Familial nocturnal facio-mandibular myoclonus mimicking sleep bruxism

A rare case of tongue biting during sleep in childhood

Bleeding tongue-biting episodes during sleep are a rare and alarming situation that can negatively impact the child's and parents' sleep, affecting their quality of life. Although highly suggestive of epilepsy, a differential diagnosis should be made with sleep-related movement disorders such as bruxism, hypnic myoclonus, facio-mandibular myoclonus, and geniospasm when this hypothesis is excluded. The clinical history, electroencephalogram, and video-polysomnography are essential for diagnostic assessment. Treatment with clonazepam can be necessary in the presence of frequent tongue biting that causes severe injuries and sleep disturbance. This study reports the challenging case of managing and diagnosing a 2-year-old boy with recurrent tongue biting during sleep since he was 12 months old, causing bleeding lacerations, frequent awakenings, and significant sleep impairment with daytime consequences for him and his family.

CITATION

Cascais I, Ashworth J, Ribeiro L, Freitas J, Rios M. A rare case of tongue biting during sleep in childhood. J Clin Sleep Med. 2024;20(4):653-656.

Sleep bruxism: The past, the present, and the future-evolution of a concept

BACKGROUND

The concept of sleep bruxism (SB) has evolved exponentially over the past several decades. Many theories and hypotheses have been proposed as to the definition, pathophysiology, and management of SB, from the early 1960s through the present. The role of peripheral factors, such as dental occlusion, in the pathogenesis of SB has been discarded.

TYPES OF STUDIES REVIEWED

The authors searched several electronic databases (ie, PubMed, Google Scholar, Web of Science, Embase, and Ovid MEDLINE) for studies on bruxism. The search was conducted from January 1961 through May 2023 and yielded 4,612 articles, of which 312 were selected for comprehensive review after eliminating duplicates and nonfocused articles.

RESULTS

There has been an evident progressive shift from the role of peripheral factors, such as dental occlusion, to more central factors, such as the involvement of a central pattern generator as well as the autonomic nervous system, in the genesis of bruxing movements. There is continued robust interest in the dental community to elucidate the contributing factors involved in SB.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The neurophysiology of SB appears to be leaning more toward central rather than peripheral factors. There is increasing evidence of the role of the autonomic nervous system, genetics, and comorbidities in the genesis of SB. The scientific literature seems to refute the role of dental occlusion in the causation of bruxing movements. As per the literature, there has been a paradigm shift in the definition and genesis of SB and its possible dental implications and management, which also highlights the need for succinct scientific studies in this regard.

Tongue Biting Event in Patients with Sleep-Related Facial Mandibular Myoclonus: A Case Series Study

Background

Sleep-related facial mandibular myoclonus (SRFMM) remains rare in clinical practice. The aim of this study was to provide a comprehensive understanding of the electroclinical manner, therapeutic regimen, and prognosis of SRFMM.

Methods

Twenty-three patients who were diagnosed with SRFMM by clinical manifestation, video-electroencephalography (EEG) and electromyography over bilateral masseter and temporalis muscles were enrolled. Clinical and electrophysiological evaluation as well as follow-up information were recorded and analyzed.

Results

The cohort involved 4 infants and 19 adults with a mean onset age of 43.5 years for SRFMM, among whom 19 were male. Twenty-one patients complained of tongue injuries and disturbed night-time sleep. SRFMM in 4 patients were ascribed to oral aripiprazole, brainstem ischemia and brain trauma. In 62 SRFMM episodes, 93.5% occurred in NREM sleep and 6.5% in REM sleep, and all events were associated with EEG arousals. In 13 patients with or without clonazepam, the motor events gradually disappeared, and the rest turned to be sporadic.

Conclusion

SRFMM is a characteristic parasomnia manifested by tongue biting and accompanying facial mandibular myoclonus, leading to disrupted sleep. Besides adults, infants can also experience SRFMM with spontaneous remission. Most patients respond well to clonazepam, eventually with favorable prognosis.

Effectiveness of bruxism treatment in young adults

OBJECTIVE

Aim: This study aimed to assess the effectiveness of the developed algorithm for treatment and prevention measures aimed at eliminating clinical manifestations of bruxism in young people.

PATIENTS AND METHODS

Materials and Methods: A cohort of 377 individuals aged 25 to 44 years underwent examination. Based on identified etiological factors, three distinct groups were delineated. Treatment and preventive strategies were then implemented and evaluated. Tailored treatment algorithms were devised for each group: Group one received selective grinding of supracontacts (up to 0.5-0.75 mm) and treatment for orthodontic issues utilizing removable and fixed orthodontic structures. Group two underwent finger self-massage of masticatory muscles, fabrication of biting dental splints, and anti-inflammatory drug therapy. Group three received sedative drug therapy in conjunction with psychiatric consultation, based on indications. Treatment efficacy was assessed 12 months post-initiation. Statistical analyses were conducted using Statistica 10.0 (StatSoft, Inc., USA) and Microsoft Office Excel 2010.

RESULTS

Results: In cases where orthodontic pathology and supracontacts predominated (r=0.99, p<0.05), employing selective grinding and orthodontic treatment according to specific indications yielded significant efficacy. This approach resulted in a notable reduction in bruxism severity, corroborated by occludogram results 12 months post-treatment initiation. Notably, 90.0% of occludogram indicators fell within the 90-100% range, accompanied by a decrease in the BruxChecker abrasion facets area (p<0.05). Further, there was a substantial enhancement in occlusal contacts (Ck=0.68, Ck =0.71, Ck =0.93). In instances where TMJ pathology predominated with high reliability (r=0.98, p<0.05), effective normalization of masticatory muscle tone and alleviation of temporomandibular joint issues were observed. After 12 months, palpation revealed minimal tenderness in specific muscle areas and normalization of electromyography readings from initial indicators (p<0.05). Moreover, when the psycho-emotional factor primarily contributed to bruxism etiology (r=0.97, p<0.05), medical intervention proved effective. This approach led to bruxism disappearance and normalization of the psycho-emotional state within 12 months (p<0.05).

CONCLUSION

Conclusions: The conducted studies provide high-confidence evidence of the effectiveness of bruxism treatment when diagnosing the prevailing etiological factor and targeting its specific impact, leading to the normalization of all other factors, a reduction in bruxism intensity, and its complete disappearance.

Sleep Disorders: Is the Trigemino-Cardiac Reflex a Missing Link?

Trigeminal innervated areas in face, nasolacrimal, and nasal mucosa can produce a wide array of cardiorespiratory manifestations that include apnea, bradypnea, bradycardia, hypotension, and arrhythmias. This reflex is a well-known entity called "trigemino-cardiac reflex" (TCR). The role of TCR is investigated in various pathophysiological conditions especially in neurosurgical, but also skull base surgery procedures. Additionally, its significance in various sleep-related disorders has also been highlighted recently. Though, the role of diving reflex, a subtype of TCR, has been extensively investigated in sudden infant death syndrome. The data related to other sleep disorders including obstructive sleep apnea, bruxism is very limited and thus, this mini review aims to investigate the possible role and correlation of TCR in causing such sleep abnormalities.

Sleep-related movement disorders

Several movement disorders may occur during nocturnal rest disrupting sleep. A part of these complaints is characterized by relatively simple, non-purposeful and usually stereotyped movements. The last version of the International Classification of Sleep Disorders includes these clinical conditions (i.e. restless legs syndrome, periodic limb movement disorder, sleep-related leg cramps, sleep-related bruxism and sleep-related rhythmic movement disorder) under the category entitled sleep-related movement disorders. Moreover, apparently physiological movements (e.g. alternating leg muscle activation and excessive hypnic fragmentary myoclonus) can show a high frequency and severity impairing sleep quality. Clinical and, in specific cases, neurophysiological assessments are required to detect the presence of nocturnal movement complaints. Patients reporting poor sleep due to these abnormal movements should undergo non-pharmacological or pharmacological treatments.

Sleep-related faciomandibular myoclonus: A sleep-related movement disorder different from bruxism

We describe a 33-year-old man who presented with lip and tongue nibbling and bleeding during sleep. Videopolysomnography revealed myoclonic jerks involving the masticatory and facial muscles recurring mainly during NREM sleep. There was no tonic EMG masticatory activity typical of bruxism. EMG analysis demonstrated the recruitment of V- to VII innervated muscles and, in half of the episodes, also the sternocleidomastoideus. Our patient had sleep-related faciomandibular myoclonus (SFMM) with spontaneous jerks of oromasticatory and cervical muscles, occurring only during sleep. Tooth grinding, temporomandibular joint pain, abnormal tooth mobility, tooth wear, and other dental problems were clinically absent. We propose that, on the basis of the clinical and EMG features, SFMM may be considered a distinct disorder and different from sleep bruxism.

Movement disorders in sleep: guidelines for differentiating epileptic from non-epileptic motor phenomena arising from sleep

Seizures, namely in certain epileptic conditions, may be precipitated by sleep. Nocturnal frontal lobe epilepsy seizures, characterized by bizarre motor behaviour and autonomic activation, appear almost exclusively during sleep. The differential diagnosis between this condition and sleep-related non-epileptic paroxysmal motor phenomena, in particular the parasomnias, is arduous. Moreover, accepted criteria for the diagnosis of nocturnal frontal lobe seizures are lacking and even ictal scalp EEG recording could fail to disclose paroxysmal abnormalities. The clinical and polygraphic features of the different types of seizures in nocturnal frontal lobe epilepsy and of the more common non-epileptic paroxysmal events during sleep are described. The main differentiating features characterizing nocturnal frontal seizures are: onset at any age, several attacks per night at any time during the night, brief duration (s) with stereotyped motor pattern. As video-polysomnographic recordings of the attack, the gold-standard for diagnosis, are expensive and not readily available everywhere, home-made video recordings may be helpful. Further investigations on pathophysiology, genetics and epidemiology are needed to clarify the relationship between epileptic and non-epileptic sleep related paroxysmal phenomena.

Paroxysmal Motor Disorders of Sleep: The Clinical Spectrum and Differentiation from Epilepsy

The diagnosis of paroxysmal events in sleep represents a significant challenge for the clinician, with the distinction of nocturnal epilepsy from nonepileptic sleep disorders often the primary concern. Diagnostic error or uncertainty is not uncommon in this situation, particularly with respect to nocturnal frontal lobe epilepsy (NFLE), which has a variable and often unusual presentation. Such errors can be minimized if the range of nonepileptic disorders with motor activity in sleep is fully appreciated. Here we review these disorders, before discussing the important clinical and electrographic features that allow their accurate differentiation from seizures. Particular emphasis is placed on the differentiation of nocturnal frontal lobe epilepsy from non-rapid eye movement (NREM) arousal disorders and other parasomnias. The value of recording episodes with video EEG polysomnography is discussed.

Non-rapid eye movement sleep parasomnias

Parasomnias are unpleasant or undesirable behavioral or experiential phenomena that occur during sleep. Once believed unitary phenomena related to psychiatric disorders, it is now clear that parasomnias result from several different phenomena and usually are not related to psychiatric conditions. Parasomnias are categorized as primary (disorders of the sleep states) and secondary (disorders of other organ systems that manifest themselves during sleep). Primary sleep parasomnias can be classified according to the sleep state of origin: rapid eye movement sleep, non-rapid eye movement sleep, and miscellaneous (those not respecting sleep state). Secondary sleep parasomnias are classified by the organ system involved.

Rhythmic tongue movements during sleep: A peculiar parasomnia in Costello syndrome

We describe a peculiar parasomnia observed in four Costello infants, characterized by periodic rhythmic movements of the tongue. Ten Costello patients (4 male; age range 9 months to 29 years) underwent 1 full-night laboratory-based video polysomnography. The four youngest patients (2 male and 2 female; age range 9-31 months) presented during sleep repeated stereotyped movements of the tongue, producing a sucking-like or licking-like movement, mostly during non-rapid eye movement (NREM) sleep. Rhythmic tongue movements in Costello syndrome show the features of an NREM sleep parasomnia. Tongue movements during sleep probably originate from brainstem structures and could be facilitated by an impaired control of the oropharyngeal and tongue muscles.