Epilepsy

Epilepsy is a neurological disorder, usually characterized by either recurrent or sporadic seizures. Epilepsy presents a particular challenge for forensic scientists because sudden, unexplained death may occur in people with epilepsy, and up to 30% of individuals with epilepsy have no demonstrable cause of death at the time of autopsy.

Known as both sudden unexplained death syndrome (SUDS) and sudden unexpected death in epilepsy (SUDEP), the condition is often under-recognized. Deaths are sometimes attributed to other causes in people with epilepsy, such as drowning, when in fact, a seizure precipitated events leading to death. One study conducted in Australia in 2003 showed that SUDEP occurs in approximately one person per 200 people with epilepsy per year. Usually, a person with (SUDEP) dies in their sleep. With awareness of the condition growing and funding for research increasing, forensic scientists are assisting in collecting data and other research into unraveling the mystery of SUDEP.

Epileptic seizures are usually convulsive, affecting autonomic reflexes, as well as motor, sensory, and cognitive neuronal (nerve cell) functions. They are caused by the synchronous hyper-excitation of isolated groups of nerve cells in one of the brain cortical areas. Seizures can last from a few seconds up to minutes, depending on the intensity of neuronal excitability.

Epilepsy may be the result of inherited gene mutations, metabolic diseases, or brain malformation, or may constitute a major symptom of a neurological disease. When the epilepsy results from an identified cerebral condition, such as cerebral concussion or brain tumor, or is a clinical manifestation of a hereditary neurodegenerative syndrome, it is classified as symptomatic. Non-symptomatic epilepsies are those occurring in persons who do not present brain abnormalities or neurological disorders other than the seizures.

Other types of epilepsy may be induced through occupational damage, due to repeated exposure to acoustic or visual stimuli, or as a result of an isolated high-intensity auditory or visual stimulus. Whatever the case, the sensory stimulation induces chemical changes in the related brain areas, causing a kind of electrical short-circuit, with a group of neurons briefly firing in a synchronous rhythm. These stimuli-induced forms of seizures are known as acquired epilepsy. A dramatic example of seizures induced by repeated sensory stimuli happened in Japan on December 17, 1997, when hundreds of children suffered simultaneous epileptic seizures induced by the flashing red eyes of a Pokemon cartoon character. Epilepsies induced by sensory stimuli are also known as reflex epilepsies.

Absence epilepsy (e.g., non-convulsive epilepsy) occurs mostly in children between three and eight years of age, usually disappearing in adolescence. Non-convulsive epileptic episodes may happen one or more times a day, being characterized by a brief impairment of consciousness, absence of response to external stimuli, "stargazed" expression, and spatial disorientation. However, in contrast to reflex epilepsies, it cannot be induced by sensory stimulation. Convulsive forms of epilepsy are generally preceded by a brief state of dizziness, or external sensory shutdown, followed by convulsion. After convulsion, the person also experiences confusion, poor body equilibrium, and a few minutes of spatial disorientation.

Ignorance and prejudice in the past led to the popular and institutional belief that epilepsy was a kind of mental illness or disability that required institutionalization in psychiatric hospitals. It was also believed that some epileptic individuals entered in a state of somnambulism (unawareness) during the seizures and could commit crimes, which they could not recollect later. Thanks to the advances in neurosciences in the last fifty years, such assumptions have been disproved. However, popular prejudice and legal confusion still persist as to the degree of legal responsibility of epileptic offenders, both from the prosecution and the defense point of view. Expert witnesses in neurology and psychiatry are often requested to evaluate epileptic defendants and to inform the court about the nature of the disorder and the characteristics of seizures. In most developed countries, epileptic seizures are not considered a legal impediment for the full fruition of individual civil rights and liberties.

Epilepsy treatment usually requires the regular intake of controlled anti-convulsive medications. Law enforcement personnel are educated about the different intensities and types of epileptic seizures in order to prevent misinterpreting behavior, such as the appearance of intoxication, exhibited by persons experiencing a seizure or in the immediate recovery period.