A seizure response dog: video recording of reacting behaviour during repetitive prolonged seizures

ARTICLE

Auteur(s) : Lidia Di Vito, Ilaria Naldi, Barbara Mostacci, Laura Licchetta, Francesca Bisulli, Paolo Tinuper

Department of Neurological Sciences, University of Bologna, Bologna, Italy

Article reçu le 22 Decembre 2009, accepté le 2 Avril 2010

Seizure-related behaviour has been documented in dog companions of humans with epilepsy. A “seizure response” dog (SRD) presents specific behaviour during or immediately after a seizure (Kirton et al., 2004), whereas a “seizure alerting” dog (SAD) demonstrates specific behaviour prior to the clinical onset of a human's seizure, alerting the person to the impending event (Dalziel et al., 2003). Seizure response and seizure alerting behaviour may spontaneously develop in dogs living with children and adults with epilepsy (Dalziel et al., 2003; Kirton et al., 2004). Some dogs can also be reliably trained to respond to and anticipate seizures (Kirton et al., 2008; Strong et al., 1999).

This report briefly reviews the main studies conducted on seizure dogs (SD) (table 1). In addition, we present, for the first time, a home video of a dog who spontaneously developed complex seizure response behaviour recorded during its owner's seizure (see video sequences).

Case study

At present, the type of seizures initially reported occur only a few times a year while the patient continues to experience the stereotyped “absence-like” seizures that may differ in length and intensity, usually in daily clusters lasting several minutes. Her current treatment is lamotrigine, valproic acid and rufinamide. A recent neuropsychological examination disclosed severe mental retardation (MMSE score 15/30).

EEG recording performed over the years constantly showed almost continuous spikes and waves or slow wave activity at about 3.5 Hertz, diffuse over both hemispheres with anterior predominance. Video-polygraphic recording of an episode of epileptic status showed almost continuous activity of generalised spikes and waves at about 3.5 Hertz, sometimes intermingled with brief periods of slow activity. These discharges were associated with clinical manifestations consisting of loss of contact and eyelid myoclonias (figure 1).

Cerebral MRI showed atrophy of the cerebellar hemispheres and a bilateral expansion of subarachnoid spaces close to the hemispheric convexity.

The patient's pet was a 10-year-old male Yorkshire terrier, not trained for assistance work. The dog entered the patient's family in March 1998 at the age of four months. At that time, the patient was 37 years old and she experienced daily clusters of seizures. After a few months of living with her, at the age of one year, the dog spontaneously developed specific behaviour related to seizures. At the very beginning of the seizure, the dog would alert the patient's parents by running to them barking and then going back to the patient. After this phase, as shown in the videos, the dog developed “protective” behaviour during the seizure which involved barking and not allowing anybody to touch the patient, jumping on her legs and stopping her from standing up. The dog tried to stimulate the patient by gently biting her feet or licking her feet or ears (see video sequences). The dog remained close to the patient during the seizure and afterwards usually calmed down and often fell asleep close to its owner. When present, the dog behaved consistently during all of the patient's seizures, without exception, showing the same response in all cases and also during both types of seizures.
Table 1 Review of the main studies on SD.

Discussion

Here we present a home video showing seizure response behaviour in a dog, not previously trained for assistance work. The dog showed the most common behaviour described for trained or untrained SRDs such as barking, jumping, licking the face, and close physical attachment to the owner (Kirton et al., 2004; Kirton et al., 2008).

Previous reports describe the development of seizure alerting behaviour in dogs trained as SRDs (Kirton et al., 2008) or SADs (Strong et al., 2002) or spontaneous development in dogs living with epileptic patients (Kirton et al., 2004). However, some authors have questioned the ability of seizure dogs to predict seizures and distinguish between seizures and pseudo-seizures in patients who present both. They also argue that SAD alerting behaviour may help promote the onset of pseudo-seizures, questioning the ability of SADs to identify seizures (Ortiz and Liporace, 2005; Krauss et al., 2007; Doherty and Haltiner, 2007). Further studies are necessary to obtain thorough assessments of patients’ seizures and also video-EEG recording to exclude the presence of psychogenic-seizures and document the epileptic nature of prolonged seizures without a predominant motor component, as in our patient.

Our patient's seizures recorded in the home videos were the same as those recorded in the EEG laboratory with an EEG tracing similar to that depicted in figure 1. Our patient never presented pseudo-seizures. Moreover the dog in our case developed a response behaviour after a few months living with the patient and was able to recognize the seizure at onset but never developed an alerting behaviour.

Some authors argue that owning untrained dogs can represent an inherent danger for human health, referring to cases of dogs exhibiting aggressive behaviour towards humans during seizures. However they suggest that these adverse reactions have not been seen in dogs especially trained as SADs (Strong and Brown, 2000).

In contrast to these findings, Kirton et al. (2004) conducted a study on untrained SADs and SRDs living with epileptic children, showing a “protective“ behaviour towards patients in which no instances of aggression or harm were ever reported (Kirton et al., 2004). In agreement with Kirton et al., the dog in our case never exhibited any potentially dangerous behaviour, even though it appeared anxious during its owner's seizures and tried to stimulate and protect the patient by jumping on her, nibbling her feet and barking at bystanders. Over the years the pet has never hurt or harmed either the patient or her caregivers and the patient's parents feel completely comfortable leaving their daughter with the dog during her seizures.

A prospective study conducted by Strong et al. (2002) on trained SADs demonstrated that owning these dogs may decrease patient seizure frequency. In our case, the patient's family observed a decrease in seizure intensity and frequency since the dog's arrival. However, this benefit cannot be attributed solely to the dog as some therapeutic adjustments were also made during recent years.

A formal evaluation of an SRD training program suggests that epileptic patients owning an SRD may have significant benefits in quality of life (Kirton et al., 2008). According to these results, living with an SRD has improved our patient's quality of life, increasing her self-confidence and independence, enhancing interpersonal interactions and helping attenuate her anxiety with a greater feeling of security. The SRD has benefited the whole family; even if the patient is not able to leave the house alone, the constant presence of the pet during the seizures makes her parents feel more confident and safe leaving the patient alone at home and helps them to worry less about the seizures. Furthermore, the patient has started new activities which include acting, working with other people and learning to ride a horse.

The possible bias of families to assume positive effects of SRDs on seizures, and the difficulty of assigning the benefits on quality life to the seizure response ability, rather than to pet companionship as emphasized by Kirton et al. (2008), are a major challenge that need to be addressed for future SRD studies.

In conclusion, owning an untrained SRD has certainly improved the quality of life of our patient and her family and may have played a role in reducing seizure frequency and intensity. Prospective studies conducted on a large scale are required to confirm the potential benefits conferred by seizure dogs to epileptic patients and their caregivers.

Legends for video sequences

These are home videos filmed by the patient's parents during two episodes of status epilepticus. The videos show the behaviour of the dog during the episodes. The patient's parents gave their written consent to show the videos.

Acknowledgments

Disclosure.

None of the authors has any conflict of interest to disclose.

References

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