Just watch the first 93 seconds. He begins with a description of a neurologically-base sudden onset act of “inexplicable aggression.
I’m reasonably sure he is describing Huntington’s disease. Some quick googling turned up…
Although some people suffering from HD may remain even tempered, others may lose the ability to control their emotions. Emotional volatility may be evident in increased irritability or episodes of explosiveness. A study on mice with the HD allele of the Huntington gene found that mice portrayed abnormal social behavior, particularlychronic aggressive behavior. For others, rigidity of thinking causes the individual to focus on one particular request. This individual may become irritable, frustrated or aggressive if demands are not met. To read more about the study on mice with the HD allele, click here.
When the caudate nucleus has deteriorated, emotions are improperly regulated, causing an increase in feelings of frustration and irritability. These feelings are often legitimate and triggered by something in the environment. The brain, however, cannot control the intensity of the emotion. Several factors may contribute to the feelings of intense frustration, etc: – The Behavioral Symptoms of Huntington’s Disease – stanford.edu
Psychiatric and behavioural manifestations of HD are varied both in nature and time of occurrence in the course of the disease, often evolving in the same individual [7,11–13]. Personality changes are the most common behavioural manifestation and probably will occur, eventually, in every patient [1,2,12–15]. Apathy, irritability, aggressive and violent behaviour are the most reported conduct problems. Depression is the second most common psychiatric disorder among HD patients, with a lifetime prevalence of 39%, and most studies report a four- to six fold increase in suicide [1,12–16]. Schizophrenia-like psychosis occurs in HD disease with an estimated frequency of 6% to 25%, the paranoid form being apparently the most common type [1,2,12–14,16]. Patients with an early age at onset of HD seem to have a greater risk of developing psychosis [14,16]. In this report we are especially interested in the association between HD and schizophrenia-like psychotic symptoms and how this may prove relevant to our understanding of the complex genetics of schizophrenia. We describe a family where all known cases of HD developed schizophrenia-like psychosis several years before other manifestations became evident. – Association of Huntington’s disease and schizophrenia-like psychosis in a Huntington’s disease pedigree NCBI