PNES and epilepsy. Diagnosis According to the Diagnostic and Statistical Manual of Mental Disorders (version 5) the criteria for receiving a diagnosis of PNES are: One or more symptoms of altered voluntary motor or sensory function. Clinical findings provide evidence of incompatibility between the symptom and recognized neurological or medical conditions. The symptom or deficit is not better explained by another medical or mental disorder. The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation. Additionally, the specific symptom type must be reported "with attacks or seizures". Some individuals with PNES have carried an erroneous diagnosis of epilepsy. On average, it takes seven years to receive a proper diagnosis. The differential diagnosis of PNES firstly involves ruling out epilepsy as the cause of the seizure episodes, along with other organic causes of non-epileptic seizures, including syncope, migraine, vertigo, anoxia, hypoglycemia, and stroke. However, 5–20% of people with PNES also have epilepsy. Frontal lobe seizures can be mistaken for PNES, though these tend to have shorter duration, stereotyped patterns of movements, and occurrence during sleep. Next, an exclusion of factitious disorder (a subconscious somatic symptom disorder, where seizures are caused by psychological reasons) and malingering (simulating seizures intentionally for conscious personal gain – such as monetary compensation or avoidance of criminal punishment) is conducted. Finally other psychiatric conditions that may superficially resemble seizures are eliminated, including panic disorder, schizophrenia, and depersonalisation disorder. The most definitive test to distinguish epilepsy from PNES is long term video-EEG monitoring, with the aim of capturing one or two episodes on both video recording and EEG simultaneously (some clinicians may use suggestion to attempt to trigger an episode). Additional clinical criteria are usually considered in addition to video-EEG monitoring when diagnosing PNES. By recording the event in question on video and EEG simultaneously, a clear diagnosis can usually be obtained. Laboratory testing can detect rising blood levels of serum prolactin if samples are taken in the right time window after most tonic-clonic or complex partial epileptic seizures. However, due to false positives and variability in results, this test is relied upon less frequently. Distinguishing features Some features are more or less likely to suggest PNES but they are not conclusive and should be considered in the broader clinical picture. Features that are common in PNES but rarer in epilepsy include: biting the tip