**4.4.3 Bruxism**

Highly co-occurring with other sleep related motor disorders such as PLMD, RLS and RMD, bruxism has also been described in ADHD reports, both subjectively and after PSG confirmation (Silvestri et al., 2009) up to 33% of the studied ADHD sample and with a gender distribution (female prevalence) confirming data in the general population (Hojo et al., 2007).

A dopaminergic dysfunction has already been accounted for this disorder (Lavigne & Montplaisir, 1994) and treated accordingly.

#### **4.5 Parasomnias**

Only few subjective studies report an overall increased number of parasomnias in ADHD children (Owens et al., 2000; Gau, 2006; Kraenz et al., 2004), whereas most studies (Corkum et al., 1999; Mick et al., 2000) notice no difference between ADHD children and controls after accounting for co-morbidity and pharmacotheraphy.

As far as objective studies are concerned, they mostly do not report about parasomnias with few exceptions (Miano et al., 2006), accounting for a maximum of 35% of generic parasomnias overall.

An increased prevalence of sleep talking (O'Brien et al., 2003b; Corkum et al., 1999) and enuresis is reported (O'Brien et al., 2003a; Kaplan et al., 1987; O'Brien et al., 2003c).

As far as REM-related parasomnias are concerned, an increased prevalence of nightmares in ADHD children was reported by three studies (Owens et al., 2000; O'Brien et al., 2003b; 2003c).

Disorders of arousal (DOA), which include sleep walking (SW), night terrors (NT) and confusional arousals (CA), albeit optimal candidates on the basis of familiar predisposition and SDB common association for a possible ADHD co-morbid occurrence have rarely been reported in ADHD subjects.

An early report (Ishii et al., 2003) found an overall low incidence (2.9%) of NT and SW in ADHD children, mean age 9.7 years. Most patients had mild ADHD, all being out-patients studied on the basis of subjective reports with an overall low co-morbidity load compared to Western countries.

On a broader sample of ADHD pediatric subjects, Gau et al. (2007) found an OR of 2.4 (95% CI 1.3-4.5) among subjects with definite ADHD, and 1.8 in probably ADHD probands (95% CI 1.4-2.3) between NT and inattention, with lower OR values between NT and hyperactivity. Similar results, not as strong, were reported for SW.

As a result of low CAP with decreased A1 sequences (Miano et al., 2006) suggested a possible disorder of arousal with a tendency to hypoarousability in their ADHD children who had otherwise no SDB nor other objectively identified sleep disorders.

On clinical interview Silvestri et al. (2009) found a 50% prevalence of DOA in a group of 55 ADHD children (28.5% CA, 47.6% SW, 38% NT), whereas on PSG, CA were recorded in 45.2% of their patients, SW in 2.3% and NT in 4.7%.

A percentage (21.8) similar to that of RLS (25.4) was reported in a group of 55 unmedicated ADHD children evaluated by means of PSG (Silvestri et al., 2009) co-occurring with other sleep related movement disoders, in particular PLMD and bruxism, but not SDB, at odds

A functional impairment of the pre-motor and striatal circuitry akin to that responsible for

Highly co-occurring with other sleep related motor disorders such as PLMD, RLS and RMD, bruxism has also been described in ADHD reports, both subjectively and after PSG confirmation (Silvestri et al., 2009) up to 33% of the studied ADHD sample and with a gender distribution (female prevalence) confirming data in the general population (Hojo et

A dopaminergic dysfunction has already been accounted for this disorder (Lavigne &

Only few subjective studies report an overall increased number of parasomnias in ADHD children (Owens et al., 2000; Gau, 2006; Kraenz et al., 2004), whereas most studies (Corkum et al., 1999; Mick et al., 2000) notice no difference between ADHD children and controls after

As far as objective studies are concerned, they mostly do not report about parasomnias with few exceptions (Miano et al., 2006), accounting for a maximum of 35% of generic

An increased prevalence of sleep talking (O'Brien et al., 2003b; Corkum et al., 1999) and

As far as REM-related parasomnias are concerned, an increased prevalence of nightmares in ADHD children was reported by three studies (Owens et al., 2000; O'Brien et al., 2003b; 2003c). Disorders of arousal (DOA), which include sleep walking (SW), night terrors (NT) and confusional arousals (CA), albeit optimal candidates on the basis of familiar predisposition and SDB common association for a possible ADHD co-morbid occurrence have rarely been

An early report (Ishii et al., 2003) found an overall low incidence (2.9%) of NT and SW in ADHD children, mean age 9.7 years. Most patients had mild ADHD, all being out-patients studied on the basis of subjective reports with an overall low co-morbidity load compared to

On a broader sample of ADHD pediatric subjects, Gau et al. (2007) found an OR of 2.4 (95% CI 1.3-4.5) among subjects with definite ADHD, and 1.8 in probably ADHD probands (95% CI 1.4-2.3) between NT and inattention, with lower OR values between NT and

As a result of low CAP with decreased A1 sequences (Miano et al., 2006) suggested a possible disorder of arousal with a tendency to hypoarousability in their ADHD children

On clinical interview Silvestri et al. (2009) found a 50% prevalence of DOA in a group of 55 ADHD children (28.5% CA, 47.6% SW, 38% NT), whereas on PSG, CA were recorded in

hyperactivity. Similar results, not as strong, were reported for SW.

45.2% of their patients, SW in 2.3% and NT in 4.7%.

who had otherwise no SDB nor other objectively identified sleep disorders.

enuresis is reported (O'Brien et al., 2003a; Kaplan et al., 1987; O'Brien et al., 2003c).

with previous records (Mayer et al., 2007).

Montplaisir, 1994) and treated accordingly.

accounting for co-morbidity and pharmacotheraphy.

**4.4.3 Bruxism** 

al., 2007).

**4.5 Parasomnias** 

parasomnias overall.

reported in ADHD subjects.

Western countries.

RLS could be hypothesized as a link between RMD and ADHD.

One patient reporting both dream enactment and SW episodes had a PSG evidence of CAs and REM without atonia, thus matching criteria for parasomnia overall disorder according to the International Classification of Sleep Disorders (ICSD-2).

Interictal epileptic discharges (IEDs), mostly on centro-temporal or frontal leads were seen in >50% of these unmedicated ADHD subjects and among them, in >40% of the DOA+ children, with nocturnal hypermotor seizures occurring in three children, none of which had ever presented evidence of diurnal paroxysmal disorders.

Complex behaviors during the DOA episodes were, however, easy to distinguish from nocturnal seizures in these children, even when co-occurring with IEDs.

Vulnerability of ADHD children to rolandinc seizures and foci is well known (Holtmann et al., 2003), along with an increased rate of DOA in patients with benign focal epilepsy of childhood.

A positive significant association of DOA with SDB in the form of snoring and with increased sleep instability was also described by the same authors (Silvestri et al., 2009), akin to previous reports emphasizing the same associations (Lopes & Guilleminault, 2006; Guilleminault et al., 2005).

A preferential impact on the cognitive domain rather than behavioral indicators is most typical of children with DOA and slow wave sleep (SWS) dysfunction, opposite to the effect of nocturnal hyperactivity which seems to preferentially influence daytime hyperactivity and oppositional behaviors.

Levitiracetam 750-1000 mg/day effectively controlled seizures and lead to total cessation of DOA with a >50% reduction of IEDs during a follow-up period of 24 months (Walters et al., 2008).
