Two Cases of Sleep-Related Dissociative Disorder with Episodes of Nocturnal Eating

Abstract

Sleep-related dissociative disorder (SRDD) is a female-predominant psychiatric parasomnia that was first identified as a condition that mimics sleepwalking in 1989, and was included in the International Classification of Sleep Disorders, 2nd edition, in 2005, with a subsequent expanding literature of case series and case reports. The objective hallmark of SRDD, found in about half of the reported cases, is sustained electroencephalogram (EEG) wakefulness during dissociative episodes emerging during wake-sleep transitions or after awakenings from light non-rapid eye movement (NREM) sleep or rapid eye movement (REM) sleep. Herein are reported two additional cases of SRDD in two female patients aged 53 and 40 years with prominent histories of multimodal abuse (typical of SRDD), with childhood emotional and food deprivation abuse in Case 1, and childhood emotional, sexual, and physical abuse in Case 2. Both patients were affected by “sleep phobia” and had recurrent nocturnal eating episodes. Major findings from the cumulative literature on SRDD are reinforced by these cases, with additional findings being described, particularly nocturnal eating behaviors and priming/triggering factors.

Keywords

sleep-related dissociative disorder - sleep-related eating - sleepwalking - PTSD - video-polysomnography

Introduction

Sleep-related dissociative disorder (SRDD) is a female-predominant psychiatric parasomnia that was formally identified as a condition that mimics sleepwalking in 1989, with a series of 8 cases.[1] [2] In 2005, SRDD was included in the “Parasomnias” section of the International Classification of Sleep Disorders, 2nd edition (ICSD-2).[3] The objective hallmark of SRDD (found in about half of the reported cases) during video-polysomnography (vPSG) involves abnormal behaviors emerging during sustained electroencephalogram (EEG) wakefulness, either during wake-sleep transitions or after awakenings from light non-rapid eye movement (NREM) sleep or rapid eye movement (REM) sleep, most often in patients with daytime dissociative disorders and other major psychopathologies that usually originate after major trauma.

The condition involves dissociative symptoms defined as “unbidden intrusions into awareness and behavior, with accompanying losses of continuity in subjective experience and/or inability to access information or to control mental functions that normally are readily amenable to access or control. Dissociative disorders are frequently found in the aftermath of trauma and encompass various clinical presentations, such as dissociative identity disorder, dissociative amnesia, and depersonalization/derealization disorders”.[2] [3]

As discussed in a previous article,[2] due to inadvertent administrative reasons, SRDD was only included in the ICSD-3[4] in the differential diagnosis of NREM and REM sleep parasomnias in the ICSD-3[4], and also in the Diagnostic and Statistical Manual of Psychiatric Disorders, 5th edition (DSM-5).[5] Although the DSM-5 contains a section on dissociative disorders, it does not include SRDD in its “Sleep Disorders” section, an unfortunate oversight.

An updated literature review on SRDD has recently been published,[2] with a subsequent report on an additional case series of 8 patients,[6] indicating that SRDD is becoming increasingly recognized (across 3 continents: North America, South America, and Europe), and emphasizing the need for prompt diagnosis and effective management, and the need to have SRDD reincluded in the ISCD.

Numerous compelling reasons have been provided for the inclusion of SRDD in the “Parasomnias” section of the ICSD:[2] it is a sleep-related behavioral and experiential disorder, which fits into the domain of parasomnias. Sleep clinicians will first turn to the “Parasomnias section” of the ICSD when evaluating a patient with abnormal sleep period behaviors resulting from SRDD. Although SRDD is a psychiatric parasomnia, nevertheless it is a parasomnia. As a pertinent analogy, a set of parasomnias is known to emerge from sleep-disordered breathing as the underlying substrate,[7] but these are still considered parasomnias.

The literature on SRDD keeps expanding. However, current review articles on dissociative disorders (as discussed in reference 9) mention SRDD and cite the ICSD-2 (but are unable to cite the ICSD-3), emphasizing the need to include SRDD in the current version of the ICSD. There is still much more to learn about SRDD and the factors that may promote its emergence during the sleep period. Inclusion in the ICSD will encourage sleep clinicians to report additional cases and further expand the literature. Parasomnia overlap disorder (included in the ICSD-3 as combined rapid eye movement sleep behavior disorder [RBD] and NREM parasomnias),[4] for example, may also include SRDD.[8]

There is an expanding literature on parasomnia borderland conditions, including trauma-related cases involving posttraumatic stress disorder (PTSD) and the proposed trauma-associated sleep disorder, further emphasizing the need to include SRDD as another trauma-associated sleep disorder in the official sleep nosology (ICSD). Finally, there can be forensic consequences from SRDD; therefore, the inclusion of SRDD in the official sleep nosology (ICSD) will help legitimize sleep expert testimony in legal cases involving SRDD.

A comprehensive resource on SRDD has recently been published by Eiser in the Encyclopedia of Sleep and Circadian Rhythms, 2nd edition,[9] encompassing the history and nomenclature; demographics and prevalence; onset, ontogeny and clinical course; etiology, pathophysiology, and pathogenesis; associative, predisposing, and precipitating factors; complications and consequences; diagnosis, differential diagnosis, and formal status of diagnosis; and treatment.

Herein, two additional cases of SRDD will be presented, involving abnormal nocturnal eating episodes and sleep phobia in patients with prominent histories of early-life-onset trauma. These two cases further reinforce the need to include SRDD in the ICSD, since it should be included in the differential diagnosis of Sleep Related Eating Disorder, besides the other NREM parasomnias that are listed in the classification.[4]

Case Reports

Case 1 (C.V.)

A 53-year-old married woman with previously diagnosed dissociative disorder (DD) (and other psychiatric disorders listed in [Table 1]) was referred by her psychiatrist for evaluation of injurious nocturnal dissociative episodes, “when she sounds like a little girl”, according to her husband, who attended the consultation. These episodes occurred 3 to 4 nights weekly, with 1 episode per night beginning 2 to 4 hours after sleep onset. Her husband would follow her around the home during these episodes that had begun 1 to 1.5 years previously, when there was a dose increase of her bedtime mirtazapine, and also around the time of starting bedtime cyproheptadine therapy for PTSD nightmares. She was seeing two therapists for weekly sessions, a general psychotherapist and a noted therapist specializing in DD. The patient had suffered from multiple forms of childhood-onset abuse inflicted by her parents, including frequently sending her to bed (along with her brother) before she could eat her supper. She then would arise “in the wee hours” and bring her younger brother to the kitchen, where they would quietly eat while their parents slept.

Table 1 Main clinical characteristics of two patients with sleep-related dissociative disorder (SRDD).

	Case 1	Case 2
Demographic characteristics
Gender: female	+	+
Age (in years)	53	40
Age (in years) at onset of episodes	52	39
Characteristics of the episodes
Stressful event(s) before the onset of episodes	−	+
Frequency of episodes	3–4 nights/week	Several nights/week
Duration of the episodes (in minutes)	30–60	Variable
Typical time of occurrence after going to bed (in hours)	2–4	Variable
Episodes during naps	−	−
Amnesia	Partial	Complete
Interaction with other people	+	−
Violent behaviors toward others	−	−
Angry behavior	+	−
Manipulating sharp objects (knives, tools)	−	−
Bizarre/dangerous behaviors	−	+
Injuries (accidental)	+	+
Going out of the home	−	−
Attempting to get out of the home	+	−
Inappropriate eating (and cooking) behaviors	+	+
Infantile behavior and infantile voice/speech	+	−
Reliving a childhood abuse scenario	+	+
Inappropriate sexual behaviors	−	−
Inappropriate urination	−	−
Sleep phobia	−	+
Parasomnia history
Personal history of non-rapid eye movement (NREM) parasomnia	−	−
Family history of NREM parasomnia	−	−
Restless legs syndrome (RLS; mild)	−	+
Comorbid psychiatric disorders
Posttraumatic stress disorder (PTSD)	+	+
PTSD nightmares	+	−
Dissociative disorder (daytime and nocturnal)	+	+
Panic disorder (with agoraphobia)	+	+
Bipolar disorder	−	+
Major depressive disorder	+	−
Past or current psychotic disorder	−	−
Personality disorder (Axis II)	−	−
Past alcohol abuse disorder	+	−
Past or current alcohol or substance use disorder	−	−

Her nocturnal episodes involved ambulation through the house and into the kitchen. She and her husband had devised a system of bells on doors that was meant to awaken her husband to enable him to intervene. During some episodes her husband would try to awaken his wife and ask her if she knew who he was, and she would typically answer: “No, I don't, but I do know you're someone who sometimes tries to help me.” He then would realize that he should repeat to her “you're safe, go back to bed, you're safe” while redirecting her back to bed. The next day he would comment to her that “you sounded just a little older than our 5 and one-half year-old granddaughter,” in reference to the mannerisms and tone of voice during her nocturnal eating episodes. She also confirmed that during these episodes “I would always eat the same food that I would get for my brother at night when we were children.” She would often say out loud, “we have to be quiet Timmy, we have to be quiet,” and her husband had even heard her utter “shhhh, we have to whisper” (Timmy was her younger brother and she was recreating a childhood abuse-related scenario). Her husband reported that she would sometimes be muttering about her brother or their parents, and otherwise act in a manner highly suggestive that she was reliving frightening events of her childhood. She had suffered from a broken toe and pulled intercostal muscles related to collisions or falls during these nocturnal ambulations.

Some nights the husband had awakened to find that “she was flailing her arms in bed, really quite angry, and she would shout ‘leave me alone, don’t touch me, get out of here.'” It was clear that she was not directing these comments to her husband, whom she was not aware of during these moments, but rather to someone in her dreams/dissociative states. Very often afterwards her husband would observe that “she is quite surprised that she is not in her childhood home.” On other occasions he would see her trying to push against a glass door trying to get out, and apparently she did this repeatedly during her childhood.

Poor appetite and at times weight loss had accompanied her anxiety symptoms and depressed mood over the years. There was considerable stabilization of mood, anxiety, and appetite with the mirtazapine therapy (22.5 mg at bedtime), and for a time she seemed to sleep more soundly after taking 8 mg of cyproheptadine at bedtime. She also took lorazepam, 0.5 mg to 1.5 mg at bedtime, and venlafaxine, 150 mg daily. Her medical history included four left knee surgeries, a right parotid gland excision, hysterectomy, and tonsillectomy. She worked in customer service and sales and liked her job very much.

On the mental status exam, she was alert, fully oriented, neatly dressed, polite; intermittently tearful in relation to the emotionally-charged subject matter being discussed. She and her husband interacted very appropriately. She repeatedly mentioned that she would not feel safe sleeping in our sleep laboratory due to her great fear over the electronic apparatus used during polysomnography (PSG), which most likely reflected episodes of prior abuse with electric devices. And given how there was no suggestion of obstructive sleep apnea (OSA) or another organic sleep disorder that would strongly indicate the need for PSG, we agreed not to pursue PSG.

The recommendation to the referring psychiatrist was a dose reduction of the mirtazapine (and perhaps also a dose reduction of the cyproheptadine), to the extent possible given the status of her major psychiatric disorders, and then consider supplemental topiramate therapy to control the nocturnal urge to eat and thereby lessen the risk for reactivating nocturnal DD events. Also, the continuation of the DD therapy remained an expressed priority.

Case 2 (M.R.)

A 40-year-old Puerto Rican woman presented with her mother for evaluation of amnestic nocturnal wandering spells with incoherence witnessed by her family. During some of these spells, she would cook and eat food in the middle of the night. At times she cut herself a piece of cake, then smeared some of the frosting on her glasses and on the faucet. She also put mashed potatoes in the freezer, put dishes in the washing machine, threw dishes into the sink, put an empty kettle on the stove and then turn on the gas, and also opened doors.

The spells had begun seven months previously, as witnessed by a mental health provider and her family. She would start picking at various objects, become rigid in her neck muscles, her eyes glazed over and would become droopy, and she held her hands in a contorted position, followed by rhythmic movements of her limbs. The spells lasted 10 to 15 minutes before she regained awareness of her environment. At the start of these spells there was an aura of seeing a yellow circle in her visual field, and then she would go to her “private place.” There was no loss of consciousness nor incontinence. She was able to verbalize during these events, but only uttered repetitive single words or short-phrase responses.

There was a history of memory, attention, and concentration problems superimposed on multiple psychiatric disorders, as listed in [Table 1]. She complained of having trouble remembering much of her daily activities, and could not recall what she had done on the previous day. She often felt “confused and foggy.” At times she would leave a room at home only to return to it and not realize that she had performed some tasks or had left some tasks undone. Other episodes observed by her sister and other family members would begin with her feeling an abnormal sensation and then she would dig her heels into the floor and her arms would start shaking, followed by total body shaking without incontinence or tongue biting. She would wander aimlessly around the house during other episodes, without recall.

The patient had just completed a comprehensive neurologic evaluation at our hospital. At the initial neurological consultation for recurrent daytime spells and cognitive impairment, she had presented with a CD-ROM of one of her spells, which was viewed in the clinic. As noted by the neurologist, she was sitting at a table, then closed her eyes and started making very slow rhythmic movements of her hands as if she was plucking at a guitar, sitting otherwise quietly with her eyes closed without apparent vocalization. The impression by the neurologist was that this recorded “spell” did not look at all like seizure activity. Prior EEGs did not find seizure activity, and there was no prior anticonvulsant medication therapy, apart from taking topiramate for mood stabilization.

The results of the neurological exam were as follows: body mass index (BMI): 26.6 kg/m². Well groomed, flat affect, responded to most questions in a very quiet matter-of-fact fashion. Mini Mental State Exam score: 28/30. Conclusion: normal exam. The results of a brain magnetic resonance imaging (MRI) scan were non-contributory. The recommendation was for inpatient video-EEG monitoring and neuropsychometric testing. Prolonged video-EEG monitoring documented two quite similar spells arising from her normal waking low-voltage fast frequency EEG pattern (details provided in the Appendix 1). The conclusion was that these were non-epileptic spells. Neuropsychological testing identified an amnestic disorder not otherwise specified (NOS), not a cognitive disorder, most likely due to PTSD (the full results of this testing are in Appendix 1). Therefore, no underlying neurological disorder was found to be responsible for the recurrent spells.

She was then referred for a sleep and psychiatric consultation with the author. [Table 1] summarizes her complex psychiatric history, along with pertinent information about her spells. She had been recently hospitalized for severe depression and suicidal ideation. However, there was no history of suicide attempt, nor of alcohol or drug abuse. Her medical history included morbid obesity with bariatric surgery (followed by a 45-kg weight loss), with subsequent recurrent partial bowel obstructions, hysterectomy, 7 surgeries for polycystic ovaries, asthma, type-2 diabetes mellitus (T2DM). Her medications included: pramipexole, 1.5 mg hora somni (HS), quetiapine, 200–300 mg quaque (q) HS and 50 mg q morning (AM), topiramate, 50 mg bis in die (bid), clonazepam, 1 mg bid, bupropion-XL, 150 mg daily, sitagliptin 25 quaque die (qd), esomeprazole, 40 mg bid, albuterol inhaler, Septra DS bid.

The patient wrote in the intake questionnaire: “I don't want to go to sleep, so I avoid it as much as possible. I was abused at night, so I relate that to going to sleep.” The patient clearly had a severe case of sleep phobia related to the extraordinary abuse to which she had been subjected throughout her life, which had begun when she was a child in Puerto Rico. At the age of 5 she started witnessing “with horror” animal sacrifices performed by her biological father and grandmother during Santería rituals. She had been submitted to various other forms of abuse, as described by the patient and her mother, particularly sexual abuse inflicted by her father. Her “sleep phobia” was so severe that “every night I fight going to sleep.” A sister described a spell lasting 20 minutes in which the patient was performing repetitive tasks, wiping everything with a towel, claiming she needed to “get rid of the blood,” apparently referring to the animal sacrifices she had witnessed.

Her dissociative episodes occurred up to several times weekly, and generally lasted less than 10 minutes, with some notable exceptions. Her family all lived in her neighborhood; the mother and sister were her personal care attendants (PCAs), and monitored her movements and activities, and would keep a running log for her. She had been married and divorced 3 times, with no children. After immigrating to the United States, she was a teaching assistant before becoming disabled. She was a talented painter who had exhibited her work in local shows, which was a source of “tremendous personal gratification.”

The results of the mental status exam were as follows: she was alert, cooperative, and pleasant, and interacted well with her mother. Her current psychiatric status was stable. The vPSG was notable for a dissociative episode arising from EEG wakefulness in her sleep laboratory room prior to falling asleep, in which she ate food that she had brought with her, without any subsequent recollection of the eating event (the patient's mother reported similar recurrent eating episodes at home, both before and after going to sleep). The vPSG findings are listed in [Table 2].

Table 2 vPSG and prolonged video-EEG findings.

	Case 1	Case 2
General PSG findings
PSG phobia (due to past abuse with electric devices)	+	−
Total sleep time (in minutes)	N/A	362
Sleep efficiency (%)	N/A	93
Sleep latency (in minutes)	N/A	0
REM sleep latency (in minutes)	N/A	134
N1 sleep (%)	N/A	0.4
N2 sleep (%)	N/A	77.5
N3 sleep (%)	N/A	0
REM sleep (%)	N/A	22.1
PLMS index (in hours of TST)	N/A	0
AHI (in hours of TST)	N/A	2.3
REM-atonia preservation	N/A	+
WASO (in minutes)	N/A	1
vPSG monitoring
Dissociative behaviors with EEG wakefulness during wake-sleep transition at the start of vPSG monitoring	N/A	+
Prolonged video-EEG monitoring
Two dissociative behavioral episodes during EEG wakefulness	N/A	+
Multiple Sleep Latency test (day after vPSG)
Mean sleep latency (in minutes)	N/A	11.7
Number of REM periods	N/A	0

Abbreviations: AHI, apnea-hypopnea index; EEG, electroencephalogram; N/A, not applicable; PLMS, periodic limb movements during sleep; PSG, polysomnography; REM, rapid eye movement; TST, total sleep time; vPSG, video-polysomnography; WASO, wake after sleep onset.

During follow-up appointments, she reported multiple stress-related nocturnal wanderings and other automatic nocturnal behaviors of which she was not aware, including getting up to cook and eat, as observed by her mother. She also had hit her head, without sequelae, during some of her “sleepwalking” episodes. Also, there were increased PTSD symptoms triggered by her ex-husband's menacing behaviors that caused “dissociative numbness” and “flooding of PTSD symptoms.” She now lived alone, right next door to her parents, “because I want to be independent.” An alarm on her bedroom door was again recommended to protect against nocturnal dissociative episodes, including leaving the house and to prevent her from entering the kitchen to cook. However, she reported not being fully compliant.

She also reported that she had been writing chapters in a journal, which she hoped to convert into a book, on her life experiences with dissociative disorder. She considered this to be a therapeutic process (excerpts from this journal are contained in the Appendix 2). Shortly after our last appointment, the author received a letter from the patient's mother: “My daughter died on the 20th of October in her sleep. We do not know what happened, but we are sure she did not die intentionally. She was looking forward to seeing you on the morning of the 26th [in 2 days].”

Discussion

Both cases satisfy the diagnostic criteria for SRDD that were first established in the ICSD-2.[3] The Montpelier group recently proposed updated diagnostic criteria for SRDD[6] that were congruent with their recent conceptual framework, developed to improve the transdiagnostic homogeneity in future revisions of the ICSD.[10] Both sets of diagnostic criteria for SRDD are presented in [Table 3] for purposes of comparison. Given the framework for diagnostic certainty proposed by the Montpelier criteria,[6] Case 1 can be diagnosed with possible SRDD, and Case 2 can be diagnosed with definite SRDD, as 2 dissociative episodes were recorded during prolonged video-EEG monitoring, and 1 episode was recorded through vPSG just prior to sleep onset.

Table 3 SRDD diagnostic criteria: ICSD-2³ and the Montpelier Updated Criteria[6].

ICSD-2 Diagnostic Criteria
A. A dissociative disorder, fulfilling DSM diagnostic criteria is present and emerges in close association with the main sleep period.
B. One of the following is present:
1) Polysomnography demonstrates a dissociative episode or episodes that emerge during sustained EEG wakefulness, either in the transition from wakefulness to sleep or after an awakening from NREM or REM sleep.
2) In the absence of a polysomnographically-recorded episode of dissociation, the history provided by observers is compelling for an SRDD, particularly if the sleep-related behaviors are similar to observed daytime dissociative behaviors.
C. The sleep disturbance is not better explained by another sleep disorder, medical or neurologic disorder, medication use, or substance use disorder.
Montpelier Updated Diagnostic Criteria
Criterion A: Episode(s) of complex dissociative behaviors that emerge throughout a rest period.[a]
Criterion B: Additional supportive features include episodes of long duration (typically more than 1 hour, although shorter episodes can occur, such as 15–30 minutes), occurrence while awake close to bedtime, self-inflicted injuries or the presence of dissociative symptoms during daytime.
Criterion C: The episodes should be associated with a partial or complete loss of conscious awareness, and with subsequent impaired recall.
Criterion D: A significant distress or functional impairment should be evidenced.
Criterion E: The behaviors should not be better explained by another sleep, medical or psychiatric disorder, medication or substance abuse. However, the presence of another sleep disorder should not automatically exclude the diagnosis, as SRDDs may co-occur with other parasomnias.
Three levels of certainty:
Possible SRDD: when the diagnosis is only based on the clinical evaluation.
Probable SRDD: when typical SRDD episodes are documented by homemade videos and/or when the vPSG shows episodes that do not fully correspond to the clinically-reported manifestations.
Definite SRDD: when the vPSG documents typical episodes of SRDD with sustained EEG wakefulness before, during, and after the event.

Abbreviations: DSM, Diagnostic and Statistical Manual of Mental Disorders; EEG, electroencephalogram; ICSD-2, International Classification of Sleep Disorders, 2nd edition; NREM, non-rapid eye movement; REM, rapid eye movement; SRDD, Sleep-related dissociative disorder; vPSG, video-polysomnography.

Note: ^aIncludes both nocturnal and daytime rest/sleep periods.

The presumed pathophysiology in Case 1 involved priming and triggering factors. This woman was primed for SRDD based on her severe childhood-onset abuse history, including dinner deprivation and wakeful nocturnal eating episodes with her brother. The triggering factor was an increased dose of bedtime mirtazapine, with the possible contribution of starting bedtime cyproheptadine therapy, which apparently triggered the urge for nocturnal eating, which, in turn, triggered nocturnal dissociative episodes in a patient who was strongly predisposed to reenacting the childhood abuse scenarios of nocturnal wandering and eating with her brother after they had been routinely deprived of their supper by their parents. The current nocturnal behaviors were most likely a dissociative disorder, not an NREM parasomnia or another sleep disorder. The observations of her nocturnal behaviors, including her infantile voice and reliving nocturnal eating scenes with her brother, as reported by her husband, provided strong support for SRDD.

Mirtazapine is known to increase appetite and promote weight gain,[11] [12] and there have been two case reports[13] [14] of mirtazapine-induced sleep-related eating disorder (SRED), an NREM parasomnia,[4] in adolescent/young adult females–including one case in which a dose increase of mirtazapine induced SRED,[14] similar to Case 1, in which nocturnal eating was triggered by a dose increase of bedtime mirtazapine. In the first reported case, a dose reduction of mirtazapine did not ameliorate the SRED, which promptly ceased when mirtazapine was discontinued.[13] In the second reported case, a dose reduction of mirtazapine ameliorated the SRED.[14] Therefore, mirtazapine-induced SRED may or may not be dose-dependent.

Moreover, in a PubMed search, the literature on cyproheptadine increasing appetite and inducing weight gain in adults is limited to patients who are underweight and those with various medical disorders (and anorexia nervosa) manifesting with anorexia and weight loss. This part of the literature is not relevant to Case 1, so cyproheptadine appears unlikely to have contributed to her nocturnal eating episodes.

However, it is unlikely that the patient described in Case 1 had a NREM parasomnia that involved an eating disorder (SRED), given how she was enacting prior abuse scenarios during her nocturnal eating episodes, with an infantile voice, as witnessed by her husband, and by how she reported immediately after these episodes that she was surprised at being with her husband rather than being back at her childhood home eating at night with her brother. Also, she would push against a glass door as she did during her childhood, along with other non-eating behaviors during her nocturnal episodes. However, it remains a remote possibility that she had recurrent dissociative episodes within SRED episodes (as a novel form of parasomnia overlap disorder[4]), but this has never been reported. A vPSG examination may have provided some clues about this remote diagnostic possibility. However, she was extremely reluctant to undergo a vPSG evaluation. Moreover, she had no history of parasomnias, and a de novo NREM parasomnia in a patient older than 50 years of age is quite uncommon. Furthermore, support for the diagnosis of SRDD with eating behavior comes from a published case[15] of dissociative disorder in a female patient who was found to have a “sleepwalking” alter personality with nocturnal binging of high-caloric sweets.

Case 1 displayed infantile speech during her nocturnal episodes of SRDD, which has previously been reported regarding SRDD,[1] [2] along with two additional cases of SRDD with prolonged and complex nocturnal wanderings associated with the emergence of child alter personalities as abreactions of childhood traumas.[16] In addition, infantile speech has been reported in cases of sleep-related sexual seizures.[17] Moreover, to our knowledge, infantile speech has not been reported in adults with NREM parasomnias, which further supports the diagnosis of SRDD in Case 1.

Regarding Case 2, stage N3 sleep of 0% during vPSG speaks strongly against a NREM parasomnia, although some patients with NREM parasomnia can have episodes arise from N2, but usually in the context of most episodes arising from N3. There was minimal evidence of a “first-night effect” with vPSG, with 0 minute sleep latency, 93% sleep efficiency, 0.4% N1 sleep, 1 minute wake after sleep onset (WASO), and only 2 brief awakenings. The delayed REM-latency was probably an effect of medication. Also, the semiology of her nocturnal episodes closely matched the semiology of her daytime episodes, as witnessed by multiple family members during many episodes. It should also be noted that her behaviors during some of the nocturnal episodes are indistinguishable from sleepwalking behaviors with identical semiology (such as putting mashed potatoes in the freezer, putting dishes in the washing machine, throwing dishes into the sink, putting an empty kettle on the stove and turning on the gas, opening doors etc.), clearly indicating how SRDD should be part of the differential diagnosis of sleepwalking and vice versa. A recently published case of SRDD[18] illustrates this point:

A 26-year-old married woman was evaluated at a sleep center after her 28-year-old husband was initially evaluated by the same sleep physician on account of his wife telling him that he was beating her during sleep, of which he had no memory. These episodes of sleep violence had begun five years previously, around the time they were married. She would awaken with bruises, and once she awakened with a rope wrapped around her wrist. She complained that he would be “angry and aggressive” during these episodes that lasted 2 to 15 minutes. He had no history of parasomnia; nevertheless, he surmised that he must have been beating his wife, which prompted his original presentation for a sleep evaluation. However, the husband videotaped himself sleeping with his wife, and recorded episodes of the wife punching herself in the face while apparently asleep. Then, the wife presented for a sleep evaluation. She had a longstanding psychiatric history involving PTSD from childhood emotional, physical, and sexual trauma, and had a recent hospitalization after a suicide attempt by drug overdose. She had prominent amnesia for major life events, such as her wedding, school graduations, and the births of her children. She had had episodes of nocturnal ambulation during adulthood, and her husband observed episodes in which she would act out her dreams while seemingly asleep. She had “struggled” at night to distinguish dreams from reality. She also had similar five-minute dissociative episodes during the daytime. Her psychotherapist also reported dissociative symptoms during sessions.

The patient underwent a prolonged (three day) evaluation at an epilepsy monitoring unit that captured a nonepileptic event of right-hand tremors that generalized to whole body tremors. She had another event that began ten minutes after an awakening from REM sleep in which she swatted the air with her left hand and thrashed about asynchronously. This episode lasted nine minutes with continuous EEG wakefulness. A vPSG examination did not capture any events; her apnea-hypopnea index (AHI) was of 4.2 events/h; a urine drug screen was negative. Thus, this case satisfied the aforementioned updated diagnostic criteria for SRDD (with three levels of certainty)[6] as having definite SRDD.

In conclusion, two cases of SRDD have been documented in females with prominent histories of multimodal abuse, with childhood emotional and food-deprivation abuse in Case 1, and childhood emotional, sexual, and physical abuse in Case 2, and with both patients being affected by prominent phobias, involving “sleep phobia” in Case 2 and electronic phobia preventing PSG monitoring in Case 1. Major findings from the current literature on SRDD have been reinforced, including the predominance of the female gender, with additional findings being described, particularly nocturnal eating behaviors. Furthermore, the major burden on the spouse and other family members to ensure the safety of patients during their high-frequency SRDD episodes by means of elaborate precautions and constant monitoring is emphasized with these two cases.

Conflict of Interests

The author has no conflict of interests to declare.

Acknowledgments

Case 1:

Kevin A. O'Connor, MD, referred the patient to the author from his private psychiatric practice.

Case 2:

Todd M. Greatens, MD (former sleep medicine fellow at the author's center), Central Minnesota Sleep Specialists, PLC, Pulmonary and Sleep Medicine, referred the patient to the author.

Barbara K. Patrick, MD, staff neurologist at Hennepin County Medical Center (HCMC), conducted and orchestrated the full neurological evaluation.

Frederick Langendorf, MD, staff neurologist at HCMC and chief of the EEG laboratory, conducted and interpreted the prolonged EEG monitoring.

Scott G. Miller, PsyD, LP, Senior Clinical Neuropsychologist at HCMC, conducted and interpreted the neuropsychological testing.

• References

• 1 Schenck CH, Milner DM, Hurwitz TD, Bundlie SR, Mahowald MW. Dissociative disorders presenting as somnambulism: polysomnographic, video and clinical documentation (8 cases). Dissociation 1989; 2: 194-204
• 2 Schenck CH, Cramer Bornemann M, Kaplish N, Eiser AS. Sleep-related (psychogenic) dissociative disorders as parasomnias associated with a psychiatric disorder: update on reported cases. J Clin Sleep Med 2021; 17 (04) 803-810
• 3 American Academy of Sleep Medicine. International Classification of Sleep Disorders, 2nd Ed.: Diagnostic and Coding Manual. American Academy of Sleep Medicine; 2005
• 4 American Academy of Sleep Medicine. International Classification of Sleep Disorders-Third Edition (ICSD-3). American Academy of Sleep Medicine; 2014
• 5 American Psychiatric Association. The Diagnostic and Statistical Manual of Mental Disorders, 5th Ed (DSM-5). APA; 2013
• 6 Lopez R, Lefevre L, Barateau L, Micoulaud-Franchi J-A, Dauvilliers Y, Schenck CH. A series of 8 cases of sleep-related psychogenic dissociative disorders and proposed updated diagnostic criteria. J Clin Sleep Med 2022; 18 (02) 563-573
• 7 Schenck CH, Mahowald MW. Parasomnias associated with sleep-disordered breathing and its therapy, including sexsomnia as a recently recognized parasomnia. Somnology. 2008; 12: 38-49
• 8 Dumitrascu O, Schenck CH, Applebee G, Attarian H. Parasomnia overlap disorder: a distinct pathophysiologic entity or a variant of rapid eye movement sleep behavior disorder? A case series. Sleep Med 2013; 14 (11) 1217-1220
• 9 Eiser AS. Sleep-related dissociative disorders. In: Kushida CA. Ed. Encyclopedia of Sleep and Circadian Rhythms, Second Edition (SLS2), vol. 5. Elsevier, Academic Press; 2023: 117-122
• 10 Gauld C, Lopez R, Geoffroy PA. et al. A systematic analysis of ICSD-3 diagnostic criteria and proposal for further structured iteration. Sleep Med Rev 2021; 58: 101439 DOI: 10.1016/j.smrv.2021.101439.
• 11 Uguz F, Sahingoz M, Gungor B, Aksoy F, Askin R. Weight gain and associated factors in patients using newer antidepressant drugs. Gen Hosp Psychiatry 2015; 37 (01) 46-48
• 12 Gill H, Gill B, El-Halabi S. et al. Antidepressant Medications and Weight Change: A Narrative Review. Obesity (Silver Spring) 2020; 28 (11) 2064-2072
• 13 Jeong JH, Bahk WM. Sleep-related eating disorder associated with mirtazapine. J Clin Psychopharmacol 2014; 34 (06) 752-753 DOI: 10.1097/JCP.0000000000000216.
• 14 Shinith D, Mathilakath A, Kim DI, Patel B. Sleep-related eating disorder with mirtazapine. BMJ Case Rep 2018; 2018: bcr2018224676 DOI: 10.1136/bcr-2018-224676.
• 15 Coons PM, Bowman ES. Dissociation and eating. Am J Psychiatry 1993; 150 (01) 171-172
• 16 Putnam FW. Diagnosis and treatment of multiple personality disorder. New York: The Guilford Press; 1989
• 17 Voges BR, Schmitt FC, House PM, Stodieck SR, Schenck CH. Complex sexual behaviors during sleep as a manifestation of epilepsy: a case series. Sleep 2019; 42 (03) zsy233 DOI: 10.1093/sleep/zsy233.
• 18 Stahl SM, Bodkin C. Parasomnias in Women. In: Khan SS, Khawaja IS. eds. A Clinical Casebook of Sleep Disorders in Women. Springer Nature, Switzerland AG; 2023: 129-135

Publication History

Received: 17 April 2023

Accepted: 22 September 2023

Article published online:
10 May 2024