompatible with cataplexy.

This clinical presentation was considered consistent with a somatoform disorder. Further questioning revealed multiple factors predisposing to stress such as perfectionistic tendencies and a desire to excel academically at college, having signed up for 17 credits per semester. She also worried about her own health and that of her family members. She was reassured by the team that narcolepsy had remained stable over time. The sodium oxybate dose was decreased to a total of 6 g nightly owing to concerns that it might be exacerbating anxiety. Psychological counseling was recommended. The patient was quite receptive to these suggestions. She returned for follow-up 2 months later with complete resolution of her falls and motor incoordination after initiation of individual and family psychological counseling. She was able to return to her daily routine and retain a 4.0 grade point average during her college semester. Telephone follow-up with her parent 3 months later indicated a relapse of the episodes of clumsiness and falling, some with clenching of the jaw and others where she became limp and fell. Further, the jaw clenching episodes did not have a clear emotional trigger whereas episodes without jaw clenching, such as being on a roller coaster ride, were associated with becoming limp. All episodes were of similar duration, 15–30 seconds.

DISCUSSION

Although non-organic spells are a common presentation of functional neurologic disorders, pseudo status cataplecticus in a patient with bona fide narcolepsy type 1 has not been described in the literature. Cataplexy is characterized by transient loss of muscle tone triggered by emotions. It is highly specific for narcolepsy.1 Based upon electrophysiological studies in animals; it is mediated by an intrusion of REM sleep into consciousness.2 A loss of tendon reflexes during cataplexy is characteristic.1 Cataplexy can be difficult to differentiate from functional spells in patients with excessive daytime sleepiness. In this case, the patient had a history of episodes consistent with cataplexy supporting her diagnosis of narcolepsy type 1. When the patient had a marked increase in her spells, status cataplecticus and other diagnoses, including seizures, were considered. The patient's known history of narcolepsy type 1 necessitated EEG monitoring and sleep lab evaluations for diagnostic clarity. When the information gathered was not consistent with cataplexy or seizures, further interviewing of the patient revealed psychological factors that lead to the diagnosis of a somatoform disorder: pseudo status cataplecticus.

Pseudocataplexy has been described in the literature. Krahn and colleagues described the first case of pseudocataplexy in a patient with known narcolepsy type 1 that was associated with psychological triggers similar to those in our case.3 Video polygraphy has been used to document pseudocataplexy in patients with known narcolepsy type 1.4 Cataplexy-like episodes have been described in patients with a conversion disorder or patients who are malingering.5 It has been well described in patients with depressed mood leading to transient functional weakness.6 It is important to differentiate between psychiatric manifestations and cataplexy because misidentifying cataplexy can lead to an inappropriate diagnosis of narcolepsy. Status cataplecticus is the extremely frequent occurrence of cataplexy over a period of time. Our patient was experiencing 60–90 episodes/d. There are case reports describing this entity.712 It has been noted with the addition of prazosin for hypertension, the abrupt withdrawal of antidepressants, during child birth, as a manifestation of a mid-brain tumor, and as an initial presentation in a late onset case of narcolepsy.712 Our patient exhibited both true cataplexy and its psychogenic mimic. A key feature that helped us recognize the latter was the preservation of tendon reflexes during some of the events.

Sodium oxybate is a medication approved for the treatment of cataplexy; its exact mechanism of action is unknown but it may act via GABAB or specific gamma-hydroxybutyrate (GHB) receptors.13 Psychiatric complications are a potential side effect of sodium oxybate.13 Up-titration of this medication in the case coincided with an increased frequency of spells in the patient, but this may be coincidental. This case demonstrates a diagnostic dilemma that can be encountered in patients with narcolepsy during the course of long-term management. It also underscores the importance of addressing the concurrent psychological comorbidities in adolescents and young adults with narcolepsy type 1.

DISCLOSURE STATEMENT

Work for this study was performed at Mayo Clinic, Rochester, MN. All authors have seen and approved the manuscript. This report contains off-label or investigational use of clomipramine. The authors report no conflicts of interest.

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