The myoclonic seizures often occur in response to visual and auditory stimuli and are characterized by sudden muscular twitching, from jerky head movements to generalized muscle fasciculations that may progress to GTCS.
Myoclonus is characterized by spontaneous onset, rapid eyelid blinking and head nodding, a jerking movement of the head sometimes extending down the thoracic limbs, occasionally involving the whole body and might cause the dog to stumble or fall. There was no apparent loss of consciousness.
Symptoms of Myoclonic Seizures
A person having a myoclonic seizure experiences a sudden increases in muscle tone as if they have been jolted with electricity. The mechanism is similar to a myoclonic jerk, the sudden spasm occasionally experienced by people as they are falling asleep.
Myoclonic (MY-o-KLON-ik) seizures are brief, shock-like jerks of a muscle or a group of muscles. "Myo" means muscle and "clonus" (KLOH-nus) means rapidly alternating contraction and relaxation—jerking or twitching—of a muscle. Usually they don't last more than a second or two.
Muscle spasms can be caused by a variety of conditions, including muscle strains or injuries, neurological disorders, allergies, dehydration, or an adverse response to medication. Seizures may also result in similar tremors, but these are distinguishable from muscle spasms by the fact that they are not localized.
A grand mal seizure is the easiest to spot. This is more generalized and typically affects the entire body. A focal seizure only affects part of the brain and resulting erratic movements can be limited to the face, one side of the body, or one limb.
Treatment Options
If your dog's myoclonic seizures occur infrequently and do not worsen, your veterinarian may not recommend any treatment. Anti-epileptic medications can be prescribed, but they may cause serious side effects, such as liver failure and rear limb weakness.
This type of seizure causes quick jerking movements. Myoclonic seizures often happen in everyday life. This includes hiccups and a sudden jerk while falling asleep. The condition is not epilepsy unless there are more than two seizures happening repeatedly over time.
Episodes of neck myoclonus occur typically during REM sleep; during NREM sleep they are detected very rarely.
Lack of sleep and fatigue, primarily after drinking too much alcohol, are the most powerful causes of myoclonic jerks and generalized tonic-clonic seizures in JME. Mental and emotional stress are also common triggers, especially excitement or frustration.
Lack of motor coordination may occur along with myoclonus, even in the absence of seizures. Mental function may be impaired, leading especially to problems with memory. Depression is not uncommon. It can become severe and should not be left untreated.
Progressive myoclonus epilepsy.
This is a very severe type of epilepsy that worsens over time. It usually involves brain deterioration or damage that also affects memory, muscle control, thinking ability and more. Some forms of this are eventually fatal.
Aura: Minutes before the actual seizure, a period of altered behavior may occur called the aura. This is not always recognizable, but many owners report their dogs may hide, appear anxious, attention seek, or whine just prior to a seizure.
Unfortunately, dogs with severe and chronic myoclonus suffer immensely. Your veterinarian may recommend euthanasia in these cases.
Common breeds that have a higher rate of epilepsy include Beagles, Bernese Mountain Dogs, Border Collies, Boxer Dogs, Cocker Spaniels, Collies, Dachshunds, Golden Retrievers, Irish Setters, Irish Wolfhounds, Keeshonds, Labrador Retrievers, Poodles, St.
Myoclonic seizures
The jerks are usually brief, bilateral, arrhythmic contractions that mainly involve the shoulders and arms. However, some patients report jerking in the lower limbs, trunk, or head. Some jerks occur unilaterally.
Myoclonic seizures usually last for less than a second. However, some people have them in clusters of several seizures over a period of time.
In the majority of cases, myoclonus is caused by harmless and temporary nerve dysfunction, which is self-limiting. Rarely, symptoms are severe, recurrent, and disruptive, in which case a medical evaluation may help discover the underlying cause and guide treatment.
Drugs used to control epileptic seizures may help reduce myoclonus symptoms. The most common anticonvulsants used for myoclonus are levetiracetam (Keppra, Elepsia XR, Spritam), valproic acid, zonisamide (Zonegran, Zonisade) and primidone (Mysoline).
Myoclonic: Short jerking in parts of the body. Clonic: Periods of shaking or jerking parts on the body.
Although myoclonus is usually not curable, it is often manageable with medication and patience. In some cases, the shaking is not medically controllable, and if the patient's quality of life is severely adversely impacted, euthanasia may be recommended.
In older dogs, benign, rapid, postural repetitive myoclonus tremor may occasionally develop in the pelvic limbs. All four limbs are rarely affected. This tremor is evident only when the dog is standing.
Generally speaking, if a dog is having more than two seizures per month, it is considered to be too many and should be investigated by a veterinarian. If a dog is having more frequent seizures, preventative measures such as medication or dietary changes may need to be taken.