Electroencephalography of rapid eye movement sleep behavior disorder in a dog with generalized tetanus.

CASE SUMMARY: A 3-month-old Airedale dog with clinically diagnosed generalized tetanus was investigated for the occurrence of excessive paddling and chewing movements when sleeping. Electroencephalogram (EEG) with time-locked video over 31 hours determined occurrence of the abnormal movements to be within 20 to 180 seconds of the onset of rapid eye movement (REM) sleep, but not at any other stage of wakefulness or sleep. No epileptiform activity was noted. Clinical signs of generalized tetanus resolved over 8 weeks with antimicrobial and symptomatic treatment, and sleep-associated movements resolved 6 weeks after presentation. CLINICAL RELEVANCE: Rapid eye movement sleep behavior disorder (RBD) has been suspected in dogs with generalized tetanus but not confirmed by correlation of repeated episodes of vocalization or motor behaviors or both with REM sleep defined by an EEG. The case further defines RBD in dogs with tetanus, and highlights the value of EEG to differentiate among different parasomnias and epileptiform activity.

Sleep Disorders in dogs: A Pathophysiological and Clinical Review.

Sleep is a fundamental process in mammals, including domestic dogs. Disturbances in sleep affect physiological functions like cognitive and physical performance, immune response, pain sensation and increase the risk of diseases. In dogs, sleep can be affected by several conditions, with narcolepsy, REM sleep behavior disorder and sleep breathing disorders being the most frequent causes. Furthermore, sleep disturbances can be a symptom of other primary diseases where they can contribute to the worsening of clinical signs. This review describes reciprocally interacting sleep and wakefulness promoting systems and how their dysfunction can explain the pathophysiological mechanisms of sleep disorders. Additionally, this work discusses the clinical characteristics, diagnostic tools and available treatments for these disorders while highlighting areas in where further studies are needed so as to improve their treatment and prevention.

Association between clinically probable REM sleep behavior disorder and tetanus in dogs.

BACKGROUND: Abnormal sleep behavior has been reported in 5 dogs during recovery from tetanus. HYPOTHESIS: REM sleep behavior disorder (RBD) is a more common consequence of tetanus than previously reported in veterinary literature and easily confused for epileptic seizures. ANIMALS: Sixty-one client-owned dogs diagnosed with tetanus at 2 UK referral centers. METHODS: A retrospective review of medical records was combined with a questionnaire sent to owners of surviving dogs, to identify cases that developed clinically probable RBD and determine its clinical progression and effect on quality of life of affected dogs and their owners. Descriptive statistical evaluation was performed. RESULTS: Eleven dogs (18%) died or were euthanized before discharge. At least 46% surviving dogs developed abnormal "dream enactment" clinically consistent with RBD. Twitching, running, and vocalization were new sleep behaviors in 53, 80, and 60% of affected dogs. Clinically probable RBD was described as violent or "nightmare"-like in 36% affected dogs, and like an epileptic seizure in 40% affected dogs. When trialed, antiepileptic medications were ineffective. Onset occurred before discharge in 25% cases. For dogs that developed clinically probable RBD postdischarge, onset occurred within 2 weeks of discharge in 77% dogs. Clinically probable RBD did not worsen in severity or frequency in any dog, and spontaneously resolved within 6 months in 43% cases. CONCLUSIONS AND CLINICAL IMPORTANCE: Clinically probable RBD is a common sequel to canine tetanus with many clinical similarities to epileptic seizure activity. Owners should be made aware of its potential development and care taken to avoid misdiagnosis with epileptic seizure activity.

Degenerative Encephalopathy in Nova Scotia Duck Tolling Retrievers Presenting with a Rapid Eye Movement Sleep Behavior Disorder.

BACKGROUND: Neurodegenerative diseases are a heterogeneous group of disorders characterized by loss of neurons and are commonly associated with a genetic mutation. HYPOTHESIS/OBJECTIVES: To characterize the clinical and histopathological features of a novel degenerative neurological disease affecting the brain of young adult Nova Scotia Duck Tolling Retrievers (NSDTRs). ANIMALS: Nine, young adult, related NSDTRs were evaluated for neurological dysfunction and rapid eye movement sleep behavior disorder. METHODS: Case series review. RESULTS: Clinical signs of neurological dysfunction began between 2 months and 5 years of age and were progressive in nature. They were characterized by episodes of marked movements during sleep, increased anxiety, noise phobia, and gait abnormalities. Magnetic resonance imaging documented symmetrical, progressively increasing, T2-weighted image intensity, predominantly within the caudate nuclei, consistent with necrosis secondary to gray matter degeneration. Abnormalities were not detected on clinicopathological analysis of blood and cerebrospinal fluid, infectious disease screening or urine metabolite screening in most cases. Postmortem examination of brain tissue identified symmetrical malacia of the caudate nuclei and axonal dystrophy within the brainstem and spinal cord. Genealogical analysis supports an autosomal recessive mode of inheritance. CONCLUSIONS AND CLINICAL IMPORTANCE: A degenerative encephalopathy was identified in young adult NSDTRs consistent with a hereditary disease. The prognosis is guarded due to the progressive nature of the disease, which is minimally responsive to empirical treatment.

Clinical characteristics, management and long-term outcome of suspected rapid eye movement sleep behaviour disorder in 14 dogs.

OBJECTIVE: To describe the clinical characteristics, management and long-term outcome in dogs with suspected rapid eye movement sleep behaviour disorder. METHOD: Medical records and video recordings of 14 dogs with suspected rapid eye movement sleep behaviour disorder were reviewed and the owners were contacted via telephone or email for further information. RESULTS: Clinical signs included episodes of violent limb movements, howling, barking, growling, chewing, or biting during sleep. Episodes occurred at night and during daytime naps. The age at onset ranged from 8 weeks to 7·5 years with a median of 6 years but 64% of dogs were one year or less. There was no apparent sex or breed predisposition. Rapid eye movement sleep behaviour disorder events were reduced in severity and frequency in 78% of the dogs treated with 40 mg/kg/day oral potassium bromide. One dog was euthanized within 3 months of the onset of signs because of their severity. The duration of the disorder in the 13 surviving dogs ranged from 1·5 to 9 years. None of the dogs spontaneously recovered. CLINICAL SIGNIFICANCE: Rapid eye movement sleep behaviour disorder is suspected to occur in dogs, as it does in human beings. It causes concern to the owners and disrupts the home environment. Unlike human beings, rapid eye movement sleep behaviour disorder of dogs often has a juvenile onset.