What is idiopathic generalised tremor syndrome?

Idiopathic generalised tremor syndrome is a fairly common disorder of acute onset whole body tremors. This syndrome is also known as corticosteroid responsive tremor syndrome or “white shaker syndrome”. This syndrome acquired its “white shaker syndrome” name due to its description in dogs with white coat, however this is commonly seen in small and young dogs, of any breed or coat colour.

What causes idiopathic generalised tremor syndrome?

Historically, due to these dogs responding positively to immunosuppressive treatments, it is suggested that it is an autoimmune inflammatory condition. Some studies looking at the brain under the microscope showed mild inflammation of the meninges, brain, and spinal cord (meningoencephalomyelitis), diffusely affecting the central nervous system, but especially the cerebellum (back of the brain).

What are the clinical signs?

This condition is rarely incapacitating, and the clinical signs are often associated with a disease process affecting the back of the brain, namely the cerebellum and the balance centres of the brainstem.

Neurological signs include generalised cerebellar ataxia and hypermetria (high stepping gait) and intention tremors (tremors when performing intentioned actions); these tremors tend to markedly subside when at rest or sleeping. Occasionally, dogs may have increased body temperature (hyperthermia) secondary to the constant generalised tremors. Other clinical signs may include decreased menace responses, head tilt, nystagmus (side-to-side flickering of the eyes) or occasionally opsoclonus (erratic eye movements), and epileptic seizure activity.

How do we investigate it?

Idiopathic generalised tremor syndrome is often suspected at the time of consultation and after performing a complete neurological examination. However, it is extremely important to rule out other debilitating conditions, which include other forms of inflammation of the brain, infections, intoxications or even metabolic (whole body) conditions that may mimic generalised body tremors.

For this, extensive blood tests (including toxin and infection testing), magnetic resonance imaging (MRI) and spinal fluid collection will be conducted. At Southfields, we can provide all these examinations and tests under the same roof, allowing a fast and accurate diagnosis.

What treatment is required?

After excluding other conditions that may mimic idiopathic generalised tremor syndrome, then treatment consists of immunosuppressive medications, often associated with diazepam. It is important that this is guided by an experienced neurologist, to make sure that the treatment is the most adequate, as otherwise this can be detrimental.

What is the prognosis?

The majority of dogs (approximately 80%) will respond to treatment within the first 3 days and tapering of the medication can last several months. Additionally, there are recent articles suggesting that around 20% of patients may have a relapse in their clinical signs, and that about 10% of dogs may experience persistent mild clinical signs, for which they may require life-long medications.

Your primary veterinary surgeon and veterinary neurologist will be able to discuss in more detail with you to assist you should your dog be suffering from idiopathic generalised tremor syndrome.