Neurological disorders, such as epilepsy, Alzheimer’s disease, Parkinson’s disease, sleep disorders, brain cancer, autism, pain, multiple sclerosis, and various types of headaches, are often insufficiently treatable using pharmacological therapies. To make things worse, lots of medications have side effects. Hence, many patients look for more natural treatments, and luckily, research has begun to support the relationship between diet and various health conditions. In the future, the ketogenic diet could become the “natural” support for treatment for a variety of general health and neurological disorders.
A great example is drug-resistant epilepsy. The ketogenic diet has been successfully used as an epilepsy treatment for decades. Although the mechanisms behind anticonvulsant effects are not yet clear, there have been enough experimental studies carried out to confirm its efficacy.
What About Other Neurological Disorders?
Admittedly, we are still lacking a sufficient amount of clinical data. Still, the literature supporting the broad use of the ketogenic diet and its variants against a variety of neurological conditions has been emerging in the past decades.
Lately, researchers in this field have been identifying mechanisms through which the ketogenic diet may provide neuroprotective activity. They speculate that the main factors for this activity are the ketone body production and the reduction in blood glucose levels.  
Aging and Longevity
Research suggests that the ketogenic diet may slow down some degenerative processes that occur in the aging brain cells. The ketogenic diet is likely to involve some neuroprotective mechanisms, especially in the context of pathological neurodegeneration. For example, studies, conducted on rats, have shown that medium-chain triglycerides (MCT) have a protective effect on some of the age-related intracellular dysfunctions.  
The ketogenic diet might also play a beneficial role in patients with Alzheimer’s disease (AD). So far, clinical studies have demonstrated some promising results. Namely, a certain type of AD patients has shown significant improvement in various memory and learning tasks after being on an MCT ketogenic diet for a while.
What is more, even diets such as the Mediterranean have shown some promise with AD. This suggests there something about a high intake of healthy fats and a low intake of carbohydrates that acts neuroprotective.     
Research suggests that ketone bodies may provide neuroprotective benefits in the case of Parkinson’s disease (PD). By providing the brain with an alternative fuel source (ketone bodies), disrupted glucose uptake can be bypassed. This prevents neuron degradation from starvation and thus helps prevent further motor dysfunctions from motor neuron death.  
If you are familiar with Amyotrophic lateral sclerosis (ALS), you know that it is a rapidly progressive disease that leaves the affected individual profoundly weak despite retained cognitive functioning. Again, animal models of ALS have shown some improvement after administration of the ketogenic diet. However, the survival time was not extended in these animals.
Investigators have been wondering whether the timing of intervention is crucial for a protective effect of the ketogenic diet treatment. In fact, this question is applicable to all neurodegenerative diseases.  
Theoretically, depriving cancer cells of their usual fuel supply (e.g. glucose) by use of the ketogenic diet could be clinically therapeutic. Studies, conducted on both humans and animals with brain tumors, have led to some interesting findings. The brain tumor growth rates decreased on the ketogenic diet.
There are several human cases with improved brain tumors on the ketogenic and MCT-based diets. Moreover, the diet seems to improve the general quality of life in some patients.   
Psychiatric and Developmental Disorders
The ketogenic diet may also have mood-stabilizing properties. Specifically, studies on depression, schizophrenia, and bipolar disorder seemed to get beneficial effects on the diet, comparable to monoamines and other mood-stabilizing medications.     
Lately, limited clinical research has even raised the intriguing possibility that the ketogenic diet might help ease some of the deviant behaviors, seen in children with an autism spectrum disorder.
This is a neurodevelopmental disorder that affects mostly language and social function. Some children seem to show significant behavior improvement on a ketogenic diet variant, consisting of MCT. On the downside, many children with autism don’t tolerate changes in dietary and other routines too well.    
Chronic Headaches & Migraines
Let us end this list of possible benefits of the ketogenic diet in neurological disorders with one of the most common headache disorders: migraines. Scientists have come to some good theoretical reasons to consider the ketogenic diet for chronic migraines.
The idea for this petition nutritional therapy comes from a potential overlap of migraines and epilepsy, although the intrinsic mechanisms, underlying both phenomena, differ in many aspects.
If you happen to be one of the chronic migraine sufferers, you might be aware that doctors can prescribe certain antiepileptic drugs for this specific form of headaches. Interestingly, the first report of using the ketogenic diet to treat migraine came as early as in the 1920s, soon after the diet’s first use for epilepsy.   
Concluding Thoughts on the Ketogenic Diet and Neurological Conditions
To conclude, we need more clinical data to support a definite conclusion, but preliminary studies show that the metabolic shifts that occur on the ketogenic diet might lead to neuroprotective actions. If you or someone close to you suffers from any neurological disorder, do consult with the treating doctor before trying the diet. Anyhow, if you are a migraine sufferer, and otherwise healthy, studies suggest that there is no harm in giving the ketogenic diet a try.