Mechanical neck pain from an upper disc, facet, or musculoligamentous sources may refer to the occiput, but is not classically lancinating or otherwise neuropathic and should not be confused with ON. A crucial step in differentiating ON from other disorders is relief with an occipital nerve block. Epidemiology
In one study investigating the incidence of facial pain in a Dutch population, ON comprised 8.3% of facial pain cases. The total incidence of ON was 3.2 per 100,000 people, with a mean age of diagnosis of 54.1 years. Treatment
There are multiple treatment options for ON. The most conservative treatments, such as immobilization of the neck by the cervical collar, physiotherapy, and cryotherapy have not been shown to perform better than placebo. Non-steroidal anti-inflammatory drugs, tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, and anticonvulsants may help to alleviate symptoms. Following diagnostic nerve blocks, therapeutic blocks may be attempted. Typically, a steroid is added to the local anesthetic with variable results. Botulinum Toxin A injection has emerged as a treatment with a conceptually lower side effect profile than many other techniques described here, with most recent trials demonstrating 50% or more improvement.It remains a common practice to utilize a landmark-only approach when performing greater and lesser occipital nerve blocks. For blockade of both nerves, medication is infiltrated along the nuchal ridge. This technique, while easy to perform and relatively safe if done correctly, may not be particularly accurate and as a result, could theoretically increase the risk of a false-positive result. To improve accuracy, ultrasound-guided techniques were developed.
The typical reaction will be a generalized tremor of the skeletal muscles, and sometimes cardiac arrhythmia. Defecation, urination and eructation are frequent during the treatment, due to pharmacological effect of calcium on the smooth muscles. Prognosis
The prognosis is generally good, even in advanced cases. However, some cows can relapse the following day, and even a third time the day after. Without treatment, between 60% and 80% of cows usually die, although death rates as high as 90% have been recorded. History
It is thought that milk fever has existed for a very long time in dairy cattle. The first reports in veterinary literature can be traced to around 1793. Early Theories
Early treatments involved venesection, but this proved ineffective. Potassium Iodide
In the late 1800s, Jurgens Schmidt proposed the use of an infused solution of potassium iodide for treatment. A follow-up study of this treatment by Danish veterinarians showed that 90% of cows recovered after use of the treatment, compared with only 20-40% survival without. A study in Iowa showed that 76.5% of cows recovered after use of the treatment. However, the premise of the Schmidt treatment was misleading, as later veterinarians used water alone to the same success rate. Udder Inflation
In 1901, Anderson and Evers trialled a treatment of udder inflation with air, which reduced mortality rates to just 1%. although with the added complication of mastitis. Although this was an effective treatment (and is still used as a backup today), it was not understood at the time why it worked, and remains the source of some debate.